氯化钙改性硅胶吸湿材料的制备及性能研究

目的 针对水溶液改性硅胶基质易破裂，普通硅胶吸水率不高等问题，采用氯化钙醇溶液浸渍法制备不同浓度的氯化钙改性硅胶吸湿材料。方法 对比采用氯化钙水溶液和醇溶液制备的氯化钙改性硅胶吸湿材料的外观质量;采用气体吸附法测试等温吸附脱附曲线，基于吸附理论和FHH模型获得氯化钙改性硅胶吸湿材料孔隙参数和分形维数;采用静态吸附法获得水蒸气静态吸附曲线，根据准一级和准二级动力学模型建立适用于氯化钙改性硅胶吸湿材料的吸附动力学方程。结果 采用氯化钙醇溶液浸渍制备的氯化钙改性硅胶吸湿材料的破裂程度明显减少;比表面积和孔容随氯化钙含量的增加而减小，孔径变化较小;吸湿量随氯化钙含量的增加而增加。在模拟吸附过程中，准二级动力学模型相关系数更高，因此能更好地模拟吸附动力学过程。结论 采用质量分数为25%的氯化钙醇溶液制备的氯化钙改性硅胶吸湿材料的吸湿率最高、基质破裂率较低、再生能力优异，具有良好的应用前景。

Preparation and Properties of Calcium Chloride Modified Silica Gel Hygroscopic Materials

The work aims to prepare calcium chloride modified silica gel hygroscopic materials of different concentrations by calcium chloride and alcohol solution impregnation method, so as to solve the problems of easy rupture of aqueous modified silica gel and low water absorption rate of ordinary silica gel. The appearance quality of hygroscopic materials prepared by calcium chloride aqueous solution and alcohol aqueous solution was compared. The isothermal adsorption curves were tested by gas adsorption method. The pore parameters and fractal dimensions of calcium chloride modified silica gel hygroscopic materials were obtained based on BET theory and FHH model, respectively. The static adsorption curve of vapor was obtained by the static adsorption method. The adsorption kinetics equation suitable for hygroscopic materials was established according to the quasi-first-order and quasi-second-order kinetic models. The calcium chloride modified silica gel hygroscopic materials prepared by calcium chloride and alcohol solution could effectively reduce the rupture. The specific surface area and pore volume of the materials decreased with the increase of CaCl2 content, but the pore size changed little. The moisture adsorption of materials increased with the increase of CaCl2 content. The quasi-second-order kinetic model was more suitable to simulate the adsorption kinetics of the materials due to the higher correlation coefficient. The calcium chloride modified silica gel hygroscopic materials prepared by 25wt.% CaCl2 alcohol solution have high hygroscopicity, low matrix rupture degree and excellent regeneration ability, thus having a good application prospect.