Abstract

Gypsum and its products have excellent performance of heat preservation and insulation, sound insulation, humidity control and fire prevention, and light weight and convenient processing, as an inorganic environmental protection, building material and attention. SiO2 aerogel gypsum slurry was synthesized by building gypsum and SiO2 and aerogel paste by different feeding sequences. The effects of SiO2 aerogel content on the setting time, mechanical properties, contact angle and thermal conductivity of the slurry were studied. Combined with X-ray diffraction (XRD) analysis and scanning electron microscopy (SEM) analysis, the mechanism of action between SiO2 aerogel and gypsum was characterized. The results show that with the increase of SiO2 and aerogel content, the water consumption of standard consistency, and dry density of slurry decrease. The contact Angle increased from 51.242° to 122.813°, and the hydrophobicity increased. When SiO2 and aerogel were added, the microstructure consisted of a short columns and a long columns (dihydrate gypsum) packed closely and transformed into irregular sheets (anhydrous gypsum), fine column (dihydrate gypsum) and agglomerated small particles (SiO2) attached to the surface.

摘要

石膏及其制品具有优良的保温隔热、隔音、调湿、防火性能，而且重量轻、加工方便，作为无机环保、建筑材料而备受关注。SiO2气凝胶石膏浆是通过建筑石膏和SiO2气凝胶浆料按不同进料顺序合成的。研究了SiO2气凝胶含量对浆料凝固时间、力学性能、接触角和导热系数的影响。结合X射线衍射（XRD）分析和扫描电子显微镜（SEM）分析，表征了SiO2气凝胶与石膏的作用机理。结果表明，随着SiO2和气凝胶含量的增加，标准稠度的耗水量和浆料的干密度降低。接触角从51.242°增加到122.813°，疏水性增加。当加入 SiO2 和气凝胶时，微观结构由一个短柱和一个长柱（二水石膏）紧密堆积并转变为不规则的片状（无水石膏）、细柱（二水石膏）和附聚的小颗粒（SiO2）。表面。