The preparation process of γ-A12O3 nanofiltration membranes were studied by N2 absorption and desorption test and retention rate vs thickness gradient curve method. It was found that template and thermal treatment we...The preparation process of γ-A12O3 nanofiltration membranes were studied by N2 absorption and desorption test and retention rate vs thickness gradient curve method. It was found that template and thermal treatment were key factors for controlling pore size and its distribution. Under the optimized experimental conditions, the BJH (Barret-Joyner-Halenda) desorption average pore diameter, BJH desorption cumulative volume of pores and BET (Brunauer-Emmett-Teller) surface area of obtained membranes were about 3.9 nm, 0.33 cm3/g and 245 m2/g respectively, the pore size distribution was very narrow. Pore size decreased with the increasing of thickness and no evident change after the dense top layer was formed. The optimum thickness can be controlled by retention rate vs thickness gradient curve method.展开更多
试验制备了以硫铝酸盐水泥为基础的泡沫混凝土,用光学数字显微镜和图像分析软件(Image-Pro plus 6.0)计算孔径,并测定了孔隙率,研究了水胶比、发泡剂掺量及搅拌时间对试样性能的影响,重点采用正交试验分析了3个因素对干密度的影响。结...试验制备了以硫铝酸盐水泥为基础的泡沫混凝土,用光学数字显微镜和图像分析软件(Image-Pro plus 6.0)计算孔径,并测定了孔隙率,研究了水胶比、发泡剂掺量及搅拌时间对试样性能的影响,重点采用正交试验分析了3个因素对干密度的影响。结果表明:3个因素对干密度的影响程度大小顺序为:发泡剂掺量>搅拌时间>水胶比;较好的组合是A3B3C3,试块干密度为221 kg/m3、抗压强度为0.23 MPa、吸水率为28%;干密度随着孔径的增大而降低,而孔隙率却恰恰相反;干密度与孔隙率之间呈线性关系,即ρ0=2 317-23P,随孔隙率的增大而降低。展开更多
文摘The preparation process of γ-A12O3 nanofiltration membranes were studied by N2 absorption and desorption test and retention rate vs thickness gradient curve method. It was found that template and thermal treatment were key factors for controlling pore size and its distribution. Under the optimized experimental conditions, the BJH (Barret-Joyner-Halenda) desorption average pore diameter, BJH desorption cumulative volume of pores and BET (Brunauer-Emmett-Teller) surface area of obtained membranes were about 3.9 nm, 0.33 cm3/g and 245 m2/g respectively, the pore size distribution was very narrow. Pore size decreased with the increasing of thickness and no evident change after the dense top layer was formed. The optimum thickness can be controlled by retention rate vs thickness gradient curve method.
