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Rossi D, Dong Y, Paradkar R, Chen X, Wu Y, Mohler C, Kuo TC, Chen Z. Quantifying Chemical Reactions and Interfacial Properties at Buried Polymer/Polymer Interfaces. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2024; 40:12689-12696. [PMID: 38842226 DOI: 10.1021/acs.langmuir.4c01214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2024]
Abstract
Maleic anhydride (MAH)-modified polymers are used as tie layers for binding dissimilar polymers in multilayer polymer films. The MAH chemistry which promotes adhesion is well characterized in the bulk; however, only recently has the interfacial chemistry been studied. Sum frequency generation vibrational spectroscopy (SFG) is an interfacial spectroscopy technique which provides detailed information on interfacial chemical reactions, species, and molecular orientations and has been essential for characterizing the MAH chemistry in both nylon and ethyl vinyl alcohol copolymer (EVOH) model systems and coextruded multilayer films. Here, we further characterize the interfacial chemistry between MAH-modified polyethylene tie layers and both EVOH and nylon by investigating the model systems over a range of MAH concentrations. We can detect the interfacial chemical reaction products between MAH and the barrier layer at MAH concentrations of ≥0.022 wt % for nylon and ≥0.077 wt % for EVOH. Additionally, from the concentration-dependent reaction reactant/product SFG peak positions and the product imide or ester/acid C═O group tilt angles extracted from the polarization-dependent SFG spectra, we quantitatively observe concentration-dependent changes to both the interfacial chemistry and interfacial structure. The interfacial chemistry and molecular orientation as a function of MAH concentration are well correlated with the adhesion strength, providing important quantitative information for the future design of MAH-modified tie layers for a variety of important applications.
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Affiliation(s)
- Daniel Rossi
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Yifan Dong
- Packaging and Specialty Plastics, The Dow Chemical Company, Lake Jackson, Texas 77566, United States
| | - Rajesh Paradkar
- Packaging and Specialty Plastics, The Dow Chemical Company, Lake Jackson, Texas 77566, United States
| | - Xiaoyun Chen
- Core R&D, The Dow Chemical Company, Midland, Michigan 48674, United States
| | - Yuchen Wu
- Department of Macromolecular Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Carol Mohler
- Core R&D, The Dow Chemical Company, Midland, Michigan 48674, United States
| | - Tzu-Chi Kuo
- Core R&D, The Dow Chemical Company, Midland, Michigan 48674, United States
| | - Zhan Chen
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
- Department of Macromolecular Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109, United States
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2
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Xu Z, Li G, Zhang Y, Wu Y, Lu X. Probing Interfacial Aging of Model Adhesion Joints under a Hygrothermal Environment at a Molecular Level. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2024; 40:9280-9288. [PMID: 38619299 DOI: 10.1021/acs.langmuir.4c00696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/16/2024]
Abstract
Generally, for adhesive joints, the polar water molecules in humid environments can have a critical effect on the interfacial structures and structural evolution adjacent to the solid substrates. Regarding this, it is still a big challenge to detect and understand the interfacial hygrothermal aging process at the molecular level in real time and in situ. In this study, to trace the interfacial hygrothermal aging process of a classical epoxy formula containing diglycidyl ether of biphenyl A (DGEBA) and 2,2'-(ethylenedioxy) diethylamine (EDDA) with sapphire and fused silica in a typical hygrothermal environment (85 °C and 85% RH), sum frequency generation (SFG) vibrational spectroscopy was used to probe the molecular-level interfacial structural change over the time. The structural evolution dynamics at the buried epoxy/sapphire and epoxy/silica interfaces upon hygrothermal aging were revealed directly in situ. The interfacial delamination during hygrothermal aging was also elucidated from the molecular level. Upon hygrothermal aging, the interfacial CH signals, such as the ones from methyl, methylene, and phenyl groups, decreased significantly and the water OH signals increased substantially, indicating the water molecules had diffused into the interfaces and destroyed the original interactions between the epoxy formula and the substrates. Further analysis indicates that when the integrated signals in the CH range declined to their minimum and leveled off, the interfacial delamination happened. The tensile experiment proved the validity of these spectroscopic experimental results. Our study provides first-hand and molecular-level evidence on a direct correlation between the diffusion of the surrounding water molecules into the interface and the evolution/destruction of the interfacial structures during hygrothermal aging. More importantly, it is proved, SFG can be developed into a powerful tool to noninvasively reveal the local interfacial delamination in real time and in situ under extreme hygrothermal conditions, complemented by the mechanic test.
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Affiliation(s)
- Zhaohui Xu
- State Key Laboratory of Digital Medical Engineering, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China
| | - Gaoming Li
- Institute of Chemical Materials, China Academy of Engineering Physics, Mianyang 621900, China
| | - Yinyu Zhang
- Institute of Chemical Materials, China Academy of Engineering Physics, Mianyang 621900, China
| | - Yeping Wu
- Institute of Chemical Materials, China Academy of Engineering Physics, Mianyang 621900, China
| | - Xiaolin Lu
- State Key Laboratory of Digital Medical Engineering, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China
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3
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Kawaguchi D, Sasahara K, Inutsuka M, Abe T, Yamamoto S, Tanaka K. Absolute local conformation of poly(methyl methacrylate) chains adsorbed on a quartz surface. J Chem Phys 2023; 159:244902. [PMID: 38146829 DOI: 10.1063/5.0184315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Accepted: 11/30/2023] [Indexed: 12/27/2023] Open
Abstract
Polymer chains at a buried interface with an inorganic solid play a critical role in the performance of polymer nanocomposites and adhesives. Sum frequency generation (SFG) vibrational spectroscopy with a sub-nanometer depth resolution provides valuable information regarding the orientation angle of functional groups at interfaces. However, in the case of conventional SFG, since the signal intensity is proportional to the square of the second-order nonlinear optical susceptibility and thereby loses phase information, it cannot be unambiguously determined whether the functional groups face upward or downward. This problem can be solved by phase-sensitive SFG (ps-SFG). We here applied ps-SFG to poly(methyl methacrylate) (PMMA) chains in direct contact with a quartz surface, shedding light on the local conformation of chains adsorbed onto the solid surface. The measurements made it possible to determine the absolute orientation of the ester methyl groups of PMMA, which were oriented toward the quartz interface. Combining ps-SFG with all-atomistic molecular dynamics simulation, the distribution of the local conformation and the driving force are also discussed.
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Affiliation(s)
- Daisuke Kawaguchi
- Department of Applied Chemistry, Kyushu University, Fukuoka 819-0395, Japan
- Center for Polymer Interface and Molecular Adhesion Science, Kyushu University, Fukuoka 819-0395, Japan
| | - Kazuki Sasahara
- Department of Applied Chemistry, Kyushu University, Fukuoka 819-0395, Japan
| | - Manabu Inutsuka
- Department of Applied Chemistry, Kyushu University, Fukuoka 819-0395, Japan
| | - Tatsuki Abe
- Department of Applied Chemistry, Kyushu University, Fukuoka 819-0395, Japan
| | - Satoru Yamamoto
- Center 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
- Center for Polymer Interface and Molecular Adhesion Science, Kyushu University, Fukuoka 819-0395, Japan
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4
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Xu Z, Zhang Y, Wu Y, Lu X. Molecular-Level Correlation between Spectral Evidence and Interfacial Bonding Formation for Epoxy Adhesives on Solid Substrates. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:5847-5856. [PMID: 35441517 DOI: 10.1021/acs.langmuir.2c00470] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Interfacial bonding strength of an epoxy-based adhesive depends on the interfacial interaction between the adhesive and the substrate. Normally, the curing process at the interface accompanied by the interfacial bonding formation is different from that in the bulk, and it is still a big challenge to probe the interfacial bonding formation at a molecular level. In this study, to trace the interfacial structural evolution of a representative formula of epoxy (digylcidyl ether of biphenyl A, DGEBA) and amine hardener [1,2-bis(2-aminoethoxy)ethane, EDDA] with the sapphire and silica substrates upon curing and post-curing steps, sum frequency generation (SFG) vibrational spectroscopy is employed to detect the molecular-level interfacial structural information. For the sapphire substrate, upon curing, backbone methylene (CH2) stretching signals decrease, indicating the formation of a rigid chain network structure and thus losing the local methylene order, while vibrational signals of the sapphire surface hydroxyl (OH) groups (including hydrogen-bonded and unbonded) increase significantly, indicating the formation of a strong hydrogen-bonding and polar interaction between the epoxy adhesive and the sapphire surface. Upon post-curing, increased backbone CH2 signals and decreased sapphire OH signals suggest interfacial chemical bonding formation due to the reaction between the epoxy rings and the sapphire surface OH groups. Orientation analysis confirms the enhanced ordering of the sapphire surface OH groups upon curing and post-curing, in comparison to the uncured epoxy formula. As for the fused silica, weak vibrational signals of the methylene (CH2) and methyl (CH3) groups are observed before curing, while both of them increase slightly for the cured and post-cured epoxy formulae, suggesting relatively less hydrophilic nature of the silica surface compared to that of the sapphire surface, also evidenced by the very weak OH signals upon curing and post-curing. Further measurement on the adhesion strength matches up with the above spectroscopic experimental results, substantiating the correlation between the macroscopic bonding strength of the epoxy adhesive and the microscopic molecular-level structure.
