脂肪醇聚氧乙烯(3)醚低温浑浊原因的探讨

通过在AEO3中添加不同加成数的AEO进行低温浑浊试验，并分析比较AEO3低温分层后的上清液与下层浑浊物中AEO的分布，发现EO加成数在5以上的AEO是导致AEO3低温浑浊的原因之一。在AEO3及其上清液中分别添加不同质量分数的脂肪醇、水以及醋酸钠进行低温浑浊试验，发现脂肪醇、水分和醋酸钠不是造成AEO3低温浑浊的原因，但会使AEO3在低温下容易冻结。     

Direct ethoxylation of fatty methyl ester over Al-Mg composite oxide catalyst

For the purpose of estimating the reaction mechanism of the direct ethoxylation of a fatty ester in the presence of an Al-Mg composite oxide catalyst, a labeled fatty methyl ester C₁₁H₂₃CO¹⁸OCH₃ containing ¹⁸O isotope was synthesized and directly ethoxylated. The product was evaluated by gas chromatography-mass spectrometry (GC-MS). The GC-MS spectra showed that the ¹⁸O isotope label was present only in the methoxy group at the molecular end of the ethoxylated fatty methyl ester. This supports the reaction mechanism of coordination anionic polymerization where the bond between the acyl and methoxy groups of the fatty methyl ester molecule was broken, caused by the bifunctional effect of the acid-base active sites; an intermediate chemisorption species was formed; and then ethylene oxide was addition-polymerized sequentially, in parallel.     

乳液型有机硅消泡剂SG的制备与性能

采用Span-Tween乳化体系及普通搅拌装置对硅油进行乳化，研制出的乳液型有机硅消泡剂SG具有良好的离心稳定性和静态稳定性，在室温下放置6个月后乳液不分层，性能不变；消泡剂SG在一定温度范围内（＞20℃），消泡性能随温度的升高而增加，但温度升高到50℃以上时，消泡性能保持在一定水平；适应的pH值范围广，在pH值为1－14的水基体系中均可有效地消除泡沫。同其他几种相同价位的市售消泡剂相比，消泡剂SG生产工艺简单，成本低廉，具有更高的性能价格比。     

PMMA/SiO2复合微球在常规乳液体系中的制备及其形态研究

以4-乙烯基吡啶(4-VP)为辅助单体,分别使用十二烷基硫酸钠(SDS)和OP-40(CA897)作乳化剂,在SiO2存在下用常规乳液聚合合成了PMMA/SiO2复合微球.在阴离子乳化剂体系中,通过改变聚合物乳胶粒大小可以得到不同形态的复合微球,在非离子乳化剂体系中,可以得到草莓型或核-壳形态的SiO2/PMMA复合微球,取决于单体滴加速度、乳化剂的浓度和单体/SiO2比.复合微球的形态通过透射电镜及扫描电镜进行表征.     

Activity and stability ofPenicillium cyclopium lipase in surfactant and detergent solutions

Activity and stability of an alkaline lipase fromPenicillium cyclopium var.album (PG 37) were studied in surfactant and detergent solutions. Three anionic surfactants [Na salts of C₁₂SO₄ ^? (sodium dodecyl sulfate), C₁₂ØSO₃/^? (linear alkyl benzene sulfonate), and C₁₁COO^? (laurate)] and four homologous series of nonionic surfactants of C_12–15 polyoxethylenated fatty alcohols (AEO₃, AEO₅, AEO₇, and AEO₉) were evaluated. At a concentration range of 3.2–40 μM, sodium dodecyl sulfate and laurate stimulated the activity of PG 37 lipase. At concentrations greater than 5.6 μM, linear alkylbenzene sulfonate inhibited PG 37 lipase activity. Nonionic surfactants, AEO₅ and AEO₇, in the concentration range of 0.25–20 mM, enhanced and stabilized the activity of PG 37 lipase. The presence of PG 37 lipase in detergent formulaton improved detergency ～20%. The mechanism of inhibition of the lipolytic activity of PG 37 lipase is proposed to be partly due to the formation of inactive (BR)_n-E complex between the hydrophobic moiety of the surfactants and the surface of the lipase. Conversely, formation of a soluble (RB)_n-E complex between the hydrophilic group of the surfactant and lipase may account for the increased lipolytic activity of PG 37 lipase.     

脂肪醇聚氧乙烯醚的厌氧与好氧生物降解性

以脂肪醇聚氧乙烯醚(AEO)为目标污染物，在等同条件下做厌氧消化污泥和好氧活性污泥对其生物降解性能的对比实验，得出了同一系列AEO分子中聚氧乙烯基与整个分子的降解难易程度的关系。表明：①污泥会对AEO分子产生吸附一脱附作用而出现假降解率，克服假降解率的干扰是准确测定AEO生物降解性的关键因素；②厌氧和好氧条件下，AEO均可降解，但厌氧降解要稍优于好氧降解；③AEO中聚氧乙烯基的单元数(n)是影响其生物降解的重要因素，相同碳链的直链烷基，生物降解率随n的增加而明显降低。     

Analysis of surfactants: Part II

We present a comprehensive review of the literature devoted to the analysis of surfactants. The period covered is 1995 through 1998. We address patents, reviews, books, journal articles, and any conference proceedings abstracted by Chemical Abstract Services. We consider classical, instrumental, and state-of-the-art analytical applications, including those not in common practice but in a developmental stage. We also include analytical techniques that make use of surfactants for improved performance, although such treatment is not comprehensive. Literature from foreign language sources is covered as completely as practical.     

