Synthesis And Properties Of Stimuli-responsive Organosilicon Hybrid Nanoparticles

External stimuli cause changes in the responsive nanoparticles properties, dimensions, structure, and interactions and lead to their rearrangement or changes in their aggregation state. Responsive nanoparticles have potential application in oil recovery, sensor and drug delivery because of their unique physical and chemical properties. Poly(ethylene oxide)(PEO) shows responsive to temperature because of hydrogen bonding between its ether linkage and water. Furthermore, PEO has been focused on due to its low toxicity, good biocompatibility and so on. The introduction of inorganic silica will facilitate PEO micelle assembly and enhance its rigid nature. In this paper, organosilicone hybrid nanoparticles were synthesized by nucleophilic addition/ring-opening reactions between epoxy and secondary amine group. By contrast to atom transfer radical polymerization(ATRP) and reversible addition fragmentation transfer polymerization(RAFT), this synthesis method is imple and green. The obtained nanoparticles displayed spherical shape with shell-core structure and showed responsive to temperature and p H by transmission electron microscopy(TEM), dynamic light scattering(DLS), cloud point(CP) and so on. The details were as follows.1. The intermediate was synthesized with polyethylene glycol diglycidyl ether(PEO-DE) and aminopropyltriethoxysilane(APTS) and characterized by 1H NMR and FT-IR. It was directly dissolved in water to form the micelle. Triethylamine was then added to induce the hydrolysis and condensation of ethoxy groups. After the sol-gel process, the organosilicon hybrid nanoparticle was obtained. The nanoparticle with narrow size distribution was characterized by DLS, whose z-average semidiameter was 76.26 nm. The morphology of hybrid nanoparticles was investigated by TEM, which displayed spherical shape with arms. We found that the hybrid nanoparticles showed response to p H by DLS.2. The intermediate was synthesized with PEO-DE, polypropylene glycol diglycidyl ether(PPO-DE) and APTS and characterized by 1H NMR, FT-IR and GPC. It was directly dissolved in water to form the micelle. Triethylamine was then added to induce the hydrolysis and condensation of ethoxy groups. After the sol-gel process, the organosilicon hybrid nanoparticle was obtained. The critical micelle concentration(CMC) of the hybrid nanoparticles was 4.3×10-6mol/L by using pyrene as fluorescence probe. The morphology of hybrid nanoparticles was investigated by scanning electron microscopy(SEM) and TEM, which displayed regular spherical shape with shell-core structure. We found that the hybrid nanoparticles showed response to temperature and p H by DLS and CP. Hydrophobic graphite could be dispersed in water in the presence of organosilicon hybrid nanoparticles, which could be proved by spectrophotometer. The hybid nanoparticles showed selective adsorption of different hydrophilic dyes(methyl orange, acid red 18 and rhodamine B) in water by UV-vis spectra.