1
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Abstract
Polymers under confinement exhibit different structures and properties from the bulk. While block copolymers (BCPs) create well-defined micelles in solution, two-dimensional (2D) spatial confinement at the air-water interface constrains the chain conformations and deforms the micellar structure, thus forming a surface micelle. The BCP surface micelles open up an opportunity in nanoscience and engineering by serving as an interfacial modifier and structural platform. Nevertheless, a scaling law, a principle governing the micellar structure, is absent. Herein, we report a unified scaling relation to describe the combinational structure of BCP surface micelles in two and three dimensions and further reveal their formation mechanism in line with the suggested scaling relation. We investigated the intrinsic scaling relations in a surface pressure-free environment by introducing a concept of excluded volume-dependent scaling exponent based on the scaling theory of 2D polymers. In addition, an extrinsic scaling relation is derived for the surface pressure-dependent corona scaling.
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Affiliation(s)
- Dong Hyup Kim
- School of Chemical and Biological Engineering, and Institute of Chemical Processes, Seoul National University, Seoul 08826, Republic of Korea
| | - So Youn Kim
- School of Chemical and Biological Engineering, and Institute of Chemical Processes, Seoul National University, Seoul 08826, Republic of Korea
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2
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Fractal Growth of Giant Amphiphiles in Langmuir-Blodgett Films. CHINESE JOURNAL OF POLYMER SCIENCE 2022. [DOI: 10.1007/s10118-022-2722-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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3
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Eickelmann S, Moon S, Liu Y, Bitterer B, Ronneberger S, Bierbaum D, Breitling F, Loeffler FF. Assessing Polymer-Surface Adhesion with a Polymer Collection. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:2220-2226. [PMID: 35138112 PMCID: PMC8867722 DOI: 10.1021/acs.langmuir.1c02724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Revised: 01/26/2022] [Indexed: 06/14/2023]
Abstract
Polymer modification plays an important role in the construction of devices, but the lack of fundamental understanding on polymer-surface adhesion limits the development of miniaturized devices. In this work, a thermoplastic polymer collection was established using the combinatorial laser-induced forward transfer technique as a research platform, to assess the adhesion of polymers to substrates of different wettability. Furthermore, it also revealed the influence of adhesion on dewetting phenomena during the laser transfer and relaxation process, resulting in polymer spots of various morphologies. This gives a general insight into polymer-surface adhesion and connects it with the generation of defined polymer microstructures, which can be a valuable reference for the rational use of polymers.
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Affiliation(s)
- Stephan Eickelmann
- Max-Planck-Institute
of Colloids and Interfaces, Biomolecular Systems, Am Muehlenberg 1, 14476 Potsdam, Germany
| | - Sanghwa Moon
- Max-Planck-Institute
of Colloids and Interfaces, Biomolecular Systems, Am Muehlenberg 1, 14476 Potsdam, Germany
| | - Yuxin Liu
- Max-Planck-Institute
of Colloids and Interfaces, Biomolecular Systems, Am Muehlenberg 1, 14476 Potsdam, Germany
| | - Benjamin Bitterer
- Institute
of Microstructure Technology, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| | - Sebastian Ronneberger
- Max-Planck-Institute
of Colloids and Interfaces, Biomolecular Systems, Am Muehlenberg 1, 14476 Potsdam, Germany
| | - Dominik Bierbaum
- Max-Planck-Institute
of Colloids and Interfaces, Biomolecular Systems, Am Muehlenberg 1, 14476 Potsdam, Germany
| | - Frank Breitling
- Institute
of Microstructure Technology, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| | - Felix F. Loeffler
- Max-Planck-Institute
of Colloids and Interfaces, Biomolecular Systems, Am Muehlenberg 1, 14476 Potsdam, Germany
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4
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Xu W, Wen G, Wu T, Chen N. Aggregation Behavior of the Blends of Homo-PS and PS- b-PEO- b-PS at the Air/Water Interface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:13435-13441. [PMID: 31550898 DOI: 10.1021/acs.langmuir.9b02388] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Aggregation behaviors of the blended Langmuir monolayers of a homopolymer polystyrene (h-PS) and a triblock copolymer polystyrene-b-poly(ethylene oxide)-b-polystyrene (PS-b-PEO-b-PS) were studied by the Langmuir film balance technique, and the morphologies of their Langmuir-Blodgett (LB) films were studied by atomic force microscopy. The isotherms of the h-PS/PS-b-PEO-b-PS blends shift to small areas with the increase of h-PS content, and a pseudoplateau appears as h-PS content is below 60 wt %. It is worth noting that the blended isotherms appear at the left of their corresponding ideal ones, which means that the blended monolayers are a little more condensed due to attractive interactions between the two components. Hysteresis phenomena exist in all of the blended monolayers, and the higher the PS-b-PEO-b-PS content, the larger the hysteresis degree becomes because of the stronger looped-PEO entanglements. All the blended LB films of h-PS and PS-b-PEO-b-PS prepared under low pressure exhibit the mixed structures of small and large isolated circular aggregates. The small aggregates are the copolymer micelle cores and the large ones are attributed to coalescence of the local h-PS chains and some PS blocks. Upon further compression, the aggregates in the blended LB films become a little denser as h-PS content is below 60 wt %, whereas those become totally close-packed with decreased size as h-PS content is 80 wt %.
