From toroidal to rod‐like nanostructure, a mechanism study for the reversible morphological control on amphiphilic triblock copolymer micelles

Abstract

Mechanism of the morphological changes between toroidal and rod‐like nanostructures of P4VP‐b‐PS‐b‐P4VP amphiphilic triblock copolymer micelles has been investigated in aqueous solution. This transition is proved to be highly reversible and tunable upon changing temperature. The toroidal structure, evolving from fibers at 20 °C, can transform to rod‐like morphology as the temperature either gradually or directly increases to 80 °C, and vice versa. However, the transition mechanisms are quite different in different temperature‐changing processes. The structure and thickness of the micelles are dependent on the specific temperature, whereas the transition mechanism is related to the method of the temperature change. These morphological changes are considered as a result from the interaction parameter between the solvent and the copolymer blocks, especially the hydrophobic block. Our research complements the external control over the reversible morphological transition of block copolymer micelles without changing the composition of the system or introducing additional influencing factors. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016, 54, 1450–1457

Nonionic Amphiphilic Linear Dendritic Block Copolymers. Solvent-Induced Self-Assembly and Morphology Tuning

“…Amphiphilic block copolymers are giant analogues of low molecular mass surfactants and as such are drawing increased attention for the preparation of nanosized materials with desirable exploitation characteristics. In block-selective solutions, they could organize into a broad range of structures including spheres, cylinders, lamellae, vesicles, 1−4 toroids, 5,6 and other more complex morphologies. 7,8 These supramolecular particles are not only more stable compared to those derived from common surfactants but are also more chemically tunable thus providing more functionality and application versatility.…”

“…Amphiphilic block copolymers are giant analogues of low molecular mass surfactants and as such are drawing increased attention for the preparation of nanosized materials with desirable exploitation characteristics. In block-selective solutions, they could organize into a broad range of structures including spheres, cylinders, lamellae, vesicles, − toroids, , and other more complex morphologies. , These supramolecular particles are not only more stable compared to those derived from common surfactants but are also more chemically tunable thus providing more functionality and application versatility. By replacing one block of the traditional linear–linear copolymer with a dendritic unit, the resulting linear–dendritic block copolymers (LDBCs) provide an attractive alternative to traditional self-assembling materials. , The amphiphilic dendritic poly­(benzyl ether)- block -poly­(ethylene glycol) or PBE–PEG LDBCs, prepared by the “coupling” strategy were forming unimolecular or multimolecular micelles in methanol and water mixtures depending on the polymer concentration and dendron generation .…”

Unexpected toroidal micelles formed from St/MMA gradient copolymers

“…1 So far, toroidal micelles have been seldom reported in some specific systems. [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] Initially, toroidal micelles were only formed from triblock copolymers. Pochan et al 2,3 constructed toroidal morphology in an ABC triblock copolymer system with the addition of a divalent organic counterion.…”

Amphiphilic Poly(dimethylsiloxane-ethylene-propylene oxide)-polyisocyanurate Cross-Linked Block Copolymers in a Membrane Gas Separation

“…Block copolymers, including multiblock copolymers of an amphiphilic nature, are currently attracting research efforts due to their ability to form various supramolecular structures [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 ]. The direct influence on the supramolecular organization of block copolymers is a way of controlling both the mechanical and physicochemical properties of polymer materials obtained on this basis.…”