WATER MOVEMENT CAUSED BY SPREADING SURFACTANTS IN UNSATURATED SYSTEMS OF PARTICLES OF NONUNIFORM SIZE

The movement of water originated by the spreading of two surfactants was analyzed in glass beads as well as on soil systems, both of particles of nonuniform size

The higher difference of surface tension produced in the system by 1 -hexadecanol compared to that of 1-tetradecanol led therefore to a higher amount of water moved. Decreased proportion of the smaller sized particles in glass beads system produced a decrease in the total water moved by both surfactants.

Organic matter acted in soil as a second surfactant in glass beads. This effect was compared in glass beads systems once 1-hexadecanol was evenly distributed among the particles as continuous film, which played a role alike that of organic matter in soil and then a second surfactant 1-tetradecanol was added. These additional surfactant effect diminished the difference between initial and final surface tension (surface tension depression) of the system and so the total water moved.

The soil organic matter (1.7%) modified the water movement curve in the presence of low (0.2g) content of 1-hexadecanol, whereas for high content of either alcohol (0.4g) or low content of 1-tetradecanol content (0.2g) the water movement curves were the same     

PHOTOSENSITIZATION BY DRUGS IN SURFACTANT SOLUTIONS

Abstract— Chlorpromazine, promazine, anthracene and furosemide were tested as photosensitizers using 365 nm UV light in micellar solutions of cationic, anionic and nonionic surfactants. In all cases, micelles enhanced the ability of these compounds to photosensitize the oxidation of 2,5-dimethylfuran and the free radical polymerization of acrylamide. pH variation showed that the base form of chlorpromazine and the acid form of furosemide are the principal photosensitizing forms of these compounds. Rate differences between cationic and anionic surfactant media indicate the cation radical to be the major photochemical species formed from chlorpromazine and promazine in micellar media. Photodechlorination of chlorpromazine accounted for a significantly higher reactivity of chlorpromazine over promazine. Anthracene was found to be a very active photosensitizer by the singlet oxygen mechanism but also yielded a small concentration of cation radicals in micellar solution. In its neutral form, furosemide reacted strongly in both photooxidation and photopolymerization systems.
The implications of this study to drug-induced photosensitivity are that (i) free radical reactions may play a major role, and (ii) these sensitizers are more reactive in a hydrophobic environment, suggesting that the cellular membrane or the hydrophobic surfaces of proteins or DNA are more important sites of action in photosensitivity.     

GELATION KINETICS OF POLYMERS CONFINED IN WATER/ OIL-SATURATED POROUS MATERIALS PROBED BY NMR

Abstract

The gelation of polyvinylalcohol with glutaraldehyde confined in a water/ oil (= 3/1 in volume ratio) saturated sandstone (Bentheimer) was characterized by H NMR spin-lattice relaxation rate (1/ T)measurements and Pulse Field Gradient (PFG) NMR diffusion measurements. The gelation rate was found to be (12.8 ± 1.3) 10^?1 5^?1 at 340 K, which is approximately an order of magnitude faster than in bulk solution. In comparison, the gelation rate within the same porous material containing no oil phase was even faster, by a factor of 2.     

A STUDY OF GEL STRUCTURE IN THE NONIONIC SURFACTANT / CETOSTEARYL ALCOHOL / WATER TERNARY SYSTEMS BY DIFFERENTIAL SCANNING CALORIMETER

Cetostearyl alcohol has been incorporated into cosmetic or pharmaceutial emulsions to give them an appropriate consistency and a long term stability. It is well known that cetostearyl alcohol forms a gel phase with a nonionic surfactant in an aqueous system, and the properties of the gel phase depend on several factors such as the ratio of fatty alcohols. The aim of the present paper is to investigate the effect of the structural difference of the lipophilic part of surfactants on the stability of the gel phase in the nonionic surfactant / cetostearyl alcohol / water ternary systems using differential scanning calorimeter.

