1
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Pallaka MR, Simon SL. The glass transition and enthalpy recovery of polystyrene nanorods using Flash differential scanning calorimetry. J Chem Phys 2024; 160:124904. [PMID: 38533885 DOI: 10.1063/5.0190076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2023] [Accepted: 01/31/2024] [Indexed: 03/28/2024] Open
Abstract
The glass transition (Tg) behavior and enthalpy recovery of polystyrene nanorods within an anodic aluminum oxide (AAO) template (supported nanorods) and after removal from AAO (unsupported nanorods) is studied using Flash differential scanning calorimetry. Tg is found to be depressed relative to the bulk by 20 ± 2 K for 20 nm-diameter unsupported polystyrene (PS) nanorods at the slowest cooling rate and by 9 ± 1 K for 55 nm-diameter rods. On the other hand, bulk-like behavior is observed in the case of unsupported 350 nm-diameter nanorods and for all supported rods in AAO. The size-dependent Tg behavior of the PS unsupported nanorods compares well with results for ultrathin films when scaled using the volume/surface ratio. Enthalpy recovery was also studied for the 20 and 350 nm unsupported nanorods with evolution toward equilibrium found to be linear with logarithmic time. The rate of enthalpy recovery for the 350 nm rods was similar to that for the bulk, whereas the rate of recovery was enhanced for the 20 nm rods for down-jump sizes larger than 17 K. A relaxation map summarizes the behavior of the nanorods relative to the bulk and relative to that for the 20 nm-thick ultrathin film. Interestingly, the fragility of the 20 nm-diameter nanorod and the 20 nm ultrathin film are identical within the error of measurements, and when plotted vs departure from Tg (i.e., T - Tg), the relaxation maps of the two samples are identical in spite of the fact that the Tg is depressed 8 K more in the nanorod sample.
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Affiliation(s)
- Madhusudhan R Pallaka
- Department of Chemical Engineering, Texas Tech University, Lubbock, Texas 79409, USA
| | - Sindee L Simon
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina 27695, USA
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2
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Lee J, Lee S, Lee K, Joung H, Choi SK, Kim M, Yang J, Paeng K. Segmental dynamics of polystyrene near polymer-polymer interfaces. J Chem Phys 2024; 160:124902. [PMID: 38516976 DOI: 10.1063/5.0189494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Accepted: 03/04/2024] [Indexed: 03/23/2024] Open
Abstract
This study investigated the segmental dynamics of polymers near polymer-polymer interfaces by probing the rotation of polymer-tethered fluorescent molecules using imaging rotational fluorescence correlation microscopy. Multilayered films were utilized to provide spatial selectivity relative to different polymer-polymer interfaces. In the experimental setup, for the overlayer polymer, polystyrene (PS) was employed and a 15 nm-thick probe-containing layer was placed ≈25 nm apart from different underlayer polymers with glass transition temperatures (Tg) either lower or higher than that of PS. The underlayer of poly-n-butyl methacrylate had 72 K lower Tg than that of PS, whereas polymethyl methacrylate and polysulfone had 22 and 81 K higher Tg, respectively, than that of PS. Two key dynamic features of the glass transition, the non-Arrhenius temperature dependence and stretched relaxation, were examined to study the influence of soft and hard confinements on the segmental dynamics of the overlayer polymer near the polymer-polymer interfaces. Although complications exist in the probing location owing to the diffusion of the polymer-tethered probe during the annealing protocol to consolidate the multilayers, the results suggest that either the segmental dynamics of the polymer near the polymer-polymer interface do not change owing to the soft and hard confinements or the interfacial perturbation is very short ranged.
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Affiliation(s)
- Jeongin Lee
- Department of Chemistry, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Soohyun Lee
- Department of Chemistry, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Keonchang Lee
- Department of Chemistry, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Hyeyoung Joung
- Department of Chemistry, Yonsei University, Wonju, Gangwon 26493, Republic of Korea
| | - Seung Kun Choi
- Department of Chemistry, Inha University, Incheon 22212, Republic of Korea
| | - Myungwoong Kim
- Department of Chemistry, Inha University, Incheon 22212, Republic of Korea
| | - Jaesung Yang
- Department of Chemistry, Yonsei University, Wonju, Gangwon 26493, Republic of Korea
| | - Keewook Paeng
- Department of Chemistry, Sungkyunkwan University, Suwon 16419, Republic of Korea
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3
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Serna S, Wang T, Torkelson JM. Eliminating the Tg-confinement and fragility-confinement effects in poly(4-methylstyrene) films by incorporation of 3 mol % 2-ethylheyxl acrylate comonomer. J Chem Phys 2024; 160:034903. [PMID: 38235797 DOI: 10.1063/5.0189409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Accepted: 12/22/2023] [Indexed: 01/19/2024] Open
Abstract
Nanoconfined poly(4-methylstyrene) [P(4-MS)] films exhibit reductions in glass transition temperature (Tg) relative to bulk Tg (Tg,bulk). Ellipsometry reveals that 15-nm-thick P(4-MS) films supported on silicon exhibit Tg - Tg,bulk = - 15 °C. P(4-MS) films also exhibit fragility-confinement effects; fragility decreases ∼60% in going from bulk to a 20-nm-thick film. Previous research found that incorporating 2-6 mol % 2-ethylhexyl acrylate (EHA) comonomer in styrene-based random copolymers eliminates Tg- and fragility-confinement effects in polystyrene. Here, we demonstrate that incorporating 3 mol % EHA in a 4-MS-based random copolymer, 97/3 P(4-MS/EHA), eliminates the Tg- and fragility-confinement effects. The invariance of fragility with nanoconfinement of 97/3 P(4-MS/EHA) films, hypothesized to originate from the interdigitation of ethylhexyl groups, indicates that the presence of EHA prevents the free surface from perturbing chain packing and the cooperative mobility associated with Tg. This method of eliminating confinement effects is advantageous as it relies on the simplest of polymerization methods and neat copolymer only slightly altered in composition from homopolymer. We also investigated whether we could eliminate the Tg-confinement effect with low levels of 2-ethylhexyl methacrylate (EHMA) in 4-MS-based or styrene-based copolymers. Although EHMA is structurally nearly identical to EHA, 4-MS-based and styrene-based copolymers incorporating 4 mol % EHMA exhibit Tg-confinement effects similar to P(4-MS) and polystyrene. These results support the special character of EHA in eliminating confinement effects originating at free surfaces.
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Affiliation(s)
- Sergio Serna
- Department of Chemical and Biological Engineering, Evanston, Illinois 60208, USA
| | - Tong Wang
- Department of Chemical and Biological Engineering, Evanston, Illinois 60208, USA
| | - John M Torkelson
- Department of Chemical and Biological Engineering, Evanston, Illinois 60208, USA
- Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, USA
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4
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Sharma T, Kashihara S, Yamasaki Y, Ozaki Y, Takahashi I, Sato H. Combined X-ray Reflectivity and Infrared Study of the Effect of Hydrogen Bonding of the OH Group on the Relaxation Behavior in Ultrathin Polyvinylphenol Films on SiO 2. J Phys Chem B 2023; 127:7602-7614. [PMID: 37611194 DOI: 10.1021/acs.jpcb.3c01491] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/25/2023]
Abstract
Utilizing X-ray reflectivity and infrared reflection absorption spectroscopy (IR-RAS), we have investigated the thermal expansion and contraction of ultrathin polyvinylphenol (PVPh) films supported on a silicon (100) substrate capped with an amorphous SiO2 layer. Despite being known to form strong interactions with the SiO2 surface, the thin PVPh films showed a reduction in the glass-transition point Tg, similar to the behavior of polystyrene thin films deposited on SiO2. We explored the relationship between thermal expansivity and film thickness using well-annealed films and found that it decreases with film thickness in the range below twice the radius of gyration of a polymer chain (2Rg) in the glassy state. Thickness expansion in the glassy state and contraction in thickness at temperatures higher than Tg bulk (melt state) showed the presence of two competing relaxation processes. The reported negative thermal expansion in PVPh thin films, which was discovered to be one of the inherent properties, may have been caused by the fast relaxations that take place at the free polymer surface. IR-RAS was utilized to investigate the effect of thickness on hydrogen bonding in PVPh, and it was confirmed that with decreasing thickness, hydrogen bonding becomes weak, and the number of free OH groups increases. Therefore, thinner PVPh samples exhibit lower Tgs as an effect of easier molecular motions.
