新型铝改性硅胶吸附材料的制备与性能

陶瓷纤维纸经水玻璃、酸性铝盐溶液顺次浸渍得到新型铝改性硅胶吸附材料．反应的优化条件为：水玻璃浓度26．6wt％、铝盐浓度10wt％、溶液pH值1．8．^29Si和^27AlMAS NMR谱显示：铝替代硅进入SiO4硅氧四面体结构单元，但并不影响其骨架结构；红外光谱显示Si—OH对称伸缩振动峰由968cm^-1移至Si(Al)-OH的954cm^-1；扫描电镜图表明铝改性硅胶能较好地分散在瓦楞陶瓷纤维表面及其孔隙中；X射线能谱(EDS)揭示材料表面微区Al^3 的存在与含量,孔隙分析显示材料起吸附作用的主要为中孔；由于铝离子改性，新型吸附材料的吸附性能、耐热性能及机械强度等均优于同等条件下反应生成的硅胶．

Preparation and Performance of Novel Al3+ Modified Silica Gel Adsorptive Materials

Al3+ modified silica gel adsorptive materials were prepared by treating ceramic fiber matrix with sequential impregnation of aqueous solution of sodium silicate(Na2SiO3), acidic aluminium salt. The results show that the optimal reaction condition is 26.67% Na2SiO3, 10% aluminium salt and 1.8 solution pH value. 29Si and27AlMAS NMR spectra show that some Al is incorporated in SiO4 tetrahedral framework structure which is not influenced by the replacement of Al for Si atoms. The Al3+ modification results in symmetric stretching vibration shifting from 968cm-1 of Si-OH to 954cm-1 of Si (Al)-OH. SEM imagine reveals Al3+ modified silica gel is well scattered on the surface corrugated ceramic paper and in the apertures between fibers of paper. EDS analysis indicates the existence and percentage of modified Al3+ in the adsorptive materials surface micro zone. Porous medium surface area analysis shows that the mesopore is dominant for adsorption in Al3+ modified silica gel. For the Al 3+ modification, the humidity adsorbing ability, heat resistance property and tensile strength and burst of Al3+ modified silica gel adsorptive materials are superior to those of silica gel.