Strategies for Constructing Polymeric Micelles and Hollow Spheres in Solution via Specific Intermolecular Interactions

Abstract

We succeeded recently in developing a series of new pathways to polymeric micelles and hollow spheres via intermolecular specific interactions. A new micellization mechanism of block copolymers was realized by using the specific interaction between a low molecular weight compound and one of the blocks in low-polarity solvents. Many more successes have been achieved by our "block copolymer-free" strategies. We are now able to use homopolymers, random copolymers, oligomers, etc. as building blocks to construct noncovalently connected micelles (NCCM), in which the core and shell are connected by hydrogen bonding. Some of such NCCMs are readily converted further into hollow spheres by cross-linking the shell and then switching the medium to one that dissolves the core. Rigid polymer chains and their complementary homopolymers can directly assemble into large hollow spheres thanks to the propensity to parallel packing of the rigid chains. In addition, some of the NCCMs show perfect stimuli-responsive properties. pH-dependent micellization and pH-dependent micelle-hollow-sphere transition are realized in water-soluble graft copolymers driven by complexation and decomplexation between the main chain and grafts.

Controlling the thickness of hollow polymeric microspheres prepared by electrohydrodynamic atomization

“…Several techniques, such as hard template (Wu et al 2000), polymeric micelles (Chen & Jiang 2005), dynamic swelling (Okubo et al 2000) and emulsification (Utada et al 2005;Zoldesi & Imhof 2005), have been explored extensively to generate a variety of such microspheres. Various materials and liquids are used as templates for hollow spheres to provide effective control over cavity size and a highly selective etching ratio (Caruso et al 1998;Lynch et al 2005).…”

Controlled Self‐Assembly Manipulated by Charge‐Transfer Interactions: From Tubes to Vesicles

“…[1] Based on this concept, nanoscale structures can potentially be precisely manipulated by rational design and modification of the selfassembling building blocks at the molecular level. Nature has provided infinite examples which perfectly elucidate this concept.…”

Encapsulation studies and selective membrane permeability properties of self-assembly hollow nanospheres

“…1c, an obvious contrast between the central and outer part of the particles was observed for the aggregates without L-asparaginase, which is a typical of TEM images of hollow nanospheres reported for different kinds of hollow particles. [15][16][17][18][19]25 In the AFM micrograph (Fig. 1a), the aggregates without L-asparaginase also showed round outline shapes and their diameters were similar to those observed by TEM (400-500 nm).…”