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Affiliation(s)
- Tulika Sharma
- Graduate School of Human Development and Environment, Kobe University, 3-11 Tsurukabuto, Nada-Ku, Kobe, Hyogo 657-8501, Japan
- Department of Physics and Astronomy, School of Science and Technology, Kwansei Gakuin University, 1 Gakuen-Uegahara, Sanda 669-1337, Japan
| | - Saki Kashihara
- Department of Physics and Astronomy, School of Science and Technology, Kwansei Gakuin University, 1 Gakuen-Uegahara, Sanda 669-1337, Japan
| | - Yuta Yamasaki
- Department of Physics and Astronomy, School of Science and Technology, Kwansei Gakuin University, 1 Gakuen-Uegahara, Sanda 669-1337, Japan
| | - Yukihiro Ozaki
- Molecular Photoscience Research Center, Kobe University, 1-1 Rokkodai, Nada, Kobe, Hyogo 657-8501, Japan
| | - Isao Takahashi
- Department of Physics and Astronomy, School of Science and Technology, Kwansei Gakuin University, 1 Gakuen-Uegahara, Sanda 669-1337, Japan
| | - Harumi Sato
- Graduate School of Human Development and Environment, Kobe University, 3-11 Tsurukabuto, Nada-Ku, Kobe, Hyogo 657-8501, Japan
- Molecular Photoscience Research Center, Kobe University, 1-1 Rokkodai, Nada, Kobe, Hyogo 657-8501, Japan
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5
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Ren W, Hong Y, Wei H, Xu J, Zhang C, Zhou X, Wang X. Structure of the Poly(methyl methacrylate) Adsorbed Layer Determined by the Surface Chemistry of the Substrate. Macromolecules 2023. [DOI: 10.1021/acs.macromol.2c02169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Affiliation(s)
- Weizhao Ren
- Department of Chemistry, Key Laboratory of Surface & Interface Science of Polymer Materials of Zhejiang Province, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Yongming Hong
- Department of Chemistry, Key Laboratory of Surface & Interface Science of Polymer Materials of Zhejiang Province, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Huidong Wei
- Department of Chemistry, Key Laboratory of Surface & Interface Science of Polymer Materials of Zhejiang Province, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Jianquan Xu
- Department of Chemistry, Key Laboratory of Surface & Interface Science of Polymer Materials of Zhejiang Province, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Cuiyun Zhang
- Department of Chemistry, Key Laboratory of Surface & Interface Science of Polymer Materials of Zhejiang Province, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Xianjing Zhou
- Department of Chemistry, Key Laboratory of Surface & Interface Science of Polymer Materials of Zhejiang Province, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Xinping Wang
- Department of Chemistry, Key Laboratory of Surface & Interface Science of Polymer Materials of Zhejiang Province, Zhejiang Sci-Tech University, Hangzhou 310018, China
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6
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Goswami M, Iyiola OO, Lu W, Hong K, Zolnierczuk P, Stingaciu LR, Heller WT, Taleb O, Sumpter BG, Hallinan DT. Understanding Interfacial Block Copolymer Structure and Dynamics. Macromolecules 2023. [DOI: 10.1021/acs.macromol.2c01814] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- Monojoy Goswami
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Oluwagbenga Oare Iyiola
- Chemical and Biomedical Engineering Department, Florida A&M University-Florida State University College of Engineering, Tallahassee, Florida 32310-6046, United States
- Aero-Propulsion, Mechatronics and Energy Center, Florida A&M University-Florida State University College of Engineering, Tallahassee, Florida 32310-6046, United States
| | - Wei Lu
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996-2200, United States
| | - Kunlun Hong
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996-2200, United States
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Piotr Zolnierczuk
- Juelich Center for Neutron Science, Outstation at the Spallation Neutron Source, Oak Ridge, Tennessee 37831-6473, United States
| | - Laura-Roxana Stingaciu
- Neutron Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - William T. Heller
- Neutron Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Omar Taleb
- Chemical and Biomedical Engineering Department, Florida A&M University-Florida State University College of Engineering, Tallahassee, Florida 32310-6046, United States
- Aero-Propulsion, Mechatronics and Energy Center, Florida A&M University-Florida State University College of Engineering, Tallahassee, Florida 32310-6046, United States
| | - Bobby G. Sumpter
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Daniel T. Hallinan
- Chemical and Biomedical Engineering Department, Florida A&M University-Florida State University College of Engineering, Tallahassee, Florida 32310-6046, United States
- Aero-Propulsion, Mechatronics and Energy Center, Florida A&M University-Florida State University College of Engineering, Tallahassee, Florida 32310-6046, United States
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7
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Jiang Z, Cheng B, Yang J, Zhao J. Free Space Makes the Polymer "Dead Layer" Alive. J Phys Chem B 2022; 126:10750-10757. [PMID: 36479883 DOI: 10.1021/acs.jpcb.2c05858] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The effect of free space on molecular motion inside the polymer "dead layer" or adsorbed nanolayers on solid surfaces is investigated. Free space is introduced into the nanolayer by choosing a polymer with a relatively big side group, poly n-butyl methacrylate (PnBMA), and polarization-resolved single-molecule fluorescence microscopy is adopted as the method. The rotational motion of the doped fluorescent probes is found to be considerably excited at moderate temperatures, attributed to the free space brought by the side group of the PnBMA. The development of the adsorbed nanolayer by the prolonged annealing of the parent film is carefully monitored, together with the evolution of the molecular motion and the glass transition temperature (Tg). The Tg values of the exposed nanolayers are considerably lower than that of the bulk system, while they become higher than those in the bulk situation when the nanolayer is covered with a polymer top layer. The experimental evidence has demonstrated that the free space made available by the side group and the air-polymer interface has considerably promoted the molecular motion inside the adsorbed nanolayers, even under the situation of overwhelming surface attraction.
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Affiliation(s)
- Zhichao Jiang
- Beijing National Research Center for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Bin Cheng
- Beijing National Research Center for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jingfa Yang
- Beijing National Research Center for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jiang Zhao
- Beijing National Research Center for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.,University of Chinese Academy of Sciences, Beijing 100049, China
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8
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Local conformations and heterogeneities in structures and dynamics of isotactic polypropylene adsorbed onto carbon fiber. POLYMER 2022. [DOI: 10.1016/j.polymer.2022.125584] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
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9
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Wang T, Hu S, Zhang S, Peera A, Reffner J, Torkelson JM. Eliminating the Tg-Confinement Effect in Polystyrene Films: Extraordinary Impact of a 2 mol % 2-Ethylhexyl Acrylate Comonomer. Macromolecules 2022. [DOI: 10.1021/acs.macromol.2c01917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Tong Wang
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois60208, United States
| | - Sumeng Hu
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois60208, United States
| | - Sipei Zhang
- The Dow Chemical Company, 400 Arcola Road, Collegeville, Pennsylvania19426, United States
| | - Asghar Peera
- The Dow Chemical Company, 400 Arcola Road, Collegeville, Pennsylvania19426, United States
| | - John Reffner
- The Dow Chemical Company, 400 Arcola Road, Collegeville, Pennsylvania19426, United States
| | - John M. Torkelson
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois60208, United States
- Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois60208, United States
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10
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Trumpour T, Forrest JA. Nanoscale surface roughness induced by poor solvents on polymer film surfaces. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2022; 45:85. [PMID: 36289136 DOI: 10.1140/epje/s10189-022-00237-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Accepted: 09/26/2022] [Indexed: 06/16/2023]
Abstract
We describe a new nanoscale morphology that is produced when polymer surfaces are exposed to a poor solvent. We have measured the morphology on polystyrene surfaces after exposure to pentane, heptane, or dodecane as well as poly(methyl methacrylate) exposed to propanol or methanol. The length scale of the morphology was determined by analyzing images obtained by atomic force microscopy. For the case of polystyrene, we perform a detailed characterization of the morphology for all solvents and molecular weight values [Formula: see text] ranging from 8 to 995 kg/mol. Comparing the results to models of dimpling morphology in densely grafted chains suggests the same mechanism is responsible.
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Affiliation(s)
- Tiana Trumpour
- Department of Physics and Astronomy, University of Waterloo, 200 University Ave. W, Waterloo, ON, N2L 3G1, Canada
- Schulich School of Medicine and Dentistry, Western University, 1151 Richmond St, London, ON, N6A 5C1, Canada
| | - James A Forrest
- Department of Physics and Astronomy, University of Waterloo, 200 University Ave. W, Waterloo, ON, N2L 3G1, Canada.
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11
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Karimata A, Fayzullin RR, Khusnutdinova JR. Versatile Method of Generating Triboluminescence in Polymer Films Blended with Common Luminophores. ACS Macro Lett 2022; 11:1028-1033. [PMID: 35905142 DOI: 10.1021/acsmacrolett.2c00348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Herein we report a versatile method for the preparation of triboluminescent polymer films by physical blending with common luminophores. This method does not require the presence of a crystalline phase or the use of materials known to be triboluminescent. Emission is generated in response to friction of the polymer surface via triboelectrification, either by rubbing directly or through an inert coating layer, even with low applied stress (<0.1 MPa). Our findings offer a convenient and practical method of preparation of triboluminescent, amorphous polymer films with easily tunable emission properties.