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Affiliation(s)
- Zhaohui Xu
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China
| | - Yinyu Zhang
- Institute of Chemical Materials, China Academy of Engineering Physics, Mianyang 621900, China
| | - Yeping Wu
- Institute of Chemical Materials, China Academy of Engineering Physics, Mianyang 621900, China
| | - Xiaolin Lu
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China
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5
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Lu T, Guo W, Datar PM, Xin Y, Marsh ENG, Chen Z. Probing protein aggregation at buried interfaces: distinguishing between adsorbed protein monomers, dimers, and a monomer-dimer mixture in situ. Chem Sci 2022; 13:975-984. [PMID: 35211262 PMCID: PMC8790787 DOI: 10.1039/d1sc04300e] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Accepted: 12/04/2021] [Indexed: 11/21/2022] Open
Abstract
Protein adsorption on surfaces greatly impacts many applications such as biomedical materials, anti-biofouling coatings, bio-separation membranes, biosensors, antibody protein drugs etc. For example, protein drug adsorption on the widely used lubricant silicone oil surface may induce protein aggregation and thus affect the protein drug efficacy. It is therefore important to investigate the molecular behavior of proteins at the silicone oil/solution interface. Such an interfacial study is challenging because the targeted interface is buried. By using sum frequency generation vibrational spectroscopy (SFG) with Hamiltonian local mode approximation method analysis, we studied protein adsorption at the silicone oil/protein solution interface in situ in real time, using bovine serum albumin (BSA) as a model. The results showed that the interface was mainly covered by BSA dimers. The deduced BSA dimer orientation on the silicone oil surface from the SFG study can be explained by the surface distribution of certain amino acids. To confirm the BSA dimer adsorption, we treated adsorbed BSA dimer molecules with dithiothreitol (DTT) to dissociate these dimers. SFG studies on adsorbed BSA after the DTT treatment indicated that the silicone oil surface is covered by BSA dimers and BSA monomers in an approximate 6 : 4 ratio. That is to say, about 25% of the adsorbed BSA dimers were converted to monomers after the DTT treatment. Extensive research has been reported in the literature to determine adsorbed protein dimer formation using ex situ experiments, e.g., by washing off the adsorbed proteins from the surface then analyzing the washed-off proteins, which may induce substantial errors in the washing process. Dimerization is a crucial initial step for protein aggregation. This research developed a new methodology to investigate protein aggregation at a solid/liquid (or liquid/liquid) interface in situ in real time using BSA dimer as an example, which will greatly impact many research fields and applications involving interfacial biological molecules.
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Affiliation(s)
- Tieyi Lu
- Department of Chemistry, University of Michigan Ann Arbor Michigan 48109 USA
| | - Wen Guo
- Department of Chemistry, University of Michigan Ann Arbor Michigan 48109 USA
| | - Prathamesh M Datar
- Department of Chemistry, University of Michigan Ann Arbor Michigan 48109 USA
| | - Yue Xin
- Department of Chemistry, University of Michigan Ann Arbor Michigan 48109 USA
| | - E Neil G Marsh
- Department of Chemistry, University of Michigan Ann Arbor Michigan 48109 USA
| | - Zhan Chen
- Department of Chemistry, University of Michigan Ann Arbor Michigan 48109 USA
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6
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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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7
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Matsumoto T, Shimizu Y, Nishino T. Analyses of the Adhesion Interphase of Isotactic Polypropylene Using Hot-Melt Polyolefin Adhesives. Macromolecules 2021. [DOI: 10.1021/acs.macromol.1c00647] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Takuya Matsumoto
- Department of Chemical Science and Engineering, Graduate School of Engineering, Kobe University, Rokko, Nada, Kobe 657-8501, Japan
| | - Yosuke Shimizu
- Department of Chemical Science and Engineering, Graduate School of Engineering, Kobe University, Rokko, Nada, Kobe 657-8501, Japan
| | - Takashi Nishino
- Department of Chemical Science and Engineering, Graduate School of Engineering, Kobe University, Rokko, Nada, Kobe 657-8501, Japan
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8
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Guo R, Li B, Lu T, Lin T, Andre J, Zhang C, Zhi L, Chen Z. Molecular Orientations at Buried Conducting Polymer/Graphene Interfaces. Macromolecules 2021. [DOI: 10.1021/acs.macromol.1c00248] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Ruiying Guo
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100039, China
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Bolin Li
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Tieyi Lu
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Ting Lin
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - John Andre
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Chengcheng Zhang
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Linjie Zhi
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100039, China
| | - Zhan Chen
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
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Abstract
The basic theory of sum-frequency generation (SFG) is revisited. A rigorous derivation showing that linear optical transmission and reflection at an interface result from the interference of the incident wave and induced radiation wave in a medium is presented. The derivation is extended to SFG in a medium with a finite interface layer to see how SFG evolves. Detailed description on interface vs bulk and electric dipole (ED) vs electric quadrupole (EQ) contribution to SFG are provided with essentially no model dependence, putting the theory of SFG on a solid ground and removing possible existing confusions. Electric-quadrupole contributions to SFG from the interface and bulk are discussed. It is seen that there is a relevant bulk EQ contribution intrinsically inseparable in measurement from the interface ED contribution but plays a major role among all EQ contributions; its importance relative to the ED part can only be judged by referring to the established reference cases.
