十四烷基芳基磺酸盐在大庆油砂上的吸附性能

利用静态吸附实验研究了实验室自制的三种高纯度十四烷基芳基磺酸盐在大庆油砂上的吸附规律,并考察了吸附时间,吸附温度及磺酸盐、NaCl、NaOH、正丁醇的浓度对吸附量的影响.结果表明:吸附量随着磺酸盐浓度的增大逐渐增加后趋于平稳,随着吸附温度和正丁醇体积浓度的降低、NaCl 和NaOH浓度的增加而增大; 磺酸盐活性剂的三种同分异构体中,随两部分碳链长度趋于均等,吸附量下降,且受助剂的影响变小.吸附热力学研究表明,十四烷基芳基磺酸盐在油砂上的吸附等温线服从Langmuir 等温方程,并且计算得到的各参数均能很好地反映磺酸盐在油砂上的吸附特征.吸附动力学研究表明,Elovich 方程能够更好地描述吸附量随时间的变化情况.     

相对分子质量对烷基芳基磺酸盐复配体系固液吸附性能的影响

测定了5种平均相对分子质量和相对分子质量(以下简称分子量)分布不同的烷基芳基磺酸盐复配体系的吸附等温线,分别考察了分子量、分子量分布、温度和无机盐对复配体系在油砂/石英砂表面的吸附量的影响。 结果表明,对5种分子量分布复配体系吸附量依次降低的顺序为递增分布、正态分布、反正态分布、递减分布和均匀分布;复配体系在油砂表面的吸附量随着磺酸盐的平均分子量的增大而增大,随温度的升高而降低,随NaCl浓度的增加而增加。另外,在低浓度时,MgCl2、CaCl2和Na2SO4比NaCl对吸附的影响显著。 NaCl对复配体系在油砂表面的吸附影响比对石英砂表面吸附的影响略大。     

不同链长烷基芳基磺酸盐形成微乳液的性质

以Winsor相态图法和拟三元相图法研究了自制的3种不同链长烷基芳基磺酸盐在多组分体系中形成的微乳液的性质, 并考察了分子结构、无机盐和短链醇等的影响. 结果表明, 无机盐浓度的增加导致表面活性剂/正丁醇/正辛烷/NaCl/水形成的微乳液体系在一定温度下发生由WinsorⅠ→ WinsorⅢ→ WinsorⅡ型转变; 随着烷基芳基磺酸盐分子的长烷基链碳原子数的增加, 耐盐能力减弱, 增溶能力提高; 随着醇碳链的增大, 微乳区面积先增大后减小. 当烷基芳基磺酸盐分子结构固定时, 最大微乳液区域醇的选择依据符合Bansal理论. 醇的链长一定时, 随着烷基芳基磺酸盐分子的长烷基链碳原子数的增加, 微乳液的区域变小.     

烷基芳基磺酸盐结构对微乳液相行为的影响

用Winsor相图法研究了自制的6种不同结构的烷基芳基磺酸盐/不同醇/正癸烷/NaCl/水体系在不同温度下所形成的微乳液。 探讨了烷基芳基磺酸盐结构对微乳液相行为的影响。 同时考察了温度和醇对微乳液相行为的影响。 结果表明,随着烷基芳基磺酸盐长烷基链的增长,中相形成盐度S1、中相消失盐度S2、中相盐宽ΔS和最佳盐浓度S*值均减小,最佳中相体积V*M和最佳增容量σ*值均增大;随着烷基芳基磺酸盐分子的芳环向长烷基链中间位置移动,S1、S2、ΔS、S*值均减小,V*M和σ*值均增大;随着温度升高,V*M和σ*值均减小,S1、S2、ΔS、S*值均增大,在25 ℃时,体系无中相微乳液形成;随着正构醇碳原子数的增加,V*M和σ*值均增大,S1、S2、ΔS、S*值均减小。     

十四烷基芳基磺酸盐形成的分子有序组合体

以表面张力法、碘光谱法、水增溶法和相态图法研究了自制的三种十四烷基芳基磺酸盐在不同条件下形成的分子有序组合体(胶束、反胶束和微乳液),并考察了分子结构、溶剂、无机盐和短链醇等对其的影响.结果表明:增加十四烷基芳基磺酸盐分子亲油基支化度,不利于其在水溶液或混合极性溶剂(乙二醇-水)中形成胶束而有利于其在非极性溶剂正庚烷中形成反胶束;溶剂极性的降低,促使表面活性剂溶液由胶束溶液→单体溶液→反胶束溶液转变;无机盐或短链醇的加入促进了水溶液中胶束的形成,且反离子价态数或醇烷基碳原子数越大,越有利于胶束形成;无机盐浓度的增加导致表面活性剂/正丁醇/正辛烷/NaCl/水形成的微乳液体系在一定温度下发生由WinsorI→WinsorIII→WinsorII型的转变.     

