改性膨润土的制备与表征

Preparation and characterization of the modified bentonite

为了提高膨润土的层间距和疏水性，用十六烷基三甲基溴化铵（CTMAB）对膨润土进行了改性，并用X射线衍射（XRD）、红外光谱（FTIR）技术和热分析（DSC）对改性土进行了结构表征，结果表明：改性后，膨润土的底面层间距由1．2443nm增加到1．9968nm；改性土在2912cm^-1和2840cm^-1附近出现了明显的甲基、亚甲基和次甲基的对称和不对称伸缩振动吸收峰，在1498cm^-1附近出现了N^＋ -CH，中C—H对称弯曲吸收峰；改性膨润土在300—600℃间有明显吸热峰，是由于CTMAB有机链逐步分解所致，说明CTMAB已经成功插入膨润土层间，且常温下性质稳定。

Bentonite is modified with cetyltrimethylammonium bromide （CTMAB） to improve interlayer space and the hydrophobic of Bentonite. The modified bentonite was characterized by XRD, IR and DSC techniques. The results show that the basal spacing values of the modified Bentonite is increased from 1. 2443 nm to 1. 9968nm; The symmetrical and dissymmetrical stretching peaks of cymene, methylene and hypocymene are present at 2912 cm^-1 and 2840 cm^- 1, and the C-H symmetrical bending peak comes out at 1498 cm^-1 in the FTIR spectra of the modified Bentonite; The endothermic peaks in the region 300 -600℃ are attributed to the stepwise removal of interlayer CTMAB of the modified Bentonite. So the cetyhrimethylammonium bromide has been intercalated into the layers of Bentonite, and its character is steady at normal temperature.