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1.
电导法测定表面活性剂溶液的临界胶束浓度   总被引:2,自引:0,他引:2  
本文用电导法测定了十二烷基磺酸钠在40℃和60℃时的临界胶束浓度(CMC),根据“相分离模型”计算了40℃时十二烷基硝酸钠溶液的胶束形成标准焓变(△Hm),标准吉布斯自由能变化(△Gm)和标准熵变(△Sm)。  相似文献   

2.
用电导、表面张力和折光指数法估算了十二烷基硫酸钠(SLS)、十二烷基苯磺酸钠(SDBS)和辛基酚聚氧乙烯基醚(OP)复合乳化剂的临界胶束浓度(CMC)。发现,SLS/OP和SDBS/OP的CMS值约为10^-3g/ml数量级,数据与乳化剂纯度有关,但与复合乳化剂中两者的比例无关。同时对三种测定方法作了评价。  相似文献   

3.
表面活性剂增效技术是近期发展起来并被认为是可对污染地下水进行有效修复的技术之一,但为避免引起新的污染,需控制其投放剂量。综述了通过表面活性剂的优化匹配及水化学组分调节等方式降低表面活性剂的临界胶束浓度,进而实现减少表面活性剂投放量的研究进展,指出其存在的问题,展望其发展前景。  相似文献   

4.
以中性红为探针,用吸伏安法测定了十六烷基三甲基溴化铵的临界胶速浓度,基本原理为:存在于表面活性剂溶液中的微量中性红在悬汞电极上的吸附伏安峰电流对表面活性剂浓度的曲线在临界胶束浓度处有一拐点,此点即为阳离子表面活性剂的临界胶束浓度。  相似文献   

5.
测量吖啶化合物作为发光剂在系列浓度的表面活性剂溶液的化学发光值,根据所得发光值的对数值与其对应的表面活性剂溶液中表面活性剂浓度的对数值进行线性拟合得出若干条拟合直线,相邻两条拟合直线的交点对应的表面活性剂浓度中的最小值即为该表面活性剂的临界胶束浓度.由测定结果可知,十二烷基三甲基氯化铵的临界胶束浓度是11.5 mmol...  相似文献   

6.
低聚型表面活性剂临界胶束浓度的分光光度法测定   总被引:1,自引:0,他引:1  
本文在前人的基础上提出了一种采用紫外分光光度法测定聚型表面活性剂的临界胶束浓度的新方法,探讨了不同条件对测定结果的影响,并确立了优化条件。通过对增溶机理的讨论,进一步说明了低聚型表面活性水溶液的特征。  相似文献   

7.
表面活性剂增效技术是对非水相液体(NAPL)污染地下水进行有效修复的技术之一。在提高NAPL水溶性的同时,寻找到表面活性剂的适宜投放量、降低其负效应的途径是表面活性剂增效修复技术能否广泛使用的前提。  相似文献   

8.
碘光谱法测定非离子表面活性剂的临界胶束浓度   总被引:6,自引:0,他引:6  
考察了碘光谱法测定非离子表面活性剂在水溶液中的临界胶束浓度(cmc)的影响因素。欲得正确结果,须将碘-胶束溶液(不同浓度)放置,待碘的分配达到平衡(例如24h)后再进行测定,这样测得TritonX-100、TritonX-305和单分散的纯化合物C12H25O(C2H4O)6H的cmc分别为2.4×10-4、3.5×10-4和8.4×10-5mol·dm-3,与文献中用表面张力法测得的结果一致。若按Ross和Oliver将预先配好的溶液稀释后1小时内测定的方法,则所得结果偏低。只要测定时碘-胶束溶液已达平衡,则碘浓度在4~12mg/100ml范围内对cmc的测定结果无明显的影响。文献中提到的碘浓度对cmc测定值的影响可能是由于碘的分配未达平衡所致。  相似文献   

9.
本文通过实验选出了适用于测定聚酯型表面活性剂临界胶束浓度的添加物二甲基偶氮苯,确定了最佳浓度区间,建立了简单,快速的测定方法。  相似文献   

10.
人工神经网络预测阴离子表面活性剂的临界胶束浓度   总被引:1,自引:0,他引:1  
根据定量结构-性能关系原理,利用人工神经网络模型,采用Wn、S和Sn三种拓扑指数描述阴离子表面活性剂的分子结构并作为网络输入,预测阴离子表面活性剂的临界胶束浓度。确定了网络参数,利用43组数据对网络进行训练和预测,并与文献值进行了比较。结果表明,预测精度较高,说明人工神经网络方法具有很好的预测能力。  相似文献   

11.
We studied the behavior of an aqueous ternary surfactant mixture composed of a nonionic surfactant and two anionic surfactants which differ in both surfactant hydrophobic tail length and surfactant hydrophilic head structure. We used an experimental design program to calculate the critical micelle concentrations (CMCs) of this ternary surfactant mixture over the entire range of solution compositions. As inputs, the experimental design methodology requires the values of the ternary surfactant mixture CMCs for a limited subset of solution compositions which is determined by the experimental design program. We showed that this subset of ternary surfactant mixture CMC values can either be measured experimentally or predicted theoretically. The theoretical CMCs were predicted by a series of userfriendly computer programs which are based on molecular-ther-modynamic theories describing single and mixed micelle formation. The experimental design program generated two surfaces describing the ternary surfactant mixture CMCs over the entire solution composition range—one based on the experimentally measured subset of CMC values, and the other based on the theoretically predicted CMC values for the same subset of solution compositions. We found that these two CMC surfaces agree very well, thus demonstrating the utility of the computerassisted molecular-thermodynamic modeling as a predictive tool in surfactant mixture characterization and design.  相似文献   

