微扰理论状态方程预测高温高压电解质水溶液的密度

由于实验条件的限制，高温高压电解质水溶液密度的测定具有一定困难，现有文献中有关该类体系的实验数据很少．Lvov和Wood[1]采用Blum－Wei的电解质水溶液非原始模型的平均球近似（MeanSphericalApproximation，简称MSA）方程，对NaCl水溶液建立了状态方程，该方程中离子的硬球     

氯化钙/水-醇溶液稀释热

电解质溶液稀释热是溶液的重要热性质之一．由它可计算不同浓度下电解质的溶解热、表现相对摩尔焓、溶液中反应热和化合物生成热等．在电解质溶液理论研究中，稀释热也是重要的基础数据．由稀释热可推算溶液中组分的活度系数、渗透系数、相对偏摩尔焓及表观摩尔热容等[1-3]．在化工生产中，稀释热是化工过程能量计算不可缺少的数据．电解质水溶液稀释热已有不少研究[2，4]．但电解质混合溶剂体系稀释热报导甚少．随着加盐精馏技术、海水淡化技术等研究的进展，急需这方面数据．本文作者已报告了CaCl2／C2H5OH－H2O体系[5]和CaCl2／n－C…     

可聚合脂质体的研究Ⅲ．可缩聚氨基酸类双亲分子的合成及其脂质体

随着脂质体作为药物载体研究的发展，多肽型脂质体以其表面众多的游活性官能团，良好的生物相容及体内降解性，成为一种理想的抗体载体^[1,2]。1982年，Folda等人首次报道了利用氨基酸酯的氨解反应，使氨基酸在脂质体表面进行缩聚，得到经缩合聚合后表面为多肽的脂质体，但由于缩聚后亲水性降低，脂质体易沉淀下来^[3].Neumann等合成了一系列氨基二羧酸化合物，形成脂质体后用缩水剂缩合，余下的另一羧基可作为亲水基团，得到稳定的多肽型脂质体^[4]。本文主要报道以天冬氨酸为骨架的可缩聚氨基酸双亲分子S－[马来酸单酰胺（N－天冬氨酸双十八酯)]半胱氨酸（Asp18-M-Cys)的合成，它在水中形成稳定脂质体的缩聚及其缩聚前后相转变的温度的变化。     

甘氨酸离子液体[C3mim][Gly]和[C4mim][Gly]水溶液的表面张力

本文用中和法合成了基于烷基咪唑的甘氨酸离子液体[C3mim][Gly]（1-丙基-3-甲基咪唑甘氨酸离子液体）和[c4miml[Gly]（1-丁基-3．甲基咪唑甘氨酸离子液体）,在298．15K下,0．0400-0．5000molkg^-1浓度范围内测定了不同浓度[C4mim][Oly]和[c3mim][Gly]离子液体水溶液的密度和表面张力,得到了溶液等张比容的实验值,提出了预测不同浓度溶液等张比容的经验方程,利用这个经验方程和李以圭等人提出的溶液表面张力模型,分别估算了这两种离子液体水溶液的表面张力,其估算值和实验值在误差范围内很好地吻合．     

镧与镍共沉积的研究

由于含稀土的合金新材料具有多种特殊功能，因此，其制备技术已为人们所关注．制备含稀土合金的方法有高温烧结法、真空蒸发法、离子溅射法及电化学法等．其中电化学法设备简单，容易获得不同组份的表层材料，但是，由于稀土元素的电位很负，从电解质水溶液中沉积稀土及其合金是相当困难的，以往曾有采用熔融盐电解质或非水电解质制备稀土合金的一些报导[1，2]，而从电解质水溶液中电沉积稀土合金的报导甚少．本研究采用适宜的络合剂，实现了从电解质水溶液中电沉积Ni－La合金，镀层中钠含量最高达22．58％（质量分数，下同）．通过XPS及…     

水溶性杯[4]芳烃衍生物与稀土铽[Ⅲ]离子形成配合物的荧光行为

近年来 ,杯芳烃衍生物与稀土离子配合物的发光因在荧光免疫分析和发光材料的开发上具有潜在的应用价值而引起了人们极大的兴趣 [1～ 3] .人们已经合成了一系列带有羧基、吡啶和羰基等官能团的杯 [4]芳烃衍生物 ,并在非水溶剂中能敏化稀土离子发光 ,但在水溶液中效果并不理想 [4～ 7] .本文报道Scheme1　 The structure of calix[4]arenesulfonate水溶性杯 [4]芳烃衍生物与稀土铽 [ ]离子形成配合物的荧光行为 .结果表明 ,乙酸修饰的磺化杯 [4]芳烃 L2 在水溶液中不仅能对 Tb3+进行有效的能量传递 ,形成高效的能量传递发光体系 ,而且也能与…     

