Nanoparticle-Loaded Cylindrical Micelles from Nanopore Extrusion of Block Copolymer Spherical Micelles

2013 ◽  
Vol 34 (23-24) ◽  
pp. 1850-1855 ◽  
Author(s):  
Qianjin Chen ◽  
Jianqi Wang ◽  
Lei Shao
Keyword(s):  
Block Copolymer ◽  
Cylindrical Micelles ◽  
Spherical Micelles

Structure and Dynamics of Spherical and Rodlike Alkyl Ethoxylate Surfactant Micelles Investigated Using NMR Relaxation and Atomistic Molecular Dynamics Simulations

2019 ◽  
Author(s):  
Allison Edwards ◽  
Abdolreza Javidialesaadi ◽  
Katie Weigandt ◽  
George Stan ◽  
Charles Eads
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Nmr Relaxation ◽  
Cross Relaxation ◽  
Relaxation Rates ◽  
Surfactant Micelles ◽  
Cylindrical Micelles ◽  
Spherical Micelles ◽  
Dynamics Simulations ◽  
Relative Motions

We study molecular arrangements and dynamics in alkyl ethoxylate nonionic surfactant micelles by combining high field (600 and 700 MHz) NMR relaxation measurements with large-scale atomistic molecular dynamics simulations. For spherical micelles, but not for cylindrical micelles, cross relaxation rates are positive only for surfactant alkyl tail atoms connected to the hydrophilic head group. All cross relaxation rates are negative for cylindrical micelles. This effect is reproducible either by changing composition (ratios of the nonionic surfactants) or changing temperature of a single surfactant in order to change the micelle shape. We validate the micelle shape by SANS and use the results as a guide for our simulations. We calculate parameters that determine relaxation rates directly from simulated trajectories, without introducing specific functional forms. Results indicate that relative motions of nearby atoms are liquid-like, in agreement with 13C T1 measurements, though constrained by micelle morphology. Relative motions of distant atoms have slower components because the relative changes in distances and angles are smaller when the moving atoms are further apart. The slow, long-range motions appear to be responsible for the predominantly negative cross relaxation rates observed in NOESY spectra. The densities of atoms from positions 1 and 2 in the boundary region are lower in spherical micelles compared to cylindrical micelles. Correspondingly, motions in this region are less constrained by micelle morphology in the spherical compared to the cylindrical cases. The two effects of morphology lead to the unusual occurrence of positive cross relaxation involving positions 1 and 2 for spheres.

Complex Spherical Micelles in A−B−C-Block Copolymer Melts

1997 ◽  
Vol 30 (7) ◽  
pp. 1980-1991 ◽  
Author(s):  
E. E. Dormidontova ◽  
A. R. Khokhlov
Keyword(s):  
Block Copolymer ◽  
Copolymer Melts ◽  
Spherical Micelles

Mechanism for Transition of Reverse Cylindrical Micelles to Spherical Micelles Induced by Diverse Alcohols

Langmuir ◽  
2020 ◽  
Vol 36 (28) ◽  
pp. 8174-8183
Author(s):  
Hwa-Jin Lee ◽  
Hyun-Jin Kim ◽  
Da-Gyun Park ◽  
Kyeong Sik Jin ◽  
Ji Woong Chang ◽  
...  
Keyword(s):  
Cylindrical Micelles ◽  
Spherical Micelles

Structure and Dynamics of Spherical and Rodlike Alkyl Ethoxylate Surfactant Micelles Investigated Using NMR Relaxation and Atomistic Molecular Dynamics Simulations

2019 ◽  
Author(s):  
Allison Edwards ◽  
Abdolreza Javidialesaadi ◽  
Katie Weigandt ◽  
George Stan ◽  
Charles Eads
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Nmr Relaxation ◽  
Cross Relaxation ◽  
Relaxation Rates ◽  
Surfactant Micelles ◽  
Cylindrical Micelles ◽  
Spherical Micelles ◽  
Dynamics Simulations ◽  
Relative Motions

We study molecular arrangements and dynamics in alkyl ethoxylate nonionic surfactant micelles by combining high field (600 and 700 MHz) NMR relaxation measurements with large-scale atomistic molecular dynamics simulations. For spherical micelles, but not for cylindrical micelles, cross relaxation rates are positive only for surfactant alkyl tail atoms connected to the hydrophilic head group. All cross relaxation rates are negative for cylindrical micelles. This effect is reproducible either by changing composition (ratios of the nonionic surfactants) or changing temperature of a single surfactant in order to change the micelle shape. We validate the micelle shape by SANS and use the results as a guide for our simulations. We calculate parameters that determine relaxation rates directly from simulated trajectories, without introducing specific functional forms. Results indicate that relative motions of nearby atoms are liquid-like, in agreement with 13C T1 measurements, though constrained by micelle morphology. Relative motions of distant atoms have slower components because the relative changes in distances and angles are smaller when the moving atoms are further apart. The slow, long-range motions appear to be responsible for the predominantly negative cross relaxation rates observed in NOESY spectra. The densities of atoms from positions 1 and 2 in the boundary region are lower in spherical micelles compared to cylindrical micelles. Correspondingly, motions in this region are less constrained by micelle morphology in the spherical compared to the cylindrical cases. The two effects of morphology lead to the unusual occurrence of positive cross relaxation involving positions 1 and 2 for spheres.

