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Zhang C, Gao L, Lin J, Wang L. Hierarchical 2D-1D micelles self-assembled from the heterogeneous seeded-growth of rod-coil block copolymers. NANOSCALE 2023; 15:1412-1421. [PMID: 36594400 DOI: 10.1039/d2nr05618f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Precise control of size and dimension is the key to constructing complex hierarchical nanostructures, particularly multi-dimensional hybrid nanoassemblies. Herein, we conducted Brownian dynamics simulations to examine the seeded-growth of rod-coil block copolymer assemblies and discovered that 2D-1D (disk-cylinder) hybrid micelles could be formed via liquid-crystallization-driven self-assembly (LCDSA). 2D nanodisk micelles with smectic-like LC cores served as seeds. After adding rod-coil block copolymers into the seed solution, the copolymers incorporated onto the 2D seed edges to generate junction points. Several cylindrical arms were formed from the elongation of junction points, resulting in 2D-1D multi-dimensional hybrid micelles. The structural transition of the micelle core from smectic-like (disk) to cholesteric-like (cylindrical arms) LC packing manners benefit from the fluidity of LC. Such a seeded-growth behavior simultaneously exhibits the features of heterogeneous nucleation and homogenous epitaxy growth. Intriguingly, the arms generate in sequence, and its junction position is in the para-position first, followed by ortho-position or meta-position, resembling the difference in the substituent activities on the benzene ring. These theoretical findings are consistent with experimental results, and provide explanations to some unaddressed issues in experiments. The obtained results also reveal that the hybrid micelles are a good stabilizer due to their high surface area and distinctive suspension behaviors.
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Affiliation(s)
- Chengyan Zhang
- Shanghai Key Laboratory of Advanced Polymeric Materials, Key Laboratory for Ultrafine Materials of Ministry of Education, Frontiers Science Center for Materiobiology and Dynamic Chemistry, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237, China.
| | - Liang Gao
- Shanghai Key Laboratory of Advanced Polymeric Materials, Key Laboratory for Ultrafine Materials of Ministry of Education, Frontiers Science Center for Materiobiology and Dynamic Chemistry, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237, China.
| | - Jiaping Lin
- Shanghai Key Laboratory of Advanced Polymeric Materials, Key Laboratory for Ultrafine Materials of Ministry of Education, Frontiers Science Center for Materiobiology and Dynamic Chemistry, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237, China.
| | - Liquan Wang
- Shanghai Key Laboratory of Advanced Polymeric Materials, Key Laboratory for Ultrafine Materials of Ministry of Education, Frontiers Science Center for Materiobiology and Dynamic Chemistry, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237, China.
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Yang K, Cao Y, Zhang Y, Fan S, Tang M, Aberg D, Sadigh B, Zhou F. Self-supervised learning and prediction of microstructure evolution with convolutional recurrent neural networks. PATTERNS (NEW YORK, N.Y.) 2021; 2:100243. [PMID: 34036288 PMCID: PMC8134942 DOI: 10.1016/j.patter.2021.100243] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Revised: 03/02/2021] [Accepted: 03/30/2021] [Indexed: 12/18/2022]
Abstract
Microstructural evolution is a key aspect of understanding and exploiting the processing-structure-property relationship of materials. Modeling microstructure evolution usually relies on coarse-grained simulations with evolution principles described by partial differential equations (PDEs). Here we demonstrate that convolutional recurrent neural networks can learn the underlying physical rules and replace PDE-based simulations in the prediction of microstructure phenomena. Neural nets are trained by self-supervised learning with image sequences from simulations of several common processes, including plane-wave propagation, grain growth, spinodal decomposition, and dendritic crystal growth. The trained networks can accurately predict both short-term local dynamics and long-term statistical properties of microstructures assessed herein and are capable of extrapolating beyond the training datasets in spatiotemporal domains and configurational and parametric spaces. Such a data-driven approach offers significant advantages over PDE-based simulations in time-stepping efficiency and offers a useful alternative, especially when the material parameters or governing PDEs are not well determined.