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Affiliation(s)
- Y R Shen
- Physics Department, University of California, Berkeley, California 94707, USA and Physics Department, Fudan University, Shanghai, China
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10
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Zhang S, Andre JS, Hsu L, Toolis A, Esarey SL, Li B, Chen Z. Nondestructive In Situ Detection of Chemical Reactions at the Buried Interface between Polyurethane and Isocyanate-Based Primer. Macromolecules 2020. [DOI: 10.1021/acs.macromol.0c01862] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Shuqing Zhang
- Department of Macromolecular Science and Engineering, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - John S Andre
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Lorraine Hsu
- Coatings and Innovation Center, PPG, 4325 Rosanna Drive, Allison Park, Pennsylvania 15101, United States
| | - Amy Toolis
- Coatings and Innovation Center, PPG, 4325 Rosanna Drive, Allison Park, Pennsylvania 15101, United States
| | - Samuel L Esarey
- Coatings and Innovation Center, PPG, 4325 Rosanna Drive, Allison Park, Pennsylvania 15101, United States
| | - Bolin Li
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Zhan Chen
- Department of Macromolecular Science and Engineering, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
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11
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Zhang L, Tan J, Pei Q, Ye S. Film thickness and surface plasmon tune the contribution of SFG signals from buried interface and air surface. CHINESE J CHEM PHYS 2020. [DOI: 10.1063/1674-0068/cjcp2006113] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Liang Zhang
- Hefei National Laboratory for Physical Sciences at the Microscale, and Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, China
- Synergetic Innovation Center of Quantum Information Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - Junjun Tan
- Hefei National Laboratory for Physical Sciences at the Microscale, and Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, China
- Synergetic Innovation Center of Quantum Information Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - Quanbing Pei
- Hefei National Laboratory for Physical Sciences at the Microscale, and Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, China
- Synergetic Innovation Center of Quantum Information Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - Shuji Ye
- Hefei National Laboratory for Physical Sciences at the Microscale, and Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, China
- Synergetic Innovation Center of Quantum Information Quantum Physics, University of Science and Technology of China, Hefei 230026, China
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12
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Li B, Andre JS, Chen X, Walther B, Paradkar R, Feng C, Tucker C, Mohler C, Chen Z. Probing Molecular Behavior of Carbonyl Groups at Buried Nylon/Polyolefin Interfaces in Situ. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:11349-11357. [PMID: 32870007 DOI: 10.1021/acs.langmuir.0c02188] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Nylon and maleic anhydride (MAH)-grafted polyolefin-based thin co-extruded multilayer films are widely used in packaging applications encountered in daily life. The molecular structure of the nylon/MAH-grafted polyolefin buried interface and molecular bonding between these two chemically dissimilar layers are thought to play an important role in achieving packaging structures with good adhesion. Here, the molecular bonds present at a nylon/maleic anhydride (MAH)-grafted polyethylene buried interface were systematically examined in situ for the first time using sum frequency generation (SFG) vibrational spectroscopy. The carbonyl stretching frequency region of the SFG spectra of a nylon/MAH-grafted polyethylene buried interface showed the presence of hydrolyzed MAH groups grafted to the polyethylene chain and very low levels of unreacted MAH enriched at the buried interface. The ability of SFG to detect these molecular species at the buried interface yields important understanding of the interfacial molecular structure and provides the basis for subsequent in situ studies of the bonding reaction between the grafted MAH and nylon directly at the interface. This understanding may guide the design of multilayer films with improved properties such as enhanced adhesion between polymer layers. The approach used in this study is general and is applicable to study the molecular characteristics of other buried interfaces of significance, such as buried interfaces involving polymers in solar cells, polymer semiconductors, and batteries. Nylon impact modification is another area of interest where the interaction between the MAH-grafted elastomer and the continuous phase of nylon is important.
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Affiliation(s)
- Bolin Li
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - John S Andre
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Xiaoyun Chen
- Core R&D, The Dow Chemical Company, Midland, Michigan 48674, United States
| | - Brian Walther
- Packaging and Specialty Plastics, The Dow Chemical Company, Lake Jackson, Texas 77541, United States
| | - Rajesh Paradkar
- Packaging and Specialty Plastics, The Dow Chemical Company, Lake Jackson, Texas 77541, United States
| | - Chuang Feng
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Christopher Tucker
- Core R&D, The Dow Chemical Company, Midland, Michigan 48674, United States
| | - Carol Mohler
- Core R&D, The Dow Chemical Company, Midland, Michigan 48674, United States
| | - Zhan Chen
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
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13
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Li B, Andre JS, Chen X, Walther B, Paradkar R, Feng C, Tucker C, Mohler C, Chen Z. Observing a Chemical Reaction at a Buried Solid/Solid Interface in Situ. Anal Chem 2020; 92:14145-14152. [DOI: 10.1021/acs.analchem.0c03228] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Bolin Li
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - John S. Andre
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Xiaoyun Chen
- Core R&D,The Dow Chemical Company, Midland, Michigan 48674, United States
| | - Brian Walther
- Packaging and Specialty Plastics,The Dow Chemical Company, Lake Jackson, Texas 77566, United States
| | - Rajesh Paradkar
- Packaging and Specialty Plastics,The Dow Chemical Company, Lake Jackson, Texas 77566, United States
| | - Chuang Feng
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Christopher Tucker
- Core R&D,The Dow Chemical Company, Midland, Michigan 48674, United States
| | - Carol Mohler
- Core R&D,The Dow Chemical Company, Midland, Michigan 48674, United States
| | - Zhan Chen
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
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14
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Li X, Rupprechter G. A modeling analysis of molecular orientation at interfaces by polarization-dependent sum frequency generation vibrational spectroscopy. CHINESE JOURNAL OF CATALYSIS 2019. [DOI: 10.1016/s1872-2067(19)63357-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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15
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Bulk-or-interface assignment of heterodyne-detected chiral vibrational sum frequency generation signal by its polarization dependence. J Chem Phys 2018; 149:244703. [DOI: 10.1063/1.5063290] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
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16
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Li X, Lu X. Evolution of Irreversibly Adsorbed Layer Promotes Dewetting of Polystyrene Film on Sapphire. Macromolecules 2018. [DOI: 10.1021/acs.macromol.8b01141] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- Xu Li
- State Key Laboratory of Bioelectronics, School of Biological Science & Medical Engineering, Southeast University, Nanjing 210096, Jiangsu Province, P. R. China
| | - Xiaolin Lu
- State Key Laboratory of Bioelectronics, School of Biological Science & Medical Engineering, Southeast University, Nanjing 210096, Jiangsu Province, P. R. China
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17
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Averett SC, Stanley SK, Hanson JJ, Smith SJ, Patterson JE. Surface Spectroscopic Signatures of Mechanical Deformation in High-Density Polyethylene (HDPE). APPLIED SPECTROSCOPY 2018; 72:1057-1068. [PMID: 29336602 DOI: 10.1177/0003702818757232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
High-density polyethylene (HDPE) has been extensively studied, both as a model for semi-crystalline polymers and because of its own industrial utility. During cold drawing, crystalline regions of HDPE are known to break up and align with the direction of tensile load. Structural changes due to deformation should also manifest at the surface of the polymer, but until now, a detailed molecular understanding of how the surface responds to mechanical deformation has been lacking. This work establishes a precedent for using vibrational sum-frequency generation (VSFG) spectroscopy to investigate changes in the molecular-level structure of the surface of HDPE after cold drawing. X-ray diffraction (XRD) was used to confirm that the observed surface behavior corresponds to the expected bulk response. Before tensile loading, the VSFG spectra indicate that there is significant variability in the surface structure and tilt of the methylene groups away from the surface normal. After deformation, the VSFG spectroscopic signatures are notably different. These changes suggest that hydrocarbon chains at the surface of visibly necked HDPE are aligned with the direction of loading, while the associated methylene groups are oriented with the local C2v symmetry axis roughly parallel to the surface normal. Small amounts of unaltered material are also found at the surface of necked HDPE, with the relative amount of unaltered material decreasing as the amount of deformation increases. Aspects of the nonresonant SFG response in the transition zone between necked and undeformed polymer provide additional insight into the deformation process and may provide the first indication of mechanical deformation. Nonlinear surface spectroscopy can thus be used as a noninvasive and nondestructive tool to probe the stress history of a HPDE sample in situations where X-ray techniques are not available or not applicable. Vibrational sum-frequency generation thus has great potential as a platform for material state awareness (MSA) and should be considered as part of a broader suite of tools for such applications.