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Affiliation(s)
- Wei Xu
- Department of Polymer Materials and Engineering, College of Material Science and Engineering , Harbin University of Science and Technology , 4 Linyuan Road , Harbin 150040 , P. R. 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 , P. R. China
| | - Tao Wu
- Department of Polymer Materials and Engineering, College of Material Science and Engineering , Harbin University of Science and Technology , 4 Linyuan Road , Harbin 150040 , P. R. China
| | - Nanyang Chen
- Department of Polymer Materials and Engineering, College of Material Science and Engineering , Harbin University of Science and Technology , 4 Linyuan Road , Harbin 150040 , P. R. China
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5
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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.
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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
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6
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Li Q, Liu R, Wu T, Zhang M. Aggregation and rheological behavior of soluble dietary fibers from wheat bran. Food Res Int 2017; 102:291-302. [PMID: 29195951 DOI: 10.1016/j.foodres.2017.09.064] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Revised: 08/10/2017] [Accepted: 09/22/2017] [Indexed: 01/12/2023]
Abstract
The present study assesses the aggregation behavior of wheat bran arabinoxylan-rich soluble dietary fiber (SDF) fractions with diverse molecular weight and substitution in order to provide useful information to prevent the formation of a block network. In the present work, dynamic and static light scattering, diffusing wave spectroscopy, small amplitude dynamic rheology, atomic force microscopy, and the water-holding and swelling capacities were evaluated to assess the SDF aggregation behavior induced by intrinsic and extrinsic factors. Furthermore, the rheological behavior was explained by the physically cross-linked or interpenetrating hydrocolloid network established during SDF self-aggregation, dependent on its molecular structure. The results indicated that the SDF fractions exhibiting a high molecular weight and a lower substitution degree and di-substituted ratio led to more significant aggregation due to the formation of disordered tangles coupled with a more solid-like behavior. The obtained information will prove useful for the development of more stable and compatible SDF fractions.
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Affiliation(s)
- Qian Li
- Key Laboratory of Food Nutrition and Safety, Tianjin University of Science & Technology, Ministry of Education, Tianjin 300457, China
| | - Rui Liu
- Key Laboratory of Food Nutrition and Safety, Tianjin University of Science & Technology, Ministry of Education, Tianjin 300457, China; Tianjin Food Safety & Low Carbon Manufacturing Collaborative Innovation Center, Tianjin 300457, China
| | - Tao Wu
- Key Laboratory of Food Nutrition and Safety, Tianjin University of Science & Technology, Ministry of Education, Tianjin 300457, China
| | - Min Zhang
- Key Laboratory of Food Nutrition and Safety, Tianjin University of Science & Technology, Ministry of Education, Tianjin 300457, China; Tianjin Food Safety & Low Carbon Manufacturing Collaborative Innovation Center, Tianjin 300457, China.
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7
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Kim DH, Kim SY. Effective Morphology Control of Block Copolymers and Spreading Area-Dependent Phase Diagram at the Air/Water Interface. J Phys Chem Lett 2017; 8:1865-1871. [PMID: 28383894 DOI: 10.1021/acs.jpclett.7b00471] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Over the past several decades, tremendous efforts have been made to understand the fundamental physics of block copolymer (BCP) self-assembly in bulk or thin films, and this has led to the development of BCP-based bottom-up nanofabrication. BCPs also form periodic nanostructures at the air/water interface, which has potential application to ultrathin-film nanopatterning with molecular-level precision. Nonetheless, controlling the nanostructure formation at the air/water interface is restricted by the inherent parameters of BCPs; BCP morphology is determined by the hydrophilic-to-hydrophobic block ratio. Here we show that controlling the spreading area of BCPs at the air/water interface can tune the shape and size of BCP structures, suggesting a new phase diagram of BCP structures as a function of the relative block fraction and spreading area. A neat polystyrene-b-poly(2-vinylpyridine), known to form a dot morphology, instead forms a strand or planar morphology when the spreading area is varied with Langmuir-Blodgett technique.