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Affiliation(s)
- Ayumu Karimata
- Coordination Chemistry and Catalysis Unit, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Okinawa 904-0495, Japan
| | - Robert R Fayzullin
- Arbuzov Institute of Organic and Physical Chemistry, FRC Kazan Scientific Center, Russian Academy of Sciences, 8 Arbuzov Street, Kazan 420088, Russian Federation
| | - Julia R Khusnutdinova
- Coordination Chemistry and Catalysis Unit, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Okinawa 904-0495, Japan
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12
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Mechanical properties, thermal behavior, miscibility and light stability of the poly(butylene adipate-co-terephthalate)/poly(propylene carbonate)/polylactide mulch films. Polym Bull (Berl) 2022. [DOI: 10.1007/s00289-022-04173-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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13
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Bai L, Luo P, Yang X, Xu J, Kawaguchi D, Zhang C, Yamada NL, Tanaka K, Zhang W, Wang X. Enhanced Glass Transition Temperature of Thin Polystyrene Films Having an Underneath Cross-Linked Layer. ACS Macro Lett 2022; 11:210-216. [PMID: 35574771 DOI: 10.1021/acsmacrolett.1c00611] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Due to the importance of the interface in the segmental dynamics of supported macromolecule ultrathin films, the glass transition temperature (Tg) of polystyrene (PS) ultrathin films upon solid substrates modified with a cross-linked PS (CLPS) layer has been investigated. The results showed that the Tg of the thin PS films on a silica surface with a ∼5 nm cross-linked layer increased with reducing film thickness. Meanwhile, the increase in Tg of the thin PS films became more pronounced with increasing the cross-linking density of the layer. For example, a 20 nm thick PS film supported on CLPS with 1.8 kDa of cross-linking degree exhibited a ∼35 and ∼50 K increase in Tg compared to its bulk and that on neat SiO2 substrate, respectively. Such a large Tg elevation for the ultrathin PS films was attributed to the interfacial aggregation states in which chains diffused through nanolevel voids formed in the cross-linked layer to the SiO2-Si surface. In such a situation, the chains were topologically constrained in the cross-linked layer with less mobility. These results offer us the opportunity to tailor interfacial effects by changing the degree of cross-linking, which has great potential application in many polymer nanocomposites.
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Affiliation(s)
- Lu Bai
- Department of Chemistry, Key Laboratory of Surface and Interface Science of Polymer Materials of Zhejiang Province, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Pan Luo
- Department of Chemistry, Key Laboratory of Surface and Interface Science of Polymer Materials of Zhejiang Province, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Xudong Yang
- Department of Chemistry, Key Laboratory of Surface and Interface Science of Polymer Materials of Zhejiang Province, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Jianquan Xu
- Department of Chemistry, Key Laboratory of Surface and Interface Science of Polymer Materials of Zhejiang Province, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Daisuke Kawaguchi
- Department of Applied Chemistry and Center for Polymer Interface and Molecular Adhesion Science, Kyushu University, Fukuoka 819-0395, Japan
| | - Cuiyun Zhang
- Department of Chemistry, Key Laboratory of Surface and Interface Science of Polymer Materials of Zhejiang Province, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Norifumi L. Yamada
- Neutron Science Division, Institute for Materials Structure Science, High Energy, Acceleration Research Organization, Naka, Ibaraki 319-1106, Japan
| | - Keiji Tanaka
- Department of Applied Chemistry and Center for Polymer Interface and Molecular Adhesion Science, Kyushu University, Fukuoka 819-0395, Japan
| | - Wei Zhang
- Department of Chemistry, Key Laboratory of Surface and Interface Science of Polymer Materials of Zhejiang Province, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Xinping Wang
- Department of Chemistry, Key Laboratory of Surface and Interface Science of Polymer Materials of Zhejiang Province, Zhejiang Sci-Tech University, Hangzhou 310018, China
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14
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Kawabata K, Totani M, Kawaguchi D, Matsuno H, Tanaka K. Two-Dimensional Cellular Patterning on a Polymer Film Based on Interfacial Stiffness. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:14911-14919. [PMID: 34902971 DOI: 10.1021/acs.langmuir.1c02776] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The mechanical properties in the outermost region of a polymer film strongly affect various material functions. We here propose a novel and promising strategy for the two-dimensional regulation of the mechanical properties of a polymer film at the water interface based on an inkjet drawing of silica nanoparticles (SNPs) underneath it. A film of poly(2-hydroxyethyl methacrylate) (PHEMA), which exhibits excellent bioinertness properties at the water interface, was well fabricated on a substrate with a pattern of SNPs. X-ray photoelectron spectroscopy and atomic force microscopy confirmed that the surface of the PHEMA film was flat and chemically homogeneous. However, the film surface was in-plane heterogeneous in stiffness due to the presence of the underlying SNP lines. It was also noted that NIH/3T3 fibroblast cells selectively adhered and formed aggregates on the areas under which an SNP line was drawn.
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Affiliation(s)
- Kento Kawabata
- Department of Applied Chemistry, Kyushu University, Fukuoka 819-0395, Japan
| | - Masayasu Totani
- Department of Applied Chemistry, Kyushu University, Fukuoka 819-0395, Japan
| | - Daisuke Kawaguchi
- Department of Applied Chemistry, Kyushu University, Fukuoka 819-0395, Japan
- Centre for Polymer Interface and Molecular Adhesion Science, Kyushu University, Fukuoka 819-0395, Japan
| | - Hisao Matsuno
- Department of Applied Chemistry, Kyushu University, Fukuoka 819-0395, Japan
- Centre for Polymer Interface and Molecular Adhesion Science, Kyushu University, Fukuoka 819-0395, Japan
| | - Keiji Tanaka
- Department of Applied Chemistry, Kyushu University, Fukuoka 819-0395, Japan
- Centre for Polymer Interface and Molecular Adhesion Science, Kyushu University, Fukuoka 819-0395, Japan
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15
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Han Y, Roth CB. Gradient in refractive index reveals denser near free surface region in thin polymer films. J Chem Phys 2021; 155:144901. [PMID: 34654302 DOI: 10.1063/5.0062054] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
A gradient in refractive index that is linear in magnitude with depth into the film is used to fit ellipsometric data for thin polymer films of poly(methyl methacrylate) (PMMA), polystyrene (PS), and poly(2-vinyl pyridine) (P2VP). We find that the linear gradient model fits provide more physically realistic refractive index values for thin films compared with the commonly used homogeneous Cauchy layer model, addressing recent reports of physically unrealistic density increases. Counter to common expectations of a simple free volume correlation between density and dynamics, we find that the direction of refractive index (density) gradient indicates a higher density near the free surface, which we rationalize based on the observed faster free surface dynamics needed to create vapor deposited stable glasses with optimized denser molecular packings. The magnitude of refractive index gradient is observed to be three times larger for PMMA than for PS films, while P2VP films exhibit a more muted response possibly reflective of a decoupling in free surface and substrate dynamics in systems with strong interfacial interactions.
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Affiliation(s)
- Yixuan Han
- Department of Physics, Emory University, Atlanta, Georgia 30322, USA
| | - Connie B Roth
- Department of Physics, Emory University, Atlanta, Georgia 30322, USA
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16
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Relaxation behavior of polymer thin films: Effects of free surface, buried interface, and geometrical confinement. Prog Polym Sci 2021. [DOI: 10.1016/j.progpolymsci.2021.101431] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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17
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Roth CB. Polymers under nanoconfinement: where are we now in understanding local property changes? Chem Soc Rev 2021; 50:8050-8066. [PMID: 34086025 DOI: 10.1039/d1cs00054c] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Polymers are increasingly being used in applications with nanostructured morphologies where almost all polymer molecules are within a few tens to hundreds of nanometers from some interface. From nearly three decades of study on polymers in simplified nanoconfined systems such as thin films, we have come to understand property changes in these systems as arising from interfacial effects where local dynamical perturbations are propagated deeper into the material. This review provides a summary of local glass transition temperature Tg changes near interfaces, comparing across different types of interfaces: free surface, substrate, liquid, and polymer-polymer. Local versus film-average properties in thin films are discussed, making connections to other related property changes, while highlighting several historically important studies. By experimental necessity, most studies are on high enough molecule weight chains to be well entangled, although aspects that connect to lower molecule weight materials are described. Emphasis is made to identify observations and open questions that have yet to be fully understood such as the evidence of long-ranged interfacial effects, finite domain size, interfacial breadth, and chain connectivity.
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Affiliation(s)
- Connie B Roth
- Department of Physics, Emory University, Atlanta, Georgia 30322, USA.
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18
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Farzin S, Zamani E, Dishari SK. Unraveling Depth-Specific Ionic Conduction and Stiffness Behavior across Ionomer Thin Films and Bulk Membranes. ACS Macro Lett 2021; 10:791-798. [PMID: 35549194 DOI: 10.1021/acsmacrolett.1c00110] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Interfacial behavior of submicron thick polymer films critically controls the performance of electrochemical devices. We developed a robust, everyday-accessible, fluorescence confocal laser scanning microscopy (CLSM)-based strategy that can probe the distribution of mobility, ion conduction, and other properties across ionomer samples. When fluorescent photoacid probe 8-hydroxypyrene-1,3,6-trisulfonic acid trisodium salt (HPTS) was incorporated into <1 μm thick Nafion films on substrates, the depth-profile images showed thickness- and interface-dependent proton conduction behavior. In these films, proton conduction was weak over a region next to substrate interface, then gradually increased until air interface at 88% RH. Conversely, consistently high proton conduction with no interface dependence was observed across 35-50 μm thick bulk, free-standing Nafion membranes. A hump-like mobility/stiffness distribution was observed across Nafion films containing mobility-sensitive probe (9-(2-carboxy-2-cyanovinyl)julolidine) (CCVJ). The proton conduction and mobility distribution were rationalized as a combinatorial effect of interfacial interaction, ionomer chain orientation, chain density, and ionic domain characteristics.
