摘要
合成了十二烷基甜菜碱（Ｃ１２ＢＥ），经提纯得到合格的样品，测定其等电点为ｐＨ＝４．９。ｐＨ＜４．９，分子带正电；ｐＨ≥４．９，分子呈电中性。研究ｐＨ值对其界面活性的影响，同时还研究了醇的种类、浓度，水的盐度、ｐＨ值等因素对Ｃ１２ＢＥ／醇／水／油体系相态的影响，得到了中相微乳液的特性参数。其中有关ｐＨ对相态的影响的研究很有特点。
A modified method was used to synthesis and purify zwitteronic surfactant dodecylbetaine C 12 BE,and the isoelectric point of C 12 BE was detemined to be pH=4.9.When pH<4.9,the molecule appears to be cationic surfactant,and if pH≥4.9,be inner salt with no charge.The affection of pH on the interface activity of C 12 BE was studied.And the influences to the phase behavior of C 12 BE/water/oil/alcohol coursed by the type and concentration of alcohol,saltness,pH of water were investigated.Characteristic parameters of middle microemulsion had been got such as γ MW , a *,a 1,a 2 ,et al..