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Affiliation(s)
- Shawn C Averett
- 1 Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT, USA
- 2 Current affiliation: Oterio Junior College, La Junta, CO, USA
| | - Steven K Stanley
- 1 Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT, USA
- 3 Current affiliation: McKetta Department of Chemical Engineering, University of Texas, Austin, TX, USA
| | - Joshua J Hanson
- 1 Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT, USA
- 4 Current affiliation: IM Flash Technologies, Lehi, UT, USA
| | - Stacey J Smith
- 1 Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT, USA
| | - James E Patterson
- 1 Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT, USA
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18
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Xiao M, Mohler C, Tucker C, Walther B, Lu X, Chen Z. Structures and Adhesion Properties at Polyethylene/Silica and Polyethylene/Nylon Interfaces. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:6194-6204. [PMID: 29716190 DOI: 10.1021/acs.langmuir.8b00930] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The molecular structures of buried interfaces of maleic anhydride grafted and ungrafted polyethylene films with silica and nylon surfaces were studied in situ using sum-frequency generation (SFG) vibrational spectroscopy. Grafting maleic anhydride to polyethylene altered the molecular structures at buried interfaces, including changing the orientation of polymer methylene groups and resulting in the presence of C═O groups at silica interfaces. These molecular level changes are correlated with enhanced adhesion properties, with ordered C═O groups and in-plane orientation of the methylene groups associated with higher levels of adhesion. While improved adhesion was observed for grafted polyethylene at the nylon interface, no C═O groups were detected at the interface using SFG, for films thermally treated at 185 °C. In this case, either no C═O groups are present at the interface or they are disordered; the latter explanation is more likely, considering the observed improvement in adhesion.
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Affiliation(s)
- Minyu Xiao
- Department of Chemistry , University of Michigan , Ann Arbor , Michigan 48109 , United States
| | - Carol Mohler
- Core R&D-Formulation Science , The Dow Chemical Company , Midland , Michigan 48674 , United States
| | - Christopher Tucker
- Core R&D-Formulation Science , The Dow Chemical Company , Midland , Michigan 48674 , United States
| | - Brian Walther
- Packaging & Specialty Plastics TS&D F&SP , The Dow Chemical Company , Freeport , Texas 77541 , United States
| | - Xiaolin Lu
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering , Southeast University , Nanjing 210096 , China
| | - Zhan Chen
- Department of Chemistry , University of Michigan , Ann Arbor , Michigan 48109 , United States
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19
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Zhang C. Sum Frequency Generation Vibrational Spectroscopy for Characterization of Buried Polymer Interfaces. APPLIED SPECTROSCOPY 2017; 71:1717-1749. [PMID: 28537432 DOI: 10.1177/0003702817708321] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Sum frequency generation vibrational spectroscopy (SFG-VS) has become one of the most appealing technologies to characterize molecular structures at interfaces. In this focal point review, we focus on SFG-VS studies at buried polymer interfaces and review many of the recent publications in the field. We also cover the essential theoretical background of SFG-VS and discuss the experimental implementation of SFG-VS.
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Affiliation(s)
- Chi Zhang
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, USA
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20
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Xiao M, Joglekar S, Zhang X, Jasensky J, Ma J, Cui Q, Guo LJ, Chen Z. Effect of Interfacial Molecular Orientation on Power Conversion Efficiency of Perovskite Solar Cells. J Am Chem Soc 2017; 139:3378-3386. [DOI: 10.1021/jacs.6b10651] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
| | | | - Xiaoxian Zhang
- CAS
Key laboratory of Standardization and Measurement for Nanotechnology,
Chinese Academy of Sciences Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, China
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21
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Takeshita N, Okuno M, Ishibashi TA. Molecular conformation of DPPC phospholipid Langmuir and Langmuir–Blodgett monolayers studied by heterodyne-detected vibrational sum frequency generation spectroscopy. Phys Chem Chem Phys 2017; 19:2060-2066. [DOI: 10.1039/c6cp07800a] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Heterodyne-detected vibrational sum frequency generation spectroscopy was used to investigate molecular structures of DPPC monolayers on water (Langmuir monolayer) and monolayers on a fused silica substrate (Langmuir-Blodgett [LB] monolayer).
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Affiliation(s)
- Naoki Takeshita
- Department of Chemistry
- Graduate School of Pure and Applied Sciences
- University of Tsukuba
- Tsukuba
- Japan
| | - Masanari Okuno
- Department of Chemistry
- Graduate School of Pure and Applied Sciences
- University of Tsukuba
- Tsukuba
- Japan
| | - Taka-aki Ishibashi
- Department of Chemistry
- Graduate School of Pure and Applied Sciences
- University of Tsukuba
- Tsukuba
- Japan
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22
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Lu X, Zhang C, Ulrich N, Xiao M, Ma YH, Chen Z. Studying Polymer Surfaces and Interfaces with Sum Frequency Generation Vibrational Spectroscopy. Anal Chem 2016; 89:466-489. [DOI: 10.1021/acs.analchem.6b04320] [Citation(s) in RCA: 91] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Xiaolin Lu
- State
Key Laboratory of Bioelectronics, School of Biological Science and
Medical Engineering, Southeast University, Nanjing 210096, Jiangsu Province, P. R. China
| | - Chi Zhang
- Department
of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Nathan Ulrich
- Department
of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Minyu Xiao
- Department
of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Yong-Hao Ma
- State
Key Laboratory of Bioelectronics, School of Biological Science and
Medical Engineering, Southeast University, Nanjing 210096, Jiangsu Province, P. R. China
| | - Zhan Chen
- Department
of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
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23
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Li X, Li B, Zhang X, Li C, Guo Z, Zhou D, Lu X. Detecting Surface Hydration of Poly(2-hydroxyethyl methacrylate) in Solution in situ. Macromolecules 2016. [DOI: 10.1021/acs.macromol.6b00389] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- Xu Li
- State Key Laboratory of Bioelectronics, School of Biological Science & Medical Engineering, Southeast University, Nanjing 210096, Jiangsu Province P. R. China
| | - Bolin Li
- State Key Laboratory of Bioelectronics, School of Biological Science & Medical Engineering, Southeast University, Nanjing 210096, Jiangsu Province P. R. China
| | - Xiaodong Zhang
- State Key Laboratory of Bioelectronics, School of Biological Science & Medical Engineering, Southeast University, Nanjing 210096, Jiangsu Province P. R. China
| | - Chengcheng Li
- State Key Laboratory of Bioelectronics, School of Biological Science & Medical Engineering, Southeast University, Nanjing 210096, Jiangsu Province P. R. China
| | - Zhirui Guo
- Department
of Geriatrics, Second Affiliated Hospital of Nanjing Medical University, Nanjing 210029, P. R. China
| | - Dongshan Zhou
- Department
of Polymer Science and Engineering, School of Chemistry and Chemical
Engineering, State Key Laboratory of Coordination Chemistry, Nanjing
National Laboratory of Microstructure, Nanjing University, Nanjing 210093, P. R. China
| | - Xiaolin Lu
- State Key Laboratory of Bioelectronics, School of Biological Science & Medical Engineering, Southeast University, Nanjing 210096, Jiangsu Province P. R. China
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24
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Xiao M, Jasensky J, Zhang X, Li Y, Pichan C, Lu X, Chen Z. Influence of the side chain and substrate on polythiophene thin film surface, bulk, and buried interfacial structures. Phys Chem Chem Phys 2016; 18:22089-99. [DOI: 10.1039/c6cp04155h] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
We elucidated the effects of the polythiophene side chain and the substrate surface hydrophobicity on polythiophene thin film–substrate interfacial interactions; such interactions influence the interfacial structure, bulk film structure, and the surface structure.
