复合表面活性剂在硝铵溶液中胶束化热力学性质研究

应用自动表面张力仪测量了对硝铵结晶有显著影响的阴阳离子复合表面活性剂和硝铵溶液中不同温度下的表面张力，求得了对应的临界胶束浓度（ＣＭＣ）。根据质量作用定律，得出了表面活性剂胶束化时的热力学模型，并对其热力学性质进行了计算和讨论。     

非离子表面活性剂BS—FJ在硼酸溶液中胶束化热力学性质研究

本文用滴体积法测定了对硼酸结晶有显著影响的非离子表面活性剂在硼酸溶液中不同温度条件下的表面张力，求得了对应的临界胶束浓度。根据质量作用定律，推出了表面活性剂胶束化时的热力学模型并对其热力学性质进行了计算和讨论。     

表面活性剂改善膨化硝铵晶变的研究

测定并比较了由典型的阴离子表面活性剂（ＳＤＳ）、阳离子表面活性剂（ＯＣＴＡ）、非离子表面活性剂（ＴＷ－８０）及其各自等摩尔混合体系处理而得的各类膨化硝铵的晶变性质及抗结块性，探讨了表面活性剂对膨化硝铵晶变性质的影响机理，并得出了效果较好的膨化硝铵抗结块剂。     

非离子型聚氨酯表面活性剂的合成及其性能

以4，4’-二苯甲烷二异氰酸酯、蓖麻油、聚乙二醇和甲醇为原料，通过逐步聚合得到一种新型的表面活性剂．并用红外光谱对其结构进行了表征。对该表面活性剂在水相中表面活性进行测试，结果表明，所制备出的聚氨酯表面活性剂的临界胶束浓度约为10^-3mol／L，水溶液的最低表面张力可达30mN／m.     

双离子表面活性剂的研究现状

双子表面活性剂具有较低的临界胶束浓度、降低水溶液表面张力或者水油之间界面张力的性能更强、更好的水溶性等优点。这些优良性能使其具有良好的应用潜力。本文介绍了双子表面活性剂的性能、合成以及应用等现状,表明这种表面活性剂具有重要的实用价值。     

羧甲基纤维素系列高分子表面活性剂在盐溶液中的胶束形态研究

采用动态激光光散射、ＧＰＣ、环境扫描电镜研究了羧甲基纤维素系列高分子表面活性剂在盐水溶液中的胶束形态,发现盐水溶液中,高分子表面活性剂形成较均一的球形胶束,盐既能使ＣＭＣ链段卷曲,胶束尺寸减小,又可破坏氧乙烯链段与水的亲合作用,使胶束聚集。分子量相近的共聚物体系形成大小相近的胶束粒子,且胶束分子量分布也基本相同     

阳-非离子型聚氨酯表面活性剂的制备与性能

以异氟尔酮二异氰酸酯(IPDI)、聚氧乙烯长链烷基胺(PAE)等为主要原料,合成了一系列兼具阳离子特性和非离子特性的新型聚氨酯高分子表面活性剂;并对产物进行了红外分析,研究了其侧链烷基碳数、环氧乙烷加合数及外加电解质对表面张力、临界胶束浓度的影响。实验结果表明,当PAE侧链烷基为C_(18),环氧乙烷加合数目为5时,其聚氨酯高分子表面活性剂综合性能优异,溶液的临界胶束浓度为39.600 mg/L,水溶液的表面张力最低可达33.131 m N/m。     

羧甲基纤维素系列高分子表面活性剂在盐溶液中的胶束形态 …

采用动态激光光散射、ＧＰＣ、环境扫描电 羧甲基纤维素系列高分子表面活性剂在盐水中溶液中的胶束形态,发现盐水溶液中,高分子表面活性剂形成较均一的球形胶束,盐既能使ＣＭＣ链段卷曲,胶束尺寸减小,又可破坏氧乙烯链段与水的亲合作用,使胶束聚集,分子量相近的共聚物体系形成大小相近的胶束粒子,且胶束分子量分布也基本相同。     

采用结晶法制取改性硝铵的方法

文章介绍了用阳离子与非离子表面活性剂经复配后制取改性硝铵的方法,改性硝铵粒度分布情况及性状,改性后的硝铵爆炸性能有所改善.试验证明,混合表面活性剂的比例、搅拌时间、硝铵溶液浓度对改性硝铵的得率及性能均有影响.     