It is concluded that the gel phase formed by the surfactant having the bended alkyl chain is more unstable than that formed by the case of     

PREPARATION OF CaCO3 PARTICLES IN WATER POOL IN NONAQUEOUS NONIONIC SURFACTANT SOLUTIONS

ABSTRACT

CaCO₃ particles were prepared by bubbling of CO₂ into the systems consisting of polyoxyethylene(6) nonylphenyl ether/aqueous Ca(OH) ₂/cyclohexane. Spherical particles were formed in any systems, but those size distribution depended on the solubility behavior of aqueous Ca(OH) ₂ in surfactant solutions, i.e., monodisperse particles were formed in colorless solution, whereas in blue translucent solution they became bimodal. Such change was also observed for the size of reversed micelles. This suggested that the formation of CaCO₃ particles were related with that of micelles. On the other hand, the particles obtained were consisted of calcite, vaterite and aragonite. Those fraction differed also from the solubility behavior of aqueous Ca(OH) ₂. Both the vaterite and aragonite were transformed into calcite and those rate constants were order of 10^?6 sec^?1.     

用固体~1H MAS NMR研究水在不同吸附质中的状态

应用固体1H MAS NMR实验技术,根据核磁共振峰线宽的不同,表征了水在不同吸附质中的微观状态。在含水的壳聚糖和明胶中,以氢键形式存在的水的共振峰线宽为2000Hz左右。在含水分子筛和含水硅胶中存在的吸附水的共振峰线宽在1000Hz左右。而自由水的核磁共振峰线宽小于3Hz。     

动态法研究苯酚在饱水细砂土中的吸附

采用流动柱法研究苯酚在饱水细砂土中的吸附。实验结果表明，从开始到吸附量达一定数额这段区域内，总速率由界膜内的扩散速率决定，且为一常数。此后，总速率由颗粒外表层内的扩散速率决定，符合一级动力学微分方程。     

关于碳氟链表面活性剂与碳氢链表面活性剂混合溶液的胶团形成

对不同比例的下列表面活性剂混合物水溶液的表面张力作了测定:C₁₀H₂₁OSO₃Na(简称10CH)-C₁₂H₂₅OSO₃Na(简称12CH),C₇E₁₅COONa(简称7CF)-10CH及7CF-12CH.自溶液的表面张力一浓度关系求得临界胶团浓度(cmc).     

DEPROTONATION DYNAMICS OF LOCAL ANESTHETICS IN HYDROPHOBIC MEDIA: DIBUCAINEHCI IN WATER/ALCOHOL OR SURFACTANT MIXTURES

Abstract— The emitting chromophores, emitting states, state orderings and phosphorescence lifetimes of neutral, hydrogen-bonded, and protonated dibucaines in water/alcohol mixtures were determined experimentally and were confirmed theoretically using a HAM/3 method. These photophysical properties are used to probe the deprotonation dynamics of dibucaine-HCl in the water/hydrophobic media. It is found that the protonated dibucaine in an aqueous solution is deprotonated and/or forms hydrogen-bonded dibucaine when it is brought into contact with the alcohols and surfactants. The observed deprotonation processes could lend some insight on the molecular basis of pharmacological action of dibucaine.     

用固体^1H MSA NMR研究水在不同吸附质中的状态

应用固体^1H MSA NMR实验技术，根据核磁共振峰线宽的不同，表征了水在不同吸附质中的微观状态。在含水的壳聚糖和明胶中，以氢键形式存在的水的共振峰线宽为2000Hz左右。在含水分子筛和含水硅胶中存在的吸附水的共振峰线宽在1000Hz左右。而自由水的核磁共振峰线宽小于3Hz。     

气相色谱法测定水中的松节油

研究了测定水中松节油的气相色谱法.采用二硫化碳萃取,DB-5型毛细管柱分离,氢火焰检测器(FID)检测水中松节油的含量.松节油浓度在1. 00～25. 0 mg/L范围内与色谱峰面积呈良好的线性关系,线性相关系数r=0. 9996.加标回收率为86. 3%～91. 3%,测定结果的相对标准偏差为8. 7%(n=6).该法可满足地表水环境质量标准的要求.     

