三维有序大孔SiW_(12)/SiO_2杂化材料的制备及表征

Synthesis and Characterization of Three-Dimensional Ordered Macroporous SiW_(12)/SiO_2 Hybrid Materials

用自然沉降法组装成规则排列的聚苯乙烯胶晶,并以此作为模板剂,用Keggin结构的杂多酸SiW12和正硅酸乙酯组成溶胶作为先驱物,成功制备了三维有序大孔(3DOM)SiW12/SiO2杂化材料.XRD和IR等测试结果表明,所得样品中的杂多酸SiW12能够保持其Keggin结构,SEM观察显示,样品具有三维大孔规则排列的结构.研究发现,溶胶组成对杂化材料的3DOM结构影响很大,纯SiW12难以形成3DOM结构,随着SiO2含量的增加,样品的孔结构三维规整性和强度明显增强,而且引入SiO2可有效提高杂多酸的热稳定性.

Three-dimensional ordered macroporous （3DOM） SiW12/SiO2 hybrid materials were synthesized by using Keggin-type heteropolyacid SiW12 and tetraethyl orthosilicate （TEOS） as raw materials and polystyrene colloidal crystal assembled by sedimentation as template. The properties and structures of the hybrid materials were determined by FT-IR, XRD, SEM and DTA. It was difficult to form 3DOM material by using heteropolyacid SiW12 only. But the 3DOM structure could be formed and the strength of the samples was significantly improved by the addition of SiO2 to SiW12, while the heteropolyacid SiW12 maintained its Keggin structure in these SiW12/SiO2 hybrid materials. Moreover, the thermal stability of SiW12 also increased obviously. The study indicated that the 3DOM SiW12/SiO2 hybrid materials with Keggin-type heterpolyacid could be successfully synthesized according to the process provided in present article.