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Affiliation(s)
- Seefat Farzin
- Department of Chemical and Biomolecular Engineering, University of Nebraska−Lincoln, Lincoln, Nebraska 68588, United States
| | - Ehsan Zamani
- Department of Chemical and Biomolecular Engineering, University of Nebraska−Lincoln, Lincoln, Nebraska 68588, United States
| | - Shudipto K. Dishari
- Department of Chemical and Biomolecular Engineering, University of Nebraska−Lincoln, Lincoln, Nebraska 68588, United States
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19
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Winkler R, Beena Unni A, Tu W, Chat K, Adrjanowicz K. On the Segmental Dynamics and the Glass Transition Behavior of Poly(2-vinylpyridine) in One- and Two-Dimensional Nanometric Confinement. J Phys Chem B 2021; 125:5991-6003. [PMID: 34048244 PMCID: PMC8279553 DOI: 10.1021/acs.jpcb.1c01245] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 05/13/2021] [Indexed: 11/30/2022]
Abstract
Geometric nanoconfinement, in one and two dimensions, has a fundamental influence on the segmental dynamics of polymer glass-formers and can be markedly different from that observed in the bulk state. In this work, with the use of dielectric spectroscopy, we have investigated the glass transition behavior of poly(2-vinylpyridine) (P2VP) confined within alumina nanopores and prepared as a thin film supported on a silicon substrate. P2VP is known to exhibit strong, attractive interactions with confining surfaces due to the ability to form hydrogen bonds. Obtained results show no changes in the temperature evolution of the α-relaxation time in nanopores down to 20 nm size and 24 nm thin film. There is also no evidence of an out-of-equilibrium behavior observed for other glass-forming systems confined at the nanoscale. Nevertheless, in both cases, the confinement effect is seen as a substantial broadening of the α-relaxation time distribution. We discussed the results in terms of the importance of the interfacial energy between the polymer and various substrates, the sensitivity of the glass-transition temperature to density fluctuations, and the density scaling concept.
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Affiliation(s)
- Roksana Winkler
- Institute
of Physics, University of Silesia, 75 Pulku Piechoty 1, 41-500 Chorzow, Poland
- Silesian
Center for Education and Interdisciplinary Research (SMCEBI), 75 Pulku Piechoty 1a, 41-500 Chorzow, Poland
| | - Aparna Beena Unni
- Institute
of Physics, University of Silesia, 75 Pulku Piechoty 1, 41-500 Chorzow, Poland
- Silesian
Center for Education and Interdisciplinary Research (SMCEBI), 75 Pulku Piechoty 1a, 41-500 Chorzow, Poland
| | - Wenkang Tu
- Institute
of Physics, University of Silesia, 75 Pulku Piechoty 1, 41-500 Chorzow, Poland
- Silesian
Center for Education and Interdisciplinary Research (SMCEBI), 75 Pulku Piechoty 1a, 41-500 Chorzow, Poland
| | - Katarzyna Chat
- Institute
of Physics, University of Silesia, 75 Pulku Piechoty 1, 41-500 Chorzow, Poland
- Silesian
Center for Education and Interdisciplinary Research (SMCEBI), 75 Pulku Piechoty 1a, 41-500 Chorzow, Poland
| | - Karolina Adrjanowicz
- Institute
of Physics, University of Silesia, 75 Pulku Piechoty 1, 41-500 Chorzow, Poland
- Silesian
Center for Education and Interdisciplinary Research (SMCEBI), 75 Pulku Piechoty 1a, 41-500 Chorzow, Poland
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20
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Jia S, Chen Y, Bian J, Pan H, Wang X, Zhao L, Han L, Zhang H, Dong L, Zhang H. Preparation and properties of poly(L-lactic acid) blends with excellent low-temperature toughness by blending acrylic ester based impact resistance agent. Int J Biol Macromol 2021; 183:1871-1880. [PMID: 34087292 DOI: 10.1016/j.ijbiomac.2021.05.177] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 05/10/2021] [Accepted: 05/26/2021] [Indexed: 10/21/2022]
Abstract
Poly(L-lactic acid) (PLLA) blends with excellent low-temperature toughness and strength were prepared by melt compounding with acrylic ester based impact resistance agent (AEIR). The morphology, thermal properties, mechanical properties and biodegradability of the blends were investigated. Morphology observations revealed the blend was immiscible but had good compatibility with the dispersed phase size of about 200-300 nm. With the addition of AEIR, dramatic improvement in toughness of PLLA was achieved in a wide temperature range, especially at low temperatures the tensile strength was effectively remained. For the blend with 20 wt% AEIR, the tensile strength, elongation at break and impact strength were 51.6 MPa, 72% and 77.1 KJ/m2 at -20 °C, respectively, much greater than that reported. The calculated Tg of AEIR was lower than the test temperatures, and the brittle-tough transition occurred. The PLLA matrix demonstrated obvious shear yielding which induced energy dissipation and therefore lead to excellent toughness of the blends. Moreover, the biodegradation of PLLA was enhanced after blends preparation.
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Affiliation(s)
- Shiling Jia
- School of Materials Science and Engineering, Changchun University of Technology, Changchun 130012, China; Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China
| | - Yunjing Chen
- Sinopec-SK (Wuhan) Petrochemical Company Limited, Wuhan 430000, China
| | - Junjia Bian
- Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China
| | - Hongwei Pan
- Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China
| | - Xiangyu Wang
- Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China
| | - Ling Zhao
- School of Materials Science and Engineering, Changchun University of Technology, Changchun 130012, China
| | - Lijing Han
- Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China.
| | - Huiliang Zhang
- Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China.
| | - Lisong Dong
- Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China
| | - Huixuan Zhang
- School of Materials Science and Engineering, Changchun University of Technology, Changchun 130012, China
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21
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Chung Y, Nam J, Son D, Lee H, Kim M, Paeng K. Direct Observations of Segmental Dynamics at the Polymer–Substrate Interface Enabled by Localizing Fluorescent Probes with Polymer Brushes. Macromolecules 2021. [DOI: 10.1021/acs.macromol.0c02869] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Yura Chung
- Department of Chemistry, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Jieun Nam
- Department of Chemistry and Chemical Engineering, Inha University, Incheon 22212, Republic of Korea
| | - Dongwan Son
- Department of Chemistry and Chemical Engineering, Inha University, Incheon 22212, Republic of Korea
| | - Hyangseok Lee
- Department of Chemistry, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Myungwoong Kim
- Department of Chemistry and Chemical Engineering, Inha University, Incheon 22212, Republic of Korea
| | - Keewook Paeng
- Department of Chemistry, Sungkyunkwan University, Suwon 16419, Republic of Korea
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22
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Mears M, Zhang ZJ, Jackson RCD, Si Y, Bradford TJB, Torkelson JM, Geoghegan M. Lateral diffusion of single poly(ethylene oxide) chains on the surfaces of glassy and molten polymer films. J Chem Phys 2021; 154:164902. [PMID: 33940801 DOI: 10.1063/5.0051351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Fluorescence correlation spectroscopy was used to show that the temperature-dependent diffusion coefficient of poly(ethylene oxide) (PEO) adsorbed on polystyrene and different poly(alkyl methacrylate) (PAMA) films in aqueous solution exhibited a maximum close to (but below) the surface glass transition temperature, Tgs, of the film. This elevated diffusion was observed over a small range of temperatures below Tgs for these surfaces, and at other temperatures, the diffusion was similar to that on silicon, although the diffusion coefficient for PEO on polystyrene at temperatures above Tgs did not completely decrease to that on silicon, in contrast to the PAMA surfaces. It is concluded that the enhanced surface mobility of the films near the surface glass transition temperature induces conformational changes in the adsorbed PEO. The origin of this narrow and dramatic increase in diffusion coefficient is not clear, but it is proposed that it is caused by a coupling of a dominant capillary mode in the liquid surface layer with the polymer. Friction force microscopy experiments also demonstrate an unexpected increase in friction at the same temperature as the increase in diffusion coefficient.