十五烷基芳基磺酸钠溶液表面性质的影响因素研究

测定了自制的四种高纯度十五烷基间二甲苯磺酸钠在纯水溶液和0.0393 mol/L异丙醇溶液中的表面性质,结果表明,随芳基向碳链中间位置的移动,临界胶束浓度cmc增大,分子极限占有面积Amin增大,标准吸附自由能 变得更负,降低表面张力的效率pc20增强,饱和吸附量Γ_max降低,临界胶束浓度时的表面张力γ_cmc降低;且异丙醇的加入使磺酸钠溶液的临界胶束浓度显著降低。从分子结构的特点探讨了分子支化程度对表面性能的影响。     

自溶液中的吸附——XIV.硅胶自Triton X—100和几种烷基硫酸钠的混合水溶液中的吸附

本文测定了硅胶自水中对Triton X-100的吸附,其吸附等温线呈不平常的S型,极限吸附量相当于1.00nm~2/分子,约比气液界面上的大一倍。加入0.1M的NaCl和改变pH对吸附无可察觉的影响。硅胶基本不吸附烷基硫酸钠。当Triton X-100的浓度低于其在混合溶液中的CMC时,烷基硫酸钠的存在对Triton X-100的吸附无影响;但其极限吸附量则随烷基硫酸钠浓度的增大而降低;烷基硫酸钠的碳氢链越长,这种效应就越显著。根据相分离模型,以及只有分子状态的Triton X-100被吸附而胶团不被吸附的假设,可以解释所得结果。     

系列烷基芳基磺酸盐在水溶液中胶束化的焓-熵补偿现象

以表面张力法研究了系列烷基芳基磺酸盐在水溶液中胶束化的热力学性质,并考察了温度与分子结构对胶束化的影响.结果表明,烷基芳基磺酸盐在水溶液中胶束化是一个自发过程,主要来自熵驱动;随着温度升高,先有利于胶束化而后又不利于胶束化,且熵变对吉布斯自由能变的贡献有下降趋势,而焓变的贡献有增大趋势;胶束化存在焓-熵补偿现象,补偿温度Tc均在(306±2)K,基本不随烷基芳基磺酸盐的分子结构的改变而变化;随着芳环上短烷基链或长烷基链碳数的增加,胶束化能力和胶束的稳定性均提高,而随着芳环向长烷基链中间位置移动,胶束化能力和胶束的稳定性均下降.     

支链异构十五烷基间二甲苯磺酸钠溶液表面性质及其溶剂行为

合成了4种高纯度十五烷基间二甲苯磺酸钠,测定了在纯水溶液和0.039 3 mol/L异丙醇溶液中的表面性质. 结果表明,随芳基向碳链中间位置的移动,临界胶束浓度(cmc)增大,分子极限占有面积(Amin)增大,标准吸附自由能(ΔG0)变得更负,降低表面张力的效率(pc20)增强,饱和吸附量(Γmax)降低,临界胶束浓度时的表面张力(γcmc)降低,异丙醇使磺酸钠溶液的cmc显著降低. 从分子结构的特点探讨了分子中脂肪链支化程度对其表面性能的影响.     

电解质对Mg-Al HTlc溶胶聚集动力学行为的影响

采用动态光散射法研究了电解质对Mg-Al类水滑石(HTlc)溶胶聚集动力学行为的影响,发现随惰性电解质(NaCl,NaNO3)浓度的增大,Mg-Al HTlc溶胶经历稳定、慢速聚集和快速聚集三个区域,而特性吸附电解质(NaOH)在所研究的浓度范围(0～4mmol/L)内未观察到快速聚集.NaCl和NaNO3的临界聚沉浓度分别为127和180mmol/L,慢速聚集区稳定比与NaCl,NaNO3和NaOH浓度间的关系式分别为：logW=10.18-4.4410gC,logW=11.98-4.7910gC,losW=1.92-0.7410gC.NaOH诱导体系聚集的能力大大高于NaCl和NaNO3.     

Effect of Alkanolamide on Interfacial Tension and Loss of Petroleum Sulfonates for Enhanced Oil Recovery

Experimental studies are conducted in order to elucidate the mechanisms of monoethanolamide responsible for synergism on lowering interfacial tension and decreasing loss due to adsorption on surface of reservoir sand and precipitation with multivalent cations in model oil/water/surfactants/brine systems. The interfacial tensions between solutions containing crude oil and monoethanolamide, petroleum sulfonates, or mixture of monoethanolamide and petroleum sulfonates at different ratios are studied without any alkali added in the solution. The results show significant synergic effect between monoethanolamide and petroleum sulfonates can reduce the interfacial tension to ultralow. Adsorption isotherms of monoethanolamide, petroleum sulfonates and mixture solution are determined to assess the effect of monoethanolamide on reducing the loss of petroleum sulfonates in formation. Static adsorption experiments indicate that the loss of petroleum sulfonates for adsorption and precipitation can be reduced on a great degree when monoethanolamide is mixed with petroleum sulfonates. The core-flooding tests show that the enhanced oil recovery with the formulation of surfactants of 0.3 wt% petroleum sulfonates and 0.2 wt% monoethanolamide can be increased by 26.6% without any alkali added in the flooding solution.     

