表面活性剂的化学结构与性能的关系

1.亲水亲油平衡值(HLB值)与性能之间的关系表面活性剂要呈现特有的界面活性,必须使疏水基和亲水基之间有一定的平衡。石蜡HLB值=0(无亲水基),聚乙二醇HLB值=20(完全     

阴离子表面活性剂亲水亲油平衡值的QSPR研究

采用分子电性距离矢量（MEDV）表征65个阴离子表面活性剂的分子结构,运用多元线性回归技术,同时采用逐步回归结合统计检测对模型变量进行筛选,建立了阴离子表面活性剂的亲水亲油平衡值（HLB）与MEDV的定量结构．性质关系（QSPR）模型。采用内外双重验证的办法深入分析和检验所得模型稳定性,建模计算值、留一法交互校验预测值和外部样本预测值的复相关系数僻）分别为0．971、0．956和0．958。结果表明：所建QSPR模烈有良好的稳定性和预测能力。该研究结果为预测表面活性剂的亲水亲油平衡值提供了理论依据。     

油基钻井液乳化剂HLB值的测定

油包水钻井液是一种不稳定体系,在钻井中始终存在乳化失效的危险,影响体系稳定性的最主要原因是乳化剂,所以合理选择乳化剂是提高体系稳定性的关健。亲水亲油平衡值(HLB值)是选择和使用表面活性剂的定量指标,本文用静置观察法,测定了市面上常用的6种油包水钻井液体系乳化剂的HLB值,根据表面活性剂的HLB值,可以推断出某种表面活性剂可用于何种用途,或用于设计合成新的表面活性剂的计算指标。     

聚氧乙烯类和硫酸盐类表面活性剂HLB值的研究

亲水亲油平衡值(Hydrophile/Lipophile Balance,HLB)是表征表面活性剂性质的重要参数。采用比较分子力场分析(comparative molecular field analysis,CoMFA)方法和比较分子相似性指数分析(comparative similarity indices analysis,CoMSIA)方法,研究了30个烷基酚聚氧乙烯醚系列非离子表面活性剂的三维定量结构与pHLB值的关系。建立的CoMFA模型交叉验证系数为0.705,非交叉验证系数为0.805:CoMSIA模型交叉验证系数为0.685,非交叉验证系数为0.813,都有较好的预侧能力。此外,运用多元线性回归方法建立一种预报硫酸盐类表面活性剂HLB的QSPR模型,模型的复相关系数为0.711。所有选取的测试集和训练集的预报结果较为吻合,说明硫酸盐类表面活性剂HLB值QSPR模型具有良好的预报能力和普适性。     

食品乳化剂的应用

乳化剂也是一种表面活性剂,其亲水亲油平衡值(HLB)在3.5～6之间的为水/油型乳化剂(亲油型),在8～18之间的为油/水型乳化剂(亲水型)。食品工业中常用的乳化剂为非离子型酯类。要得到稳定的乳浊液,必须选择适当的乳化剂(适应的HLB值),时常用复方以便取得更佳的协同效应。     

表面活性剂的HLB及其加和性的研究

本文介绍了用气液色谱法测定表面活性剂的亲水亲油平衡值(HLB值)的方法,并用此法测定了甘油单硬脂酸酯等十种非离子型表面活性剂的HLB值,所得数据与文献值比较具有一致性。通过研究两对混合表面活性剂的HLB值与混合物浓度的关系,对HLB值的加和性进行了初步探索。     

气液色谱测定非离子型表面活性剂的HLB

亲水亲油平衡值HLB为表面活性剂的重要性质，测定HLB的方法很多，气液色谱法被认为是“最有前途”的方法，此法基于溶液热力学性质，在概念上可直接联系表面活性剂的溶解性能，所得结果准确，并可获得更多的热力学数据。     