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Affiliation(s)
- Minyu Xiao
- Department of Chemistry
- University of Michigan
- Ann Arbor
- USA
| | | | - Xiaoxian Zhang
- Key laboratory of Standardization and Measurement for Nanotechnology
- Chinese Academy of Sciences
- National Center for Nanoscience and Technology
- Beijing 100190
- China
| | - Yaoxin Li
- Department of Chemistry
- University of Michigan
- Ann Arbor
- USA
| | - Cayla Pichan
- Department of Chemistry
- University of Michigan
- Ann Arbor
- USA
| | - Xiaolin Lu
- State Key Laboratory of Bioelectronics
- School of Biological Science and Medical Engineering
- Southeast University
- Nanjing 210096
- China
| | - Zhan Chen
- Department of Chemistry
- University of Michigan
- Ann Arbor
- USA
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25
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Leng C, Buss HG, Segalman RA, Chen Z. Surface Structure and Hydration of Sequence-Specific Amphiphilic Polypeptoids for Antifouling/Fouling Release Applications. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:9306-11. [PMID: 26245923 DOI: 10.1021/acs.langmuir.5b01440] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Amphiphilic polypeptoids can be designed with specific sequences of hydrophilic and hydrophobic units, which determine their surface properties for antifouling/fouling release purposes. Although the sequence-dependent surface structures of polypeptoids have been extensively investigated, e.g., with X-ray spectroscopy, their molecular structures under the aqueous conditions relevant to marine fouling have not been studied. In this work, we applied sum frequency generation (SFG) vibrational spectroscopy to study the surface structures and hydration of a series of amphiphilic polypeptoid coatings with different sequences in air and water. SFG spectra, in agreement with X-ray spectroscopy studies, revealed that the surface coverage of the hydrophilic N-(2-methoxyethyl)glycine (Nme) units in air is affected by both the number and position of the hydrophobic N-(heptafluorobutyl)glycine (NF) units in the peptoid chain and is negatively correlated with the surface concentration of the fluorine element. Our ability to probe the SFG signals of water molecules at the peptoid surface provides new information on the hydrated film properties. From these SFG signals and the time evolution of water contact angles on the polymers, we see that the hydrated film properties are also dependent upon the peptoid sequence. This work indicates that the surface presence of the Nme groups and the ability of the polymers to order and strongly hydrogen bond with interfacial water molecules determine their antifouling properties, whereas the surface restructuring rate upon contact with water affects their fouling release behaviors.
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Affiliation(s)
- Chuan Leng
- Department of Chemistry, University of Michigan , Ann Arbor, Michigan 48109, United States
| | - Hilda G Buss
- Department of Chemical Engineering, University of California , Berkeley, California 94720, United States
| | - Rachel A Segalman
- Departments of Materials and Chemical Engineering, University of California , Santa Barbara, California 93106, United States
| | - Zhan Chen
- Department of Chemistry, University of Michigan , Ann Arbor, Michigan 48109, United States
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26
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Soblosky L, Ramamoorthy A, Chen Z. Membrane interaction of antimicrobial peptides using E. coli lipid extract as model bacterial cell membranes and SFG spectroscopy. Chem Phys Lipids 2015; 187:20-33. [PMID: 25707312 DOI: 10.1016/j.chemphyslip.2015.02.003] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Revised: 02/17/2015] [Accepted: 02/18/2015] [Indexed: 12/17/2022]
Abstract
Supported lipid bilayers are used as a convenient model cell membrane system to study biologically important molecule-lipid interactions in situ. However, the lipid bilayer models are often simple and the acquired results with these models may not provide all pertinent information related to a real cell membrane. In this work, we use sum frequency generation (SFG) vibrational spectroscopy to study molecular-level interactions between the antimicrobial peptides (AMPs) MSI-594, ovispirin-1 G18, magainin 2 and a simple 1,2-dipalmitoyl-d62-sn-glycero-3-phosphoglycerol (dDPPG)/1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoglycerol (POPG) bilayer. We compared such interactions to those between the AMPs and a more complex dDPPG/Escherichia coli (E. coli) polar lipid extract bilayer. We show that to fully understand more complex aspects of peptide-bilayer interaction, such as interaction kinetics, a heterogeneous lipid composition is required, such as the E. coli polar lipid extract. The discrepancy in peptide-bilayer interaction is likely due in part to the difference in bilayer charge between the two systems since highly negative charged lipids can promote more favorable electrostatic interactions between the peptide and lipid bilayer. Results presented in this paper indicate that more complex model bilayers are needed to accurately analyze peptide-cell membrane interactions and demonstrates the importance of using an appropriate lipid composition to study AMP interaction properties.
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Affiliation(s)
- Lauren Soblosky
- Department of Chemistry, University of Michigan, Ann Arbor, MI 48109, USA
| | - Ayyalusamy Ramamoorthy
- Department of Chemistry, University of Michigan, Ann Arbor, MI 48109, USA; Biophysics, University of Michigan, Ann Arbor, MI 48109, USA
| | - Zhan Chen
- Department of Chemistry, University of Michigan, Ann Arbor, MI 48109, USA; Biophysics, University of Michigan, Ann Arbor, MI 48109, USA.
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27
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Myers JN, Zhang X, Bielefeld J, Lin Q, Chen Z. Nondestructive in Situ Characterization of Molecular Structures at the Surface and Buried Interface of Silicon-Supported Low-k Dielectric Films. J Phys Chem B 2015; 119:1736-46. [DOI: 10.1021/jp510205u] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- John N. Myers
- Department
of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Xiaoxian Zhang
- Department
of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Jeff Bielefeld
- Intel Corporation, Hillsboro, Oregon 97124, United States
| | - Qinghuang Lin
- IBM Thomas J. Watson Research Center, Yorktown Heights, New York 10598, United States
| | - Zhan Chen
- Department
of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
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28
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Zhang X, Myers JN, Lin Q, Bielefeld JD, Chen Z. Probing the molecular structures of plasma-damaged and surface-repaired low-k dielectrics. Phys Chem Chem Phys 2015; 17:26130-9. [DOI: 10.1039/c5cp03649f] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A comprehensive characterization on the plasma-damaged and silylation-repaired low-k dielectrics was demonstrated here at the molecular level.
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Affiliation(s)
- Xiaoxian Zhang
- Department of Chemistry
- University of Michigan
- Ann Arbor
- USA
| | - John N. Myers
- Department of Chemistry
- University of Michigan
- Ann Arbor
- USA
| | | | | | - Zhan Chen
- Department of Chemistry
- University of Michigan
- Ann Arbor
- USA
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29
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Jha KC, Zhu H, Dhinojwala A, Tsige M. Molecular structure of poly(methyl methacrylate) surface II: Effect of stereoregularity examined through all-atom molecular dynamics. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:12775-12785. [PMID: 25310276 DOI: 10.1021/la5023328] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Utilizing all-atom molecular dynamics (MD), we have analyzed the effect of tacticity and temperature on the surface structure of poly(methyl methacrylate) (PMMA) at the polymer-vacuum interface. We quantify these effects primarily through orientation, measured as the tilt with respect to the surface normal, and the surface number densities of the α-methyl, ester-methyl, carbonyl, and backbone methylene groups. Molecular structure on the surface is a complex interplay between orientation and number densities and is challenging to capture through sum frequency generation (SFG) spectroscopy alone. Independent quantification of the number density and orientation of chemical groups through all-atom MD presents a comprehensive model of stereoregular PMMA on the surface. SFG analysis presented in part I of this joint publication measures the orientation of molecules that are in agreement with MD results. We observe the ester-methyl groups as preferentially oriented, irrespective of tacticity, followed by the α-methyl and carbonyl groups. SFG spectroscopy also points to ester-methyl being dominant on the surface. The backbone methylene groups show a very broad angular distribution, centered along the surface plane. The surface number density ratios of ester-methyl to α-methyl groups show syndiotactic PMMA having the lowest value. Isotactic PMMA has the highest ratios of ester- to α-methyl. These subtle trends in the relative angular orientation and number densities that influence the variation of surface structure with tacticity are highlighted in this article. A more planar conformation of the syndiotactic PMMA along the surface (x-y plane) can be visualized through the trajectories from all-atom MD. Results from conformation tensor calculations for chains with any of their segments contributing to the surface validate the visual observation.
