稻壳制备MCM-41分子筛疏水改性研究

Study on the Hydrophobicity and Modification of MCM-41 Molecular Sieve Prepared from Rice Husk

以稻壳灰为硅源,水热法合成MCM-41分子筛。因MCM-41分子筛亲水性强,对疏水性有机污染物吸附效果欠佳的问题,以二甲基二乙氧基硅烷、甲基三乙氧基硅烷和乙烯基三甲氧基硅烷为改性剂分别对其进行疏水改性。通过润湿接触角、XRD和FT-IR等进行性能表征,以亚甲基蓝染料为目标污染物,考察疏水改性后分子筛的吸附性能。结果表明,改性剂中的硅烷基已顺利地接枝在MCM-41分子筛表面,并由疏水性基团≡Si-O-Si≡替代了MCM-41分子筛表面的羟基,使MCM-41分子筛表面疏水。经乙烯基三甲氧基硅烷和甲基三乙氧基硅烷修饰后的分子筛的疏水性能优于二甲基二乙氧基硅烷修饰的分子筛疏水性,相应地前两者对亚甲基蓝的吸附容量也高于后者。

MCM-41 molecular sieve was synthesized with RHA by hydrothermal treatment. The MCM-41 molecular sieve has a strong hydrophilicity and a poor adsorption effect on the hydrophobic organic pollutants. The dimethyldiethoxysilane,methyl triethoxysilane or vinyltrimethoxy silane was used as modifiers. The effects of modifiers on the hydrophobic property of MCM-41 molecular sieve were studied,and the performances were mainly characterized by the Contact Angle Analyzer,XRD and FT-IR. The results show that the silane groups in the modifier had been successfully grafted onto the surface of MCM-41 zeolite,and the hydrophobic groups with ≡Si-O-Si≡ replaced the hydroxy of the surface of MCM-41,which made MCM-41 molecular sieve hydrophobic. The hydrophobicity and adsorption capacity of MCM-41 modified by vinyltrimethoxy silane and methyl triethoxysilane was higher than dimethyldiethoxysilane.