表面活性剂在砂岩上吸附规律研究

发布时间：2018-04-10 14:52

本文选题：表面活性剂 + 吸附等温线　；参考：《西南石油大学》2017年硕士论文

【摘要】：本文采用电导率法、表面张力法测定十六烷基三甲基溴化铵(CTAB)、十二烷基苯磺酸钠(SDBS)、聚乙二醇辛基苯基醚(TX-100)、3-磺丙基十四烷基二甲基甜菜碱等四种表面活性剂的CMC值,通过静态吸附法研究四种表面活性剂在砂岩上的吸附规律和吸附机理。分别采用了四种吸附等温线模型(Langmuir、Freundlich、Temkin和linear吸附等温线)和四种吸附动力学模型(拟一级、拟二级、粒内扩散和Elovich动力学吸附模型)来拟合实验所得数据,筛选出表面活性剂在砂岩上吸附的最佳等温模型及动力学模型。通过大量的实验探索和数据分析,得出以下结论:(1)XRD分析表明砂岩的主要成分是Si02,是一类有强烈带负电吸附位的吸附剂,且由77.49%的伊蒙混层黏土和22.51%的石英组成,SEM分析表明砂岩表面比较粗糙,且存在大量的空隙,孔径大小在几微米到十几微米;通过电导率法测得 CTAB 的 CMC 值为9.5 76×10-4mol/L,SDBS 的 CMC 值为 1.72×1O-3mol/L,表面张力法测得TX-100的CMC值为1.73×10-4 mol/L,Betaine型两性离子表面活性剂的CMC值为2.93×10-4mol/L。表面活性剂的CMC值:非离子表面活性剂TX-100Betaine型两性离子表面活性剂阳离子离子表面活性剂CTAB阴离子表面活性剂SDBS。(2)表面活性剂不同,在砂岩上的吸附情况存在差异,其对应的平衡吸附量也不同,吸附平衡时间也不尽相同。实验研究表明SDBS在砂岩上吸附达到平衡的时间是72 h,另外三种表面活性剂在砂岩上吸附达到平衡的时间均是48 h;平衡吸附量:Betain型两性离子表面活性剂在砂岩上的平衡吸附量阳离子离子表面活性剂CTAB的平衡吸附量非离子表面活性剂TX-100的平衡吸附量阴离子表面活性剂SDBS在砂岩上的平衡吸附量。(3)不同的吸附剂,吸附等温线模型不同,四种表面活性剂在砂岩表面的吸附均符合Freundlich吸附等温线模型,同时也说明了砂岩表面的异质性;拟二级反应动力学模型可以更好的描述四种表面活性剂在砂岩表面的吸附过程,其线性相关系数R20.99,为驱油过程中,表面活性剂的选择提供指导。(4)表面活性剂不同,在砂岩上的吸附作用机理不尽相同。CTAB在砂岩表面上发生吸附的主要作用力是静电力与疏水作用;SDBS在砂岩表面上发生吸附的主要作用力的是π电子极化作用与疏水作用;TX-100在砂岩表面上发生吸附的主要作用力的是色散力、氢键与疏水作用;Betaine型两性离子表面活性剂在砂岩表面上发生吸附的主要作用力的是静电力。总之,表面活性剂在砂岩上的吸附是非常复杂的,表面活性剂结构种类的不同是引起吸附行为差异的根本原因。
[Abstract]:The CMC values of four surfactants, cetyltrimethylammonium bromide, sodium dodecylbenzenesulfonate, poly (ethylene glycol octyl phenyl ether) TX-100 and 3-sulfopropyl tetradecyl dimethyl betaine, were determined by the method of electrical conductivity and surface tension.The adsorption law and mechanism of four surfactants on sandstone were studied by static adsorption method.The best isothermal model and kinetic model for adsorption of surfactants on sandstone were selected.Through a lot of experiments and data analysis, the following conclusions can be drawn: the main composition of sandstone is Si02, which is a kind of adsorbent with strong negative electrically adsorbed potential.SEM analysis of 77.49% of the mixed layer clay and 22.51% of quartz shows that the sandstone surface is rough and has a large number of voids with pore sizes ranging from several microns to more than ten microns.The CMC value of CTAB is 9.576 脳 10 ~ (-4) mol / L ~ (-1) mol / L, the CMC value of TX-100 is 1.72 脳 1O-3 mol / L, and the CMC value of TX-100 is 1.73 脳 10 ~ (-4) mol / L ~ (-1). The CMC value of amphoteric surfactant is 2.93 脳 10 ~ (-4) mol 路L ~ (-1).CMC value of surfactants: Nonionic surfactants, TX-100Betaine amphoteric ionic surfactants, cationic ionic surfactants, CTAB anionic surfactants, CTAB anionic surfactants, have different adsorption conditions on sandstone.The corresponding equilibrium adsorption capacity is different, and the adsorption equilibrium time is also different.The experimental results show that the equilibrium time of SDBS adsorption on sandstone is 72 h, and that of the other three surfactants on sandstone is 48 h.Equilibrium adsorption capacity of Cationic Ion Surfactant CTAB the equilibrium adsorption of Nonionic Surfactant TX-100 Anionic Surfactant SDBS on SandstoneThe adsorption isotherm model is different, and the adsorption of four surfactants on sandstone surface accords with Freundlich adsorption isotherm model, which also shows the heterogeneity of sandstone surface.The pseudo-second-order reaction kinetic model can better describe the adsorption process of four surfactants on sandstone surface. The linear correlation coefficient R20.99 provides guidance for the selection of surfactants in the process of oil displacement.The adsorption mechanism on sandstone is different. The main force of CTAB adsorption on sandstone surface is electrostatic and hydrophobic interaction. The main force of SDBS adsorption on sandstone surface is 蟺 electron polarization and hydrophobicity.The main force of adsorption on sandstone surface is dispersion force.Hydrogen bond and hydrophobic interaction Betaine type amphoteric surfactant adsorbs on sandstone surface mainly by electrostatic force.In a word, the adsorption of surfactants on sandstone is very complicated, and the difference of surfactant structure is the root cause of the difference of adsorption behavior.
【学位授予单位】：西南石油大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TE39

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