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Affiliation(s)
- Kshitij C Jha
- Department of Polymer Science, The University of Akron , Akron, Ohio 44325, United States
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30
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Zhang C, Myers JN, Chen Z. Molecular behavior at buried epoxy/poly(ethylene terephthalate) interface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:12541-12550. [PMID: 25263030 DOI: 10.1021/la502239u] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Epoxies are widely used as main components in packaging underfills for microelectronics. Their strong adhesion to different substrate materials is an important factor for the functioning of electronic devices. Amines are commonly used cross-linking agents for epoxides. However, the molecular mechanisms of epoxide-amine mixture adhesion to substrate materials remain unclear. In this research we investigated the adhesion mechanism of epoxide-amine mixtures at poly(ethylene terephthalate) (PET) interfaces using attenuated total-internal reflection Fourier transform infrared (ATR-FTIR) spectroscopy and sum frequency generation (SFG) vibrational spectroscopy. Results show that both epoxide and amine could diffuse into the PET film. They could also dissolve or modify the PET film at the interphase region. In the process of epoxy curing on PET, epoxide molecules could cross-link with the modified PET film, providing strong adhesion. This hypothesis was further confirmed by adding reactive and nonreactive silanes to the epoxies and measuring the adhesion strengths of such mixtures to PET. The reactive silanes could cross-link with the system, showing good adhesion, while the nonreactive silane prevented sufficient cross-linking, showing poor adhesion. This research developed an in-depth insight for molecular behaviors at the epoxy/PET interface which helped clarify the related adhesion mechanism.
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Affiliation(s)
- Chi Zhang
- Department of Chemistry, University of Michigan , 930 North University Avenue, Ann Arbor, Michigan 48109, United States
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31
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Zhu H, Jha KC, Bhatta RS, Tsige M, Dhinojwala A. Molecular structure of poly(methyl methacrylate) surface. I. Combination of interface-sensitive infrared-visible sum frequency generation, molecular dynamics simulations, and ab initio calculations. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:11609-11618. [PMID: 25215928 DOI: 10.1021/la502333u] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The chemical composition and molecular structure of polymeric surfaces are important in understanding wetting, adhesion, and friction. Here, we combine interface-sensitive sum frequency generation spectroscopy (SFG), all-atom molecular dynamics (MD) simulations, and ab initio calculations to understand the composition and the orientation of chemical groups on poly(methyl methacrylate) (PMMA) surface as a function of tacticity and temperature. The SFG spectral features for isotactic and syndiotactic PMMA surfaces are similar, and the dominant peak in the spectra corresponds to the ester-methyl groups. The SFG spectra for solid and melt states are very similar for both syndiotactic and isotactic PMMA. In comparison, the MD simulation results show that both the ester-methyl and the α-methyl groups of syndiotactic-PMMA are ordered and tilted toward the surface normal. For the isotactic-PMMA, the α-methyl groups are less ordered compared to their ester-methyl groups. The backbone methylene groups have a broad angular distribution and are disordered, independent of tacticity and temperature. We have compared the SFG results with theoretical spectra calculated using MD simulations and ab initio calculations. Our analysis shows that the weaker intensity of α-methyl groups in SFG spectra is due to a combination of smaller molecular hyperpolarizability, lower ordering, and lower surface number density. This work highlights the importance of combining SFG spectroscopy with MD simulations and ab initio calculations in understanding polymer surfaces.
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Affiliation(s)
- He Zhu
- Department of Polymer Science, The University of Akron , Akron, Ohio 44325, United States
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32
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Lu X, Myers JN, Chen Z. Molecular ordering of phenyl groups at the buried polystyrene/metal interface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:9418-9422. [PMID: 25022826 DOI: 10.1021/la502037h] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Understanding molecular structures of buried polymer/metal interfaces is important for the design and development of polymer adhesives used in advanced microelectronic devices and polymer anticorrosion coatings for metals. The buried interfacial molecular structure between polystyrene (PS) and silver (Ag) was investigated using infrared-visible sum frequency generation (SFG) vibrational spectroscopy via a "sandwiched" sample geometry. SFG resonant signals from the phenyl C-H stretching vibrational modes were detected from the PS/Ag interface, suggesting that the PS phenyl groups at this buried polymer/metal interface are ordered. Spectral analysis indicated that the phenyl groups at the buried PS/Ag interface tilt toward the interface, pointing away from the Ag side.
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Affiliation(s)
- Xiaolin Lu
- State Key Laboratory of Bioelectronics, School of Biological Science & Medical Engineering, Southeast University , Nanjing 210096, Jiangsu Province, P. R. China
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33
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Lu X, Li B, Zhu P, Xue G, Li D. Illustrating consistency of different experimental approaches to probe the buried polymer/metal interface using sum frequency generation vibrational spectroscopy. SOFT MATTER 2014; 10:5390-5397. [PMID: 24926859 DOI: 10.1039/c4sm00582a] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
In this paper, we demonstrate our ability to directly probe the molecular structures of the buried polymer/metal interface using sum frequency generation (SFG) vibrational spectroscopy. Spectroscopic data from different experimental approaches were compared and analyzed to deduce the molecular ordering information at a buried polymer/metal interface, i.e. the poly(n-butyl methylacrylate) (PBMA)/silver (Ag) interface. Solid spectroscopic evidence suggested that we successfully detected the molecular vibrational signals generated from the buried PBMA/Ag interface. It was found that the side butyl methyl groups at the PBMA/Ag interface are polar-ordered and have different orientational ordering from those at the PBMA surface in air. We believe that this study will provide a useful experimental and analytical framework for the SFG spectroscopy to probe the buried polymer/metal interfaces in the future.
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Affiliation(s)
- Xiaolin Lu
- State Key Laboratory of Bioelectronics, School of Biological Science & Medical Engineering, SoutheastUniversity, Nanjing, 210096, Jiangsu Province, P. R. China
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34
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Prasad S, Zhu H, Kurian A, Badge I, Dhinojwala A. Interfacial segregation in polymer blends driven by acid-base interactions. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:15727-31. [PMID: 24313915 DOI: 10.1021/la403418h] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Infrared-visible sum frequency generation spectroscopy (SFG) was used to measure the interfacial concentrations of poly(methyl methacrylate) (PMMA)/polystyrene (PS) blends next to a sapphire substrate. The acid-base interactions of carbonyl groups of PMMA with the hydroxyl groups on the sapphire drive the interfacial segregation of PMMA next to the sapphire substrate. Using the shift of sapphire surface OH peaks, we have determined the difference in interfacial energy between the PMMA/sapphire and the PS/sapphire to be ~44-45 mJ/m(2). These results highlight the importance of acid-base interactions and their role in controlling the interfacial segregation next to solid substrates in polymer blends.
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Affiliation(s)
- Shishir Prasad
- Department of Polymer Science, The University of Akron , Akron, Ohio 44325, United States
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35
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Inoue R, Nakamura M, Matsui K, Kanaya T, Nishida K, Hino M. Distribution of glass transition temperature in multilayered poly(methyl methacrylate) thin film supported on a Si substrate as studied by neutron reflectivity. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2013; 88:032601. [PMID: 24125286 DOI: 10.1103/physreve.88.032601] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2013] [Indexed: 05/26/2023]
Abstract
We studied the distribution of glass transition temperature (Tg) through neutron reflectivity in a poly(methyl methacrylate) (PMMA) thin film supported on a silicon substrate with a five-layered PMMA thin film consisting of deuterated-PMMA and hydrogenated-PMMA. The depth distribution of Tg was successfully observed in the PMMA thin film. Compared to the previously reported distribution of Tg in a polystyrene thin film, the presence of a long-range interfacial effect, supposedly caused by an interaction between PMMA and the substrate, is considered to be responsible for the differences in both the distribution of Tg and the thickness dependence of Tg in both polymers. Therefore, it is expected that the thickness dependence of Tg reported for single-layered polymer thin films can, in principle, be understood from the viewpoint of the difference in the depth distribution of Tg.
