阳离子型表面活性剂CTAB的泡沫性能研究

Study on foaming properties of CTAB cationic surfactant

添加起泡剂是调节泡沫性能的重要手段。为研究表面活性剂十六烷基三甲基溴化铵(CTAB)的泡沫衰变过程,利用复合泡沫扫描分析仪Foam Scan测定了不同浓度下CTAB的起泡速率(单位时间单位体积起泡剂溶液所产生的泡沫量)、起泡时间、泡沫体积、排液速率及泡沫所含的液体体积等。结果表明,CTAB的临界胶束浓度(CMC)为0.90mmol/L。起泡速率起初随CTAB浓度的增加而增大,直至浓度增加到CMC时,起泡速率达到最大值0.09m L/(m L·s),超过CMC后起泡速率不再随浓度变化;起泡时间随浓度的变化趋势与之相反,最小起泡时间为38s。低浓度下CTAB的泡沫稳定性随浓度的增加而增强,当浓度增加到CMC时稳定性最强,超过CMC后稳定性有所减弱,但与CMC时的稳定性相比差异不大。起泡剂通过影响泡沫的衰变过程以调控泡沫的稳定性,起泡和衰变过程在CTAB浓度达到CMC后不再出现明显变化。

Adding frother is a crucial method to adjust the foam properties. To research the foam decay process of cetyltrimethyl ammonium bromide（CTAB）, the foaming rate, foam volume, content of liquid and drainage rate were tested using Foam Scan,and relationship between the surface tension and the foam properties were analyzed. The results showed that the critical micelle concentration（CMC） of CTAB was 0. 90 mmol/L. The foaming rate initially increased with an increase in solution concentration,then reached the maximum value which is 0. 09 m L·（m L·s）^-1 at CMC. The trend of foaming time versus concentration was opposite to the foaming rate versus concentration,and the minimum foaming time was 38 s. At low concentrations,the foam stability increased with increasing CTAB concentration and reached the most stable stage at CMC,but appeared a little decrease when solution concentration exceeded the CMC. Frother adjusts the stability of foam by affecting the foam decay process,while the foaming and decay processes would not change when solution concentration reaches to CMC.