1
|
Khechine E, Noack S, Schlaad H, Xu J, Reiter G, Reiter R. Reversible Dehydration-Hydration of Poly(ethylene glycol) in Langmuir Monolayers of a Diblock Copolymer Inferred from Changes in Filament Curvature. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023; 39:2710-2718. [PMID: 36757479 DOI: 10.1021/acs.langmuir.2c03179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
We investigated changes in the hydration state of poly(ethylene glycol) (PEG) through morphological changes in Langmuir monolayers of a PEG-poly(l-lactide) (PlLA) (PEG-b-PlLA) diblock copolymer. When the PEG blocks were hydrated, we observed a remarkable morphology of bundles of ring-like filaments, arranged concentrically, yielding densely packed disk-like objects with a hollow center. We attribute the uniform curvature of these filaments to a strong mismatch between the molecular volumes occupied by PlLA blocks and hydrated PEG blocks. Under the constraint that each hydrated PEG block is attached to a hydrophobic PlLA block anchored to the air-water interface, this mismatch of molecular volumes caused strong repulsion within the PEG layer, in particular when the PlLA blocks packed tightly. Induced by a transition in the ordering of the PlLA blocks, the PEG blocks lost their hydration shell and packed into a dense polymer brush, accompanied by a reduction of the pressure within the PEG layer. During this packing process, the curvature of the filaments was eliminated and the ring-like filaments fractured into small linear pieces. Upon compression, the linear pieces coalesced and formed long filaments aligned in parallel. Importantly, upon expansion of the Langmuir film, these changes in morphology were reversible, and the PEG blocks could be rehydrated and bundles of concentrically arranged ring-like filaments were reformed. We conclude that the change in curvature of the filaments provides a means for distinguishing between the hydrated and dehydrated states of PEG.
Collapse
Affiliation(s)
- Emna Khechine
- Institute of Physics, University of Freiburg, Hermann-Herder Street 3, 79104 Freiburg, Germany
| | - Sebastian Noack
- Institute of Chemistry, University of Potsdam, Karl-Liebknecht Street 24-25, 14476 Potsdam, Germany
| | - Helmut Schlaad
- Institute of Chemistry, University of Potsdam, Karl-Liebknecht Street 24-25, 14476 Potsdam, Germany
| | - Jun Xu
- Advanced Materials Laboratory of Ministry of Education, Department of Chemical Engineering, Tsinghua University, Beijing 100084, China
| | - Günter Reiter
- Institute of Physics, University of Freiburg, Hermann-Herder Street 3, 79104 Freiburg, Germany
| | - Renate Reiter
- Institute of Physics, University of Freiburg, Hermann-Herder Street 3, 79104 Freiburg, Germany
| |
Collapse
|
2
|
Flouda P, Stryutsky AV, Buxton ML, Adstedt KM, Bukharina D, Shevchenko VV, Tsukruk VV. Reconfiguration of Langmuir Monolayers of Thermo-Responsive Branched Ionic Polymers with LCST Transition. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:12070-12081. [PMID: 36150123 DOI: 10.1021/acs.langmuir.2c01940] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Thermo-responsive ionic polymers have the ability to form adaptive and switchable morphologies, which may offer enhanced control in energy storage and catalytic applications. Current thermo-responsive polymers are composed of covalently attached thermo-responsive moieties, restricting their mobility and global dynamic response. Here, we report the synthesis and assembly at the water-air interface of symmetric and asymmetric amphiphilic thermo-responsive branched polymers with weakly ionically bound arms of amine-terminated poly(N-isopropylacrylamide) (PNIPAM) macro-cations. As we observed, symmetric branched polymers formed multimolecular nanosized micellar assemblies, whereas corresponding asymmetric polymers formed large, interconnected worm-like aggregates. Dramatic changes in localized and large-scale chemical composition confirmed the reversible adsorption and desorption of the mobile PNIPAM macro-cations below and above the low critical solution temperature (LCST) and their non-uniform redistribution within polymer monolayer. Increasing the temperature above LCST led to the formation of large interconnected micellar aggregates because of the micelle-centered aggregation of the hydrophobized PNIPAM macro-cationic terminal chains in the aqueous subphase. Overall, this work provides insights into the dynamic nature of the chemical composition of branched ionic polymers with weakly ionically bound thermo-responsive terminal chains and its effect on both morphology and local/surface chemistry of monolayers at LCST transition.
Collapse
Affiliation(s)
- Paraskevi Flouda
- School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Alexandr V Stryutsky
- Institute of Macromolecular Chemistry of the National Academy of Sciences of Ukraine, Kharkivske Shosse 48, Kyiv 02160, Ukraine
| | - Madeline L Buxton
- School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Katarina M Adstedt
- School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Daria Bukharina
- School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Valery V Shevchenko
- Institute of Macromolecular Chemistry of the National Academy of Sciences of Ukraine, Kharkivske Shosse 48, Kyiv 02160, Ukraine
| | - Vladimir V Tsukruk
- School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| |
Collapse
|
3
|
Li J, Du Y, Su H, Cheng S, Zhou Y, Jin Y, Qi XR. Interfacial properties and micellization of triblock poly(ethylene glycol)-poly( ε-caprolactone)-polyethyleneimine copolymers. Acta Pharm Sin B 2020; 10:1122-1133. [PMID: 32642417 PMCID: PMC7332608 DOI: 10.1016/j.apsb.2020.01.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Revised: 10/24/2019] [Accepted: 11/11/2019] [Indexed: 01/30/2023] Open
Abstract
This study aimed to explore the link between block copolymers' interfacial properties and nanoscale carrier formation and found out the influence of length ratio on these characters to optimize drug delivery system. A library of diblock copolymers of PEG-PCL and triblock copolymers with additional PEI (PEG-PCL-PEI) were synthesized. Subsequently, a systematic isothermal investigation was performed to explore molecular arrangements of copolymers at air/water interface. Then, structural properties and drug encapsulation in self-assembly were investigated with DLS, SLS and TEM. We found the additional hydrogen bond in the PEG-PCL-PEI contributes to film stability upon the hydrophobic interaction compared with PEG-PCL. PEG-PCL-PEI assemble into smaller micelle-like (such as PEG-PCL4006-PEI) or particle-like structure (such as PEG-PCL8636-PEI) determined by their hydrophilic and hydrophobic block ratio. The distinct structural architectures of copolymer are consistent between interface and self-assembly. Despite the disparity of constituent ratio, we discovered the arrangement of both chains guarantees balanced hydrophilic-hydrophobic ratio in self-assembly to form stable construction. Meanwhile, the structural differences were found to have significant influence on model drugs incorporation including docetaxel and siRNA. Taken together, these findings indicate the correlation between molecular arrangement and self-assembly and inspire us to tune block compositions to achieve desired nanostructure and drug loading.