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Affiliation(s)
- Rintaro Inoue
- Institute for Chemical Research, Kyoto University, Uji, Kyoto-fu 611-0011, Japan
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36
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Zhang C, Chen Z. Quantitative molecular level understanding of ethoxysilane at poly(dimethylsiloxane)/polymer interfaces. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:610-619. [PMID: 23241016 DOI: 10.1021/la3041727] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Because of the wide applications of silicone adhesives, it is important to study adhesion mechanisms of silicone elastomers to polymers. Adhesion properties are believed to be directly related to the molecular structures at the adhesive/substrate interfaces. To improve adhesion, adhesion promoters such as silanes are commonly used to modify the interfacial structures. It is difficult to study buried interfacial molecular structures between two materials in situ using conventional analytical techniques. In this study, sum frequency generation (SFG) vibrational spectroscopy was used to investigate molecular structures at buried silicone/poly(ethylene terephthalate) (PET) interfaces. Environmental-friendly epoxysilanes including (3-glycidoxypropyl)triethoxysilane (γ-GPES), (3-glycidoxypropyl)methyldiethoxysilane (γ-GPDES), and (3-glycidoxypropyl)dimethylethoxysilane (γ-GPDMES) and their mixtures with methylvinylsiloxanol (MVS) were used as adhesion promoters to modify silicone adhesion properties to PET. Various PET/silane, PET/uncured silicone, and PET/cured silicone interfaces were examined. The interfacial structures deduced from SFG spectra were correlated to adhesion testing results. It was found that silane headgroup order at the polymer interfaces is an important factor for improving adhesion. The decrease of silane headgroup order due to chemical reaction and disordering of such groups at the polymer interfaces can be associated with improved adhesion. The molecular level understanding on polymer/adhesive interfacial structures helps to design and develop adhesion promoters and polymer adhesives with improved performance.
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Affiliation(s)
- Chi Zhang
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
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Zhang C, Myers J, Chen Z. Elucidation of molecular structures at buried polymer interfaces and biological interfaces using sum frequency generation vibrational spectroscopy. SOFT MATTER 2013; 9:4738-4761. [PMID: 23710244 PMCID: PMC3661304 DOI: 10.1039/c3sm27710k] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Sum frequency generation (SFG) vibrational spectroscopy has been developed into an important technique to study surfaces and interfaces. It can probe buried interfaces in situ and provide molecular level structural information such as the presence of various chemical moieties, quantitative molecular functional group orientation, and time dependent kinetics or dynamics at such interfaces. This paper focuses on these three most important advantages of SFG and reviews some of the recent progress in SFG studies on interfaces related to polymer materials and biomolecules. The results discussed here demonstrate that SFG can provide important molecular structural information of buried interfaces in situ and in real time, which is difficult to obtain by other surface sensitive analytical techniques.
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Affiliation(s)
- Chi Zhang
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
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Zhang C, Hankett J, Chen Z. Molecular level understanding of adhesion mechanisms at the epoxy/polymer interfaces. ACS APPLIED MATERIALS & INTERFACES 2012; 4:3730-7. [PMID: 22709337 DOI: 10.1021/am300854g] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
It is important to understand the buried interfacial structures containing epoxy underfills as such structures determine the interfacial adhesion properties. Weak adhesion or delamination at such interfaces leads to failure of microelectronic devices. Sum frequency generation (SFG) vibrational spectroscopy was used to examine buried interfaces at polymer/model epoxy and polymer/commercial epoxy resins (used as underfills in flip chip devices) at the molecular level. We investigated a model epoxy: bisphenol A digylcidyl ether (BADGE) at the interfaces of poly (ethylene terephthalate) (PET) before and after curing. Furthermore, small amounts of different silanes including (3-glycidoxypropyl) trimethoxysilane (γ-GPS), (3-Aminopropyl)trimethoxysilane (ATMS), Octadecyltrimethoxysilane (OTMS(18C)), and Octyltrimethoxysilane (OTMS(8C)) were mixed with BADGE. Silane influences on the polymer/epoxy interfacial structures were studied. SFG was also used to study molecular interfacial structures between polymers and two commercial epoxy resins. The interfacial structures probed by SFG were correlated to the adhesion strengths measured for corresponding interfaces. The results indicated that a small amount of silane molecules added to epoxy could substantially change the polymer/epoxy interfacial structure, greatly affecting the adhesion strength at the interface. It was found that ordered methyl groups at the interface lead to weak adhesion, and disordered interfaces lead to strong adhesion.
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Affiliation(s)
- Chi Zhang
- Department of Chemistry, University of Michigan , Ann Arbor, Michigan 48109, United States
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Lu X, Xue G, Wang X, Han J, Han X, Hankett J, Li D, Chen Z. Directly Probing Molecular Ordering at the Buried Polymer/Metal Interface 2: Using P-Polarized Input Beams. Macromolecules 2012. [DOI: 10.1021/ma301088g] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- Xiaolin Lu
- Department of Chemistry, Key
Laboratory of Advanced Textile Materials and Manufacturing Technology
of Education Ministry, Zhejiang Sci-Tech University, Hangzhou, 310018, China
| | - Gi Xue
- Department of Polymer Science, Nanjing University, Nanjing, 210093, China
| | - Xinping Wang
- Department of Chemistry, Key
Laboratory of Advanced Textile Materials and Manufacturing Technology
of Education Ministry, Zhejiang Sci-Tech University, Hangzhou, 310018, China
| | - Jianglong Han
- Department of Polymer Science, Nanjing University, Nanjing, 210093, China
| | - Xiaofeng Han
- Department of Chemistry, University of Michigan, 930 North University Avenue,
Ann Arbor, Michigan 48109, United States
| | - Jeanne Hankett
- Department of Chemistry, University of Michigan, 930 North University Avenue,
Ann Arbor, Michigan 48109, United States
| | - Dawei Li
- Department of Polymer Science, Nanjing University, Nanjing, 210093, China
| | - Zhan Chen
- Department of Chemistry, University of Michigan, 930 North University Avenue,
Ann Arbor, Michigan 48109, United States
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Padermshoke A, Konishi S, Ara M, Tada H, Ishibashi TA. Novel SiO2-deposited CaF2 substrate for vibrational sum-frequency generation (SFG) measurements of chemisorbed monolayers in an aqueous environment. APPLIED SPECTROSCOPY 2012; 66:711-718. [PMID: 22732544 DOI: 10.1366/11-06583] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
A novel SiO(2)-deposited CaF(2) (SiO(2)/CaF(2)) substrate for measuring vibrational sum-frequency generation (SFG) spectra of silane-based chemisorbed monolayers in aqueous media has been developed. The substrate is suitable for silanization and transparent over a broad range of the infrared (IR) probe. The present work demonstrates the practical application of the SiO(2)/CaF(2) substrate and, to our knowledge, the first SFG spectrum at the solid/water interface of a silanized monolayer observed over the IR fingerprint region (1780-1400 cm(-1)) using a back-side probing geometry. This new substrate can be very useful for SFG studies of various chemisorbed organic molecules, particularly biological compounds, in aqueous environments.
