有机包覆改性SiC粉体表面结构与性质的表征

本研究中的有机包覆改性SiC微粉通过硅烷偶联剂处理以及有机单体在其表面上的接枝聚合而获得。通过X-射线衍射分析改性前后粉体的主要物相成分;以粉体悬浮液离心清液的离子电导率和粉体胶粒的Zeta电位曲线来表征粉体表面的吸附离子浓度及表面电性;通过TEM、FTIR等测试手段表征粉体有机包覆层的形貌和化学组成结构。研究表明:以提高SiC粉体水基分散固含量为目的的有机包覆改性工艺在未改变粉体基本成分的基础上,有效降低了粉体表面吸附离子的浓度,提高了表面电荷;其完整的表面有机包覆层体现包覆物质的结构和性质,有效地掩蔽了SiC粉体原有的表面,使有机包覆改性成为SiC粉体水基分散性能提高的有效方法。

Characterizations of Surface Structure and Properties of Modified SiC Powder Prepared by Organics Coating

In this research, the modified silicon carbide (SiC) fine powder is prepared by organics coating through silane coupling agent bonding and organomonomer graft polymerization on its surface. The chemical compositions of the SiC powder are analyzed by X-ray diffraction analysis. The soluble ions concentration adsorbed on the SiC particles surface is characterized by the ionic conductivity of the suspension's centrifugate prepared by various of SiC powder. The curve of Zeta potential versus pH is measured to show the potential nature of the SiC particles surface too. The appearance of the organics coating layer is displayed by the transmission electron microscope(TEM) photos, and its chemical compositions and structure is characterized by Fourier transformation infra-red(FTIR) spectrum. The testing and analyses results show that the processing of organic coating for improving the solid loading of SiC aqueous suspension do not change the powder's chemical compositions, but dercease the particle's soluble ions concentration and increased its surface potential effectively. This coating layer displays the structure and properties of the materials used in coating process. The layer covers the pristine surface of SiC particles perfectly. By organics coating modification, the dispersity of SiC powder is developed to match to disperse in water.