梳状结构硅表面活性剂的溶液性质

采用氢硅化法制备得到了一系列具有梳状结构的非离子有机硅表面活性剂(PESO)。利用红外光谱和核磁共振氢谱对产物的结构进行了表征,分析了疏水基团的含量对PESO表面活性剂表面张力和临界胶束浓度的影响,研究了PESO表面活性剂在水溶液表面的吸附现象及在水溶液中的聚集行为,探讨了其在水溶液中形成的胶束的尺寸和分布。研究表明,随着疏水组分含氢硅油(PHMS)含量的增加,PESO表面活性剂分子越易缔合形成胶束且胶束的平均粒径增大。当PHMS含量由25%增加至67%时,临界胶束浓度(CMC)由0.828 g/L降至0.613 g/L,γCMC可降至22.11 mN/m,表面吸附量(Γ)可达3.31μmol/m2,每个表面活性剂分子吸附在空气/水界面的平均面积(A)仅为0.502 nm2,PESO表现出较好的表面活性。此外,荧光光谱法研究PESO聚合物在水溶液中的聚集行为发现,随着表面活性剂浓度的增加,第一、第三发射峰的荧光强度比值(I1/I3)不断减小,达到PESO的临界缔合浓度后,芘分子增溶于PESO胶束中,I1/I3趋于恒定。     

Surface tension of low-temperature aqueous solutions

Measurements of the surface tension have been carried out to determine the effects of both temperature and concentration on the surface tension of aqueous solutions of sodium chloride, propylene glycol, and ethylene glycol. A differential capillary-rise method was employed for the measurements. The results show that the surface tension of the ethylene glycol solution and the propylene glycol solution increases as the concentration of the solution decreases, while for the sodium chloride solution the surface tension increases monotonically as the concentration increases. The surface tension of the liquids was found to be an almost-linear function of temperature from 20°C to just above the freezing temperature. Equations for the surface tension of the three binary aqueous solutions as a function of temperature and concentration are presented.     

Investigation of the influence of surface-activated carbon fibres on debonding energy and frictional stress in polymer-matrix composites by the micro-indentation technique

The influence on fibre/matrix adhesion of the acidic and basic nature of surface-activated carbon fibres in epoxy and PPS matrices has been investigated by means of the micro-indentation method. The fibre ‘push-out’ and ‘push-in’ techniques were used for this study. The debonding energy and frictional stress are calculated, and the adhesion behaviour is compared with the calculated thermodynamical work of adhesion (as derived from the fibre surface tension) and surface oxygen content. Influence of surface activation on the interfacial frictional stress is discussed.     

Surface tension of aqueous binary solutions at low temperatures

The paper is concerned with measurements of the surface tension of aqueous binary solutions at low temperatures. The effects of both temperature and concentration on the surface tension of CaCl₂, NaClO₃, and propylene glycol have been investigated. A differential capillary-rise method was employed for the measurements. The results showed that the surface tension of CaCl₂ and NaClO₃ increases monotonically as the concentration of the solution increases, while for the propylene glycol solution the surface tension decreases with increasing concentration. The surface tension of the testing liquids was found to be an almost-linear function of temperature from 20°C to just above the freezing temperature. Equations for the surface tension of the three aqueous binary solutions as a function of temperature and concentration are presented. Paper presented at the Fourth Asian Thermophysical Properties Conference, September 5–8, 1995, Tokyo, Japan.     

Surface tension of aqueous binary solutions

Measurements of surface tension have been performed to determine the effects of both temperature and concentration on the surface tension of aqueous solutions of D-Sorbitol, potassium chloride, and ammonium chloride. A differential capillary-rise method was employed for the measurements. The results showed that the surface tension of test solutions increased as the temperature decreased and that the surface tension of chloride solutions increased with an increase in its concentration, while for D-Sorbitol solution the surface tension decreased with increasing concentration. Correlation equations for the surface tension of three aqueous binary solutions as a function of temperature and concentration were determined.     

超声对清洗剂溶液性能的影响

文章从试验上分析了超声对清洗剂溶液液面上压力和表面张力的影响。超声效应与纯热效应明显不同，即使剔除热效应的影响，纯超声效应对密闭容器中流体液面上气体压力的影响也是很明显的，而且当超声作用足够长的时间后，压力随时间的经在某一压力值附近波动。超声对溶液表面张力的影响与溶液的溶质及其浓度有关，在一定的浓度范围内，超声能引起溶液表面张力降低，并在某一浓度（PM）上达到极小。     

Microtexture and electrical properties of PAN-ACF

Microstructure and electric conductivity of PAN-based activated carbon fibers (PAN-ACF) were investigated using tension and KOH activation. The application of tension during stabilization decreased pore volume as well as specific surface area. Increase of KOH solution concentration caused serious damage to the surface of PAN-ACF. This surface damage of PAN-ACF resulted in increase of specific surface, pore volume and wider pore size distribution. PAN-ACF with higher tension showed higher electric conductivity. However, the electric conductivity was decreased by the increased BET surface area.     