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Affiliation(s)
- Dong Hyup Kim
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST) , 50 UNIST-gil, Ulsan 44919, Republic of Korea
| | - So Youn Kim
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST) , 50 UNIST-gil, Ulsan 44919, Republic of Korea
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8
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Interactions between soluble dietary fibers and wheat gluten in dough studied by confocal laser scanning microscopy. Food Res Int 2017; 95:19-27. [PMID: 28395821 DOI: 10.1016/j.foodres.2017.02.021] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Revised: 02/23/2017] [Accepted: 02/26/2017] [Indexed: 11/24/2022]
Abstract
Four soluble dietary fiber (SDF) fractions characterized by major components of AXs, relatively narrow molecular weight distribution, different substituted ratio, and structure-sensitive parameter (ρ) were prepared from wheat bran. The fractions were added to wheat dough to determine the interactions between the dough's network and the SDF fractions relative to their physicochemical characteristics. Furthermore, a comprehensive study focusing on the dough texture characteristic, tensile properties, thermodynamic stability, and the microstructure was conducted by performing texture profile analysis (TPA), differential scanning calorimetry (DSC), and confocal laser scanning microscopy (CLSM) experiments. Additionally, an estimation function of the interactions parameters between the dough's network and the SDF fractions related to the factor molecular weight and ρ of the SDFs was established. The results indicated that the SDF fractions exhibiting a medium molecular weight, and a higher substitution degree and di-substituted ratio, were the most suitable fortifier providing benefits to the dough's qualities. Furthermore, the research methodology might support the high potential of SDF fractions as fortifier for flour-based products.
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9
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Han T, Wei W, Yuan J, Duan Y, Li Y, Hu L, Dong Y. Solvent-assistant self-assembly of an AIE+TICT fluorescent Schiff base for the improved ammonia detection. Talanta 2016; 150:104-12. [DOI: 10.1016/j.talanta.2015.12.022] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Revised: 11/29/2015] [Accepted: 12/10/2015] [Indexed: 12/17/2022]
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10
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Guennouni Z, Cousin F, Fauré MC, Perrin P, Limagne D, Konovalov O, Goldmann M. Self-Organization of Polystyrene-b-polyacrylic Acid (PS-b-PAA) Monolayer at the Air/Water Interface: A Process Driven by the Release of the Solvent Spreading. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:1971-1980. [PMID: 26824719 DOI: 10.1021/acs.langmuir.5b02652] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We present an in situ structural study of the surface behavior of PS-b-PAA monolayers at the air/water interface at pH 2, for which the PAA blocks are neutral and using N,N-dimethyformamide (DMF) as spreading solvent. The surface pressure versus molecular area isotherm shows a perfectly reversible pseudoplateau over several cycles of compression/decompression. The width of such plateau enlarges when increasing temperature, conversely to what is classically observed in the case of an in-plane first order transition. We combined specular neutron reflectivity (SNR) experiments with contrast variation to solve the profile of each block perpendicular to the surface with grazing-incidence small-angle scattering (GISAXS) measurements to determine the in-plane structure of the layer. SNR experiments showed that both PS and PAA blocks remain adsorbed on the surface for all surface pressure probed. A correlation peak at Q(xy)* = 0.021 Å(-1) is evidenced by GISAXS at very low surface pressure which intensity first increases on the plateau. When compressing further, its intensity decays while Q(xy)* is shifted toward low Q(xy). The peak fully disappears at the end of the plateau. These results are interpreted by the formation of surface aggregates induced by DMF molecules at the surface. These DMF molecules remain adsorbed within the PS core of the aggregates. Upon compression, they are progressively expelled from the monolayer, which gives rise to the pseudoplateau on the isotherm. The intensity of the GISAXS correlation peak is set by the amount of DMF within the monolayer as it vanishes when all DMF molecules are expelled. This result emphizes the role of the solvent in Langmuir monolayer formed by amphiphilic copolymers which hydrophobic and hydrophilic parts are composed by long polymer chains.
