摘要
在甲苯溶剂中,用三甲基氯硅烷对全硅介孔K IT-1分子筛进行有机改性,制备了疏水性的介孔K IT-1分子筛(记为S-K IT-1分子筛);利用傅里叶变换红外光谱、X射线衍射、低温N2吸附-脱附法对K IT-1和S-K IT-1分子筛的结构进行了表征;通过测定K IT-1和S-K IT-1分子筛在水或正己烷饱和蒸气中的吸附量,考察了S-K IT-1分子筛的疏水性。实验结果表明,S-K IT-1分子筛仍保持了K IT-1分子筛完整的介孔结构,孔径在3nm以上;由于体积较大的—S i(CH3)3基团接枝在K IT-1分子筛的孔道表面,占据了孔道内部空间,使其比表面积、孔体积和孔径减小;同时由于K IT-1分子筛表面亲水性的硅羟基已转变为疏水性的≡S i—O—S i≡键,使S-K IT-1分子筛表现出较好的疏水性。
The hydrophobic mesoporous KIT-1 molecular sieve （assigned as S-KIT-1 molecular sieve） was prepared by organic modification of silica KIT-1 molecular sieve with trimethylchlorosilane in toluene solvent. The KIT-1 and S-KIT-1 molecular sieve were characterized by means of FFIR, XRD and nitrogen adsorption-desorption. FTIR spectra show that trimethylsilyl group is grafted onto internal surface of KIT-1 molecular sieve after functionalization with trimethylchlorosilane. Comparing with KIT-1 molecular sieve,S-KIT-1 molecular sieve keeps the original mesoporous structure and pore diameter of more than 3 nm, but its BET specific surface area, pore volume and pore size lessen due to the grafted -Si （CH3 ）3 group within pore. Hydrophobicities of KIT-1 and S-KIT-1 molecular sieves were measured by adsorbance of saturated H20 and n-hexane vapour on molecular sieves. Hydrophobicity of S-KIT-1 molecular sieve is better than that of KIT-1 molecular sieve because hydrophilic silanol groups were transformed into hydrophobic≡ Si-O-Si≡ bonds by the organic modification.
出处
《石油化工》
EI
CAS
CSCD
北大核心
2006年第9期828-831,共4页
Petrochemical Technology
基金
安阳市科技攻关项目(200504009)
安阳师范学院物理化学重点学科资助课题
关键词
KIT-1分子筛
介孔
三甲基氯硅烷
吸附
疏水性
KIT-1 molecular sieve
mesopore
trimethylchlorosilane
adsorption
hydrophobicity