Collapse
Key Words
- AFM, atomic force microscope
- Amin, critical molecular area
- Block copolymers
- CMC, critical micelle concentration
- DLS, dynamic light scattering
- DTX, docetaxel
- GPC, gel permeation chromatography
- LB, Langmuir–Blodgett
- Langmuir films
- Molecular arrangement
- Nagg, polymer aggregation number
- Nanostructure
- Np, nano-assembly numbers
- PCL, poly(ε-caprolactone)
- PDI, polydispersity
- PEG, poly(ethylene glycol)
- PEI, polyethyleneimine
- Rg, gyration radius
- Rh, hydrodynamic radius
- SLS, static light scattering
- Self-assembly
- TEM, transmission electron microscope
Collapse
Affiliation(s)
- Ji Li
- Key Laboratory of Molecular Pharmaceutics and New Drug Delivery System, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China
| | - Yitian Du
- Key Laboratory of Molecular Pharmaceutics and New Drug Delivery System, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China
| | - Haitao Su
- Key Laboratory of Molecular Pharmaceutics and New Drug Delivery System, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China
| | - Shixuan Cheng
- Key Laboratory of Molecular Pharmaceutics and New Drug Delivery System, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China
| | - Yanxia Zhou
- Key Laboratory of Molecular Pharmaceutics and New Drug Delivery System, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China
| | - Yiguang Jin
- Department of Pharmaceutical Sciences, Beijing Institute of Radiation Medicine, Beijing 100850, China
| | - Xian-Rong Qi
- Key Laboratory of Molecular Pharmaceutics and New Drug Delivery System, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China
| |
Collapse
|
4
|
Phase behavior of poly(ε-caprolactone)-b-poly(tert-butyl acrylate) block copolymer at the air/water interface. Colloids Surf A Physicochem Eng Asp 2020. [DOI: 10.1016/j.colsurfa.2019.124346] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
|
5
|
Lee H, Stryutsky AV, Korolovych VF, Mikan E, Shevchenko VV, Tsukruk VV. Transformations of Thermosensitive Hyperbranched Poly(ionic liquid)s Monolayers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:11809-11820. [PMID: 31418576 DOI: 10.1021/acs.langmuir.9b01905] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
We synthesized amphiphilic hyperbranched poly(ionic liquid)s (HBPILs) with asymmetrical peripheral composition consisting of hydrophobic n-octadecylurethane arms and hydrophilic, ionically linked poly(N-isopropylacrylamide) (PNIPAM) macrocations and studied low critical solution temperature (LCST)-induced reorganizations at the air-water interface. We observed that the morphology of HBPIL Langmuir monolayers is controlled by the surface pressure with uniform well-defined disk-like domains formed in a liquid phase. These domains are merged and transformed to uniform monolayers with elevated ridge-like network structures representing coalesced interdomain boundaries in a solid phase because the branched architecture and asymmetrical chemical composition stabilize the disk-like morphology under high compression. Above LCST, elevated individual islands are formed because of the aggregation of the collapsed hydrophobized PNIPAM terminal macrocations in a solid phase. The presence of thermoresponsive PNIPAM macrocations initiates monolayer reorganization at LCST with transformation of surface mechanical contrast distribution. The heterogeneity of elastic response and adhesion distributions for HBPIL monolayers in the wet state changed from highly contrasted two-phase distribution below LCST to near-uniform mechanical response above LCST because of the hydrophilic to hydrophobic transformation of the PNIPAM phase.
Collapse
Affiliation(s)
- Hansol Lee
- School of Materials Science and Engineering , Georgia Institute of Technology , Atlanta , Georgia 30332 , United States
| | - Alexandr V Stryutsky
- Institute of Macromolecular Chemistry of the National Academy of Sciences of Ukraine , Kyiv 02160 , Ukraine
| | - Volodymyr F Korolovych
- School of Materials Science and Engineering , Georgia Institute of Technology , Atlanta , Georgia 30332 , United States
| | - Emily Mikan
- School of Materials Science and Engineering , Georgia Institute of Technology , Atlanta , Georgia 30332 , United States
| | - Valery V Shevchenko
- Institute of Macromolecular Chemistry of the National Academy of Sciences of Ukraine , Kyiv 02160 , Ukraine
| | - Vladimir V Tsukruk
- School of Materials Science and Engineering , Georgia Institute of Technology , Atlanta , Georgia 30332 , United States
| |
Collapse
|
6
|
Gao M, Wen G, Wang L. Effects of Spreading Conditions on the Aggregation Behavior of a Symmetric Diblock Copolymer Polystyrene- block-poly(methyl methacrylate) at the Air/Water Interface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:9272-9278. [PMID: 30004714 DOI: 10.1021/acs.langmuir.8b01649] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Langmuir monolayers and Langmuir-Blodgett (LB) films of a symmetric diblock copolymer polystyrene- block-poly(methyl methacrylate) (PS- b-PMMA) were characterized by the film balance technique and tapping mode atomic force microscopy, respectively. Effects of both the spreading solution concentration and the surface concentration on the aggregation behavior of PS- b-PMMA at the air/water interface and the morphologies of its LB films were studied in detail. When the monolayers spread in different concentrations (≤0.50 mg/mL), all their initial morphologies exhibit tiny circular micelles because of the long hydrophilic PMMA block in the copolymer. The initial tiny circular micelles form spontaneously and then aggregate into small ones upon compression, which can further coalesce into rodlike aggregates or large micelles depending on the spreading concentrations. The LB films of PS- b-PMMA usually exhibit various mixed structures of rodlike aggregates and circular micelles, which can further transform into labyrinth patterns under some special spreading conditions. Besides spreading concentration and volume, we discover that the detailed spreading process should also be responsible for the initial and final morphologies of the LB films. Furthermore, the LB films prepared under different spreading conditions can be regarded as in the equilibrium or nonequilibrium structures because of the kinetic effect difference resulting from the different PS chain entanglement degrees.