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Affiliation(s)
- Matthew Mears
- Department of Physics and Astronomy, University of Sheffield, Sheffield S3 7RH, United Kingdom
| | - Zhenyu J Zhang
- Department of Physics and Astronomy, University of Sheffield, Sheffield S3 7RH, United Kingdom
| | - Ryan C D Jackson
- Department of Physics and Astronomy, University of Sheffield, Sheffield S3 7RH, United Kingdom
| | - Yuchen Si
- Department of Physics and Astronomy, University of Sheffield, Sheffield S3 7RH, United Kingdom
| | - Tigerlily J B Bradford
- Department of Physics and Astronomy, University of Sheffield, Sheffield S3 7RH, United Kingdom
| | - John M Torkelson
- Department of Chemical and Biological Engineering and Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, USA
| | - Mark Geoghegan
- Department of Physics and Astronomy, University of Sheffield, Sheffield S3 7RH, United Kingdom
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23
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DeFelice J, Lipson JEG. The influence of additives on polymer matrix mobility and the glass transition. SOFT MATTER 2021; 17:376-387. [PMID: 33169780 DOI: 10.1039/d0sm01634a] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
In the region near an interface, the microscopic properties of a glass forming liquid may be perturbed from their equilibrium bulk values. In this work, we probe how the interfacial effects of additive particles dispersed in a matrix can influence the local mobility of the material and its glass transition temperature, Tg. Experimental measurements and simulation results indicate that additives, such as nanoparticles, gas molecules, and oligomers, can shift the mobility and Tg of a surrounding polymer matrix (even for relatively small concentrations of additive; e.g., 5-10% by volume) relative to the pure bulk matrix, thus leading to Tg enhancement or suppression. Additives thus provide a potential route for modifying the properties of a polymer material without significantly changing its chemical composition. Here we apply the Limited Mobility (LM) model to simulate a matrix containing additive species. We show that both additive concentration, as well as the strength of its very local influence on the surrounding matrix material, will determine whether the Tg of the system is raised or lowered, relative to the pure matrix. We demonstrate that incorporation of additives into the simple LM simulation method, which has successfully described the behavior of bulk and thin film glassy solids, leads to direct connections with available experimental and simulation results for a broad range of polymer/additive systems.
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Affiliation(s)
- Jeffrey DeFelice
- Department of Chemistry, Dartmouth College, Hanover, NH 03755, USA.
| | - Jane E G Lipson
- Department of Chemistry, Dartmouth College, Hanover, NH 03755, USA.
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24
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Xu Q, Zhu N, Fang H, Wang X, Priestley RD, Zuo B. Decoupling Role of Film Thickness and Interfacial Effect on Polymer Thin Film Dynamics. ACS Macro Lett 2021; 10:1-8. [PMID: 35548993 DOI: 10.1021/acsmacrolett.0c00760] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The film thickness and substrate interface are the two most common parameters to tune the dynamics of supported thin films. Here, we investigated the glass transition temperature (Tg) and thermal expansion of thin poly(methyl methacrylate) (PMMA) films with various thicknesses and different interfacial effects. We showed that, although the Tg of the thin films can be modulated equivalently by the two factors, their ability to change the expansivity (β) is quite different; that is, β increases notably with a reduction in the thickness, while it is insensitive to perturbations at the interface. We attribute the deviation in modulating β by the thickness and the interfacial effect to the disparate abilities to change the free volume content in the film by a free surface and substrate interface. This leads to a situation where thin films with dissimilar thicknesses and interfacial properties can have the same Tg but very different β values, suggesting that Tg alone cannot unequivocally quantify thin film dynamics.
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Affiliation(s)
- Quanyin Xu
- Department of Chemistry, Zhejiang Sci-Tech University, Hangzhou, 310018, China
- Department of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey 08544, United States
| | - Ningtao Zhu
- Department of Chemistry, Zhejiang Sci-Tech University, Hangzhou, 310018, China
| | - Huasong Fang
- Department of Chemistry, Zhejiang Sci-Tech University, Hangzhou, 310018, China
| | - Xinping Wang
- Department of Chemistry, Zhejiang Sci-Tech University, Hangzhou, 310018, China
| | - Rodney D. Priestley
- Department of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey 08544, United States
| | - Biao Zuo
- Department of Chemistry, Zhejiang Sci-Tech University, Hangzhou, 310018, China
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25
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Ko J, Berger R, Lee H, Yoon H, Cho J, Char K. Electronic effects of nano-confinement in functional organic and inorganic materials for optoelectronics. Chem Soc Rev 2021; 50:3585-3628. [DOI: 10.1039/d0cs01501f] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This review provides a comprehensive overview of the electronic effects of nano-confinement (from 1D to 3D geometries) on optoelectronic materials and their applications.
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Affiliation(s)
- Jongkuk Ko
- Department of Chemical and Biological Engineering
- Korea University
- Seoul 02841
- Republic of Korea
- School of Chemical & Biological Engineering
| | - Rüdiger Berger
- Physics at Interfaces
- Max Planck Institute for Polymer Research
- D-55128 Mainz
- Germany
| | - Hyemin Lee
- Department of Chemical & Biomolecular Engineering
- Seoul National University of Science & Technology
- Seoul 01811
- Republic of Korea
| | - Hyunsik Yoon
- Department of Chemical & Biomolecular Engineering
- Seoul National University of Science & Technology
- Seoul 01811
- Republic of Korea
| | - Jinhan Cho
- Department of Chemical and Biological Engineering
- Korea University
- Seoul 02841
- Republic of Korea
- KU-KIST Graduate School of Converging Science and Technology
| | - Kookheon Char
- School of Chemical & Biological Engineering
- Seoul National University
- Seoul 08826
- Republic of Korea
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26
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Hedrick MM, Wu F, Mohanty AK, Misra M. Morphology and performance relationship studies on biodegradable ternary blends of poly(3-hydroxybutyrate- co-3-hydroxyvalerate), polylactic acid, and polypropylene carbonate. RSC Adv 2020; 10:44624-44632. [PMID: 35516230 PMCID: PMC9058669 DOI: 10.1039/d0ra07485c] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Accepted: 10/26/2020] [Indexed: 11/21/2022] Open
Abstract
A biodegradable ternary blend fabricated from polylactic acid (PLA), poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and polypropylene carbonate (PPC) with a good balance of stiffness and toughness via optimizing the composition ratio and morphological structure is, to the best of the authors' knowledge, reported here for the first time. The optimal blend formulation is comprised of 20% PLA, 40% PHBV, and 40% PPC, which possesses a tensile strength measuring 44 MPa and an elongation at break measuring at 215%. Thermal performance analysis revealed an HDT value of 72 °C. The Harkins equation predicts that the three immiscible polymers formed a complete wetting morphology, which was confirmed by scanning electrical microscopy. As the PPC content of the ternary blends is increased, the material undergoes morphological transition from droplet to co-continuous structure, resulting in significant improvement of elongation at break (approximately 40 times higher than that of the PLA-PHBV binary blend). Excellent stiffness and over 200% elongation at break make these sustainable ternary blends feasible for use in packaging as substitutes for certain non-biodegradable petroleum-based single use plastics.
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Affiliation(s)
- Mary M Hedrick
- School of Engineering, University of Guelph Thornbrough Building Guelph Ontario Canada
- Bioproducts Discovery & Development Centre, Department of Plant Agriculture, University of Guelph Crop Science Building Guelph Ontario Canada
| | - Feng Wu
- Bioproducts Discovery & Development Centre, Department of Plant Agriculture, University of Guelph Crop Science Building Guelph Ontario Canada
| | - Amar K Mohanty
- School of Engineering, University of Guelph Thornbrough Building Guelph Ontario Canada
- Bioproducts Discovery & Development Centre, Department of Plant Agriculture, University of Guelph Crop Science Building Guelph Ontario Canada
| | - Manjusri Misra
- School of Engineering, University of Guelph Thornbrough Building Guelph Ontario Canada
- Bioproducts Discovery & Development Centre, Department of Plant Agriculture, University of Guelph Crop Science Building Guelph Ontario Canada
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27
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Gagnon YJ, Roth CB. Local Glass Transition Temperature Tg( z) Within Polystyrene Is Strongly Impacted by the Modulus of the Neighboring PDMS Domain. ACS Macro Lett 2020; 9:1625-1631. [PMID: 35617064 DOI: 10.1021/acsmacrolett.0c00659] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Profiles in the local glass transition temperature Tg(z) within polystyrene (PS) next to polydimethylsiloxane (PDMS) domains were determined using a localized fluorescence method. By changing the base to cross-linker ratio, we varied the cross-link density and, hence, the Young's modulus of PDMS (Sylgard 184). The local Tg(z) in PS at a distance of z = 50 nm away from the PS/PDMS interface was found to shift by 40 K as the PDMS modulus was varied from 0.9 to 2.6 MPa, demonstrating a strong sensitivity of this phenomenon to the rigidity of the neighboring domain. The extent the Tg(z) perturbation persists away from the PS/PDMS interface, z ≈ 65-90 nm before bulk Tg is recovered, is much shorter for this strongly immiscible system compared with the weakly immiscible systems studied previously, which we attribute to a smaller interfacial width, as the χ parameter for PS/PDMS is an order of magnitude larger.
