四硫代富瓦烯/四氰基对二次甲基苯醌单分子膜气-液界面性质及LB膜组装体的紫外可见光谱

几种电子给体（四硫代富瓦烯，ＴＴＦ）、电子受体（长链四氰基对二次甲基苯醌；Ｃ１８ ＴＣＮＱ）及它们相应的 １：１摩尔比复合物的气－液界面分子行为表明：不带长链的 ＴＴＣ１－ ＴＴＦ、ＢＥＤＴ－ＴＴＦ的成膜性在其与Ｃ１８ＴＣＮＱ形成复合物之后均得到显著改善。Ｃ１６ＴＴＦ、Ｃ１８ ＴＣＮＱ及两者不同结构ＬＢ膜组装体的紫外可见光谱研究发现：Ｃ１８ＴＣＮＱ在其单独的Ｙ－型 膜中摩尔吸光系数是７．５×１０３，而在交替组装体中其摩尔吸光系数是１．３×１０３，给受体之间 的相互作用导致跃迁偶极矩减小，从而引起吸光系数减小４倍多。

L-α-二油酸磷酯酰胆碱和芦丁硬脂酸酯混合单分子膜的相容性

Rutin was acylated with stearic acid in esterification reaction catalyzed by immobilized Candida antarctica lipase B(Novozym 435).The results suggested that the regioselectivity of the lipase-catalyzed esterification of rutin was specific at the C4’’’ position of the rhamnose moiety.The monolayer of dioleoylphosphatidylcholine(DOPC) was used as the model membrane to study their molecular interaction with RS.The miscibility of DOPC/RS mixed monolayers has been investigated by Langmuir film balance to yield quantitative information on the nature of the molecular interaction,which could provide valuable insights to reveal the antioxidative activity mechanism of flavonoids.Pure RS and pure DOPC were capable of forming monolayers with liquid-phase at the air/water interface.The two components of DOPC/RS monolayer were miscible throunghout the mixture composition range.The effects of the temperature of the subphase on the miscibility and molecular interaction of DOPC/RS monolayers were investigated.The miscibility was more excellent at higher temperature.The condensing effect of RS,which represented the attractive forces between DOPC and RS,could be ascribed to the match of molecular shapes of RS and DOPC on the monolayers packing.

Langmuir films stability phenomenon of glycerol dialkyl nonitol tetraether at the air-water interface for variations spreading time

Langmuir films behavior of asymmetric glycerol dialkyl nonitol tetraether (GDNT) lipids at the air-water interface (temperature 19℃ ± 1℃) investigated the stability of the mean ratio of Langmuir films for different spreading time prior to the transfer film. Floating monolayer films stability is an important parameter to obtain high-quality Langmuir-Blodgett films for their aplications. Hysteresis loop of the compression-decompression (μ-A) isotherms of Langmuir film GDNT used to analyze the thermodynamic stability of the monolayer films and its features. Langmuir films stability of tetraether lipid GDNT shown more stable at the time of spreading longer than a short time.

The Dependence of the Miscibility, Stability and Compressibility of L-<i>α</i>Dioleoylphosphatidylcholine/Rutin Laurate Monolayer at the Air/Water on Temperature

The miscibility, stability and compressibility of L-α dioleoylphosphatidylcholine/rutin laurate mixed monolayer at the air/water were investigated by Langmuir film balance to reveal the characteristic of the molecular interaction. The two components of DOPC/RL mixed monolayer were miscible throughout the mixture composition range and at three experimental temperatures of 10°C, 25°C and 37°C. At all experimental conditions, RL increased the compressibility and elasticity of the DOPC monolayer. Both the temperature and the composition of the membrane affected the form of intermolecular forces in the mixed monolayer.