Collapse
Affiliation(s)
- Mingming Gao
- Department of Polymer Materials and Engineering, College of Material Science and Engineering , Harbin University of Science and Technology , 4 Linyuan Road , Harbin 150040 , People's Republic of China
| | - Gangyao Wen
- Department of Polymer Materials and Engineering, College of Material Science and Engineering , Harbin University of Science and Technology , 4 Linyuan Road , Harbin 150040 , People's Republic of China
| | - Liang Wang
- Department of Polymer Materials and Engineering, College of Material Science and Engineering , Harbin University of Science and Technology , 4 Linyuan Road , Harbin 150040 , People's Republic of China
| |
Collapse
|
7
|
Appel C, Kraska M, Rüttiger C, Gallei M, Stühn B. Crossover from semi-dilute to densely packed thin polymer films at the air-water interface and structure formation at thin film breakup. SOFT MATTER 2018; 14:4750-4761. [PMID: 29796572 DOI: 10.1039/c8sm00629f] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
A series of poly(n-butyl acrylate) (PnBA, 5 to 32 kg mol-1) homopolymers and diblock copolymers with poly(ethylene glycol) (PEG, constant molecular weight of 0.3 kg mol-1) is synthesized for the purpose of the investigation of quasi-2D polymer films at the air-water interface. The presented compression isotherms show a transition from θ solvent behavior for PnBA homopolymers to good solvent conditions when the volume fraction of the PEG in the block copolymers is increased by decreasing the molecular weight of PnBA. A transition from a semi-dilute regime to a densely packed layer is observed in the pressure isotherms for all the polymers. In the densely packed films we found first evidence for thin film breakup of a thin polymer film directly at the air-water interface. Combination of results from Brewster-Angle-Microscopy and Surface X-ray scattering provide a consistent picture of the film breakup. Our results suggest a preferred length scale of 2.5 μm. This scenario is analogous to a spinodal mechanism driven by thermal fluctuations of the film height.
Collapse
Affiliation(s)
- Christian Appel
- Institute of Condensed Matter Physics, Technische Universität Darmstadt, Hochschulstr. 8, D-64289 Darmstadt, Germany.
| | | | | | | | | |
Collapse
|
8
|
Fuchs C, Busse K, Flieger AK, Kressler J. Polymer Crystallization on the Surface of Water or Aqueous Salt Solution. Chem Eng Technol 2016. [DOI: 10.1002/ceat.201600034] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
9
|
Fujimori A, Kikkawa T, Meng Q, Shibasaki Y. Control of Fine Structure in "Polymer Nanosphere Multilayered Organization" and Enhancement of Its Optical Property. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:9177-9187. [PMID: 26255718 DOI: 10.1021/acs.langmuir.5b01162] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
This paper reports on a new functionality exhibited by "polymer nanosphere multilayered organization", a new type of molecular organization, and the relationship between their structure and function. The polymer nanosphere multilayered organization is a fine structural material formed by the accumulation of single-particle layers of a hydrophobic polymer at the air/water interface; these single-particle layers have uniform height along the c-axis. By employing the "alternate compression-relaxation method", high-density, low-defect particle layers are formed with a clear increase in their crystallite sizes. In the case of a ternary comb copolymer containing a carbazole ring, one particle is formed by the assembly of approximately 60 units of collapsed monolayer-like double layers. This structure is stabilized by the formation of side-chain crystals in the interlayer, with oriented π-π stacking of carbazole rings, resulting in enhanced fluorescence emission intensity.
Collapse
Affiliation(s)
- Atsuhiro Fujimori
- Graduate School of Science and Engineering, Saitama University , 255 Shimo-okubo, Sakura-ku, Saitama 338-8570, Japan
| | - Takahiro Kikkawa
- Graduate School of Science and Engineering, Saitama University , 255 Shimo-okubo, Sakura-ku, Saitama 338-8570, Japan
| | - Qi Meng
- Graduate School of Science and Engineering, Saitama University , 255 Shimo-okubo, Sakura-ku, Saitama 338-8570, Japan
| | - Yuji Shibasaki
- Department of Chemistry and Bioengineering, Faculty of Engineering, Iwate University , Ueda 4-3-5, Morioka, Iwate 020-8551, Japan
| |
Collapse
|
10
|
Molecular arrangement of symmetric and non-symmetric triblock copolymers of poly(ethylene oxide) and poly(isobutylene) at the air/water interface. J Colloid Interface Sci 2015; 437:80-89. [PMID: 25313470 DOI: 10.1016/j.jcis.2014.09.050] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2014] [Revised: 09/12/2014] [Accepted: 09/15/2014] [Indexed: 12/16/2022]
Abstract
The behavior of a series of amphiphilic triblock copolymers of poly(ethylene oxide) (PEO) and poly(isobutylene) (PIB); including both symmetric (same degree of polymerization (DP) of the terminal PEO blocks) PEOm-b-PIBn-b-PEOm and non-symmetric (different DP of the terminal PEO blocks) PEOm-b-PIBn-b-PEOz, is investigated at the air/water interface by measuring surface pressure vs mean molecular area isotherms (π vs mmA), Langmuir-Blodgett (LB) technique, and infrared reflection-absorption spectroscopy (IRRAS). The block copolymer (PEO32-b-PIB160-b-PEO32) with longer PEO segments forms a stable monolayer and the isotherm reveals a pseudo-plateau starting at π∼5.7 mN/m, also observed in the IRRAS, which is assigned to the pancake-to-brush transition related to the PEO dissolution into the subphase and subsequent PEO brush dehydration. Another plateau is observed at π∼40 mN/m, which is attributed to the film collapse due to multilayer formation. The pancake-to-brush transition could not be observed for samples with smaller PEO chains. The isotherms for block copolymers, with short PEO chains, both symmetric (PEO3-b-PIBn-b-PEO3) and non-symmetric (PEO12-b-PIBn-b-PEO3), reveal another transition at π∼20-25 mN/m. This is interpreted to be due to the conformational transition from a folded state where the middle PIB block is anchored to the water surface at both ends by the terminal hydrophilic segments to an unfolded state with PIB anchored to the water surface at one end. It is assumed that this transition involves the removal of PEO3 chains from the water surface in case of non-symmetric PEO12-b-PIB85-b-PEO3 and in case of symmetric, probably one PEO3 of each PEO3-b-PIB85-b-PEO3 chain. Because of the weaker interaction of the short PEO3 chains with the water surface as compared with the relatively longer PEO12 chains, the film of PEO3-b-PIB85-b-PEO3 collapses at much lower surface pressure after the transition as compared with the PEO12-b-PIB85-b-PEO3. The AFM images reveal the formation of microdomains of almost uniform height (6-7 nm) in LB films of PEO3-b-PIB85-b-PEO3 and PEO12-b-PIB85-b-PEO3 after transferring onto silicon surfaces. These domains are assumed to be the mesomorphic domains of ordered and folded PIB chains.