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Affiliation(s)
- Adchara Padermshoke
- Center for Quantum Life Sciences, Hiroshima University, Higashi-Hiroshima, Japan
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Zhang C, Shephard NE, Rhodes SM, Chen Z. Headgroup effect on silane structures at buried polymer/silane and polymer/polymer interfaces and their relations to adhesion. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:6052-6059. [PMID: 22424184 DOI: 10.1021/la300004x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Sum frequency generation (SFG) vibrational spectroscopy was used to study the effect of silane headgroups on the molecular interactions that occur between poly(ethylene terephthalate) (PET) and various epoxy silanes at the PET/silane and PET/silicone interfaces. Three different silanes were investigated: (3-glycidoxypropyl) trimethoxysilane (γ-GPS), (3-glycidoxypropyl) methyl-dimethoxysilane (γ-GPMS), and (3-glycidoxypropyl) dimethyl-methoxysilane (γ-GPDMS). These silanes share the same backbone and epoxy end group but have different headgroups. SFG was used to examine the interfaces between PET and each of these silanes, as well as silanes mixed with methylvinylsiloxanol (MVS). We also examined the interfaces between PET and uncured or cured silicone with silanes or silane-MVS mixtures. Silanes with different headgroups were found to exhibit a variety of methoxy group interfacial segregation and ordering behaviors at various interfaces. The effect of MVS was also dependent upon silane headgroup choice, and the interfacial molecular structures of silane methoxy headgroups were found to differ at PET/silane and PET/silicone interfaces. Epoxy silanes have been widely used as adhesion promoters for polymer adhesives; therefore, the molecular structures probed using SFG were correlated to adhesion testing results to understand the molecular mechanisms of silicone-polymer adhesion. Our results demonstrated that silane methoxy headgroups play important roles in adhesion at the PET/silicone interfaces. The presence of MVS can change interfacial methoxy segregation and ordering, leading to different adhesion strengths.
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Affiliation(s)
- Chi Zhang
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, USA
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Xiong H, Si LG, Ding C, Yang X, Wu Y. Second-harmonic generation of cylindrical electromagnetic waves propagating in an inhomogeneous and nonlinear medium. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2012; 85:016606. [PMID: 22400694 DOI: 10.1103/physreve.85.016606] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2011] [Revised: 12/02/2011] [Indexed: 05/31/2023]
Abstract
A general description of cylindrical electromagnetic waves propagating in nonlinear and inhomogeneous media is given by deducing cylindrical coupled-wave equations. Based on the cylindrical coupled-wave equations, we analyze second-harmonic generation (SHG) of some special cases of inhomogeneity, and find that the inhomogeneity of the first- and second-order polarization can influence the amplitude of the SHG. From a different point of view, exact solutions of cylindrical electromagnetic waves propagating in a nonlinear medium with a special case of inhomogeneity have been obtained previously. We show that cylindrical SHG in an inhomogeneous and nonlinear medium can also be deduced from exact solutions. As verification, we compare the results obtained from the two different methods and find that descriptions of SHG by the coupled-wave equations are in good agreement with the exact solutions.
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Affiliation(s)
- Hao Xiong
- Wuhan National Laboratory for Optoelectronics and School of Physics, Huazhong University of Science and Technology, Wuhan 430074, People's Republic of China.
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Avery CW, Palermo EF, McLaughlin A, Kuroda K, Chen Z. Investigations of the interactions between synthetic antimicrobial polymers and substrate-supported lipid bilayers using sum frequency generation vibrational spectroscopy. Anal Chem 2011; 83:1342-9. [PMID: 21229969 DOI: 10.1021/ac1025804] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Sum frequency generation (SFG) vibrational spectroscopy was used to analyze interactions between solid-supported lipid bilayers acting as models for cellular membranes and several membrane-active random copolymers with different lipophilic side chains, named 0R (no group), 33Me (methyl group), 11Bz (benzyl group), and 33Bu (butyl group), according to both the identity and percentage of the side chains within the polymer. Biological tests of the minimum inhibitory concentration (MIC) and hemolytic concentration were performed. The inherent surface sensitivity of SFG allowed for independent monitoring of isotopically labeled lipid bilayer leaflets as a function of concentration to study polymer-bilayer interaction mechanisms. Concentrations at which each bilayer leaflet was disrupted were quantitatively determined for each copolymer. Spectroscopic evidence of interaction with the bilayer below the critical concentrations was observed for the 11Bz polymer. The lipophilic butyl side chain of the 33Bu polymer was found to be oriented parallel to the surface normal. This research shows that SFG is a useful analytical technique which provides unique details regarding the interaction mechanisms of these membrane-active copolymers and lipid bilayers.
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Affiliation(s)
- Christopher W Avery
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, USA
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Investigation of sub-monolayer, monolayer, and multilayer self-assembled semifluorinated alkylsilane films. J Colloid Interface Sci 2011; 353:322-30. [DOI: 10.1016/j.jcis.2010.09.057] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2010] [Accepted: 09/18/2010] [Indexed: 11/20/2022]
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Probing polymer surfaces and interfaces using sum frequency generation vibrational spectroscopy - a powerful nonlinear optical technique. ACTA ACUST UNITED AC 2010. [DOI: 10.1007/s11458-010-0220-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Kristalyn CB, Lu X, Weinman CJ, Ober CK, Kramer EJ, Chen Z. Surface structures of an amphiphilic tri-block copolymer in air and in water probed using sum frequency generation vibrational spectroscopy. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:11337-11343. [PMID: 20465236 DOI: 10.1021/la100701b] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Sum frequency generation (SFG) vibrational spectroscopy has been applied to investigate surface structures of an amphiphilic surface-active block copolymer (SABC) film deposited on a CaF(2) substrate, in air and in water in situ. Developed as a surface-active component of an antifouling coating for marine applications, this amphiphilic triblock copolymer contains both hydrophobic fluorinated alkyl groups as well as hydrophilic ethoxy groups. It was found that surface structures of the copolymer film in air and in water cannot be probed directly using the SFG experimental geometry we adopted because SFG signals can be contributed from the polymer/air (or polymer/water) interface as well as the buried polymer/CaF(2) substrate interface. Using polymer films with varied thicknesses, structural information about the polymer surfaces in air and in water can be deduced from the detected SFG signals. With SFG, surface restructuring of this polymer has been observed in water, especially the methyl and methylene groups change orientations upon contact with water. However, the hydrophobic fluoroalkyl group was present on the surface in both air and water, and we believe that it was held near the surface in water by its neighboring ethoxy groups.
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Affiliation(s)
- Cornelius B Kristalyn
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, USA
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Cecchet F, Lis D, Guthmuller J, Champagne B, Caudano Y, Silien C, Addin Mani A, Thiry PA, Peremans A. Orientational Analysis of Dodecanethiol and p-Nitrothiophenol SAMs on Metals with Polarisation-Dependent SFG Spectroscopy. Chemphyschem 2010; 11:607-15. [DOI: 10.1002/cphc.200900733] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Tateishi Y, Kai N, Noguchi H, Uosaki K, Nagamura T, Tanaka K. Local conformation of poly(methyl methacrylate) at nitrogen and water interfaces. Polym Chem 2010. [DOI: 10.1039/b9py00227h] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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Lu X, Li D, Kristalyn CB, Han J, Shephard N, Rhodes S, Xue G, Chen Z. Directly Probing Molecular Ordering at the Buried Polymer/Metal Interface. Macromolecules 2009. [DOI: 10.1021/ma901757w] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Xiaolin Lu
- Department of Polymer Science, Nanjing University, Nanjing, People’s Republic of China 210093
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109
| | - Dawei Li
- Department of Polymer Science, Nanjing University, Nanjing, People’s Republic of China 210093
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109
| | - Cornelius B. Kristalyn
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109
| | - Jianglong Han
- Department of Polymer Science, Nanjing University, Nanjing, People’s Republic of China 210093
| | - Nick Shephard
- Specialty Chemicals Business, Materials Science Technology Platform, Dow Corning Corporation, 2200 W. Salzburg Road, Midland, Michigan 48686
| | - Susan Rhodes
- Specialty Chemicals Business, Materials Science Technology Platform, Dow Corning Corporation, 2200 W. Salzburg Road, Midland, Michigan 48686
| | - Gi Xue
- Department of Polymer Science, Nanjing University, Nanjing, People’s Republic of China 210093
| | - Zhan Chen
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109
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Allen HC, Casillas-Ituarte NN, Sierra-Hernández MR, Chen X, Tang CY. Shedding light on water structure at air–aqueous interfaces: ions, lipids, and hydration. Phys Chem Chem Phys 2009; 11:5538-49. [DOI: 10.1039/b901209e] [Citation(s) in RCA: 106] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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