Surface properties of organic-modified rectorite by inverse gas chromatography

The surface properties of rectorite directly affect the application in the field of environment protection and catalysis, and make great contribution to the structure and mechanical properties of composite materials. Surface properties of the natural rectorite (REC), organic-modified rectorite with dodecyl benzyl dimethyl ammonium bromide (12-OREC) and organic-modified rectorite with hexadecyl trimethyl ammonium bromide (16-OREC) were studied by inverse gas chromatography using non-polar and polar probes. The results indicate that the dispersive component of surface energy is directly influenced by surface treatment. The dispersive component of surface energy of 12-OREC and 16-OREC (24.85, 30.43 mJ/m²) are lower markedly than that of REC (75.19 mJ/m²) at 100°C. The dispersive component of surface energy decreases with the increase of temperature, and 12-OREC is more sensitive to temperature. In addition, the acid-base properties of rectorite are also changed after treating. Quaternary ammonium salt modifies the behavior of the acidic REC, resulting in a mainly basic surface.