Collapse
|
11
|
Li Z, Ma X, Zang D, Guan X, Zhu L, Liu J, Chen F. Interfacial rheology and aggregation behaviour of amphiphilic CBABC-type pentablock copolymers at the air–water interface: effects of block ratio and chain length. RSC Adv 2015. [DOI: 10.1039/c5ra08109b] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The interfacial rheology, aggregation behaviour and packing model of the structure evolution of three amphiphilic CBABC-type pentablock copolymers were investigated at the air–water interface.
Collapse
Affiliation(s)
- Zhiguang Li
- Key Laboratory of Space Applied Physics and Chemistry
- Ministry of Education
- School of Science
- Northwestern Polytechnical University
- Xi’an 710129
| | - Xiaoyan Ma
- Key Laboratory of Space Applied Physics and Chemistry
- Ministry of Education
- School of Science
- Northwestern Polytechnical University
- Xi’an 710129
| | - Duyang Zang
- Key Laboratory of Space Applied Physics and Chemistry
- Ministry of Education
- School of Science
- Northwestern Polytechnical University
- Xi’an 710129
| | - Xinghua Guan
- Key Laboratory of Space Applied Physics and Chemistry
- Ministry of Education
- School of Science
- Northwestern Polytechnical University
- Xi’an 710129
| | - Lin Zhu
- Key Laboratory of Space Applied Physics and Chemistry
- Ministry of Education
- School of Science
- Northwestern Polytechnical University
- Xi’an 710129
| | - Jinshu Liu
- Key Laboratory of Space Applied Physics and Chemistry
- Ministry of Education
- School of Science
- Northwestern Polytechnical University
- Xi’an 710129
| | - Fang Chen
- Key Laboratory of Space Applied Physics and Chemistry
- Ministry of Education
- School of Science
- Northwestern Polytechnical University
- Xi’an 710129
| |
Collapse
|
12
|
Foster LM, Worthen AJ, Foster EL, Dong J, Roach CM, Metaxas AE, Hardy CD, Larsen ES, Bollinger JA, Truskett TM, Bielawski CW, Johnston KP. High interfacial activity of polymers "grafted through" functionalized iron oxide nanoparticle clusters. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:10188-96. [PMID: 25111153 DOI: 10.1021/la501445f] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
The mechanism by which polymers, when grafted to inorganic nanoparticles, lower the interfacial tension at the oil-water interface is not well understood, despite the great interest in particle stabilized emulsions and foams. A simple and highly versatile free radical "grafting through" technique was used to bond high organic fractions (by weight) of poly(oligo(ethylene oxide) monomethyl ether methacrylate) onto iron oxide clusters, without the need for catalysts. In the resulting ∼1 μm hybrid particles, the inorganic cores and grafting architecture contribute to the high local concentration of grafted polymer chains to the dodecane/water interface to produce low interfacial tensions of only 0.003 w/v % (polymer and particle core). This "critical particle concentration" (CPC) for these hybrid inorganic/polymer amphiphilic particles to lower the interfacial tension by 36 mN/m was over 30-fold lower than the critical micelle concentration of the free polymer (without inorganic cores) to produce nearly the same interfacial tension. The low CPC is favored by the high adsorption energy (∼10(6) kBT) for the large ∼1 μm hybrid particles, the high local polymer concentration on the particles surfaces, and the ability of the deformable hybrid nanocluster cores as well as the polymer chains to conform to the interface. The nanocluster cores also increased the entanglement of the polymer chains in bulk DI water or synthetic seawater, producing a viscosity up to 35,000 cP at 0.01 s(-1), in contrast with only 600 cP for the free polymer. As a consequence of these interfacial and rheological properties, the hybrid particles stabilized oil-in-water emulsions at concentrations as low as 0.01 w/v %, with average drop sizes down to 30 μm. In contrast, the bulk viscosity was low for the free polymer, and it did not stabilize the emulsions. The ability to influence the interfacial activity and rheology of polymers upon grafting them to inorganic particles, including clusters, may be expected to be broadly applicable to stabilization of emulsions and foams.
Collapse
Affiliation(s)
- Lynn M Foster
- McKetta Department of Chemical Engineering and ‡Department of Chemistry, The University of Texas at Austin , Austin, Texas 78712-0231, United States
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
13
|
Crystallization Behaviors and Structure Transitions of Biocompatible and Biodegradable Diblock Copolymers. Polymers (Basel) 2014. [DOI: 10.3390/polym6082116] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
|
14
|
Li Destri G, Miano F, Marletta G. Structure-rheology relationship in weakly amphiphilic block copolymer Langmuir monolayers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:3345-3353. [PMID: 24650052 DOI: 10.1021/la4043777] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The linear viscoelastic behavior in the low-frequency regime at the water/air interface of three different polystyrene-b-poly(methyl methacrylate) (PS-b-PMMA) copolymer monolayers, with block length ratio varying from 66-33 to 50-50 and 25-75 in molecular units, was studied and related to the interfacial behavior, characterized by means of Langmuir isotherms, and their structure, characterized by means of the atomic force microscopy technique. The two monolayers with the highest PMMA amount showed a single phase transition at about 12 mN/m, the viscoelastic behavior changing from a predominantly elastic to a viscoelastic one. This change in the viscoelastic properties was ascribed to the beginning of entanglement among the PMMA coronas of the predominantly circular quasi-2D micelles formed by the two copolymer systems. Conversely, the polymer with the lowest PMMA amount, despite having the same PMMA block length of the PS-PMMA 50-50 block copolymer, was found to behave as a viscoelastic system at any surface pressure value. This characteristic behavior cannot therefore be simply related to the molecular weight difference, but it has been put in connection to the irregular micelle structure observed in this case, consisting of a mixture of spherical and wormlike micelles, and to the different conformation adopted by the PMMA block. By blending this copolymer with an immiscible elastic homopolymer, namely poly(2-vinylpyridine), it was possible to tune the micelle nanostructure, obtaining regular circular quasi-2D micelles, with viscoelastic properties as expected for the PMMA-rich copolymer monolayers. To the best of our knowledge, this study shows for the first time the explicit dependence upon the relative block length and, in turn, upon the nanostructure of the quasi-2D micelles, of the viscoelastic properties of Langmuir monolayers and suggests that molecular weight and intermolecular interactions are not the only parameters governing the polymer conformation and, in turn, the polymer rheology and dynamics in quasi-2D confined systems.