糖类对水合DHPE相变的影响

人们发现,许多据说是处在脱水生存（anhydrobiosis）状态下的干生物在无水情况下可以坚持存活数十年之久．在这些干生物体中经常包含大量的糖类和糖醇,而后两者似乎和这些生物在干燥状态存活有关[1]．此外,已经证明某些糖类能够保护磷脂膜[2]和细胞膜[3]不受冷冻和脱水造成的伤害．对耐干旱、耐霜冻生物的企求,对冷冻保存细胞、组织或器官时所用的冷冻保护剂（cryoprotectant）的求索,唤起了人们对糖类和磷脂膜相互作用研究的兴趣．在已经进行过的研究中,极大部分是使用磷脂酰胆碱（PC）或PC和磷脂酰丝氨酸的二元混合物作为形成双分…     

卵磷脂有序体中碳酸钙超微颗粒的研究

近些年来，国内外对超微颗粒的研究正处方兴未艾，由于纳米级材料与大块物质的特性截然不同，引起了国内外科学工作者的关注，试图用各种方法制备各种超微颗粒．在有序体中制备铂、佬、金、银、锅等超微颗粒已有文献介绍山，在表面活性剂AOT与水形成的有序体中制各碳酸钙超细颗粒也有报导问，用脂质体合成某些超微颗粒的工作也有文章发表［3］．但是由卵磷脂（PC）与水组成人。膜体系制备碳酸钙超微颗粒尚未见到报导．我们根据分子有序组合体具有”隔室化”作用，形成纳米级空间的思路，采用PC－H。0有序体系作为生成碳酸钙的反应场所．…     

反胶团相转移法提纯酵母脂肪酶

反胶团相转移法是80年代兴起的一种新型分离技术，它利用表面活性剂分子在有机溶剂中自发形成的反向胶团（反胶团），在一定条件下将水溶性蛋白质分子增溶进反胶团的极性核（水池）中，再创造条件将蛋白质抽提至另一水相，实现蛋白质的相转移，达到分离和提纯蛋白质的目的[1]．反胶团中的蛋白质分子受到周围水分子和表面活性剂极性头的保护，仍保持一定的活性，甚至表现出超活性[2]．由于蛋白质增溶于反胶团与蛋白质所带电荷及反胶团内表面电荷间的静电作用及反胶团的大小有关[3～5]，因而表面活性剂的种类、水溶液的PH值及离子强度等因素…     

混合阴、阳离子表面活性剂溶液中的分子相互作用和相分离

混合阴、阳离子表面活性剂的表面活性比单一组份的表面活性高得多[1]．多年来，该体系的界面化学性质得到了广泛的研究［1，2］．但是，一旦该体系在水溶液中的浓度超过其临界胶团浓度（cmc）后，就将沉淀[3]或分层［2，4］，从而失去其表面活性．后来发现卜，司，在某些情况下，阴、阳离子混合表面活性剂的沉淀现象有所改善；但一直不易找到在相当大浓度范围内仍不分层的阴、阳离子表面活性剂混合体系．本文较为简明、系统地讨论了阴、阳离子表面活性剂的相互作用与沉淀或分相的关系．这对于该体系的深入研究以及实际应用，具有积极的意义…     

Solution properties of amitriptyline and its partitioning into lipid bilayers

Solution properties of a drug and its partitioning into lipid bilayers were studied for drug extraction using several different techniques, such as surface tension, zeta potential, ultra filtration and UV-Vis spectroscopy. From the surface tension study it was found that the presence of salt makes the drug molecules more surface-active. Zeta potential revealed the adsorption of the drug into the liposome bilayers to be governed mostly by electrostatic forces. The drug retention volume was expressed as a capacity factor, K, and that was normalized with respect to the amount of the immobilized phospholipids. The K-values for the positively charged drug on the liposomes decreased in the presence of phosphate buffer due to the presence of the oppositely charged ions. The above methods can thus be used to understand the mechanism of drug-membrane interaction and quantification of drug absorption into liposomes.     

Physico-chemical properties and cytotoxicity assessment of PEG-modified liposomes containing human hemoglobin

PEGylated liposomes encapsulating human hemoglobin as oxygen carriers were prepared from purified carbonylhemoglobin (HbCO) solution and a lipid mixture composed of 1,2-dipalmitoyl-sn-glycero-3-phosphatidylcholine (DPPC), cholesterol, 1,2-dimyristoyl-sn-glycero-3-phosphoethanolamine-N-[poly(ethylene glycol) 2000] (DMPE-PEG(2000)) and palmitic acid. Hemoglobin was extracted and purified from human blood samples. SDS-PAGE was used to assess its purity. Diameter of liposomes containing hemoglobin was controlled to approximately 200 nm using extrusion as measured by dynamic light scattering and transmission electron microscopy. Liposome size distributions were shown to remain unimodal over 14 days, even at different storage temperatures. Zeta potential measurements revealed that liposome containing hemoglobin have a net surface charge of -7.16+/-0.33 mV. Also, hemoglobin encapsulated in liposomes was able to perform several cycles of oxygen loading and unloading using oxygen (O(2)) and carbon monoxide (CO). The hemoglobin vesicle dispersion showed some toxicity as revealed by three in vitro assays in which endothelial cell (HUVECs) monolayers were exposed to these dispersions. Cytotoxicity was function of the liposome concentration in the culture medium.     