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Affiliation(s)
- Yannic J. Gagnon
- Department of Physics, Emory University, Atlanta, Georgia 30322, United States
| | - Connie B. Roth
- Department of Physics, Emory University, Atlanta, Georgia 30322, United States
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28
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Wei T, Torkelson JM. Molecular Weight Dependence of the Glass Transition Temperature ( Tg)-Confinement Effect in Well-Dispersed Poly(2-vinyl pyridine)–Silica Nanocomposites: Comparison of Interfacial Layer Tg and Matrix Tg. Macromolecules 2020. [DOI: 10.1021/acs.macromol.0c01577] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Tong Wei
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois 60208, United States
| | - John M. Torkelson
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois 60208, United States
- Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, United States
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29
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Han Y, Huang X, Rohrbach ACW, Roth CB. Comparing refractive index and density changes with decreasing film thickness in thin supported films across different polymers. J Chem Phys 2020; 153:044902. [PMID: 32752678 DOI: 10.1063/5.0012423] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Density changes in thin polymer films have long been considered as a possible explanation for shifts in the thickness-dependent glass transition temperature Tg(h) in such nanoconfined systems, given that the glass transition is fundamentally associated with packing frustration during material densification on cooling. We use ellipsometry to compare the temperature-dependent refractive index with decreasing thickness n(h) for supported films of poly(2-vinyl pyridine) (P2VP), poly(methyl methacrylate) (PMMA), and polystyrene (PS), as these polymers have different silica substrate interactions. We observe similar n(h) trends for all three polymers, with near equivalence of P2VP and PS, characterized by a large apparent increase in refractive index for h ≤ 40 nm-65 nm depending on the polymer. Possible sources of molecular dipole orientation within the film are tested by varying molecular weight, polydispersity, chain conformation, and substrate chemistry. Such film inhomogeneities associated with non-uniform polarizability would invalidate the use of homogeneous layer approximations inherent in most thin film analysis methods, which we believe likely explains recent reports of large unphysical increases in film density with decreasing thickness by a variety of different experimental techniques.
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Affiliation(s)
- Yixuan Han
- Department of Physics, Emory University, Atlanta, Georgia 30322, USA
| | - Xinru Huang
- Department of Physics, Emory University, Atlanta, Georgia 30322, USA
| | - Alan C W Rohrbach
- Department of Physics, Emory University, Atlanta, Georgia 30322, USA
| | - Connie B Roth
- Department of Physics, Emory University, Atlanta, Georgia 30322, USA
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30
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Hou T, Yang J, Wang W, Zhao J. Polymeric liquid layer densified by surface acoustic wave. J Chem Phys 2020; 152:224901. [PMID: 32534545 DOI: 10.1063/5.0010869] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Creating densified and stable liquid is a straightforward strategy for the fabrication of strong and ultra-stable amorphous or glassy materials. The current study has discovered that a liquid polymeric thin film is densified under the application of a high frequency surface acoustic wave (SAW). The experimental evidence is the decrease in film thickness and the increase in refractive index, measured by ellipsometry, of polyisobutylene thin films deposited on the solid substrates, when a high frequency SAW (39.5 MHz) is applied to the system. Further investigations by polarization-resolved single molecule fluorescence microscopy have demonstrated that the rotational motion of fluorescent probes doped inside the liquid film is retarded and the dynamical heterogeneity is reduced. The results demonstrate that the application of SAW of high frequency makes the thin polymeric liquid film densified and more dynamically homogeneous.
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Affiliation(s)
- Tianhao Hou
- Beijing National Research Center for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Jingfa Yang
- Beijing National Research Center for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Wen Wang
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jiang Zhao
- Beijing National Research Center for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
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31
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Wang XY, Pan HW, Jia SL, Cao ZW, Han LJ, Zhang HL, Dong LS. Mechanical Properties, Crystallization and Biodegradation Behavior of the Polylactide/Poly(3-hydroxybutyrate-co-4-hydroxybutyrate)/Poly(butylene adipate-co-terephthalate) Blown Films. CHINESE JOURNAL OF POLYMER SCIENCE 2020. [DOI: 10.1007/s10118-020-2418-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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32
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Davis MJB, Randazzo K, Zuo B, Priestley RD. Revealing Interfacial Interactions in Random Copolymer Adsorbed Layers by Solvent Leaching. Macromol Rapid Commun 2020; 41:e1900582. [DOI: 10.1002/marc.201900582] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Revised: 01/05/2020] [Indexed: 11/11/2022]
Affiliation(s)
- Mary J. B. Davis
- Department of Chemical and Biological EngineeringPrinceton University Princeton NJ 08544 USA
| | - Katelyn Randazzo
- Department of Chemical and Biological EngineeringPrinceton University Princeton NJ 08544 USA
| | - Biao Zuo
- Department of Chemical and Biological EngineeringPrinceton University Princeton NJ 08544 USA
- Department of ChemistryKey Laboratory of Advanced Textile Materials and Manufacturing Technology of the Education MinistryZhejiang Sci‐Tech University Hangzhou 310018 China
| | - Rodney D. Priestley
- Department of Chemical and Biological EngineeringPrinceton University Princeton NJ 08544 USA
- Princeton Institute for the Science and Technology of MaterialsPrinceton University Princeton NJ 08544 USA
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33
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Ma MC, Guo YL. Physical Properties of Polymers Under Soft and Hard Nanoconfinement: A Review. CHINESE JOURNAL OF POLYMER SCIENCE 2020. [DOI: 10.1007/s10118-020-2380-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Jo KI, Oh Y, Sung BJ, Kim TH, Um MS, Choi WJ, Bang J, Yuan G, Satija SK, Koo J. Enhanced Dynamics of Confined Polymers near the Immiscible Polymer-Polymer Interface: Neutron Reflectivity Studies. ACS Macro Lett 2020; 9:210-215. [PMID: 35638684 DOI: 10.1021/acsmacrolett.9b01011] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
For polymer-blend films, local dynamics in confined polymer domains tend to differ from the bulk because of significant contributions from the polymer-polymer interface. Herein, we investigated the diffusion dynamics of entangled polymer thin films confined between different polymers in a direction perpendicular to the surface using neutron reflectivity. We found that a bilayer of poly(methyl methacrylate) (PMMA) and deuterated PMMA (dPMMA) sandwiched between polystyrene (PS) layers exhibited significant increase in mobility near the polymer-polymer interface with decreasing PMMA thickness. This indicates that the contribution of repulsive interactions at the immiscible polymer-polymer interface becomes more significant as the film thickness decreases. We also found that the interfacial roughness between PMMA and PS (28 Å at equilibrium) and soft confinement of PS layers did not significantly affect the change in the diffusion dynamics of the adjacent PMMA. This was evidenced by comparison with the diffusion results of multilayers with a flat interface (8 Å at equilibrium) between PMMA and hard PS by UV cross-linking.
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Affiliation(s)
- Kyoung-Il Jo
- Neutron Science Center, Korea Atomic Energy Research Institute (KAERI), Daejeon 34057, Korea
- Department of Chemical and Biological Engineering, Korea University, Seoul 02841, Korea
| | - Younghoon Oh
- Department of Chemistry and Research Institute for Basic Science, Sogang University, Seoul 04107, Korea
| | - Bong June Sung
- Department of Chemistry and Research Institute for Basic Science, Sogang University, Seoul 04107, Korea
| | - Tae-Ho Kim
- Department of Organic Materials Engineering, Chungnam National University, Daejeon 34134, Korea
| | - Min Seop Um
- Chemical Materials Solutions Center, Korea Research Institute of Chemical Technology, Daejeon 34114, Korea
| | - Woo Jin Choi
- Chemical Materials Solutions Center, Korea Research Institute of Chemical Technology, Daejeon 34114, Korea
| | - Joona Bang
- Department of Chemical and Biological Engineering, Korea University, Seoul 02841, Korea
| | - Guangcui Yuan
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States
| | - Sushil K. Satija
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States
| | - Jaseung Koo
- Department of Organic Materials Engineering, Chungnam National University, Daejeon 34134, Korea
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Owusu-Ware SK, Boateng JS, Chowdhry BZ, Antonijevic MD. Glassy state molecular mobility and its relationship to the physico-mechanical properties of plasticized hydroxypropyl methylcellulose (HPMC) films. Int J Pharm X 2019; 1:100033. [PMID: 31528853 PMCID: PMC6744590 DOI: 10.1016/j.ijpx.2019.100033] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Revised: 08/20/2019] [Accepted: 08/21/2019] [Indexed: 12/02/2022] Open
Abstract
Changes in tensile properties and the glass transition temperature (Tg) of plasticized polymer films are typically attributed to molecular mobility, often with no empirical data to support such an assertion. Herein solvent cast HPMC films containing varying amounts of PEG, as the plasticizer, were used to assess the dependence of tensile properties and the Tg on glassy state molecular mobility. Molecular mobility (molecular relaxation time and temperature) parameters were determined by Thermally Stimulated Current Spectroscopy (TSC). The tensile properties and Tg of the HPMC films were determined by texture analysis and DSC, respectively. Molecular mobilities detected by TSC were cooperative and occurred at temperatures (Tg′) well below (113 to 127 °C) the bulk Tg. The relaxation times (τ) were 71 ± 1, 46 ± 1, 42 ± 1, 36 ± 1 and 29 ± 1 s for HPMC films containing 0, 6, 8, 11 and 17% (w/w) PEG, respectively. The Tg and glassy state molecular mobility were found to be intimately linked and demonstrated a linear dependence. While tensile strength was found to be linearly related to molecular relaxation time, tensile elongation and elastic modulus exhibited a non-linear dependence on molecular mobility. The data presented in this work demonstrates the complex nature of the relationship between plasticizer content, molecular mobility, Tg and tensile properties for plasticized polymeric films. It highlights the fact that the dependence of the bulk physico-mechanical properties on glassy state molecular mobility, differ greatly. Therefore, empirical characterization of molecular mobility is important to fully understand and predict the thermo-mechanical behavior of plasticized polymer films. This work demonstrates the unique capability of TSC to provide key information relating to molecular mobility and its influence on the bulk properties of materials. Data generated using TSC could prove useful for stability and performance ranking, in addition to the ability to predict materials behavior using data generated at or below typical storage conditions in the pharmaceutical, food, and polymer industries.
