Hybrid Nanoscale Vesicles of Polyhedral Oligomeric Silsesquioxane-Based Star Block Copolymers for Thermal Insulation Applications

Abstract

Organic–inorganic hybrid vesicles of the polyhedral oligomeric silsesquioxane (POSS)-based star block copolymer of poly­(N-isopropylacrylamide)-block-polystyrene [POSS-(PNIPAM-b-PS)8] were synthesized by polymerization-induced self-assembly via reversible addition–fragmentation chain transfer (RAFT) polymerization employing a POSS-based macromolecular chain transfer agent. The average diameter, the membrane thickness, and the cavity volume fraction of the POSS-(PNIPAM-b-PS)8 vesicles are 212 nm, 21 nm, and 52%, respectively. The POSS-(PNIPAM-b-PS)8 vesicles exhibit good thermal stability and have 12% higher Young’s modulus than the vesicles of linear block copolymer counterparts. Due to the high mechanical strength, the POSS-(PNIPAM-b-PS)8 vesicles can keep structural integrity in the dried state. The coating of the POSS-(PNIPAM-b-PS)8 vesicles is prepared by casting the dispersion of the star block copolymer vesicles at room temperature, and then, its application as a thermal insulation coating is investigated. It is found that the POSS-(PNIPAM-b-PS)8 vesicles can be used as qualified thermal insulation materials with the thermal conductivity as low as 0.131 W/m·K.

Mechanoresponsive Drug Delivery Systems for Vascular Diseases

“…[65] Polymers can either be coated on the liposome's surface or partially integrated within the composition. [66] A complete replacement of lipids with block copolymers will result in polymer-based vesicles or polymersomes, which are generally regarded as more stable and relatively rigid, thus more resistant against mechanical forces. [67] Disorder of the membrane due to mechanical stress is mathematically translated to a lower melting temperature, which means under identical environmental conditions, the bilayer will be more unstable.…”

“…[ 65 ] Polymers can either be coated on the liposome's surface or partially integrated within the composition. [ 66 ] A complete replacement of lipids with block copolymers will result in polymer‐based vesicles or polymersomes, which are generally regarded as more stable and relatively rigid, thus more resistant against mechanical forces. [ 67 ]…”

Preparation of diblock copolymer nano-assemblies by ultrasonics assisted ethanol-phase polymerization-induced self-assembly

“…To address these issues, the PISA method was developed. It can directly prepare diblock copolymer nanoparticles with controllable morphology [24] , [25] , [26] , [27] , [28] , [29] , [30] , [31] , [32] , [33] , [34] , [35] , [36] , [37] , [38] , [39] , [40] , [41] , [42] , [43] , [44] , [45] , and high concentration (50 wt%), offering the advantages of simplicity, efficiency, and repeatability. With the advancement of PISA, initiation is no longer limited to thermal methods, leading to the emergence of greener and more energy-efficient initiation mechanisms and supportive methods.…”

Single-step synthesis of prominently selective and easily regenerable POSS functionalized with high loadings of sulfur and carboxylic acids

“…The modications to the organic periphery enable easy attachment of various functional moieties, leading to enhanced efficacy of functionalized POSS for potential applications. [25][26][27][28][29][30] Therefore, the ease of peripheral and single-step structural modication represents a signicant advancement in increasing the efficacy of the fabrication process, the binding sites, and the overall sorbent performance.…”