Effects of a bolaamphiphile on the structure of phosphatidylcholine liposomes

This paper describes the morphological characterization of aqueous dispersions of PC amphiphiles and bolaamphiphile AEC by microscopy, the liposomal membrane fluidity, and the zeta potential. Results indicate that the bolaamphiphile AEC can be included within conventional egg-PC liposome bilayers. This behavior could be due to their preference for the stretched conformation within the PC membranes.     

ASYMMETRY IN LIPOSOME

Asymmetry of phospholipid distribution along the vertical axis of the bimoiecular membrane in a liposome prepared with soybean phospholipids, PC and PE, was studied by using on ESR technique. From the difference in the values of the order parameter of doxylstearic acid radicals between the sample solutions into which the radicals were added before and after preparation of the liposome, it was concluded that PE is incorporated only in the inner layer of the liposome in the range of 0-30% of PE in mixed PC/PE systems and PE is incorporated in both layers of the liposome over about 30% of PE in the mixture.     

Triggered Liposomal Release through a Synthetic Phosphatidylcholine Analogue Bearing a Photocleavable Moiety Embedded within the sn‐2 Acyl Chain

Liposomes represent promising carriers for drug delivery applications. To maximize this potential, there has been significant interest in developing liposomal systems encapsulating molecular cargo that are highly stable until their contents are released remotely in a controlled manner. Herein, we describe the design, synthesis, and analysis of a photocleavable analogue of the ubiquitous lipid phosphoatidylcholine (PC) for the development of highly stable and controllable photodisruptable membranes. Our strategy was to develop a lipid that closely mimics the structure of PC to optimize favorable properties including biocompatibility and stability of subsequent liposomes when mixed with lipids possessing a broad range of physicochemical properties. Thus, NB‐PC was designed, which contains a photocleavable 2‐nitrobenzyl group embedded within the acyl chain at the sn‐2 position. Following the synthesis of NB‐PC , liposome disruption efficacy was evaluated through photolysis studies involving the detection of nile red release. Studies performed using a range of liposomes with different percentages of NB‐PC , PC, phosphatidylethanolamine (PE), cholesterol, and polyethylene glycol‐PE (PEG‐PE) demonstrated minimal background release in controls, release efficacies that correlate directly with the amount of NB‐PC incorporation, and that release is only minimally impacted by the inclusion of the lipids PE and cholesterol that possess disparate properties. These results demonstrate that the NB‐PC system is a highly stable, flexible, and tunable system for photoinitiated release from liposomal systems.     

不同水煤浆分散剂与煤之间的相互作用规律研究: Ⅺ 分散剂改性煤粒的界面性质及其对CWS性质的影响

测定了10种分散剂与14种煤所形成分散体系的Zeta电位，研究了分散剂对改性煤粒界面电化学性质的影响。结果表明，煤的变质程度越低、溶出高价离子越多，分散剂改性煤粒的Zeta电位越低。阴离子分散剂亲水基团的数量和所带电荷越多，改性煤粒的Zeta电位越高。非离子分散剂使改性煤粒的Zeta电位降低。阴离子分散剂改性的煤粒，Zeta电位大小能很大程度反映煤粒的亲水性强弱，很多阴离子分散剂改性煤粒的Zeta电位都与其吸水量成正相关。建立了包括煤自身亲水性（Mad）、分散剂亲水改性程度（△MHC）, 以及Zeta电位（ζ）和分散剂在单位煤表面积上的吸附量（Γs）在内的成浆性经验模型：CFV = 76.62 1.896Mad 3.430△MHC+0.489Γs·ζ。该模型的计算值与实验结果很相近，而且还能反应出各变量对煤的成浆性所产生的影响。     

Liposome electrokinetic capillary chromatography in the study of analyte-phospholipid membrane interactions. Application to pesticides and related compounds

