In Situ Synthesis Of Block Copolymer Nano-assembly And Ag/block Copolymer Nanocomposites By Dispersion RAFT Polymerization And Dispersion ATRP Polymerization

Hollow polymeric nanotubes have the potential to be employed as advanced nanomaterials in a variety of applications.However,the reports on the synthesis of block copolymer?BCP?nanotubes were scarce so far.However,the most reports of BCP nanotubes were focus on rod-coil BCPs,chiral BCPs and linear-dendritic BCPs.The reports on the synthesis of coil-coil BCPs nanotube were scarce.In view of this,the first part of this paper investigated a new method of the synthesis of coil-coil diblock copolymer nanotubes,which is processed by RAFT dispersion polymerization in poly?ethylene glycol??PEG?.Besides,BCP nanotube was considered to be a wonderful structure to load metal-nanoparticles?NPs?because of its big specific surface area and hollow structure.However,the processes of synthesis of the metal-NPs/BCPs nanocomposites reported previously were complicated.As a result,in the second part of this paper,we afford a new method of the synthesis of tubular metal-NPs/BCPs nanocomposites by dispersion RAFT polymerization.Besides,the third part of this paper investigated a method of the synthesis of block copolymer nanoparticles,which is processed by dispersion ATRP polymerization.The details are as follow:1.In situ synthesis of coil-coil diblock copolymer nanotubes by dispersion RAFT polymerization in poly?ethylene glycol?Inthispart,arangeofblockcopolymersincluding poly?N-isopropylacrylamide?-block-polystyrene(PNIPAM₁₈-b-PS),poly?4-vinylpyridine?-block-polystyrene(P4VP₂₇-b-PS)andpoly?methyl methacrylate?-block-polystyrene(PMMA₄₆-b-PS)were achieved.As a result,different tubular morphologies are observed including single-wall nanotubes,porous nanotubes and multi-wall nanotubes.It is found that the kinetics of macro-RAFT agent PNIPAM₁₈-TTC mediated dispersion polymerization in PEG follows pseudo-first-order kinetics.And the date showed that dispersion RAFT polymerization in PEG was controlled/living radical polymerization.When the the dispersion RAFT polymerization was proceed in 80/20 methol/water mixture keeping the other condition same,the nanospheres and vesicles of PNIPAM₁₈-b-PS and P4VP₂₇-b-PS were formed.In addition,the PMMA₄₆-b-PS block copolymer with low DP of hydrophobic PS clain was synthesized,and the irregular vesicles was formed.A range of contrast experiment suggested two essential condition for synthesis of coil-coil diblock copolymer nanotubes,including the medium of PEG and the low packing parameter p.In conclusion,the method suggested in this part is valuable for synthesis of coil-coil block copolymer nanotubes.2.Synthesis of tubular Ag/polymer nanocomposites by dispersion RAFT polymerization in poly?ethylene glycol?In this part,we prepared Ag nanoparticles by hydrogen reduction process in PEG400.Next,the tubular Ag/PNIPAM-b-PS nanocomposites were synthesized by dispersion RAFT polymerization in PEG400.According to the kinetics of the polymerization,multi-wall nanotubes,porous nanotubes and pica-like nanorods were formed at different polymerization time.Comparing the morphology of PNIPAM₁₈-b-PSnano-assemblieswithoutAgnanoparticleswiththe Ag/PNIPAM₁₈-b-PS nanocomposites,it is evident that the loading of the Ag nanoparticles significantly affects the DBCP morphology.Fortunately,the polymerization still was controlled/living radical polymerization.With the increasing content of Ag nanoparticles,the morphology of Ag/PNIPAM₁₈-b-PS nanocomposites changed from nanotubes to a mixture of nanotubes and multi-wall nanotubes,which suggested that the content of Ag nanoparticles could make a difference on the morphology of Ag/PNIPAM₁₈-b-PS nanocomposites.In conclusion,the method suggested in this part is valuable for synthesis of metal-NPs/polymer anocomposites.And these tubular Ag NPs/BCP nanocomposites will find potential applications in the area of catalytic or antimicrobial.3?Synthesis of the block copolymer nanoparticles by dispersion ATRP polymerizationIn this part,the block copolymer of PEG₄₅-b-PBzMA were achieved.And the kinetics of the dispersion ATRP polymerization.This polymerization was controllable proved by GPC and ¹H NMR.As a result of TEM,different morphologies were observed including sphere,thin walled vesicles and irregular.In conclusion,the method suggested in this part is valuable for synthesis of block copolymer nanoparticles.