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

Abstract

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, 1H 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.