New Method of Preparation and Property Study of the Montmorillonite Modified with CTAB

摘要

In this paper, Ca~(2+)-montmorillonite (Ca~(2+)-Mt) was modified with cationic surfactant hexadecyl trimethyl ammonium Bromide (CTAB) directly, without changing Ca~(2+)-Mt into Na+-montmorillonite (Na~+-Mt). X-ray diffraction (XRD), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), contact angle tests and rotary viscosity tests were used to characterize the structure and property of the organo-montmorillonite. The results of XRD show that interlayer space (d_(001)) of the product is 4.05nm. The results of TGA indicate the ratio of weight loss of the organic components in the product is 37.7%. The results of FT-IR indicate there are organic components and hardly any water molecules in the product. All these findings indicate that the CTAB has intercalated into the galleries of Ca~(2+)-Mt. Contact angle tests shows the product is well hydrophobic and the hydrophobic property is as good as that of organo-montmorillonite modified from Na~+-Mt. Rotary viscosity tests show that the viscosity of the product at the rotational speed of 6R/min is 1226mPa·s, much better than that of the organo- montmorillonite modified from Na~+-Mt which is 1070 mPa·s. The thixotropy index of the product is 9.22, much better than that of the organo-montmorillonite modified from Na~+-Mt which is 5.88. It can be concluded that organo-montmorillonite with perfect interlayer expansion and thixotropic property was prepared by modifying Ca~(2+)-Mt with CTAB directly.