摘要
以正硅酸乙酯、钛酸正丁酯和聚乙二醇等为主要原料,采用溶胶-凝胶法合成了多孔SiO2-TiO2系块状材料．着重研究了不同含钛量下材料的红外光谱、孔径分布和化学稳定性．实验表明:500℃焙烧2h后,可有效去除残余有机物,形成以Si-O和Ti-O键共存的无定形网络结构．引入较多钛量时,使材料的孔径分布变窄、平均孔径下降,同时样品的体积密度增加、而开口气孔率和吸水率则均下降．在80℃热水中浸泡72h后,吸附-脱附曲线的类型和形状几乎没有变化．随着Ti含量的增加,比表面积、孔容积和平均孔径的变化率减小, 耐水性提高． SiO2多孔材料在95℃的1％NaOH碱液中不稳定而溶碎,但随着Ti含量的增加,材料在碱液中的重量损失有显著减小的趋势,耐碱性明显改善．但引入Ti并不能提高该类多孔材料在98℃的20％硫酸液中的耐蚀性．
Porous SiO2-TiO2 blocks were successfully synthesized by polymerization of tetraethy- oxysilane and tetrabutyl titanate in the presence of polyethylene glycol via a sol-gel route. Their infrared spectra, pore distribution and chemical durability were mainly studied. The results showed that the residual organic component can be removed after heat-treated at 500℃ for 2h, and then a vitreous structure with Si-O and Ti-O bonds was formed. The porous materials containing Ti had a narrower pore distribution and the peak of the pore distribution curve shifted to the smaller pore diameter. With the increase of TiO2 content, the density of porous blocks increased, whereas open porosity and adsorbed water ratio decreased at the same time. After immersion in water at 80℃ for 72h, the type and shape of adsorption-desorption curves changed slightly. Since the change of specific surface area, pore volume and average pore diameter for the obtained materials decreased with the increase of Ti content, it indicated an improvement of water resistance. The durability of porous blocks in 1% NaOH basic solutions at 95℃ was apparently improved due to an addition of titanium as compared with SiO2 porous block which was collapsed in such solution. However, anti-acid resistance of porous materials in 20% H2SO4 solutions at 98℃ can not be improved by an addition of titanium.
出处
《无机材料学报》
SCIE
EI
CAS
CSCD
北大核心
2006年第1期181-186,共6页
Journal of Inorganic Materials
基金
上海市科委资助项目(0252NM006)