驱油用磺酸盐表面活性剂的研究进展

综述了驱油用石油磺酸盐、重烷基苯磺酸盐、脂肪醇聚氧乙烯醚磺酸盐及磺酸盐双子表面活性剂四种磺酸盐表面活性剂的研究进展,指出了这四种表面活性剂在油田应用中存在的问题以及未来的发展方向;阐述了油水乳化提高原油采收率的机理,初步分析了影响表面活性剂乳化能力的因素,强调了从分子结构的角度研究表面活性剂性能的重要性.     

Studies of Interfacial Activities of Four Kinds of Surfactants at Oil/Water Interface

This article aims to compare the interfacial activities of different kinds of surfactants in the same oil/water system. The anionic surfactants of alkylbenzene sulfonates, the polyoxyethylenated nonionic surfactants, the cationic surfactants of alkyl trimethyl ammonium chlorides, and the zwitterionic surfactants of alkyl hydroxyl sulfobetaines were used, and the interfacial tensions of the surfactant solutions against kerosene at different NaCl concentrations were measured. It is found that the interfacial activities of the alkylbenzene sulfonates are high and ultralow interfacial tensions (<0.01 mN/m) can be obtained at proper salinities. While, the nonionic surfactants have relatively low interfacial activities and the minimum tensions are around 0.01 mN/ms. The salinity scanning curves of the alkylbenzene sulfonates and nonionic surfactants decrease first, then increase, showing their interfacial activities can be changed by the salinity effectively. The cationic and zwitterionic surfactants have very low interfacial activities, of which all the tensions are higher than 0.1 mN/ms and are hard to be changed by the salinity. The experimental results may have important reference values for enhanced oil recovery.     

十二烷基硫酸钠水溶液的动态表面吸附性质

利用MPTC型气泡压力张仪研究了十二烷基硫酸钠(SDS)溶液在不同NaCl 浓度下的动态表面吸附性质, 分析了离子型表面活性剂在表面吸附层和胶束中形成双电层结构产生表面电荷对动态表面扩散过程和胶束性质的影响. 结果表明, SDS在表面吸附过程中, 表面电荷的存在会产生5.5 kJ·mol^-1的吸附势垒(E_a), 显著降低十二烷基硫酸根离子(DS^-)的有效扩散系数(D_eff). 十二烷基硫酸根离子的有效扩散系数与自扩散系数(D)的比值(D_eff/D)仅为0.013, 这表明SDS与非离子型表面活性剂不同, 在吸附初期为混合动力控制吸附机制. 加入NaCl可以降低吸附势垒. 当加入不小于80 mmol·L^-1 NaCl后, E_a小于0.3 kJ·mol^-1, D_eff/D在0.8-1.2之间, 表现出与非离子型表面活性剂相同的扩散控制吸附机制. 同时, 通过分析SDS胶束溶液的动态表面张力获得了表征胶束解体速度的常数(k₂). 发现随着NaCl 浓度的增大, k₂减小, 表明SDS胶束表面电荷的存在会增加十二烷基硫酸根离子间的排斥力, 促进胶束解体.     

Adsorption of nonionic mixtures at the air-water interface: effects of temperature and electrolyte

Specular neutron reflection has been used to investigate the effects of temperature and added electrolyte on the adsorption of nonionic surfactants and nonionic surfactant mixtures at the air-water interface. For the alkyl poly-oxyethylene oxide nonionic surfactants, C(n)EO(m), the adsorption at the air-water interface is independent of temperature for surfactants with shorter ethylene oxide groups, whereas there is an increasing tendency for increased adsorption with temperature for surfactants with longer ethylene oxide groups. The addition of "salting in" (sodium thiocyanate, NaSCN) and "salting out" (sodium chloride, NaCl, sodium sulphate, Na2SO4) electrolyte results in reduced and enhanced adsorption, respectively, for C12EO8, whereas both types of electrolyte result in enhanced adsorption for C12EO12. The addition of electrolyte does not substantially alter the temperature dependence of the adsorption of the pure monolayers. For the nonionic mixtures of C12EO3/C12EO8 increasing temperature results in a surface richer in the least surface-active component, C12EO8. For the same nonionic mixture, the addition of "salting in" and "salting out" electrolyte results in an reduced and increased adsorption, respectively. The addition of "salting in" electrolyte results in a surface more rich in C12EO3, whereas for the addition of both "salting in" and "salting out" electrolyte the surface composition is essentially unaltered.