Synthesis, modification and applications of polymer colloids

• Main Author: Wu, Lin
• Published: University of Leeds 2012
• Subjects: 541.345
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.581974

Three approaches were used for the preparation of polymer colloids, including block copolymer micellization, miniemulsion and dispersion polymerisation. Polymers, ego PDMAEMA, PDMAEMA-b-PBMA, P(PDMA-PS)4, P(PS-PDMA)4, involved in the preparation were synthesized using reversible addition fragmentation chain transfer (RAFT) polymerisation. The details of each approach are given below. In the first approach, well-defined amphiphilic star block copolymers, P-(PS- PDMA)4 and P-(PDMA-PS)4 (P: porphyrin) were prepared from a free base porphyrin-cored chain transfer agent (CTA-FBP) and used for self-assembly studies. In methanol, a selective solvent for PDMA, spherical micelles were observed for both block copolymers, as characterized by TEM. UV-VIS studies suggested that star-like micelles were formed from P-(PS-PDMA)4, while P-(PDMA-PS)4 aggregated into flower-like micelles. In the second approach, miniemulsions, prepared using PDMAEMA-b-PBMA or PDMAEMA polymers were used as templates for the synthesis of polymer nanocapsules via the quaternization cross-linking of PDMAEMA (block), using 1, 2- bis(2-iodoethoxy)ethane (BIEE) as a bifunctional crosslinker. The miniemulsion prepared from block copolymers of PDMAEMA-b-PBMA were used as templates for the synthesis of Prussian Blue nanoshells, while cross-linked PDMAEMA homopolymer miniemulsions were used as capsules for hydrophobic dyes. In the last approach, PDMS-CTAs (poly(dimethylsiloxane)-based chain transfer agents) were prepared and used as stabilizers in the dispersion polymerisation of methyl methacrylate (MMA) in hexane. The effect of several factors, including the molecular weight of the PDMS and the concentration of the initiator, on the MMA polymerisation was investigated. The kinetics of the polymerisation in the presence of two CTAs were also investigated.