13X分子筛吸附性能及其比表面积的研究

对于真空绝热压力容器来说,如何获得并且能够长期维持满足要求的夹层真空度,主要在于吸附剂的吸附性能和微观结构。为此,采用巨正则系综的蒙特卡罗方法,结合13X分子筛在298 K下吸附CO2的实验数据,优化了模拟力场参数。通过模拟308 K下的CO2吸附和298 K下的N2吸附并与实验数据进行对比,验证了优化的力场参数的准确性和可靠性,表明该力场参数在不同温度和吸附质的条件下能够较准确的模拟13X分子筛的吸附行为。最后使用优化调整后的力场参数模拟13X分子筛在77K温度下的N2吸附等温线,同时采用ASAP2020物理吸附仪对13X分子筛样品进行微观结构测试。对比模拟与实验的吸附等温线,发现压力在0~70 k Pa内两者比较接近,并计算了其比表面积,模拟所得分子筛比表面积为455.52m2/g,与实验值的相对误差为4.3%,表明利用模拟的方法可以获得吸附剂的比表面积。研究结果将会极大地促进真空绝热压力容器的快速发展。

二茂铁亚胺环钯化合物Langmuir膜和Langmuir-Blodgett膜的性质研究

通过表面压(π)-单分子面积(A)等温线研究了二茂铁亚胺环钯化合物的气-液界面行为。结果表明:升高亚相的温度、降低滴加成膜物质的浓度和挤压速度、挤压前停留一段时间均有利于亚相上形成致密、稳定的Langmuir膜。其原因可能是升高亚相温度能够增强亚相水分子和其表面成膜物质的流动性,降低挤压速度和挤压之前停留一段时间能够使聚集的成膜物质分散,从而有利于成膜物质在亚相表面形成致密、稳定的Langmuir膜。在优化的单层膜形成条件下,制备了二茂铁亚胺环钯化合物的Langmuir-Blodgett膜,其层数与紫外-可见光谱中的最大紫外吸收呈现良好的线性关系,表明此Langmuir-Blodgett膜具有良好的纵向均匀性和结构周期性,也进一步证实了亚相表面形成了致密、稳定的Langmuir膜。

酸性有机磷类萃取剂单分子膜的气-液界面行为:亚相pH和铺展溶剂的影响

液-液两相萃取过程中,有机磷类萃取剂分子的界面行为决定了其以何种形式参与到界面萃取反应中.为了阐明萃取剂分子界面行为的变化特点,采用Langmuir单分子膜技术研究了单分子膜中P507分子在气-液界面的吸附和聚集行为随亚相pH、有机溶剂极性的变化.通过测定表面压-分子面积等温线,并采用界面红外反射吸收光谱(IRRAS)分析表征气-液界面P507分子间相互作用,结果发现,以正己烷作铺展溶剂时,随亚相pH的降低,P507单分子膜质子化程度提高,P507分子极性端水化能力削弱,分子间相互作用增强,单分子膜中形成含有分子间氢键的聚集体.但采用极性有机溶剂(二氯甲烷和氯仿)铺展P507单分子膜,膜内P507分子界面聚集状态发生变化.铺展溶剂极性增强,单分子膜内会含有更多极性端水化能力强的P507分子单体,并且亚相pH降低,单分子膜不会出现类似正己烷条件下的π-A曲线收缩和P-O-H基团峰位红移现象.这证实了有机铺展溶剂极性可以改变P507单分子膜中分子界面存在形式和聚集状态.本工作为深入理解溶剂萃取过程中水油两相界面处酸性有机磷类萃取剂分子的聚集行为变化及其对界面反应活性的影响机制奠定了基础.

MPEG胆甾醇酯与卵磷脂作用的LB技术研究

采用酰氯法合成了3种不同分子量的高分子表面活性剂端甲基聚乙二醇胆甾醇酯(mPEG-chol),并用表面张力法测得其临界胶束浓度(CMC)值。结果表明,随着PEG链长的增加,其CMC值逐渐增大。同时,利用LB膜天平研究了3种mPEG-chol在空气/水界面上单分子膜的π-A等温曲线及其与磷脂单分子膜的相互作用。结果表明,PEG的链长不仅决定了胆甾醇酯在空气/水界面上的表面性质,还影响了mPEG-chol与卵磷脂分子的相互作用。PEG的链越长,与磷脂分子间的作用力越强;mPEG-chol以胆甾基团为锚与磷脂分子发生作用,较长的PEG链反而影响了胆甾基团在磷脂单分子膜中的吸附。