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Affiliation(s)
- Zineb Guennouni
- Sorbonne Universités, UPMC Univ Paris 06, CNRS-UMR 7588, Institut des NanoSciences de Paris, 4 place Jussieu F-75005 Paris, France
- Laboratoire Léon Brillouin, CEA Saclay, 91191 Gif sur Yvette Cedex, France
| | - Fabrice Cousin
- Laboratoire Léon Brillouin, CEA Saclay, 91191 Gif sur Yvette Cedex, France
| | - Marie-Claude Fauré
- Sorbonne Universités, UPMC Univ Paris 06, CNRS-UMR 7588, Institut des NanoSciences de Paris, 4 place Jussieu F-75005 Paris, France
- Faculté des Sciences Fondamentales et Biomédicales, Université Paris Descartes , 45 rue des Saints Pères , 75006 Paris, France
| | - Patrick Perrin
- Ecole Supérieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI), ParisTech, PSL Research University, Sciences et Ingénierie de la Matière Molle (SIMM), CNRS UMR 7615, 10, Rue Vauquelin, F-75231 Cedex 05 Paris, France
- Sorbonne-Universités, UPMC Univ Paris 06, SIMM, 10, Rue Vauquelin, F-75231 Cedex 05 Paris, France
| | - Denis Limagne
- Sorbonne Universités, UPMC Univ Paris 06, CNRS-UMR 7588, Institut des NanoSciences de Paris, 4 place Jussieu F-75005 Paris, France
| | - Oleg Konovalov
- European Synchrotron Radiation Facility , 6 rue Jules Horowitz 38000 Grenoble, France
| | - Michel Goldmann
- Sorbonne Universités, UPMC Univ Paris 06, CNRS-UMR 7588, Institut des NanoSciences de Paris, 4 place Jussieu F-75005 Paris, France
- Faculté des Sciences Fondamentales et Biomédicales, Université Paris Descartes , 45 rue des Saints Pères , 75006 Paris, France
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint-Aubin, BP 48, 91192 Gif-sur-Yvette, France
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11
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Deschênes L, Lyklema J, Danis C, Saint-Germain F. Phase transitions in polymer monolayers: Application of the Clapeyron equation to PEO in PPO-PEO Langmuir films. Adv Colloid Interface Sci 2015; 222:199-214. [PMID: 25488283 DOI: 10.1016/j.cis.2014.11.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Revised: 11/04/2014] [Accepted: 11/05/2014] [Indexed: 11/19/2022]
Abstract
In this paper we investigate the application of the two-dimensional Clapeyron law to polymer monolayers. This is a largely unexplored area of research. The main problems are (1) establishing if equilibrium is reached and (2) if so, identifying and defining phases as functions of the temperature. Once this is validated, the Clapeyron law allows us to obtain the entropy and enthalpy differences between two coexisting phases. In turn, this information can be used to obtain insight into the conformational properties of the films and changes therein. This approach has a wide potential for obtaining additional information on polymer adsorption at interfaces and the structure of their monolayer films. The 2D Clapeyron law was applied emphasizing polyethylene oxide (PEO) in polypropylene oxide (PPO)-PEO block copolymers, based on new well-defined data for their Langmuir films. Values for enthalpy per monomer of 0.12 and 0.23 kT were obtained for the phase transition of two different PEO chains (Neo of 2295 and 409, respectively). This enthalpy was estimated to correspond to 1.2±0.4 kT per EO monomer present in train conformation at the air/water interface.
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Affiliation(s)
- Louise Deschênes
- Food Research and Development Centre, 3600 Casavant Blvd West, Saint-Hyacinthe, QC J2S 8E3, Canada
| | - Johannes Lyklema
- Laboratory for Physical Chemistry and Colloid Science, Wageningen University, Dreijenplein 6, 6703 HB Wageningen, Netherlands
| | - Claude Danis
- Food Research and Development Centre, 3600 Casavant Blvd West, Saint-Hyacinthe, QC J2S 8E3, Canada
| | - François Saint-Germain
- Food Research and Development Centre, 3600 Casavant Blvd West, Saint-Hyacinthe, QC J2S 8E3, Canada
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12
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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.
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13
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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.