Interactions between low-molar mass analytes and phospholipid membranes were studied by liposome electrokinetic capillary chromatography (LEKC). The analytes were pesticides, some degradation products, and compounds associated with the manufacture of pesticides. Negatively charged liposome dispersions with different zwitterionic lipids (PC) were applied to the determination of retention factors (k) of 15 charged and uncharged compounds. The liposome dispersions consisted of 80:20 mol% of 1,2-dilauroyl-sn-glycero-3-phosphocholine (DLPC)/1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-L-serine (POPS), 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC)/POPS, and 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC)/POPS. Retention factors were calculated from the effective electrophoretic mobilities of the analytes under LEKC and CZE conditions and from the effective electrophoretic mobilities of the liposomes, determined by CZE with a polyacrylamide-coated capillary. Determining the liposome mobilities in this way proved to be a good alternative to the conventional method employing a liposome marker compound. The log k values of the analytes for the different liposome dispersed phases were correlated with one another. In addition, correlation curves were determined between log k and calculated octanol-water partition coefficients. The results showed that the zwitterionic phospholipid in the liposome has a major impact on the interactions between the tested compounds and the lipid membranes.     

Physicochemical aspects of the liposome-wool interaction in wool dyeing

Despite the promising application of liposomes in wool dyeing, little is known about the mechanism of liposome interactions with the wool fiber and dyestuffs. The kinetics of wool dyeing by two dyes, Acid Green 27 (hydrophobic) and Acid Green 25 (hydrophilic), were compared in three experimental protocols: (1) without liposomes, (2) in the presence of phosphatidylcholine (PC) liposomes, and (3) with wool previously treated with PC liposomes. Physicochemical interactions of liposomes with wool fibers were studied under experimental dyeing conditions with particular interest in the liposome affinity to the fiber surface and changes in the lipid composition of the wool fibers. The results obtained indicate that the presence of liposomes favors the retention of these two dyes in the dyeing bath, this effect being more pronounced in case of the hydrophobic dye. Furthermore, the liposome treatment is accompanied by substantial absorption of PC by wool fibers with simultaneous partial solubilization of their polar lipids (more evident at higher temperatures). This may result in structural modification of the cell membrane complex of wool fibers, which could account for a high level of the dye exhaustion observed at the end of the liposome dyeing process.     

The effect of added liposomes on the rheological properties of a hydrogel: a systematic study

Rheological characteristics of liposome-containing-hydrogels were studied. Sonicated unilamellar vesicles (SUV), prepared by probe sonication and multilamellar vesicles (MLV) prepared by thin film hydration were loaded in a hydrogel containing carbopol 974 NF and hydroxyethylcellulose (Natrosol 250 HX). Phosphatidylcholine (PC) or hydrogenated-PC (HPC) liposomes, plain or mixed with cholesterol (chol) were used. Static (steady-stress sweep-tests) and dynamic (frequency sweep-tests) rheological measurements were carried out. All gels had a shear thinning behaviour (fitted well by Cross model). Zero-rate shear viscosity and power law index values, revealed that PC liposome addition in the hydrogel had minimum effect on its rheological properties even at the highest lipid concentration used (20 mg/ml). Oppositely, HPC (or HPC/chol) liposome addition resulted in significant modulations of the same rheological characteristics (which increased with increasing lipid concentration). HPC liposomes also caused a significant increase in gel relaxation time, which indicates that the elastic character of the gel strengthens as HPC liposome concentration increases. Concluding, liposome composition (membrane rigidity) and lipid concentration, but not liposome size, seem to be very important factors that determine the rheological modulations caused by liposome addition in gels.     

酯化淀粉乳化剂制备的高效氯氟氰菊酯O/W乳液的稳定机制

通过测定辛烯基琥珀酸淀粉钠的用量、盐离子、pH值和温度等因素对油滴Zeta电位及表面吸附量的影响,分析了以酯化淀粉辛烯基琥珀酸淀粉钠为乳化剂制备的5％高效氯氟氰菊酯水乳剂的稳定机制.结果表明,辛烯基琥珀酸淀粉钠质量分数为7％时,Zeta电位达到最大值,油滴表面吸附量接近饱和;Na+、Mg2+和Al3+压缩油滴表面的双电层,降低Zeta电位,削弱静电排斥作用,增加辛烯基琥珀酸淀粉钠分子柔性,提高辛烯基琥珀酸淀粉钠表面吸附量,且随着Na+、Mg2、Al3+离子强度依次增大,压缩双电层能力依次增强,Zeta 电位降低和表面吸附量增加程度依次增大;pH值影响辛烯基琥珀酸淀粉钠在水中的解离,在碱性范围内解离出较多羧酸根,静电排斥力较大,Zeta电位较高,但表面吸附量有所降低;温度升高,辛烯基琥珀酸淀粉钠在水溶液中溶解度增大,呈舒展状态,且辛烯基琥珀酸淀粉钠从油滴表面逃逸的趋势增加,油滴表面Zeta电位和表面吸附量均随着温度升高而降低,在低温区差别不大,温度越高二者变化越明显.辛烯基琥珀酸淀粉钠通过吸附于油滴表面为其提供较强的静电斥力和空间位阻作用而维持O/W乳液稳定.