Shape Transition of Block Copolymer/Gold Nanoparticles Hybrid Vesicles under UV-Irradiation

Shape-changeable inorganic/organic hybrid particles in response to light stimulus have received great interest due to their potential applications in sensors and catalysis. However, the light-induced precise shape transition of hybrid block copolymer/inorganic nanoparticles (BCP/NPs) particles remains a considerable challenge. Herein, the light-responsive hybrid BCP/NPs vesicles are fabricated by introducing PS tethered gold nanoparticles (AuNPs@PS) into polystyrene-o-nitrobenzyl ester-polyethylene oxide (PS-o-NBE-PEO) scaffolds. Upon UV irradiation, the hybrid PS-o-NBE-PEO /NPs vesicles incorporated with smaller AuNPs can transform into hybrid porous spherical particles due to the photocleavage of the o-NBE bond in PS-o-NBE-PEO scaffolds. Besides, attributed to the difference in conformational entropy loss of the BCP/AuNPs co-assembly system, the eventual distribution of AuNPs and the correspondingly shape-converted degree of BCP/NPs assemblies depends on the size of NPs. Furthermore, hybrid BCP/AuNPs and BCP/PtNPs assemblies can be prepared by the in situ reduction of metal precursors in BCP templates. Thus, light-responsive hybrid BCP/NPs particles with various internal structures are generated and the adjustable shape transformation of hybrid BCP/NPs particles is realized by UV stimulus, the obtained results open a unique and promising route to fabricate smart materials.