Collapse
Affiliation(s)
- Giovanni Li Destri
- Laboratory for Molecular Surfaces and Nanotechnology (LAMSUN), Department of Chemistry, University of Catania and CSGI , V.le A Doria 6, 95125 Catania, Italy
| | | | | |
Collapse
|
15
|
Naolou T, Busse K, Lechner BD, Kressler J. The behavior of poly( ε $$ \boldsymbol{\upvarepsilon} $$ -caprolactone) and poly(ethylene oxide)-b-poly( ε $$ \boldsymbol{\upvarepsilon} $$ -caprolactone) grafted to a poly(glycerol adipate) backbone at the air/water interface. Colloid Polym Sci 2014. [DOI: 10.1007/s00396-014-3168-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
16
|
Wang X, Wen G, Huang C, Wang Z, Shi Y. Aggregation behavior of the blends of PS-b-PEO-b-PS and PS-b-PMMA at the air/water interface. RSC Adv 2014. [DOI: 10.1039/c4ra08579e] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Upon compression, large close-packed aggregates in the mixed LB films split into small uniform ones. Hysteresis degree can be interpreted with chain entanglement and block mobility.
Collapse
Affiliation(s)
- Xiaoqun Wang
- Department of Polymer Materials and Engineering
- College of Materials Science and Engineering
- Harbin University of Science and Technology
- Harbin 150040, P. R. China
| | - Gangyao Wen
- Department of Polymer Materials and Engineering
- College of Materials Science and Engineering
- Harbin University of Science and Technology
- Harbin 150040, P. R. China
| | - Changchun Huang
- Department of Polymer Materials and Engineering
- College of Materials Science and Engineering
- Harbin University of Science and Technology
- Harbin 150040, P. R. China
| | - Zhuang Wang
- Department of Polymer Materials and Engineering
- College of Materials Science and Engineering
- Harbin University of Science and Technology
- Harbin 150040, P. R. China
| | - Yunbo Shi
- Institute of Measurement and Communication
- Harbin University of Science and Technology
- Harbin 150080, P. R. China
| |
Collapse
|
17
|
Wang Z, Wen G, Zhao F, Huang C, Wang X, Shi T, Li H. Effect of selective solvent on the aggregate behavior of the mixed Langmuir monolayers of PS-b-PEO and PS-b-PMMA. RSC Adv 2014. [DOI: 10.1039/c4ra04161e] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
An interesting way to control morphology evolution in the mixed LB films was performed by mainly using a selective spreading solvent. Furthermore, a peculiar hysteresis phenomenon in the polymeric Langmuir monolayers is reported.
Collapse
Affiliation(s)
- Zhuang Wang
- Department of Polymer Materials and Engineering
- College of Materials Science and Engineering
- Harbin University of Science and Technology
- Harbin 150040, P. R. China
| | - Gangyao Wen
- Department of Polymer Materials and Engineering
- College of Materials Science and Engineering
- Harbin University of Science and Technology
- Harbin 150040, P. R. China
| | - Fengyang Zhao
- Department of Polymer Materials and Engineering
- College of Materials Science and Engineering
- Harbin University of Science and Technology
- Harbin 150040, P. R. China
| | - Changchun Huang
- Department of Polymer Materials and Engineering
- College of Materials Science and Engineering
- Harbin University of Science and Technology
- Harbin 150040, P. R. China
| | - Xiaoqun Wang
- Department of Polymer Materials and Engineering
- College of Materials Science and Engineering
- Harbin University of Science and Technology
- Harbin 150040, P. R. China
| | - Tongfei Shi
- State Key Laboratory of Polymer Physics and Chemistry
- Changchun Institute of Applied Chemistry
- Chinese Academy of Sciences
- Changchun 130022, P. R. China
| | - Hongfei Li
- State Key Laboratory of Polymer Physics and Chemistry
- Changchun Institute of Applied Chemistry
- Chinese Academy of Sciences
- Changchun 130022, P. R. China
| |
Collapse
|
18
|
Kowal J, Zhang X, Dinu IA, Palivan CG, Meier W. Planar Biomimetic Membranes Based on Amphiphilic Block Copolymers. ACS Macro Lett 2013. [DOI: 10.1021/mz400590c] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- Justyna Kowal
- Chemistry Department, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland
| | - Xiaoyan Zhang
- Chemistry Department, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland
| | - Ionel Adrian Dinu
- Chemistry Department, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland
| | - Cornelia G. Palivan
- Chemistry Department, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland
| | - Wolfgang Meier
- Chemistry Department, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland
| |
Collapse
|
19
|
Ribeiro A, Sandez-Macho I, Casas M, Alvarez-Pérez S, Alvarez-Lorenzo C, Concheiro A. Poloxamine micellar solubilization of α-tocopherol for topical ocular treatment. Colloids Surf B Biointerfaces 2013; 103:550-7. [DOI: 10.1016/j.colsurfb.2012.10.055] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2012] [Revised: 10/04/2012] [Accepted: 10/18/2012] [Indexed: 10/27/2022]
|
20
|
Paczesny J, Gregorowicz J, Nikiforov K. Phase transitions in monolayer formed by hyperbranched polyester with alkyl-terminated branches at the air/water interface. POLYMER 2013. [DOI: 10.1016/j.polymer.2012.11.014] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
21
|
Park HW, Choi J, Ohn K, Lee H, Kim JW, Won YY. Study of the air-water interfacial properties of biodegradable polyesters and their block copolymers with poly(ethylene glycol). LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:11555-11566. [PMID: 22830444 DOI: 10.1021/la300810q] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
It has been reported that the surface pressure-area isotherm of poly(D,L-lactic acid-ran-glycolic acid) (PLGA) at the air-water interface exhibits several interesting features: (1) a plateau at intermediate compression levels, (2) a sharp rise in surface pressure upon further compression, and (3) marked surface pressure-area hysteresis during compression-expansion cycles. To investigate the molecular origin of this behavior, we conducted an extensive set of surface pressure and AFM imaging measurements with PLGA materials having several different molecular weights and also a poly(D,L-lactic acid-ran-glycolic acid-ran-caprolactone) (PLGACL) material in which the caprolactone monomers were incorporated as a plasticizing component. The results suggest that (i) the plateau in the surface pressure-area isotherm of PLGA (or PLGACL) occurs because of the formation (and collapse) of a continuous monolayer of the polymer under continuous compression; (ii) the PLGA monolayer becomes significantly resistant to compression at high compression because under that condition the collapsed domains become large enough to become glassy (such behavior was not observed in the nonglassy PLGACL sample); and (iii) the isotherm hysteresis is due to a coarsening of the collapsed domains that occurs under high-compression conditions. We also investigated the monolayer properties of PEG-PLGA and PEG-PLGACL diblock copolymers. The results demonstrate that the tendency of PLGA (or PLGACL) to spread on water allows the polymer to be used as an anchoring block to form a smooth biodegradable monolayer of block copolymers at the air-water interface. These diblock copolymer monolayers exhibit protein resistance.