非离子表面活性剂对阳离子复合杀菌剂杀菌性能的影响

在棕榈油乙氧基化物(NOE-Pn)(n=3,6,9,12和14)质量浓度为50 mg/L的条件下,通过研究其EO加合数(n)对由双癸基二甲基甲酸铵(DDAF)、双烷基(碳数8~10)二甲基氯化铵(D8-10)、聚六亚甲基双胍盐酸盐(IB)、双癸基甲基羟乙基氯化铵(DEQ)和十二烷基二甲基苄基氯化铵(1227)5种阳离子表面活性剂复合组成的杀菌剂(阳离子复合杀菌剂,总质量浓度为140 mg/L,其中m(DDAF)∶m(D8-10)∶m(IB)∶m(DEQ)∶m(1227)=3∶2∶3∶3∶3)杀菌性能的影响,结果发现杀菌时间为20 min的条件下在n=9时(NOE-P9),对阳离子复合杀菌剂的影响最小,与脂肪醇聚氧乙烯(9)醚(AEO9)基本一致。在阳离子复合杀菌剂中引入非离子表面活性剂NOE-P9、AEO9和烷基糖苷(APG0810)以及阴-非离子表面活性剂脂肪醇聚氧乙烯(9)醚羧酸(AE9C),发现其对白色念珠菌的影响较大。在此基础上,对比了提高杀菌剂的总质量浓度至180 mg/L和延长杀菌时间至1 h的杀菌效果。结果发现浓度的提高使得杀菌性能略有增强;延长杀菌时间可以明显提升复合体系的杀菌效果,尤其是非离子表面活性剂质量浓度较低时,对金黄色葡萄球菌和大肠杆菌的杀灭对数值均大于6。     

Immunochromatographic assay using gold nanoparticles for measuring salivary secretory IgA in dogs as a stress marker

Abstract

The concentration of salivary secretory immunoglobulin A (sIgA) is a well-known stress marker for humans. The concentration of salivary sIgA in dogs has also been reported as a useful stress marker. In addition, salivary sIgA in dogs has been used to determine the adaptive ability of dogs for further training. There are conventional procedures based on enzyme-linked immunosorbent assay (ELISA) for measuring salivary sIgA in dogs. However, ELISA requires long assay time, complicated operations and is costly. In the present study, we developed an immunochromatographic assay for measuring salivary sIgA in dogs using a dilution buffer containing a non-ionic surfactant. We determined 2500-fold dilution as the optimum condition for dog saliva using a phosphate buffer (50 mM, pH 7.2) containing non-ionic surfactant (3 wt% Tween 20). The results obtained from the saliva samples of three dogs using immunochromatographic assay were compared with those obtained from ELISA. It was found that the immunochromatographic assay is applicable to judge the change in salivary sIgA in each dog. The immunochromatographic assay for salivary sIgA in dogs is a promising tool, which should soon become commercially available for predicting a dog's psychological condition and estimating adaptive ability for training as guide or police dogs.     

Importance of micellar relaxation time on detergent properties

As we enter the new millennium, manufacturers of laundry detergents would like to provide new products for the twenty-first century. With the goal of achieving new and better performance characteristics, design strategies for research and development should be defined. This paper highlights the importance of micellar relaxation kinetics in processes involved in detergency. Earlier Shah and coworkers showed that the stability of sodium dodecyl sulfate (SDS) micelles plays an important role in various technological processes. The slow relaxation time (τ₂) of SDS micelles, as measured by the pressure-jump technique, was in the range of 10⁻⁴ to 10¹ s, depending on the surfactant concentration. A maximal relaxation time and thus a maximal micellar stability was found at 200 mM SDS (5 s), corresponding to the least-foaming, largest bubble size, longest wetting time of textile, largest emulsion droplet size, and the most rapid solubilization of oil. These results are explained in terms of the flux of surfactant monomers from the bulk to the interface, which determines the dynamic surface tension. More stable micelles lead to less monomer flux and hence to a higher dynamic surface tension. The relaxation time for nonionic surfactants (as measured by the stopped-flow technique) was much longer than for ionic surfactants because of the absence of ionic repulsion between the head groups. The τ₂ was related to dynamic surface-tension experiments. Stability of SDS micelles can be greatly enhanced by the addition of long-chain alcohols or cationic surfactants. In summary, relaxation time data of surfactant solutions enable us to predict the performance of a given surfactant solution. Moreover, results suggest that one can design appropriate micelles with specific stability, or τ₂, by controlling surfactant structure, concentration, and physicochemical conditions, as well as by mixing anionic/cationic or ionic/nonionic surfactants for a desired technological application, e.g., detergency.