12.
以中性红为探针,用吸附伏安法测定了溴化十六烷基三甲铵的临界胶束浓度。  相似文献   

13.
A proposed method of determining the composition of mixed micelles in equilibrium with monomer of known composition is described. The systems were sodium dodecyl sulfate-polyoxyethylene 23 lauryl ether (Brij 35) in water and in 0.1 M sodium chloride solution at 25°C. This technique applies the Gibbs-Duhem equation to the mixed micelle, which is treated as a pseudophase. This proposed methodology which needs only critical micelle concentration data as a function of monomer composition, is applied to an anionic/nonionic surfactant pair. The calculated monomer-micelle equilibrium is found to be very similar to the much-used regular solution for nonideal systems.  相似文献   

14.
用电导法对十二烷基硫酸钠(SDS)的临界胶团浓度(CMC)进行了研究,考虑了温度、pH值、金属离子(Cd2+、Zn2+、Pb2+)浓度变化以及SDS和3种非离子表面活性剂(Brij35、TritonX-100、APG)的复配对溶液CMC值的影响。结果表明,随温度升高,pH值上升,金属离子浓度增加以及Brij35/SDS、TritonX-100/SDS、APG/SDS混合体系配比的增加,溶液CMC值减小。特别当复配比在0.13~1时,CMC值的下降趋势非常明显。这一结果为采用胶团强化超滤技术处理电解锌废水时SDS最佳添加量的确定提供了有效的依据。  相似文献   

15.
以K12表面张力仪为主要手段研究了十二烷基苯磺酸钠(LAS)和聚醚组成的混合表面活性剂体系的增效作用。实验表明,十二烷基苯磺酸钠(LAS)和聚醚组成的混合表面活性剂体系的临界胶束浓度(cmc)大大低于任一单一组分溶液的cmc,且在其中一组分的溶液中加入少量的另一组分即可使体系的cmc大为降低。在很大的配比范围内cmc都维持在一较低水平且随配比改变变化的幅度不大。此外,混合表面活性剂体系在形成胶束能力以及降低表面张力效率方面都显示出较强的增效作用。但在降低表面张力能力方面,未显示出增效作用。  相似文献   

16.
In this work, a novel trimeric octadecyl zwitterionic surfactant (TOCC) was successfully synthesized. TOCC was compounded with sodium salicylate (NaSal) for an optimized formulation to form viscoelastic micelles. The effects of NaSal concentration, pH, and temperature on the rheological properties of TOCC and TOCC/NaSal micelle solutions were investigated. The flow curves for both TOCC and TOCC/NaSal micelle solutions can be fitted with the Carreau–Yasuda model. Zero shear viscosity of TOCC/NaSal micelle solution increased and then decreased with increasing NaSal concentration, and the same trend was observed for viscoelasticity. Some micelle solutions exhibited significant thixotropy with stress overshoot. The optimal composition of the TOCC/NaSal micelle solution obtained was 5.0/0.5 wt%. Frequency sweep in the form of Cole–Cole plots indicated that the viscoelastic modulus of the TOCC/NaSal micelle solution fitted the Maxwell model at low and medium frequencies. With increasing pH, 5.0 wt% TOCC micelle solution had the maximum zero shear viscosity at pH = 6.9. The steady-state viscosities of different concentrations of TOCC micelle solutions reached their maximum at neutral conditions (pH = 6.5 ~ 7.0). Viscoelastic modulus of 5.0 wt% TOCC and TOCC/NaSal (5.0/0.5 wt%) micelle solutions decreased with increasing temperature, and thermal thixotropy was observed in both micelle solutions. The novel TOCC and TOCC/NaSal micelle solutions enrich the variety of trimeric surfactants and viscoelastic micelle solutions. This study provides a rheological reference for the applications of viscoelastic trimeric surfactants in smart materials and oil fields.  相似文献   

17.
The individual binary polymer blends of phenolic/phenoxy, phenolic/poly(vinyl phenol) (PVPh), and phenoxy/PVPh have specific interaction through intermolecular hydrogen bonding of hydroxyl–hydroxyl group to form homogeneous miscible phase. In addition, the miscibility and hydrogen bonding behaviors of ternary hydrogen bond blends of phenolic/phenoxy/PVPh were investigated by using differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy, and optical microscopy. According to the DSC analysis, every composition of the ternary blend shows single glass transition temperature (Tg), indicating that this ternary hydrogen‐bonded blend is totally miscible. The interassociation equilibrium constant between each binary blend was calculated from the appropriate model compounds. The interassociation equilibrium constant (KA) of each individually binary blend is higher than any self‐association equilibrium constant (KB), resulting in the hydroxyl group tending to form interassociation hydrogen bond. Photographs of optical microscopy show this ternary blend possess lower critical solution temperature (LCST) phase diagram. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009  相似文献   

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