Collapse
Affiliation(s)
- Hae-Woong Park
- School of Chemical Engineering, Purdue University, West Lafayette, Indiana 47907, United States
| | | | | | | | | | | |
Collapse
|
22
|
Zhou C, Chen N, Yang J, Liu H, Li Y. Ion-Specific Self-Assembly of Low-Dimension Aggregate Structures of Conjugated Polymer at Two-Phase Interface. Macromol Rapid Commun 2012; 33:688-92. [DOI: 10.1002/marc.201100828] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2011] [Revised: 12/27/2011] [Indexed: 11/06/2022]
|
23
|
Giner I, Haro M, Gascón I, Barrio JD, Carmen López M. Air–water interfacial behavior of linear-dendritic block copolymers containing PEG and azobenzene chromophores. J Colloid Interface Sci 2011; 359:389-98. [DOI: 10.1016/j.jcis.2011.03.091] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2011] [Revised: 03/24/2011] [Accepted: 03/26/2011] [Indexed: 11/30/2022]
|
24
|
Formation mechanism, chain folding, and growth behavior of the intriguing fiber-like crystal of poly (ethylene oxide-b-ε-caprolactone) block copolymer in ultrathin films. POLYMER 2011. [DOI: 10.1016/j.polymer.2011.02.044] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
25
|
Stocco A, Tauer K, Pispas S, Sigel R. Dynamics of amphiphilic diblock copolymers at the air-water interface. J Colloid Interface Sci 2010; 355:172-8. [PMID: 21194709 DOI: 10.1016/j.jcis.2010.11.049] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2010] [Revised: 11/17/2010] [Accepted: 11/17/2010] [Indexed: 11/30/2022]
Abstract
Two polyisoprene-polyethyleneoxide diblock copolymers with different block length ratios adsorbed to the water surface were investigated by multiple angle of incidence ellipsometry, evanescent wave light scattering, and surface tension experiments. In a semidilute interfacial regime, the transition from a two-dimensional to a "mushroom" regime, in which polymer chains form loops and tails in the subphase, was discussed. A diffusion mechanism parallel to the interface was probed by evanescent wave dynamic light scattering. At intermediate concentrations, the interfacial diffusion coefficient D(∥) scales with the surface concentration Γ, as D(∥) ~ Γ(0.77) in agreement with the scaling observed for polymer solutions in a semidilute regime. At relatively high concentrations a decreasing of D(∥) is discussed in terms of increasing friction due to interactions between polyisoprene chains.
Collapse
Affiliation(s)
- Antonio Stocco
- Max Planck Institute of Colloids and Interfaces, 14476 Potsdam-Golm, Germany.
| | | | | | | |
Collapse
|
26
|
Lu H, Lee DH, Russell TP. Temperature tunable micellization of polystyrene-block-poly(2-vinylpyridine) at Si-ionic liquid interface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:17126-32. [PMID: 20973541 DOI: 10.1021/la102890s] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Highly ordered and stable micelles formed from both symmetric and asymmetric block copolymers of polystyrene-block-poly(2-vinylpyridine) (PS-b-P2VP) at the Si-ionic liquid (IL) interface have been investigated by scanning force microscopy (SFM) and transmission electron microscopy (TEM). The 1-butyl-3-methylimidazolium trifluoromethanesulfonate IL, a selective and temperature-tunable solvent for the P2VP block, was used and gave rise to block copolymer micelles having different morphologies that strongly depended on the annealing temperature. The effects of film thickness, molecular weight of block copolymers, and experimental conditions, such as preannealing, rinsing, and substrate properties, on the morphologies of block copolymer micelles were also studied. In addition, spherical micelles consisting of PS core and P2VP shell could also be obtained by core-corona inversion by annealing the as-coated micellar film in the IL at high temperatures. The possible mechanism for micelle formation is discussed.