电导率法和光度法测定乙醇含量

通过测定不同含水量的硝酸钴乙醇溶液的电导率和吸光度，从而建立回归方程，并通过显著性检验，发现溶液的水含量与其电导率成正相关；与其在520nm波长处的吸光度成负相关。根据此特性，可用于乙醇中水含量的快速测定。     

FORMATION OF O/W EMULSIONS BY SURFACTANT PHASE EMULSIFICATION AND THE SOLUTION BEHAVIOR OF NONIONIC SURFACTANT SYSTEM IN THE EMULSIFICATION PROCESS

Surfactant-Phase Emulsification is a very useful method to produce oil-in-water emulsions having fine and uniform droplets. The mechanism of this emulsification method and the effect of hydrophile-lipophile balance (HLB) of the surfactants on the process of this emuisification were investigated by using phase diagrams of nonionic surfactant/hexadecane/water/1,3-butanediol four component systems.

It was shown that the process of this emulsification begins with the formation of isotropic surfactant solution, followed by formation of oil-in-surfactant clear gel emulsion, and finally by formation of oil-in-water emulsion. By using this emulsification technique, fine oil-in-water emulsions were formed without a need for adjusting of HLB.     

A COMPARISON OF THERMALLY INDUCED CHANGES IN SONICATED PHOSPHOLIPID AND SURFACTANT VESICLES BY MEANS OF INTRA-MOLECULAR EXCIMER-FORMING PROBE

Abstract The molecule (1,l'-dipyrenyl)-methyl ether (dipyme) was used for monitoring the bilayer fluidity of surfactant and sonicated phospholipid vesicles. In the latter systems, the observed transition temperatures ( Tc ) are identical with those found by different methods. Surfactant vesicles prepared from dioctadecyldimethylammonium bromide (DODAB) and dihexadecylphosphate (DHP) molecules manifest a similar fluidity of their bilayers as those of sonicated phospholipid vesicles below their Tc. However, unlike in phospholipid vesicles, there was no significant change of the bilayer structure above Tc observed in surfactant vesicles. DHP vesicles formed in pure water provide a different solubilization site for dipyme than those prepared in a buffer solution. Such sites are characterized by a relatively high local concentration of the probe and the appearance of the blue shifted spectrum of the excimer.     

离子色谱法测定水样中的氯化物

建立离子色谱法测定水样中氯化物的方法,Cl^-浓度在0．40～4．00mg／L范围内与色谱峰面积呈线性关系,线性方程为A=0．0680c＋0．0011,线性相关系数r=0．9995。样品6次测定结果的相对标准偏差为1．01％,加标回收率为91．8％～97．3％。与硝酸银滴定法进行比对试验,两种方法测定结果基本一致。离子色谱法操作方便快捷,污染少,测定结果准确、可靠。     

高效液相色谱法测定水和尿中氟

建立了测定氟的高效液相色谱法。通过加入三乙胺使F~--La~(3 )-茜素氨羧络合剂体系更稳定。C_(18)柱,甲醇-水(18:82)作流动相,流速为1ml·min~(-1),检测波长为566nm,线性范围为0.010～1.0μg·ml~(-1),相关系数为0.9991,检出限为1ng·ml~(这-1)。用于水和尿样测定时,相对标准偏差为2.8％～4.5％,加标回收率为95％～104％。     

气相色谱-质谱联用快速测定饮用水源水中半挥发性有机物

利用液-液萃取与气相色谱-质谱联用技术,快速测定4个城市取水口断面和自来水中的24种6大类半挥发性有机物.250 mL水样,苯液液萃取定容到2 mL,碱中性组分的加标回收率为66.8%-156%,酸性组分的加标回收率为32.5% -45.6%,测定结果的相对标准偏差为1.23% -6.55%(n=7).在<水和废水监测...     

顶空毛细管柱气相色谱法测定水中的二氯甲烷

采用毛细管柱分离、顶空气相色谱法测定水中的二氯甲烷,讨论了恒温平衡时间和盐效应对气液平衡的影响。该方法检出限为0.001 mg/L,二氯甲烷的加标回收率为87.7%~110%,测定结果的相对标准偏差为6.2%~8.7%(n=6)。