Synthesis and characterization of multi stimuli-responsive block copolymer-silica hybrid nanocomposite with core-shell structure via RAFT polymerization

摘要

A novel multi stimuli-responsive silica nanocomposite with a core-shell structure is synthesized using reversible addition-fragmentation chain transfer (RAFT) polymerization. The SiO2 nanoparticles are chemically modified via 3-(trimethoxylsilyl) propyl methacrylate (MPS) which they are used in the core of nanocomposite. The macro-RAFT agent is prepared by RAFT polymerization of N-isopropylacrylamide (NIPAM), spirooxazine acryloyl monomer (SOM), and 2-(dodecylthiocarbonothioylthio)-2-methylpropionic acid (DDMAT as a RAFT agent). Finally, the smart nanocomposite is prepared by reaction between the macro-RAFT agent and 2-(Dimethylamino) ethyl methacrylate (DMAEMA) as a monomer. SOM as a photochromic monomer, DMAEMA and NIPAM as temperature and pH sensitive were used in the synthesized nanocomposite. The finally smart nanocomposite was characterized by using FT-IR, H-1 NMR, UV-Vis, GPC, DLS, and TEM techniques. The responsiveness of synthesized smart nanocomposite in different conditions (UV-Vis light, pH, temperature and the combination of pH and temperature) was investigated. The results show that the fabricated smart nanocomposite are good candidate nanomaterials for sensors application.