organic-inorganic hybrid SiO2 particles were synthesized in situ by a novel route
which is definitely superior to traditional synthesis route of organicinorganic hybrid materials due to environmentfriendly
simple
economic
etc.Besides experimental convenience
hybrid particles obtained possess sophisticated structures due to polymer microgel as templates that controls silica deposition.In our investigation
polyamine mocrogel was selected as templates which induced the formation of sophisticated structure of hybrid particles that possessed dramatic surface and inner properties.The poly(acrylamide-co-dimethylaminoethylacrylate-methyl chloride) (P(AM-co-DMC)) microgel was prepared by inverse emulsion polymerization in the presence of a crosslinker.By controlling the swallowing degree of microgel
the silica deposition was conducted by simply stirring a mixture aqueous dispersion of the microgel and tetramethyl orthosilicate (TMOS) as a stable silica source at pH 7.2 and 20℃.We found that there was no evidence for nontemplated silica structures
which suggests that silica deposition was well-controlled to occur in the polymeric network of microgel template.The obtained particles were carefully characterized with FT-IR spectroscopy
dynamic lighter scattering (DLS)
transmission electron microscopy (TEM)
energy dispersive analysis system of X-ray (EDX)
scanning electron microscopy (SEM).In FT-IR and EDX spectra
it’s indicated that microgel/SiO2 hybrid particles was formed
and pure silica particle was retained after calcinations.Studies on mean diameter
morphology and surface properties of hybrid particles indicated that microgel played a leading role in the process of silica deposition
which determined the morphology and dimension of hybrid particles.Silica deposition proceeded in the microgel microenvironment
and organicinorganic hybrid construction was formed.Silica nano-particles were located in the whole microgel possessing good mechanical stability that kept morphology of templates after calcinations.TMOS also has influence on hybrid particles.Low amount of TMOS led to rough surface while smooth surface was obtained by increasing TMOS quantity.The roughness of surface increased after calcinations.Either the hybrid microgelsilica particles or the calcined silica particles exhibited nanostructural character (porosity)
and the nanostructures in the particles can be well controlled by tuning the level of TMOS addition
suggesting the potential applications for the encapsulation and controlled release for drug and other active molecules.