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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
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14
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Perepichka II, Lu Q, Badia A, Bazuin CG. Understanding and controlling morphology formation in Langmuir-Blodgett block copolymer films using PS-P4VP and PS-P4VP/PDP. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:4502-19. [PMID: 23383750 DOI: 10.1021/la3040962] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
This contribution offers a comprehensive understanding of the factors that govern the morphologies of Langmuir-Blodgett (LB) monolayers of amphiphilic diblock copolymers (BCs). This is achieved by a detailed investigation of a wide range of polystyrene-poly(4-vinyl pyridine) (PS-P4VP) block copolymers, in contrast to much more limited ranges in previous studies. Parameters that are varied include the block ratios (mainly for similar total molecular weights, occasionally other total molecular weights), the presence or not of 3-n-pentadecylphenol (PDP, usually equimolar with VP, with which it hydrogen bonds), the spreading solution concentration ("low" and "high"), and the LB technique (standard vs "solvent-assisted"). Our observations are compared with previously published results on other amphiphilic diblock copolymers, which had given rise to contradictory interpretations of morphology formation. Based on the accumulated results, we re-establish early literature conclusions that three main categories of LB block copolymer morphologies are obtained depending on the block ratio, termed planar, strand, and dot regimes. The block composition boundaries in terms of mol % block content are shown to be similar for all BCs having alkyl chain substituents on the hydrophilic block (such as PS-P4VP/PDP) and are shifted to higher values for BCs with no alkyl chain substituents (such as PS-P4VP). This is attributed to the higher surface area per repeat unit of the hydrophilic block monolayer on the water surface for the former, as supported by the onset and limiting areas of the Langmuir isotherms for the BCs in the dot regime. 2D phase diagrams are discussed in terms of relative effective surface areas of the two blocks. We identify and discuss how kinetic effects on morphology formation, which have been highlighted in more recent literature, are superposed on the compositional effects. The kinetic effects are shown to depend on the morphology regime, most strongly influencing the strand and, especially, planar regimes, where they give rise to a diversity of specific structures. Besides film dewetting mechanisms, which are different when occurring in structured versus unstructured films (the latter previously discussed in the literature), kinetic influences are discussed in terms of chain association dynamics leading to depletion effects that impact on growing aggregates. These depletion effects particularly manifest themselves in more dilute spreading solutions, with higher molecular weight polymers, and in composition regimes characterized by equilibrium degrees of aggregation that are effectively infinite. It is by understanding these various kinetic influences that the diversity of structures can be classified by the three main composition-dependent regimes.
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Affiliation(s)
- Iryna I Perepichka
- Département de Chimie, Centre de Recherche sur les Matériaux Auto-Assemblés (CRMAA/CSACS), Université de Montréal, C.P. 6128, Succursale Centre-Ville, Montréal (QC), Canada H3C 3J7
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Nanopatterning of substrates by self-assembly in supramolecular block copolymer monolayer films. Sci China Chem 2012. [DOI: 10.1007/s11426-012-4776-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Glagola CP, Miceli LM, Milchak MA, Halle EH, Logan JL. Polystyrene-poly(ethylene oxide) diblock copolymer: the effect of polystyrene and spreading concentration at the air/water interface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:5048-5058. [PMID: 22339480 DOI: 10.1021/la204100d] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Polystyrene-block-poly(ethylene oxide) (PS-PEO) is an amphiphilic diblock copolymer that undergoes microphase separation when spread at the air/water interface, forming nanosized domains. In this study, we investigate the impact of PS by examining a series of PS-PEO samples containing constant PEO (~17,000 g·mol(-1)) and variable PS (from 3600 to 200,000 g·mol(-1)) through isothermal characterization and atomic force microscopy (AFM). The polymers separated into two categories: predominantly hydrophobic and predominantly hydrophilic with a weight percent of PEO of ~20% providing the boundary between the two. AFM results indicated that predominantly hydrophilic PS-PEO forms dots while more hydrophobic samples yield a mixture of dots and spaghetti with continent-like structures appearing at ~7% PEO or less. These structures reflect a blend of polymer spreading, entanglement, and vitrification as the solvent evaporates. Changing the spreading concentration provides insight into this process with higher concentrations representing earlier kinetic stages and lower concentrations demonstrating later ones. Comparison of isothermal results and AFM analysis shows how polymer behavior at the air/water interface correlates with the observed nanostructures. Understanding the impact of polymer composition and spreading concentration is significant in leading to greater control over the nanostructures obtained through PS-PEO self-assembly and their eventual application as polymer templates.
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Affiliation(s)
- Cameron P Glagola
- Department of Chemistry, Washington & Jefferson College, Washington, Pennsylvania 15301, United States
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