纳米CaCO_3的制备、表面改性及表征

主要进行了超重力法制备纳米碳酸钙及纳米碳酸钙的表面改性工作 ,并应用TEM、BET、XPS和接触角等方法对改性前后的纳米碳酸钙进行了分析和表征。未改性纳米碳酸钙的粒径约为 30nm ,而改性之后粒子的粒径约在 35～40nm之间 ;未改性纳米碳酸钙的比表面积为 2 9.8m2 / g ,改性碳酸钙的比表面积 38.4m2 /g ,有较大程度的增大 ;改性碳酸钙的XPS能谱图中Ca2 + 的结合能改变了 0 .35eV ,表明改性剂以化学键结合于碳酸钙表面 ;改性剂加入量在 6 % (质量分数 )时改性CaCO3 与极性溶剂的接触角发生反转 ,说明改性剂适宜加入量应在 6 %左右

Preparation,Surface Modific ation and Characterization of Nano-sized Calcium Carbonate

The preparation of nano sized CaCO 3 by high gravity method and the surface modification of such made nano sized CaCO 3 are investigated.The morphology and the dispersion of the particles were characterized by TEM,BET techniques.The rusults showed that the mean size of modified nano sized CaCO 3 is 35～40nm and its BET area is 38.4m 2/g,which is larger about 30% than that of unmodified nano sized CaCO 3.According to the difference of 2p orbital electron energy of Ca in XPS after being modified,it can be inferred that modifier chemical combines to CaCO 3 surface through the chemical bond.The value of contact angle of powder of modified CaCO 3 in polar solvent reaches maximum value when the ratio of modifier to CaCO 3 (by weight)is about 6%,which indicated that optimum amount of modifier in around 6%.