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Affiliation(s)
| | - Joshua S. Boateng
- School of Science, Faculty of Engineering and Science, University of Greenwich (Medway Campus), Chatham Maritime, Kent ME4 4TB, UK
| | - Babur Z. Chowdhry
- School of Science, Faculty of Engineering and Science, University of Greenwich (Medway Campus), Chatham Maritime, Kent ME4 4TB, UK
| | - Milan D. Antonijevic
- School of Science, Faculty of Engineering and Science, University of Greenwich (Medway Campus), Chatham Maritime, Kent ME4 4TB, UK
- Corresponding authors.
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Sasaki T, Ito Y, Sasai T, Irie S. Glass transition of a polystyrene surface as detected via two-dimensional diffusion of Au atoms during physical vapor deposition. POLYMER 2019. [DOI: 10.1016/j.polymer.2019.121577] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Nguyen HK, Sugimoto S, Konomi A, Inutsuka M, Kawaguchi D, Tanaka K. Dynamics Gradient of Polymer Chains near a Solid Interface. ACS Macro Lett 2019; 8:1006-1011. [PMID: 35619492 DOI: 10.1021/acsmacrolett.9b00351] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The relaxation dynamics of polyisoprene (PI) and nitrile butadiene rubber (NBR) chains at the SiO2 interface were directly probed as a function of distance from the SiO2 surface using time-resolved evanescent wave-induced fluorescence anisotropy, dielectric relaxation spectroscopy, and sum-frequency generation spectroscopy. We found the presence of the dynamics gradient of chains in the interfacial region with the SiO2 surface and tried to assign it to the two kinds of adsorbed chains, namely, loosely and strongly adsorbed, at the interface. The segmental relaxation of chains in the strongly adsorbed layer at the interface could be slower than that of bulk chains by more than 10 orders.
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Sugimoto S, Inutsuka M, Kawaguchi D, Tanaka K. The effect of interfacial dynamics on the bulk mechanical properties of rubber composites. Polym J 2019. [DOI: 10.1038/s41428-019-0254-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Kang E, Graczykowski B, Jonas U, Christie D, Gray LAG, Cangialosi D, Priestley RD, Fytas G. Shell Architecture Strongly Influences the Glass Transition, Surface Mobility, and Elasticity of Polymer Core-Shell Nanoparticles. Macromolecules 2019; 52:5399-5406. [PMID: 31367064 PMCID: PMC6659035 DOI: 10.1021/acs.macromol.9b00766] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 06/14/2019] [Indexed: 01/29/2023]
Abstract
Despite the growing application of nanostructured polymeric materials, there still remains a large gap in our understanding of polymer mechanics and thermal stability under confinement and near polymer-polymer interfaces. In particular, the knowledge of polymer nanoparticle thermal stability and mechanics is of great importance for their application in drug delivery, phononics, and photonics. Here, we quantified the effects of a polymer shell layer on the modulus and glass-transition temperature (T g) of polymer core-shell nanoparticles via Brillouin light spectroscopy and modulated differential scanning calorimetry, respectively. Nanoparticles consisting of a polystyrene (PS) core and shell layers of poly(n-butyl methacrylate) (PBMA) were characterized as model systems. We found that the high T g of the PS core was largely unaffected by the presence of an outer polymer shell, whereas the lower T g of the PBMA shell layer decreased with increasing PBMA thickness. The surface mobility was revealed at a temperature about 15 K lower than the T g of the PBMA shell layer. Overall, the modulus of the core-shell nanoparticles decreased with increasing PBMA shell layer thickness. These results suggest that the nanoparticle modulus and T g can be tuned independently through the control of nanoparticle composition and architecture.
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Affiliation(s)
- Eunsoo Kang
- Max
Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Bartlomiej Graczykowski
- Max
Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
- Faculty
of Physics, Adam Mickiewicz University, Umultowska 85, 61614 Poznan, Poland
| | - Ulrich Jonas
- Department
of Chemistry and Biology, University of
Siegen, Adolf-Reichwein-Strasse 2, 57076 Siegen, Germany
| | - Dane Christie
- Department
of Chemical and Biological Engineering and Princeton Institute for the Science
and Technology of Materials, Princeton University, Princeton, New Jersey 08544, United States
| | - Laura A. G. Gray
- Department
of Chemical and Biological Engineering and Princeton Institute for the Science
and Technology of Materials, Princeton University, Princeton, New Jersey 08544, United States
| | - Daniele Cangialosi
- Centro
de
Física de Materiales (CSIC-UPV/EHU), Paseo Manuel de Lardizabal 5, 20018 San Sebastián, Spain
- Donostia
International Physics Center, Paseo Manuel de Lardizabal 4, 20018 San Sebastián, Spain
| | - Rodney D. Priestley
- Department
of Chemical and Biological Engineering and Princeton Institute for the Science
and Technology of Materials, Princeton University, Princeton, New Jersey 08544, United States
| | - George Fytas
- Max
Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
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Sasaki T, Nakane T, Sato A. Segmental dynamics of free-standing and supported polymer thin films predicted from a surface-controlled model. POLYMER 2019. [DOI: 10.1016/j.polymer.2019.04.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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The Glass-Transition Temperature of Supported PMMA Thin Films with Hydrogen Bond/Plasmonic Interface. Polymers (Basel) 2019; 11:polym11040601. [PMID: 30960584 PMCID: PMC6523344 DOI: 10.3390/polym11040601] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2019] [Revised: 03/23/2019] [Accepted: 03/27/2019] [Indexed: 11/28/2022] Open
Abstract
The interfacial effect is one of the significant factors in the glass-transition temperature (Tg) of the polymeric thin film system, competing against the free surface effect. Herein, the Tgs of poly (methyl methacrylate) (PMMA) films with different thicknesses and substrates are studied by fluorescence measurements, focusing on the influence of interfacial effects on the Tgs. The strong interaction between PMMA and quartz substrate leads to increased Tgs with the decreased thickness of the film. The plasmonic silver substrate causes enhanced fluorescence intensity near the interface, resulting in the delayed reduction of the Tgs with the increasing film thickness. Moreover, as a proof of the interface-dependent Tgs, hydrogen bonds of PMMA/quartz and molecules orientation of PMMA/silver are explored by the Raman spectroscopy, and the interfacial interaction energy is calculated by the molecular dynamics simulation. In this study, we probe the inter-relationship between the interfacial interactions arising from the different substrates and the Tg behavior of polymer thin films.
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Thees MF, Roth CB. Unexpected Molecular Weight Dependence to the Physical Aging of Thin Polystyrene Films Present at Ultra‐High Molecular Weights. ACTA ACUST UNITED AC 2019. [DOI: 10.1002/polb.24797] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
| | - Connie B. Roth
- Department of Physics Emory University Atlanta Georgia 30322
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Lewis EA, Stafford CM, Vogt BD. Effect of Adjacent Hydrophilic Polymer Thin Films on Physical Aging and Residual Stress in Thin Films of Poly(butylnorbornene- ran-hydroxyhexafluoroisopropyl norbornene). JOURNAL OF POLYMER SCIENCE. PART B, POLYMER PHYSICS 2019; 57:10.1002/polb.24855. [PMID: 32165786 PMCID: PMC7067284 DOI: 10.1002/polb.24855] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Accepted: 06/03/2019] [Indexed: 11/10/2022]
Abstract
The properties of thin supported polymer films can be dramatically impacted by the substrate upon which it resides. A simple way to alter the properties of the substrate (chemistry, rigidity, dynamics) is by coating it with an immiscible polymer. Here we describe how ultrathin (ca. 2 nm) hydrophilic polymer layers of poly(acrylic acid), PAA, and poly(styrenesulfonate), PSS, impact the aging behavior and the residual stress in thin films of poly(butylnorbornene-ran-hydroxyhexafluoroisopropyl norbornene), BuNB-r-HFANB. The aging rate decreases as the film thickness (h) is decreased, but the extent of this change depends on the adjacent layer. Even for the thickest films (h>500 nm), there is a decrease in the aging rate at 100 °C when BuNB-r-HFANB is in contact with PSS. In an effort to understand the origins of these differences in the aging behavior, the elastic modulus and residual stress (σR) in the films were determined by wrinkling as a function of aging time. The change in the elastic modulus during aging does not appear to be directly correlated with the densification or expansion of the films, but the aging rates appear to roughly scale as hσR 1/3. These results illustrate that the physical aging of thin polymer films can be altered by adjacent polymers.