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Affiliation(s)
- Kaiqi Yang
- Department of Materials Science and NanoEngineering, Rice University, Houston, TX 77005, USA
| | - Yifan Cao
- Department of Materials Science and NanoEngineering, Rice University, Houston, TX 77005, USA
| | - Youtian Zhang
- Department of Materials Science and NanoEngineering, Rice University, Houston, TX 77005, USA
| | - Shaoxun Fan
- Department of Materials Science and NanoEngineering, Rice University, Houston, TX 77005, USA
| | - Ming Tang
- Department of Materials Science and NanoEngineering, Rice University, Houston, TX 77005, USA
| | - Daniel Aberg
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA 94550, USA
| | - Babak Sadigh
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA 94550, USA
| | - Fei Zhou
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA 94550, USA
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Berlepsch HV, Thota BNS, Wyszogrodzka M, de Carlo S, Haag R, Böttcher C. Controlled self-assembly of stomatosomes by use of single-component fluorinated dendritic amphiphiles. SOFT MATTER 2018; 14:5256-5269. [PMID: 29888366 DOI: 10.1039/c8sm00243f] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
A series of novel non-ionic amphiphiles with dendritic oligoglycerol head groups of different generations ([G1]-[G3]) and lipophilic/fluorophilic tail segments, comprising single or double tail alkyl chains, C8F17-perfluoro rod segments as well as flexible spacer groups of different lengths were designed and synthesized. We expected that the differences in the size of the dendritic head groups in combination with perfluorinated segments would have an impact on the supramolecular structures formed in aqueous solution if compared with the hydrogenated analogues. Investigating the self-assembly behavior mainly by cryogenic transmission electron microscopy (cryo-TEM) and cryo-electron tomography (cryo-ET) we found as a new result the formation of perforated bilayer vesicles (stomatosomes) and bicontinuous network structures. Surprisingly, we have observed stomatosome formation by self-assembly of single component fluorinated dendritic amphiphiles. These assembly structures turned out to be extremely robust against harsh conditions, although there are strong indications that they represent non-equilibrium structures, which eventually transform into a bicontinuous cubic network structure of double diamond symmetry. In general, the molecular asymmetry of amphiphiles tuned by chemical design induced the expected trend from spherical micelles through worm-like micelles to perforated bilayers and three-dimensional network structures.
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Affiliation(s)
- H V Berlepsch
- Forschungszentrum für Elektronenmikroskopie, Institut für Chemie und Biochemie, Freie Universität Berlin, Fabeckstraße 36a, 14195 Berlin, Germany.
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Asgari M. Micro-mechanical, continuum-mechanical, and AFM-based descriptions of elasticity in open cylindrical micellar filaments. SOFT MATTER 2017; 13:7112-7128. [PMID: 28858368 PMCID: PMC5636689 DOI: 10.1039/c7sm00911a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We present theoretical and experimental descriptions of the elasticity of cylindrical micellar filaments using micro-mechanical and continuum theories, and atomic force microscopy. Following our micro-mechanical elasticity model for micellar filaments [M. Asgari, Eur. Phys. J. E: Soft Matter Biol. Phys., 2015, 38(9), 1-16], the elastic bending energy of hemispherical end caps is found. The continuum description of the elastic bending energy of a cylindrical micellar filament is also derived using constrained Cosserat rod theory. While the continuum approach provides macroscopic description of the strain energy of the micellar filament, the micro-mechanical approach has a microscopic view of the filament, and provides expressions for kinetic variables based on a selected interaction potential between the molecules comprising the filament. Our model predicts the dependence of the elastic modulus of the micellar filaments on their diameter, which agrees with previous experimental observations. Atomic force microscopy is applied to estimate the elastic modulus of the filaments using force volume analysis. The obtained values of elastic modulus yield the persistence length of micellar filaments on the same order of the previously reported values. Consistent with previous studies, our results indicate that semi-flexible linear micelles have a relatively large local strain energy at their end points, which explains their tendency to fuse to minimize the number of end caps at relatively low total surfactant volume fractions. Also, the elastic modulus of micellar filaments was found to increase when the indentation frequency increases, a finding which agrees with previous rheological observations on the bulk shear modulus of micellar solutions.
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Affiliation(s)
- Meisam Asgari
- Department of Mechanical Engineering, McGill University, 817 Sherbrooke Street West, Montreal, QC H3A 0C3, Canada.
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Asgari M. A molecular model for the free energy, bending elasticity, and persistence length of wormlike micelles. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2015; 38:98. [PMID: 26362658 DOI: 10.1140/epje/i2015-15098-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Revised: 07/15/2015] [Accepted: 08/05/2015] [Indexed: 06/05/2023]
Abstract
An expression for the elastic free-energy density of a wormlike micelle is derived taking into account interactions between its constituent molecules. The resulting expression is quadratic in the curvature and torsion of the centerline of micelle and thus resembles free-energy density functions for polymer chains and helical filaments such as DNA. The model is applied on a wormlike micelle in the shape of a circular arc, open or closed. Conditions under which linear chains in dilute systems transform into toroidal rings are analyzed. Two concrete anisotropic soft-core interaction potentials are used to calculate the elastic moduli present in the derived model, in terms of the density of the molecules and their dimensions. Expressions for the persistence length of the wormlike micelle are found based on the flexural rigidities so obtained. Similar to previous observations, our results indicate that the persistence length of a wormlike micelle increases as the aspect ratio of its constituent molecules increases. A detailed application of the model on wormlike micelles of toroidal geometry, along with employing statistical-thermodynamical concepts of self-assembly is performed, and the results are found to be well consistent with the literature. Steps to obtain the material parameters through possible experiments are discussed.
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Affiliation(s)
- Meisam Asgari
- Department of Mechanical Engineering, McGill University, 817 Sherbrooke Street West, H3A0C3, Montreal, QC, Canada.