The Role and the Effect of Calcium Ion Content of Photographic Gelatins on Coating Defects

The influence of the calcium ion content of some photographic gelatins on the adhesion of gelatin solutions to emulsion layers was investigated by surface tension, pH and viscosity measurements and by coating using the dip method.

Adhesion of the gelatin layers was examined in the coating process under the following conditions:

Surface tension at varying wetting agent concentrations, for gelatin solutions which contain calcium ions from 0 to 5760 ppm concentration.

Surface tension at varying gelatin concentrations.

Surface tension at varying pH values of the gelatin solutions used in the coating process.

The experimental results demonstrate that, at gelatin concentrations between 2 and 4%, the adhesion ability of a gelatin solution on a dry or wet gelatin (emulsion) layer depends on the Ca2* content of the coating solution. It is necessary to have at least 1000 ppm Ca2* concentration to guarantee a perfect adhesion and a perfect coating. Gelatin source, pH and the viscosity of the system are unimportant.     

高表面活性的水性聚氨酯乳液的制备及性能

以甲苯二异氰酸酯(TDI)、嵌段聚醚二醇PE6100以及聚醚胺ED-2003为原料,采用自乳化法合成了固含量40%的非离子型水性聚氨酯(WPU),通过红外光谱(FT-IR)对产物的结构进行了分析,并对产物的粒径、流变性能、表面张力、临界胶束浓度(CMC)进行了研究,结果表明,得到的WPU具有一定的触变性,平均粒径大多为100nm~400nm,在1g/L的浓度时水溶液的表面张力不超过37mN/m,具有较好的降低水溶液表面张力的能力。     

PASS溶液性质对静电纺丝可纺性及纤维形貌的影响

选取苯酚和四氯乙烷的混合物作溶剂,采用不同分子量的聚芳硫醚砜(PASS)树脂配制不同浓度的溶液,考察了溶液动态流变性能、表面张力、导电率对静电纺丝可纺性以及纤维形貌的影响。结果发现溶液的可纺性有实数黏度依赖性,纤维直径受溶液黏度的影响最大。     

Dynamic surface tension and adhesion detection for the rapid analysis of surfactants in flowing aqueous liquids

A multidimensional dynamic surface tension detector (DSTD) for flowing liquid samples is reported. The DSTD is based on measuring the pressure with time of a repeating drop formed by the flow of liquid out the end of a pointed stainless steel capillary. This pressure-based DSTD provides information on dynamic surface tension at the air-liquid interface and adhesion at the solid-liquid interface on the side of the pointed capillary tip for each drop of surfactant solution, resulting in rapid characterization of complex samples. The signal obtained with the pressure-based DSTD is characterized, and a method is developed for extraction of the desired analytical information from the pressure signal. The DSTD was calibrated with 2-propanol over the range of 0-0.30 in relative surface tension lowering, Δγ/γ. The experimentally obtained Δγ/γ was in agreement with a theoretical model and published data for Δγ/γ over this range. A data analysis method was developed to adapt the DSTD to applications such as liquid chromatography and flow injection analysis, where the concentration of surfactant changes as a function of time. The DSTD signal yields a pressure-based Δγ/γ that is due to surface tension alone and a time-based Δγ/γ that is a combination of both surface tension and adhesion, providing essentially a contact angle measurement on a flowing sample. The data analysis method involves plotting the pressure-based and time-based surface tension measurements against each other at the same surfactant concentration for each pair of measurements, yet over a range of concentrations to establish a slope. This is referred to as a dynamic analysis plot and is applied in the characterization of various surfactants such as dodecyl sulfate ion-paired with tetrabutylammonium, industrial surfactant solutions FC-171 and FC-129, and biological surfactants tetradecyl maltoside, benzyldimethyldodecylammonium bromide, and 3-(N-decyl-N,N-dimethylammonio)-1-propanesulfonate. The slopes of the dynamic analysis plots for these surfactants were found to be unique, generally independent of concentration, and useful for understanding the type and degree of operating surface interactions. The FC-171 solution was found to exhibit considerable adhesion at the capillary tip, while dodecyl sulfate was found to have a small adhesion effect. Adhesion for dodecyl sulfate solutions was significantly enhanced by coating the stainless steel capillary tip with a hydrophobic polymer. Thus, there is potential for tuning the extent of the surface tension and adhesion effects for selective chemical analysis. The detection limit for dodecyl sulfate ion-paired with tetrabutylammonium is 0.9 ppm. Application of the DSTD for liquid chromatography is demonstrated, and the multidimensional data are shown to be useful in identifying and characterizing the poly(ethylene glycol)s separated from 2-propanol.