蔗糖脂肪酸酯HLB值测定方法的研究

本测定法根据亲水—亲油平衡值原理和HLB值的加和性特点,利用已知HLB值的非离子表面活性剂与水数的关系求得蔗糖脂肪酸酯的HLB值。     

W/O型微乳液稳定性实验及PAM水溶液微胶囊制备

基于电导率的测定得到最大增容水量,探究表面活性剂种类、复配后亲水亲油平衡值(HLB)、用量、温度等因素对油包水(W/O)微乳液体系稳定性的影响。结果表明,以Span 80和Tween 80复配的表面活性剂,在HLB值等于5.5的条件下,W/O型微乳液的稳定性最佳。以此为基础,以甲基丙烯酸甲酯(MMA)和甲基丙烯酸丁酯(BMA)的共聚物为壁材,聚丙烯酰胺(PAM)水溶液为芯材,通过原位聚合法合成了微胶囊,并对其形貌及理化性质进行了表征。     

农药乳化剂HLB值的测定方法

<正> 研究表面活性剂亲水亲油平衡值(简称HLB值)的文章很多,本文根据我们的实践经验,重点介绍几种有实用价值的农药乳化剂HLB值的测定方法。一、乳化试验法乳化试验法测定HLB值的依据,是乳化剂和被乳化物所要求的HLB值,应当是相同的。(一)乳化剂HLB值的测定     

Nucleation behavior of blended high‐melting fractions of milk fat as affected by emulsifiers

The effect of highly hydrophobic emulsifiers, the palmitic sucrose ester P‐170 (hydrophilic/lipophilic balance (HLB) = 1.0), the stearic sucrose ester S‐170 (HLB = 1.0), the polyglycerol ester decaglycerol decastearate DAS 7S (HLB = 3.7) and the polyglycerol ester decaglycerol dodecabehenate DDB 750 (HLB = 2.6), on the nucleation of a high melting point milk fat fraction (HMF) and its blends with sunflower oil (SFO) was investigated by polarized laser light turbidimetry, X‐ray diffractometry and polarized light microscopy (PLM). Addition of polyglycerol esters accelerated nucleation, giving shorter induction times for the same supercooling. On the contrary, sucrose esters inhibited nucleation since induction times were elongated in all conditions selected. Addition of emulsifiers modified the polymorphic behavior in the blends with SFO. The β' form was promoted especially with the addition of S‐170. DAS 7S and DDB 750 promoted crystallization. PLM images showed many small crystals that did not appear in HMF images. Addition of P‐170 and S‐170 delayed nucleation and inhibited crystal growth. Crystals were notoriously smaller than the ones that appeared in HMF images. The Fisher–Turnbull model was used to calculate activation free energies of nucleation. In all cases, sucrose esters elevated the energy barrier for nucleation. Polyglycerol esters, however, if they had an effect on the energy barrier, lowered the values.     

Further studies of detergency correlation

The significance of the relationships of the linearity constants of a previously reported detergency-micellar solubilization function (1) to surfactant HLB (hydrophile-lipophile balance), boundary tensions, and soil dipole moment was extended, first, by demonstrating their existence in systems of four homologous surfactants with one soil or four classes of soil with one surfactant, and second, by showing in every case that they are probably physical rather than random because they contain fewer constants than the number of points (four) used in their derivation. A study of a series of surfactant-soil systems consisting of a family of polyoxyethylated nonyl phenols and a family of saturated fatty acid soils (12–18 carbon) revealed linearity of the R-log (M/CMC) and surfactant HLB-log (M/CMC) functions for values of R (ethylene oxide mole ratio) between 15–50 and 10–100, respectively (M=surfactant concentration giving ca 100% removal of 16 and 18 carbon fatty acids, and CMC=critical micelle concentration). The validity of the semi-logarithmic functions was confirmed by the fact that they indicated linearity between R and surfactant HLB as previously reported (2). Abnormally high nonyl phenol adduct concentrations (2.7–3.8%) were required to give good fatty acid removal. It was suggested that the initial decrease in detergency with increase of fatty acid soil HLB from 6.5–9.8, followed by increasing detergency as the soil HLB continued to increase to 11.25, was due to differences in the relative magnitudes of the soilsubstrate adhesive forces and micellar solubilization existing in the soil HLB range. Sodium dodecyl benzene sulphonate was a good detergent of the saturated fatty acids, soil removal being independent of soil HLB for the 12–18 carbon acids. The fatty acid soaps were poor detergents of these soils. A “net ethylene oxide solubilizing power” method of computing HLB was proposed, based on known polar group hydrophobe-solubilizing values.     