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Rheological behavior of mixed system of ionic liquid [C8mim]Br and sodium oleate in water. Front Chem Sci Eng 2015. [DOI: 10.1007/s11705-015-1511-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Qiu H, Gao Y, Du VA, Harniman R, Winnik MA, Manners I. Branched Micelles by Living Crystallization-Driven Block Copolymer Self-Assembly under Kinetic Control. J Am Chem Soc 2015; 137:2375-85. [DOI: 10.1021/ja5126808] [Citation(s) in RCA: 90] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Huibin Qiu
- School
of Chemistry, University of Bristol, Bristol BS8 1TS, United Kingdom
| | - Yang Gao
- School
of Chemistry, University of Bristol, Bristol BS8 1TS, United Kingdom
| | - Van An Du
- School
of Chemistry, University of Bristol, Bristol BS8 1TS, United Kingdom
| | - Rob Harniman
- School
of Chemistry, University of Bristol, Bristol BS8 1TS, United Kingdom
| | - Mitchell A. Winnik
- Department
of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6, Canada
| | - Ian Manners
- School
of Chemistry, University of Bristol, Bristol BS8 1TS, United Kingdom
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Singh K, O'Toole Z, McLachlan A, Marangoni DG. Nonaromatic hydrotropic cationic ammonium salts as a rheology modifier for an anionic/zwitterionic surfactant mixture. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:3673-3680. [PMID: 24625067 DOI: 10.1021/la404631u] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
In this article, we report additive-induced micellar growth and rheology modification for mixtures of anionic (sodium dodecyl sulfate, SDS) and zwitterionic (N-alkylated glycine derivative, Empigen BB or EBB) surfactants. Two nonaromatic hydrotropic salts (hexyltrimethylammonium bromide, C6TAB, and/or dibutylenebis(dimethylbutylammonium bromide), 4-4-4) are used as novel additives to induce micellar growth in these systems. Nuclear magnetic resonance (NMR), photon correlation spectroscopy (PCS), transmission electron microscopy (TEM), the Weissenberg effect, and rheology measurements were employed to assess mixed micelle formation, micellar growth, and rheology modifications. Finally, the manner in which the surfactants and hydrotropes self-assemble into aggregates has also been deduced from 2D NMR NOESY measurements. In this study, both hydrotropic ions have been found to contribute to similar structural modifications in the mixed micelles of the anionic and zwitterionic surfactants. However, the extent of the rheology modification in solution is found to be quite different when the gemini hydrotrope (4-4-4) versus the monomeric hydrotrope (C6TAB) is employed.
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Affiliation(s)
- Kulbir Singh
- Department of Chemistry, St. Francis Xavier University , Antigonish, Nova Scotia, B2G 2W5 Canada
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Disclike vs. cylindrical micelles: Generalized model of micelle growth and data interpretation. J Colloid Interface Sci 2014; 416:258-73. [DOI: 10.1016/j.jcis.2013.11.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2013] [Revised: 11/03/2013] [Accepted: 11/06/2013] [Indexed: 11/18/2022]
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Kralchevsky PA, Danov KD, Anachkov SE, Georgieva GS, Ananthapadmanabhan KP. Extension of the ladder model of self-assembly from cylindrical to disclike surfactant micelles. Curr Opin Colloid Interface Sci 2013. [DOI: 10.1016/j.cocis.2013.11.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Qiu H, Du VA, Winnik MA, Manners I. Branched Cylindrical Micelles via Crystallization-Driven Self-Assembly. J Am Chem Soc 2013; 135:17739-42. [DOI: 10.1021/ja410176n] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Huibin Qiu
- School
of Chemistry, University of Bristol, Bristol BS8 1TS, United Kingdom
| | - Van An Du
- School
of Chemistry, University of Bristol, Bristol BS8 1TS, United Kingdom
| | - Mitchell A. Winnik
- Department
of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6, Canada
| | - Ian Manners
- School
of Chemistry, University of Bristol, Bristol BS8 1TS, United Kingdom
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α-helical structures drive early stages of self-assembly of amyloidogenic amyloid polypeptide aggregate formation in membranes. Sci Rep 2013; 3:2781. [PMID: 24071712 PMCID: PMC3784961 DOI: 10.1038/srep02781] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2013] [Accepted: 09/03/2013] [Indexed: 12/17/2022] Open
Abstract
The human islet amyloid polypeptide (hIAPP) is the primary component in the toxic islet amyloid deposits in type-2 diabetes. hIAPP self-assembles to aggregates that permeabilize membranes and constitutes amyloid plaques. Uncovering the mechanisms of amyloid self-assembly is the key to understanding amyloid toxicity and treatment. Although structurally similar, hIAPP's rat counterpart, the rat islet amyloid polypeptide (rIAPP), is non-toxic. It has been a puzzle why these peptides behave so differently. We combined multiscale modelling and theory to explain the drastically different dynamics of hIAPP and rIAPP: The differences stem from electrostatic dipolar interactions. hIAPP forms pentameric aggregates with the hydrophobic residues facing the membrane core and stabilizing water-conducting pores. We give predictions for pore sizes, the number of hIAPP peptides, and aggregate morphology. We show the importance of curvature-induced stress at the early stages of hIAPP assembly and the α-helical structures over β-sheets. This agrees with recent fluorescence spectroscopy experiments.
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