以微凝胶模板合成P(AM-co-DMC)/SiO_2杂化粒子

以聚(丙烯酰胺-co-甲基丙烯酰氧乙基三甲基氯化铵)P(AM-co-DMC)]微凝胶为模板,TMOS为硅前驱体,中性水环境下合成了一系列P(AM-co-DMC)/SiO2有机-无机杂化粒子.对杂化粒子的大小、形态及表面形貌等进行研究,发现微凝胶对杂化粒子的形态和大小起主导作用,SiO2在模板上沉积,即使经过灼烧依然保持模板的形态;TMOS的用量对杂化粒子的性质也有重要影响——用量少时,得到的杂化粒子表面粗糙,增加用量会使表面变得光滑.杂化粒子经过灼烧后,表面会变得更加粗糙.

P(AM-co-DMC)/SiO2 Hybrid Particles Synthesized via Microgel Templates

Inspired by biomineralization in nature,organic-inorganic hybrid SiO_2 particles were synthesized in situ by a novel route,which is definitely superior to traditional synthesis route of organic-inorganic hybrid materials due to environment-friendly,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/SiO_2 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 organic-inorganic 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 microgel-silica 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.