碳酸钙颗粒表面改性及其稳定的石蜡Pickering乳液

Surface modification of CaCO3 particles and CaCO3 stabilized paraffin Pickering emulsion

用丁烷四羧酸、油酸和丙烯酰胺原位复合调控碳酸钙表面特性,并用改性碳酸钙颗粒制备了高固含量的石蜡Pickering乳液。用红外光谱、扫描电镜、热失重法、水接触角法和表面电位法等对改性碳酸钙的表面组成结构和形貌进行表征,并用光学显微镜和激光共聚焦显微镜对Pickering乳液形貌进行表征。试验结果表明:脂肪酸与丙烯酰胺抑制碳酸钙晶粒的生长,丁烷四羧酸钙以介孔超分子结构覆盖在碳酸钙表面,明显降低了碳酸钙的亲水性。改性碳酸钙颗粒中,纯碳酸钙60%,脂肪酸钙40%。改性碳酸钙粒径约为250 nm,水接触角为84.7°,表面电位为-23.5 mV。用改性碳酸钙制备了水包油型固含量70%的石蜡Pickering乳液。

The surface characteristics of calcium carbonate particles are regulated by in-situ modification with butanetetracarboxylic acid,oleic acid and acrylamide.Liquid paraffin Pickering emulsion with high solid content is prepared by resultant calcium carbonate granules.The experimental results show that fatty acid and acryl⁃amide inhibit the crystal growth of calcium carbonate grains,and the surfaces of calcium carbonate are covered with mesoporous supramolecular calcium butanetetracarboxylate,which significantly reduces the hydrophilicity of calcium carbonate particles.The relative content of calcium carbonate in modified calcium carbonate is 60%,whereas calcium fatty acid accounts for 40%.The modified calcium carbonate particle size is about 250 nm,its water contact angle is 84.7°and its Zeta potential is-23.5 mV.Finally the oil-in-water type 70%paraffin Picker⁃ing emulsion is obtained with modified calcium carbonate.