阳离子型Gemini表面活性剂改性膨润土的制备及结构表征

以膨润土为原料,以系列阳离子Gemini表面活性剂(Gm-n-m)为插层剂制备了有机膨润土,利用红外光谱、X射线衍射及差热-热重分析对产物结构进行了表征,并探讨了温度、时间、搅拌速率及插层剂用量对有机膨润土结构的影响。结果表明,当Gm-n-m分子进入到膨润土层间后,其疏水性增强,层间距由1.51 nm增大到3.91 nm,有机物含量达到23.53%,且层间距明显大于单链CTAB改性膨润土的层间距。适宜的制备条件为:插层剂用量为钠基膨润土的40%,70℃下水浴反应3 h,搅拌速率为205 r/min。

Preparation and structure characterization of the bentonite modified with the cationic Gemini surfactants

The organic bentonite was prepared using bentonite and a class of cationic Gemini surfactant alkanediyl-α-ω-bis(alkyldimethylammonium)dibromides(Gm-n-m) as initiating material and intercalation agent respectively.The structure of the product was characterized by fourier transform infrared spectroscopy(FTIR),X-ray diffractometer(XRD),and differential thermal analysis and thermogravimetric analysis(DTA-TGA).The effects of the reaction temperature,reaction time,stirring speed,and the amount of G12-6-12 on the structure of the organic bentonite were investigated.Results show that when Gm-n-m entered the layers of bentonite,the hydrophobic ability was improved,the lamellar distance was increased from1.51 nm to 3.91 nm,the organic content reached 23.53%,and the lamellar distance was widened significantly than the single chain CTAB modified bentonite.It is found that the optimized preparation conditions were the ratio of intercalation agent to sodium bentonite was 40%,the reaction happened at the temperature of 70 ℃ for 3 h,and the stirring speed was 205 r/min.