Preparation And Applications Of Nanoaggregates With Complex Morphologies Via Polymerization-induced Self-assembly

Polymerization induced self-assembly(PISA)is a promising strategy for the preparation of polymeric nanoaggregates with different morphologies(e.g.,spheres,worms,vesicles)in one pot.It thus has become a very effective method of producing polymeric nanomaterials in large quantities.During the past several years,lots of effort has been paid to reveal the polymerization mechanism of PISA,as well as the morphological evolution and regulation of nanoaggregates.However,it is rarely reported on how to utilize the advanteges of PISA nanoaggregates for further construction of functional nanomaterials with complex morphologies,so as to realize and broaden the application fields of polymeric nanomaterials.In this thesis,core-crosslinked worm-like and vesicle-like nanoaggregates were firstly prepared through RAFT-PISA,then anisotropic Janus nanoparticles were produced via seeded dispersion polymerization,using the core-crosslinked vesicles as seeds;soap-free emulsion polymerization system and high internal phase emulsion were experimentally constructed through the introduction of interfacial stabilization by worm-like nanoaggregates,resulting in monodisperse polystyrene microspheres and ultralight aerogel materials;hydrogels of selective dye adsorption capabilities were successfully prepared by secondary crosslinking.The main contents and results are as follows:(1)Janus nanoparticles with different morphologies such as snowman,dumbbell and strawberry,have been prepared through seeded dispersion polymerization by using cross-linked vesicles prepared from RAFT-PISA as the seeds.Through the regulation of the cross-linking degree of vesicle seeds,the adding amount of monomer and initiator,the morphology of Janus nanoparticles could be precisely controlled.(2)Stable styrene/water soap-free Pickering emulsion system has been successfully constructed,as stabilized by the worm-like nanoaggregates prepared by RAFT-PISA.Free radical polymerization further led to the successful production of monodispersed polystyrene microspheres with well-defined particle sizes.(3)The first Pickering high internal phase emulsion(HIPE)system stabilized solely by core-crosslinked worm-like nanoaggregates has been successfully developed via one-step homogenization.The effects of the types and volume of internal phase,as well as the worm concentration on the stability of the resulting Pickering HIPEs were thoroughly investigated.Furthermore,by adding a small amount of silica nanoparticles or magnetic nanoparticles as the binder in the continuous aqueous phase,followed by freeze-drying,3D hierarchical porous monoliths of ultralow density were successfully prepared.(4)A multi interpenetrating network crosslinked hydrogel has been constructed from core-crosslinked worm-like nanoaggregates,by using dibromohexane as the secondary crosslinker.The effects of polymer concentration and adding amount of crosslinker on the mechanical properties of hydrogels were investigated.Selective dye adsorption performance of hydrogels,as well as their separation capability of mixed dyes were further study.