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Affiliation(s)
- Elizabeth A Lewis
- Department of Polymer Engineering, University of Akron, Akron, OH 44325 USA
| | - Christopher M Stafford
- Materials Science and Engineering Division, National Institute of Standards and Technology, Gaithersburg, MD 20899 USA
| | - Bryan D Vogt
- Department of Polymer Engineering, University of Akron, Akron, OH 44325 USA
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Zhang Y, Woods CN, Alvarez M, Jin Y, Riggleman RA, Fakhraai Z. Effect of substrate interactions on the glass transition and length-scale of correlated dynamics in ultra-thin molecular glass films. J Chem Phys 2018; 149:184902. [PMID: 30441931 DOI: 10.1063/1.5038174] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Interfacial interactions can play an important role in the glass transition temperature (T g ) and relaxation dynamics of ultra-thin glass polymer films. We have recently shown that similar to the polymeric systems in ultra-thin molecular glass films of N, N'-Bis(3-methylphenyl)-N, N'-diphenylbenzidine (TPD), the T g is reduced and dynamics are enhanced. Furthermore, in molecular glass systems, as the film thickness is reduced below ∼30 nm, the dynamics at the two interfaces correlate such that the range of the gradients in the dynamics induced by the free surface narrows compared to thicker films. These observations indicate that the dynamics of the glassy thin films are strongly correlated and cannot be explained by a simple two-layer model consisting of a bulk and a thin interfacial layer with a constant thickness and constant range of dynamical gradients. Here, we investigate the effect of film/substrate interactions on the film dynamics by varying the TPD/substrate interfacial interactions. We show that thin TPD films with thicknesses below ∼60 nm show a smaller extent of T g reduction and enhanced dynamics when supported on a near-neutral substrate (wetting) compared to a weakly interacting (dewetting) substrate. However, the ∼30 nm length scale, where the activation energy significantly reduces from its bulk value as measured by the onset of the glass transition remains unchanged. Coarse-grained molecular dynamics simulation also shows a narrowing in the range of relaxation times once the thickness is sufficiently reduced for the two interfaces to dynamically correlate, consistent with previous work. These results suggest that the length-scale for the correlated dynamics is independent of interfacial interactions and the polymeric nature of the film and may originate from the bulk glass properties.
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Affiliation(s)
- Yue Zhang
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, USA
| | - Connor N Woods
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, USA
| | - Mauricio Alvarez
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, USA
| | - Yi Jin
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, USA
| | - Robert A Riggleman
- Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6315, USA
| | - Zahra Fakhraai
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, USA
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Katsumata R, Dulaney AR, Kim CB, Ellison CJ. Glass Transition and Self-Diffusion of Unentangled Polymer Melts Nanoconfined by Different Interfaces. Macromolecules 2018. [DOI: 10.1021/acs.macromol.8b00475] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Reika Katsumata
- McKetta Department of Chemical Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Austin R. Dulaney
- McKetta Department of Chemical Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Chae Bin Kim
- McKetta Department of Chemical Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Christopher J. Ellison
- McKetta Department of Chemical Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
- Department of Chemical Engineering and Materials Science, The University of Minnesota - Twin Cities, Minneapolis, Minnesota 55455, United States
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Davis MJB, Zuo B, Priestley RD. Competing polymer-substrate interactions mitigate random copolymer adsorption. SOFT MATTER 2018; 14:7204-7213. [PMID: 30131985 DOI: 10.1039/c8sm01433g] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Annealing a supported polymer film in the melt state, a common practice to relieve residual stresses and erase thermal history, can result in the development of an irreversibly adsorbed nanolayer. This layer of polymer chains physically adsorbed to the substrate interface has been shown to influence thin film properties such as viscosity and glass transition temperature. Its growth is attributed to many simultaneous interactions between individual monomer units and the substrate stabilizing chains against desorption. A better understanding of how these specific polymer-substrate interactions influence the growth of the adsorbed layer is needed, particularly given how strongly the properties of geometrically-confined polymeric systems are impacted by interfaces. Here, we use homopolymers and random copolymers of styrene and methyl methacrylate to form adsorbed layers and examine the influence of chemical composition and the resulting polymer-substrate interactions on adsorbed layer growth and structure. Ellipsometric measurements reveal a non-monotonic trend between composition and thickness of the adsorbed layers that is inconsistent with the behavior normally exhibited by random copolymers, being intermediate to their respective homopolymers. We examine this trend in terms of plateau thickness and growth kinetics at two different annealing temperatures and propose a mechanism for how different polymer-substrate interactions combine to influence adsorption when copolymer films are annealed. By introducing compositional heterogeneity, this mechanism extends the study of irreversible adsorption to complex chemistries and provides for a more general understanding of how annealing should be accounted for in the proper selection and processing of polymer thin films for applications in nanotechnology.
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Affiliation(s)
- Mary J B Davis
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544, USA.
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Monnier X, Fernandes Nassar S, Domenek S, Guinault A, Sollogoub C, Dargent E, Delpouve N. Reduced physical aging rates of polylactide in polystyrene/polylactide multilayer films from fast scanning calorimetry. POLYMER 2018. [DOI: 10.1016/j.polymer.2018.07.017] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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49
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Wang H, Hor JL, Zhang Y, Liu T, Lee D, Fakhraai Z. Dramatic Increase in Polymer Glass Transition Temperature under Extreme Nanoconfinement in Weakly Interacting Nanoparticle Films. ACS NANO 2018; 12:5580-5587. [PMID: 29792676 DOI: 10.1021/acsnano.8b01341] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Properties of polymers in polymer nanocomposites and nanopores have been shown to deviate from their respective bulk properties due to physical confinement as well as polymer-particle interfacial interactions. However, separating the confinement effects from the interfacial effects under extreme nanoconfinement is experimentally challenging. Capillary rise infiltration enables polymer infiltration into nanoparticle (NP) packings, thereby confining polymers within extremely small pores and dramatically increasing the interfacial area, providing a good system to systematically distinguish the role of each effect on polymer properties. In this study, we investigate the effect of spatial confinement on the glass transition temperature ( Tg) of polystyrene (PS) infiltrated into SiO2 NP films. The degree of confinement is tuned by varying the molecular weight of polymers, the size of NPs (diameters between 11 and 100 nm, producing 3-30 nm average pore sizes), and the fill-fraction of PS in the NP films. We show that in these dense NP packings the Tg of confined PS, which interacts weakly with SiO2 NPs, significantly increases with decreasing pore size such that for the two molecular weights of PS studied the Tg increases by up to 50 K in 11 nm NP packings, while Tg is close to the bulk Tg in 100 nm NP packings. Interestingly, as the fill-fraction of PS is decreased, resulting in the accumulation of the polymer in the contacts between nanoparticles, hence an increased specific interfacial area, the Tg further increases relative to the fully filled films by another 5-8 K, indicating the strong role of geometrical confinement as opposed to the interfacial effects on the measured Tg values.
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Affiliation(s)
- Haonan Wang
- Department of Chemistry , University of Pennsylvania , Philadelphia , Pennsylvania 19104 , United States
| | - Jyo Lyn Hor
- Department of Chemical and Biomolecular Engineering , University of Pennsylvania , Philadelphia , Pennsylvania 19104 , United States
| | - Yue Zhang
- Department of Chemistry , University of Pennsylvania , Philadelphia , Pennsylvania 19104 , United States
| | - Tianyi Liu
- Department of Chemistry , University of Pennsylvania , Philadelphia , Pennsylvania 19104 , United States
| | - Daeyeon Lee
- Department of Chemical and Biomolecular Engineering , University of Pennsylvania , Philadelphia , Pennsylvania 19104 , United States
| | - Zahra Fakhraai
- Department of Chemistry , University of Pennsylvania , Philadelphia , Pennsylvania 19104 , United States
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50
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Glor EC, Angrand GV, Fakhraai Z. Exploring the broadening and the existence of two glass transitions due to competing interfacial effects in thin, supported polymer films. J Chem Phys 2018; 146:203330. [PMID: 28571332 DOI: 10.1063/1.4979944] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
In this report, we use ellipsometry to characterize the glass transition in ultra-thin films of poly(2-vinyl pyridine) (P2VP) supported on a silicon substrate. P2VP is known to have attractive substrate interactions, which can increase the Tg of ultra-thin films compared to the bulk value. Here, we use an extended temperature range to show that the glass transition can be extremely broad, indicating that a large gradient of the dynamics exists through the film with slow dynamics near the substrate and enhanced dynamics at the free surface. To observe the effect of these two interfaces on the average thin film dynamics, cooling rate-dependent Tg (CR-Tg) measurements were used to indirectly probe the average relaxation times of the films. We demonstrate that ultra-thin films have lower fragility compared to bulk films, and, when cooled at slow cooling rates (<1 K/min), exhibit extreme broadening of the dynamics (<70 nm) and eventually complete decoupling between the free surface and substrate regions to produce films with two distinct Tg's (<16 nm). Tg,high increases with decreasing thickness in a similar manner to what has been observed in previous studies on P2VP, and Tg,low decreases with decreasing film thickness in a similar manner to what has been observed in polymer films with enhanced free surfaces and neutral substrate interactions. These observations indicate that the dynamics in thin films of P2VP can be strongly coupled over a length scale of ∼10-20 nm, resulting in two co-existing layers with two distinct glass transitions when the range of the dynamical gradients become too large to sustain (breadth of the transition > 50 K).
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Affiliation(s)
- Ethan C Glor
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Gabriel V Angrand
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Zahra Fakhraai
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
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