Collapse
Affiliation(s)
- Haiyun Lu
- Department of Polymer Science and Engineering, University of Massachusetts, Amherst, Massachusetts 01003, United States
| | | | | |
Collapse
|
27
|
Scheibe P, Barz M, Hemmelmann M, Zentel R. Langmuir-Blodgett films of biocompatible poly(HPMA)-block-poly(lauryl methacrylate) and poly(HPMA)-random-poly(lauryl methacrylate): influence of polymer structure on membrane formation and stability. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:5661-5669. [PMID: 20345113 DOI: 10.1021/la903725k] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Membranes based on functional biocompatible polymers can be regarded as a useful model system to study biological interactions, e.g. antibody-antigen interactions or protein polymer interactions. These model systems may give a better insight into these processes and may help to find suitable polymeric structures offering biocompatibility as well as reduced polymer protein interaction. In this respect, Langmuir-Blodgett (LB) layer formation at the air/water (A/W) interface is studied in respect to polymer architecture in this article. For this purpose, narrowly distributed N-(2-hydroxypropyl)-methacrylamide (HPMA) random and block copolymers have been prepared by the RAFT polymerization method. For random copolymers different molecular weights were prepared. As for the block copolymers also the ratio of hydrophilic and hydrophobic units was varied in order to study the influence of hydrophobic block length on collapse pressure and area. The molecular weights of all polymers were around 15 kDa and 30 kDa. In the case of block copolymers we found a direct correlation of the length of the hydrophobic block to the collapse area. Furthermore, hysteresis experiments clearly point out that block copolymers form stable LB layers. No remarkable changes in collapse pressure or area could be observed. In contrast the area occupied by random copolymers changes at each hysteresis cycle indicating a loss of polymer to the aqueous subphase. In addition the LB layers were transferred onto mica substrates. The block copolymers formed stable and defect free membranes over an area of 100 microm(2) with a roughness (rms) 1.3-1.4 A. On the contrary, membranes based on random copolymers turned out to have a higher surface roughness. Our findings clearly underline the influence of polymer structure on the LB layer formation at the A/W interface.
Collapse
Affiliation(s)
- Patrick Scheibe
- Institute of Organic Chemistry, Johannes Gutenberg-University Mainz, Duesbergweg 10-14, 55099 Mainz, Germany
| | | | | | | |
Collapse
|
28
|
Park SW, Choi JM, Lee KH, Yeom HW, Im S, Lee YK. Amorphous-to-Crystalline Phase Transformation of Thin Film Rubrene. J Phys Chem B 2010; 114:5661-5. [DOI: 10.1021/jp910459p] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Se-Woong Park
- Institute of Physics and Applied Physics, Yonsei University, Seoul 120-749, Korea
| | - Jeong-Min Choi
- Institute of Physics and Applied Physics, Yonsei University, Seoul 120-749, Korea
| | - Kwang Hyun Lee
- Institute of Physics and Applied Physics, Yonsei University, Seoul 120-749, Korea
| | - Han Woong Yeom
- Institute of Physics and Applied Physics, Yonsei University, Seoul 120-749, Korea
| | - Seongil Im
- Institute of Physics and Applied Physics, Yonsei University, Seoul 120-749, Korea
| | - Young Kook Lee
- Department of Metallurgical Engineering, Yonsei University, Seoul 120-749, Korea
| |
Collapse
|
29
|
Wang CW, Xin GQ, Lee YI, Hao J, Jiang J, Liu HG. Poly(9-vinylcarbazole)/silver composite nanotubes and networks formed at the airâwater interface. J Appl Polym Sci 2010. [DOI: 10.1002/app.31443] [Citation(s) in RCA: 127] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
30
|
Wen G. Network Structure Control of Binary Mixed Langmuir Monolayers of Homo-PS and PS-b-P2VP. J Phys Chem B 2010; 114:3827-32. [DOI: 10.1021/jp909588p] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Gangyao Wen
- Department of Polymer Materials and Engineering, College of Materials Science and Engineering, Harbin University of Science and Technology, Harbin 150040, P. R. China
| |
Collapse
|
31
|
|
32
|
Lerum RV, Bermudez H. Controlled Interfacial Assembly and Transfer of Brushlike Copolymer Films. Chemphyschem 2009; 11:665-9. [DOI: 10.1002/cphc.200900738] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
33
|
WELL-DEFINED LADDER POLYMERS SYNTHESIZED via SUPRAMOLECULAR ARCHITECTURE AND THEIR APPLICATIONS. ACTA POLYM SIN 2009. [DOI: 10.3724/sp.j.1105.2007.00918] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
34
|
Li H, Sachsenhofer R, Binder WH, Henze T, Thurn-Albrecht T, Busse K, Kressler J. Hierarchical organization of poly(ethylene oxide)-block-poly(isobutylene) and hydrophobically modified Fe(2)O(3) nanoparticles at the air/water interface and on solid supports. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:8320-8329. [PMID: 19441824 DOI: 10.1021/la900549h] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Langmuir monolayers and Langmuir-Blodgett (LB) film morphologies of block copolymers and hydrophobically modified iron oxide nanoparticles were studied by surface pressure-mean molecular area (pi-mmA) measurements and by tapping mode atomic force microscopy (AFM). The amphiphilic diblock copolymers consisted of a hydrophilic poly(ethylene oxide) (PEO) block and a hydrophobic poly(isobutylene) (PIB) block. The pi-mmA isotherm of PEO(97)-b-PIB(37) (the subscripts refer to the respective degrees of polymerization) at the air/water interface had an extended plateau reflecting the extension of PEO chains into the water subphase at a surface pressure of 10 mN.m(-1), which is absent for the more hydrophobic PEO(19)-b-PIB(130). Iron oxide (Fe(2)O(3)) nanoparticles capped with oleic acid ligands as the shell were dispersed in the amphiphilic block copolymers at the air/water interface to prevent macroscopic aggregation of the particles. When the nanoparticles were mixed with PEO(97)-b-PIB(37), using a particle to polymer chain ratio of 1:100, macroscopic aggregation of the nanoparticles was not observed, and the pi-mmA isotherm was dominated by PEO(97)-b-PIB(37). Monolayers of block copolymers were transferred at different surface pressures from the air/water interface to hydrophilic silicon substrates using the Langmuir-Blodgett technique. The AFM images of PEO(97)-b-PIB(37) LB films depicted not only the typical finger-like morphology of the crystallized PEO blocks but also PIB blocks arranged in vertical columns growing perpendicular to the substrate surface. The columns are characteristic for PEO(19)-b-PIB(130) LB films after transfer at high surface pressures and can be assigned to a mesomorphic PIB phase with ordered chains. Finally, it was observed that small clusters of a few Fe(2)O(3) nanoparticles occupy the top of PIB phases after compression and transfer of the block copolymer nanoparticle mixtures to solid supports.
