Synthesis and characterization of organo-silica hybrid nanoparticles

Polyvinylsiloxane particles (PVP) were prepared via a Sol-gel reaction. Vinyltrimethoxysilane (VTS) was hydrolyzed and condensed in a water/ethanol/ammonium hydroxide solution. The resulting particles were large aggregates of micron-sized primary particles. The primary particle size did not depend on the initial reaction conditions in the systems studied. It was observed in the FT-IR spectrum of the particles that the vinyl group survived the reaction conditions and that hydrolysis and condensation were incomplete.; Polyvinylsiloxane nanoparticles (PVN) were prepared by addition of 10 mL aliquots the VTS Sol-gel reaction system to sodium dodecyl sulfate (SDS) solutions at various reaction times. The SDS acted as a steric stabilizer, retarding particle growth. The particle size obtained initially increased rapidly at short reaction times and slowed with reaction time.; PVN were also synthesized in emulsion media. Particle sizes from ∼30–200 nm were obtained using 1%–5% w/v Tergitol/VTS/ammonium hydroxide emulsions. The particle size was linearly dependent on the concentration of surfactant for most systems, with the particle size increasing with decreasing surfactant concentration. The polydispersity of the particles also increased with decreasing surfactant concentration. FT-IR of these particles were similar to that of polyvinylsiloxane particles prepared in Sol-gel systems but the network appeared to be more hydrolyzed and condensed due to relatively smaller peaks for residual alkoxy groups and silanols.; Composite organo-silica nanoparticles, containing aminopropyltriethoxysilane (APS), were prepared in aqueous Tergitol emulsions. APS was used as a self-catalyst and comonomer with other organo-silanes. APS was used to catalyze its co-condensation with vinyltrimethoxysilane (VTS), allyltrimethoxysilane (ATS), and chloromethylphenyltrimethoxysilane (CMPTS). The presence of APS in the particles obtained was determined by the reaction of its amine groups with ninhydrin and oleoyl chloride. The particle size of the composite particles was controlled by adjustment of the surfactant concentration and APS/comonomer ratio. Co-condensation of APS with ATS produced particles between 10–300 nm. APS/VTS particle size obtained varied between 60 nm-1 μm as did the APS/CMPTS particles.; A monolayer of APS/ATS composite organo-silica nanoparticles was chemically bonded to the surface of polyethylene naphthalate) (PEN) film as well as on the surfaces of glass beads (GB).