柠檬醛基抗油茶炭疽病菌衍生物的定量构效关系研究

为探讨柠檬醛基衍生物的结构与其对油茶炭疽病菌的抗菌活性之间的关系，研究了柠檬醛基抗油茶炭疽病菌衍生物的定量构效关系。使用计算化学软件Gauss View05、Gaussian 09W、Ampac和Codessa分别完成了柠檬醛基衍生物分子结构的构建、优化、描述符计算与筛选，以及QSAR模型建立。结果表明：建立了一个含有4个描述符：氢原子之间的相互斥力、分子中带正电荷加权部分表面积比例、氢原子的数量、分子表面正电荷分布以及分子总表面积的最佳QSAR模型，相关系数(R²)为0.926 5。对最佳QSAR模型进行内部检验和外部检验，其中留一法内部检验的R_CV²=0.865 7，三重内部检验的R_training²=0.879 3、R_test²=0.882 4；外部检验的R_外²=0.946 7，表明该模型具有良好的稳定性和预测能力。解析建模描述符可知，柠檬醛基衍生物分子结构中与氢键供体相关的描述符对抗菌活性具有显著影响。本研究可为新型柠檬醛抗油茶炭疽病菌衍生物的设计与合成提供理论指导。     

近红外光谱在中药大黄乙醇提取液快速分析中的应用研究

用声光可调滤光器(AOTF)-近红外(NIR)光谱法在线分析中药大黄乙醇提取液比重及大黄素含量,用偏最小二乘(PLS1)法分别建立NIR光谱与含量、比重的校正模型。结果表明,提取液NIR光谱与比重、含量的校正模型相关系数R2分别为0.989 0,0.988 4,相对偏差分别为0.26%,2.66%,精密度分别为0.15%,2.84%;5 h稳定性分别为0.13%,2.03%,回收率分别为99.8%,95.6%。该方法具有快速、直接、多成分同时测定特点,并能实现现场在线分析。     

Novel evaluation method for the water- in- oil (W/O) emulsion stability by Turbidity Ratio Measurements

The turbidity ratio method of evaluating the stabilities of water-in-oil emulsions has been established with two wavelengths (450 and 850 nm) by taking the intensity ratio of two beams. The slopes of turbidity ratio of several water-in-oil emulsions with time were calculated to evaluate the emulsion stabilities at different HLB (Hydrophilie-Lipophile Balance), the amounts of emulsifiers, and water contents. The results of the turbidity ratio technique were consistent with the amount of phase separation of emulsions incubated for 30 days at room temperature. From the turbidity ratio measurements, we determined that the required HLB of diesel oil was about 6.0, and that the stability of emulsion increased with the amount of emulsifier. The increasing amount of the water showed a negative effect on emulsion stability. Finally, this method provides a useful tool for the quick evaluation of the required HLB and the condition of emulsification throughout this study.     

脂肪族硝基含能化合物撞击感度的QSPR研究

基于定量结构-性质相关性(QSPR)原理,研究脂肪族硝基化合物撞击感度与其分子结构间的内在定量关系。应用遗传函数算法筛选出与撞击感度密切相关的6个参数作为分子描述符;采用多元线性回归方法建立基于该6参数的脂肪族硝基化合物撞击感度预测模型。分别采用内部验证及外部验证的方式对模型性能进行验证,研究结果表明模型具有较高的稳定性、预测能力及泛化性能。     

芳烃分子描述符的修正和沸点预测建模

根据芳烃分子中碳原子所处化学环境的差异,修正分子描述符Randi?连接性指数中碳原子支化度参数δ_i ,提出新的分子描述符Modran;通过对比分析表明描述符Modran对芳烃分子的化学结构具有更好的选择性。分析芳烃沸点的影响因素,采用最优子集选择法,发现Modran一阶和二阶支化度指数、分子极化率和芳环碳原子占比四个分子描述符参数的组合对芳烃沸点具有良好的预测能力,进而建立包含Modran等四分子描述符的线性组合模型和神经网络模型。与Marrero-Pardillo基团贡献法比较,四分子描述符的神经网络模型将芳烃沸点预测的平均绝对误差由12.26 K降低到4.56 K。