Collapse
Affiliation(s)
- Hangsheng Li
- Martin Luther University Halle-Wittenberg, D-06099 Halle, Germany
| | | | | | | | | | | | | |
Collapse
|
35
|
Price EW, Guo Y, Wang CW, Moffitt MG. Block copolymer strands with internal microphase separation structure via self-assembly at the air-water interface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:6398-6406. [PMID: 19466788 DOI: 10.1021/la804317s] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Block copolymer microphase separation in the bulk is coupled to amphiphilic block copolymer self-assembly at the air-water interface to yield hierarchical Langmuir-Blodgett (LB) structures combining organization at the meso- and nanoscales. A blend of polystyrene-b-poly(ethylene oxide) (PS-b-PEO) (Mn=141K, 11.4 wt % PEO) and polystyrene-b-poly(butadiene) (PS-b-PB) (Mn=31.9K, 28.5 wt % PB) containing a PS-b-PB weight fraction of f=0.75 was deposited at the air-water interface, resulting in the spontaneous generation of aggregates with multiscale organization, including nanoscale cylinders in mesoscale strands, via evaporation of the spreading solvent. The resulting features were characterized in LB films via AFM and TEM and at the air-water interface via Langmuir compression isotherms. Blends containing lower PS-b-PB contents formed mesoscale aggregate morphologies of continents and strands (f=0.50) or mesoscale continents with holes (f=0.25), but without the internal nanoscale organization found in the f=0.75 blend. The interfacial self-assembly of pure PS-b-PB at the air-water interface (f=1) yielded taller and more irregularly shaped aggregates than blends containing PS-b-PEO, indicating the integral role of the amphiphilic copolymer in regulating the mesoscale organization of the hierarchically structured features.
Collapse
Affiliation(s)
- Eric W Price
- Department of Chemistry, University of Victoria, P.O. Box 3065, Victoria, BC V8W 3V6, Canada
| | | | | | | |
Collapse
|
36
|
Tanaka M, Ogura K, Abiko S, Koshikawa N, Kinoshita T. Two-dimensional Self-assembly of a Designed Amphiphilic Peptide at Air/Water Interface. Polym J 2008. [DOI: 10.1295/polymj.pj2008154] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
37
|
Poly(ε-caprolactone)-block-poly(ethyleneoxide) -block-poly(ε-caprolactone): Biodegradable triblock copolymer spread at the air–water interface. Eur Polym J 2008. [DOI: 10.1016/j.eurpolymj.2008.06.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
38
|
Wen G, Chung B, Chang T. Aggregation Behavior of Homo‐PS/PS‐b‐P2VP Blends at the Air/Water Interface. Macromol Rapid Commun 2008. [DOI: 10.1002/marc.200800106] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
39
|
Guo S, Zhang Y. Concentration controlled multilevel self-assembly of 3-armed poly(ethylene glycol)-b-poly(ε-caprolactone) block copolymers investigated by AFM. ACTA ACUST UNITED AC 2008. [DOI: 10.1002/polb.21467] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
40
|
Chandrasekar K, Vijay R, Baskar G. Ionic polymeric amphiphiles with cholesterol mesogen: adsorption and organization characteristics at the air/water interface from Langmuir film balance studies. Biomacromolecules 2008; 9:1264-72. [PMID: 18307308 DOI: 10.1021/bm701252y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Ionic polymeric amphiphiles consisting of cholesterol mesogen were investigated for the interfacial adsorption characteristics at the air/water interface using a Langmuir film balance with an aim to understand the influence of ionic segment from 2-acrylamido-2-methyl-1-propane sulfonic acid (AMPS) on the packing behavior of cholesterol at the interface. From surface pressure (pi)-area (A) isotherm characteristics, it is demonstrated that the homopolymer and the copolymer C consisting of 0.15 mol fraction CAB segments exhibit the most expanded structures contributing to surface area of about 84 A(2)/molecule. It is shown that the copolymer B with 0.1 mol fraction CAB provides optimum hydrophilic liphophilic balance to form the most compact structures contributing to a surface area of 35.75 A(2)/molecule. The high surface pressure, >40 mN/m, in contrast to that of PAMPS demonstrates significant adsorption of the copolymers at the interface. An interesting correlation among interfacial packing characteristics, thermal behavior, and solution structures is demonstrated. From molecular models developed for CAB, it is shown that the horizontal orientation of the linker group with respect to cholesterol chain in CAB underlies the expanded structures observed in PCAB and copolymer C.
Collapse
Affiliation(s)
- K Chandrasekar
- Industrial Chemistry Laboratory, Central Leather Research Institute, Adyar, Chennai 600 020, India
| | | | | |
Collapse
|
41
|
Shankar BV, Patnaik A. Equilibrium structure and dynamics of (2R, 3R)-(+)-bis(decyloxy)succinic acid at the air-water interface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2008; 24:758-766. [PMID: 18177056 DOI: 10.1021/la701998c] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
A twin-tailed, twin-chiral fatty acid, (2R,3R)-(+)-bis(decyloxy)succinic acid was synthesized and its two dimensional behavior at the air-water interface was examined. The pH of the subphase had a profound effect on the monolayer formation. On acidic subphase, stable monolayers with increased area per molecule due to hydrogen bonding and bilayers at collapse pressures were observed. Highly compressible films were formed at 40 degrees C, while stable monolayers with increased area were observed at sub-room temperatures. Langmuir monolayers formed on subphases containing 1 mM ZnCl2 and CaCl2 revealed two dimensional metal complex formation with Zn2+ forming a chelate-type complex, while Ca2+ formed an ionic-type complex. Monolayers transferred from the condensed phase onto hydrophilic Si(100) and quartz substrates revealed the formation of bilayers through transfer-induced monolayer buckling. Compression induced crystallites in 2D from monolayers and vesicle-like supramolecular structures from multilayers were the noted LB film characteristics, adopting optical imaging and electron microscopy. The interfacial monolayer structure studied through molecular dynamics simulation revealed the order and packing at a molecular level; monolayers adsorbed at various simulated specific areas of the molecule corroborated the (pi-A) isotherm and the formation of a hexagonal lattice at the air-water interface.
Collapse
Affiliation(s)
- B Vijai Shankar
- Department of Chemistry, Indian Institute of Technology Madras, Chennai 600036, India
| | | |
Collapse
|
42
|
Casse O, Colombani O, Kita-Tokarczyk K, Müller AHE, Meier W, Taubert A. Calcium phosphate mineralization beneath monolayers of poly(n-butylacrylate)–block–poly(acrylic acid) block copolymers. Faraday Discuss 2008; 139:179-97; discussion 213-28, 419-20. [DOI: 10.1039/b716353c] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|