柴油微乳液的相图及稳定性研究

选用双(2-乙基己基)琥珀酸酯磺酸钠(AOT)和辛酸(OA)作为表面活性剂制备柴油微乳液。体系中加入的混合表面活性剂总浓度为0.22mol/L。通过绘制R0-T相变图、研究微乳液体系在不同温度、不同乳化剂配比及不同水与甲醇比例时的相变化。实验结果表明:当AOT和OA的物质的量比为1∶1时,柴油微乳液W/O单相区域的面积最大。当温度为30℃,R0值小于22.5时,得到澄清透明的柴油微乳液。对于含有甲醇的体系,当水与甲醇体积比为2∶1时,相图中单相区域的面积最大。R0值小于15.1时,体系能够达到均匀稳定状态。使用AOT和OA作为表面活性剂可以制备澄清透明的柴油微乳液,样品放置64d后未出现分层现象,且仍为澄清透明乳液。

Study on Phase Diagram and Stability of Diesel Micro-emulsion

The sodium bis （2-ethylhexyl）sulfosuccinate （AOT） and octanoic acid （OA） were selected as the surfactants for the preparation of diesel micro-emulsion. The concentration of mixed surfactants added into system was 0.22mol/L. The R0-T phase diagrams were constructed to illustrate phase transformations of samples with various surfactant ratios and ratio of water to methanol and at different temperature. The results indicated that the single-phase region of W/O micro-emulsion increased to maximum when the molar ratio of AOT to OA was 1：1. The clear and transparent diesel micro-emulsion could be obtained when the temperature was 30＆#176;C and R0 was less than 22.5. For the system containing methanol, the maximum single-phase region was formed when the volume ratio of water to methanol was 2：1. The system with this ratio achieved uniform and stable state when R0 was less than 15.1. It was found that the diesel micro-emulsion prepared with using AOT and OA as surfactants were clear and transparent, and it could keep this state without separation after being placed for 64 days.