Functional micelles formed from glucose-, thermo- and pH-triple responsive copolymers for controlled release

2017 ◽  
Vol 8 (33) ◽  
pp. 4869-4877 ◽  
Author(s):  
Hui Zou ◽  
Chunyao Wang ◽  
Weizhong Yuan ◽  
Shanfeng Wang ◽  
Maoquan Li
Keyword(s):  
Controlled Release ◽  
Block Copolymer ◽  
Spherical Micelles ◽  
Self Assembled

Spherical micelles self-assembled from the block copolymer PPBDEMA-b-PDMAEMA presented glucose, thermo- and pH-triple responsive properties.

scholarly journals Fusion and clustering of spherical micelles by extruding through a cylindrical channel

RSC Advances ◽  
2019 ◽  
Vol 9 (42) ◽  
pp. 24394-24400
Author(s):  
Manman Chen ◽  
Xinghua Zhang ◽  
Hui Zhang
Keyword(s):  
Cylindrical Channel ◽  
Cylindrical Micelles ◽  
Spherical Micelles

Experiments have shown that worm-like cylindrical micelles can be obtained by extruding spherical micelles through a cylindrical channel.

Size effects of self-assembled block copolymer spherical micelles and vesicles on cellular uptake in human colon carcinoma cells

2014 ◽  
Vol 2 (19) ◽  
pp. 2883-2891 ◽  
Author(s):  
Teddy Chang ◽  
Megan S. Lord ◽  
Björn Bergmann ◽  
Alex Macmillan ◽  
Martina H. Stenzel
Keyword(s):  
Block Copolymer ◽  
Size Effects ◽  
Raft Polymerization ◽  
Human Colon ◽  
Carcinoma Cells ◽  
Colon Carcinoma Cells ◽  
Human Colon Carcinoma ◽  
Spherical Micelles ◽  
Self Assembled ◽  
Glycol Methyl Ether

Block copolymers, poly(oligo ethylene glycol methyl ether methacrylate)-block-poly(styrene), POEGMEMA-b-PS, with various block lengths were prepared via RAFT polymerization and subsequently self-assembled into various aggregates to investigate their uptake ability into cancer cells.

From Spherical Micelles to Hexagonally Packed Cylinders: The Cure Cycle Determines Nanostructures Generated in Block Copolymer/Epoxy Blends

2013 ◽  
Vol 46 (12) ◽  
pp. 4854-4861 ◽  
Author(s):  
Hernán E. Romeo ◽  
Ileana A. Zucchi ◽  
Maite Rico ◽  
Cristina E. Hoppe ◽  
Roberto J. J. Williams
Keyword(s):  
Block Copolymer ◽  
Cure Cycle ◽  
Spherical Micelles ◽  
Epoxy Blends

scholarly journals Computational Investigations of a pH-Induced Structural Transition in a CTAB Solution with Toluic Acid

Molecules ◽  
2021 ◽  
Vol 26 (22) ◽  
pp. 6978
Author(s):  
Tingyi Wang ◽  
Hui Yan ◽  
Li Lv ◽  
Yingbiao Xu ◽  
Lingyu Zhang ◽  
...  
Keyword(s):  
Electrostatic Interactions ◽  
Carboxyl Groups ◽  
Electrostatic Repulsion ◽  
Structural Transitions ◽  
Density Distributions ◽  
Cylindrical Micelles ◽  
Spherical Micelles ◽  
Aqueous Surfactants ◽  
Dynamics Simulations ◽  
Almost All

In this work, molecular dynamics simulations were performed to study the pH-induced structural transitions for a CTAB/p-toluic acid solution. Spherical and cylindrical micelles were obtained for aqueous surfactants at pH 2 and 7, respectively, which agrees well with the experimental observations. The structural properties of two different micelles were analyzed through the density distributions of components and the molecular orientations of CTA+ and toluic acid inside the micelles. It was found that the bonding interactions between CTA+ and toluic in spherical and cylindrical micelles are very different. Almost all the ionized toluic acid (PTA−) in the solution at pH 7 was solubilized into the micelles, and it was located in the CTA+ headgroups region. Additionally, the bonding between surfactant CTA+ and PTA− was very tight due to the electrostatic interactions. The PTA− that penetrated into the micelles effectively screened the electrostatic repulsion among the cationic headgroups, which is considered to be crucial for maintaining the cylindrical micellar shape. As the pH decreased, the carboxyl groups were protonated. The hydration ability of neutral carboxyl groups weakened, resulting in deeper penetration into the micelles. Meanwhile, their bonding interactions with surfactant headgroups also weakened. Accompanied by the strengthen of electrostatic repulsion among the positive headgroups, the cylindrical micelle was broken into spherical micelles. Our work provided an atomic-level insights into the mechanism of pH-induced structural transitions of a CTAB/p-toluic solution, which is expected to be useful for further understanding the aggregate behavior of mixed cationic surfactants and aromatic acids.

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