The spectroscopy characterization of kaolinite-organic intercalation materials

Kaolinite/formamide intercalation materials are characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy(FT-IR), Raman spectroscopy and H-1 magic angle spinning nuclear magnetic resonance spectroscopy (H-1 MAS NMR). The d(001) spacing of kaolinite treated with formamide is 1.020nm, which is larger than that of the original clay. The H-1 MAS NNIR graphs show that the proton chemical shifts of the inner hydroxyl and inner surface hydroxyl of kaolinte are delta-1.3 and delta 2.4 respectively. After formamide intercalation, the proton peaks of the inner surface hydroxyls shifted to high-field with delta 2.3, the proton peak of the inner hydroxyl shifted to delta-0.3 toward low-field. In the hydroxyl stretching vibration region of Raman spectrum, the formamide intercalation resulted in the decrease of the intensities of kaolinite inner surface hydroxyl bands at 3699cm(-1),3682cm(-1), 3665cm(-1) and 3642cm(-1), and the appearance of additional bands at 3610cm(-1),3628cm(-1). In the NH stretching region of FT-IR spectrum, two bands are observed at 3336cm(-1) and 3466cm(-1) corresponding to the two types of the hydrogen bonds between formamide and kaolinite. In the carboxyl stretching region, an additional band at 1667cm(-1) is assigned to C=O group that bonded to the inner surface hydroxyl of kaolinite.