新型牙膏用SiO₂颗粒的制备和性能表征

Preparation and Characterization of Novel SiO₂ Used in Toothpaste

摘要: 以水合硅酸钠为硅源、硫酸为沉淀剂和硫酸钠为分散剂，经过两次沉淀法制备了SiO₂颗粒，测量了产物的应用性能，并利用SEM、FTIR、TG和XRD对产物的形貌结构进行了表征。结果表明：经二次沉淀制备的SiO₂产物吸水量46.8 mL/20g、吸油量3.42 mL/g、铜片磨损值180，可用作牙膏中的增稠剂兼摩擦剂；SEM表征显示二次沉淀SiO₂比一次沉淀SiO₂表面疏松，FTIR分析显示SiO2特征峰明显，XRD说明产物是非晶态无定形结构，TG和XRD分析表明产物SiO₂的纯度很高。

Abstract: Novel SiO₂ particles were made by two-step chemical precipitation method using sodium silicate as precursor, H₂SO₄ as precipitator and Na₂SO₄ as dispersant. Morphologies and structures of these products were characterized by means of SEM, FTIR, TG and XRD. The water absorption capacity of novel SiO₂ is 46.8 mL/20 g, the oil absorption value is 3.42 mL/g, and the copper abrasion value is 180, accounting for the product can be used both as thickening agent and abrasive in toothpaste. Results of SEM demonstrated the surface of particles made by two-step is rougher than that of particles made by one-step. FITR analysis showed the characteristic peaks of SiO₂ are obviously. XRD indicated the novel SiO₂ is amorphous structure, and TG and XRD revealed that they are high purity.