摘要
以2-氰乙基三乙氧基硅烷(CTES)和正硅酸乙酯(TEOS)为硅源,聚氧乙烯聚氧丙烯聚氧乙烯三嵌段共聚物(P123)为模板剂,采用共缩聚法在酸性条件下合成了氰基功能化的介孔二氧化硅.通过XRD、SEM、氮气吸附脱附、FT-IR和元素分析等技术对样品的结构、形貌、孔性质和官能团等进行了表征.研究结果表明,硅源的混合方式对氰基的引入量和分布有一定影响,其中以直接混合方式所得样品中基团含量最高,其分布也最均匀.另外,随着氰基引入量的增加,样品的形貌与孔结构略有变化.当CTES加入量超过20mol%时,材料的介孔由圆柱形的直孔道向瓶颈型的孔道结构发生转变.同时随着材料中氰基含量增大,样品的孔容由0.70 cm3/g降到0.22 cm3/g、表面积从666 m2/g降到312 m2/g,孔径由4.2 nm减小到2.7 nm,表明氰基分子占据了部分孔道空间.
Cyano-functionalized mesoporous silicas were synthesized by one-pot co-condensation of tetraethoxysilane（TEOS） and 2-cyanoethyltriethoxysilane（CTES）,using Pluronic P123 triblock copolymer as the structuredirecting agent under strongly acidic conditions.The physicochemical properties,such as structure,morphology,pore property and cyano content were characterized by XRD,SEM,N2 adsorption-desorption isotherm,FT-IR and elemental analysis,respectively.It was found that the order for adding the two silicon sources,namely CTES and TEOS has a profound influence on the content and distribution of cyano group.Within three mixture orders,the sample synthesized with pre-mixed TEOS and CTES as silica sources is best,with highest cyano content and uniform distribution.As cyano content increasing,surface morphology and pore properties are changed.The straight cylindrical pore structure is transformed into bottle-neck-like structure with up to 20mol% CTES loading in the synthesis mixture.Pore volume,surface area and pore size decrease from 0.70 cm3/g to 0.22 cm3/g,666 m2/g to 312 m2/g,4.2 nm to 2.7 nm,respectively when cyano content is increased,which maybe result from that cyano group occupies part of pore channel.
出处
《无机材料学报》
SCIE
EI
CAS
CSCD
北大核心
2012年第2期134-138,共5页
Journal of Inorganic Materials
基金
国家自然科学基金(20803068)~~
