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用退火使条带织构装饰在全芳共聚酯的取向膜上,在偏光显微镜下同时观察到微纤和条带。微纤分三个层次,即直径分别为数十微米的微纤束、数微米的微纤和0.3微米的亚微纤,退火后三个层次的微纤松弛成不同的形态,微纤束仍笔直沿剪切方向取向,微纤松弛成螺旋形,而亚微纤松弛成波浪形从而观察到条带织构:微纤直径越小越易松弛,另一方面,非取向态织构退火后由亚微纤形成的条带装饰结果直观地揭示了微区内外分子指向矢的分布和它们在边界上的变化。退火时条带织构的形成被解释为分子的弹性回缩力缓慢发生作用使分子松弛所致。 相似文献
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聚苯乙烯微球表面的链段堆积状态徐伟,陈殿勇,华中一,吕绪良,胡建华,府寿宽(复旦大学材料科学系,上海,200433)(复旦大学高分子科学系)关键词聚苯乙烯微球,聚合物链段,聚集态,扫描隧道显微镜用微乳液聚合法制备的聚苯乙烯微球与常规聚苯乙烯相比有许多... 相似文献
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阳离子表面活性剂中相微乳的形成和特性 总被引:10,自引:0,他引:10
自1943年SdriAn。等人山发现微乳液体系并予以命名以来,对微乳液研究不断深入·微乳液是由油、水、表面活性剂和助表面活性剂组成的各向同性、透明的、热力学稳定的分散体系,微乳液可分为单相微乳液和多相微乳液问.中相微乳液是多相微乳液中,与过剩盐水相和过剩油相达到三相平衡的Winsor皿型微乳液,它在三次采油、日用化工、微环境、酶催化等方面具有特殊重要的应用I‘,‘].近年来对阴离子表面活性剂中相微乳液的形成和特性进行了较多研究[5。8].但对阳离子表面活性剂中相微乳液的研究,目前尚未见报导,本文以澳代十四烷基毗… 相似文献
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着重介绍嵌段共聚物/均聚物共混体系的微相分离,微胶束的形成,微区的形态结构以及形态的控制。 相似文献
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单分散聚苯乙烯微球的制备及影响因素研究 总被引:13,自引:2,他引:11
以聚乙烯吡咯烷酮为分散剂,无水乙醇为反应介质,偶氮二异丁腈为引发剂,采用分散聚合工艺,通过优化反应条件,制备出了粒径为5μm单分散(分散系数≤5%)聚苯乙烯微球。所制备的聚苯乙烯微球标准偏差δ=0.16μm,分散系数ε=0.02,且具有良好的球形度,表面非常光滑,无破损,无缺损。对影响单分散聚苯乙烯微球的因素进行了研究,结果表明:随着分散稳定剂用量的增加,聚苯乙烯微球的粒径减小;随着单体和引发剂用量的增加,聚苯乙烯微球的粒径增大。分散稳定剂和单体用量是影响聚苯乙烯微球粒径分布的两个主要因素。 相似文献
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A W/O microemulsion of Tween‐80‐Span‐80/n‐butylalcohol/ethyl‐oleate/H2O to envelop insulin (INS) was prepared. In order to obtain the maximum solved water, the components of microemulsion to envelop INS were chosen with the pseudo‐ternary phase diagram and the influences of temperature, salinity as well as the pH on microemulsion areas also were investigated. To test the properties of the microemulsion, the conductance was used to divide O/W, W/O and BC regions, the dynamic light scattering to evaluate the particle diameters of microemulsion, the 125I isotope tracing method to measure the release rate of INS loaded in W/O microemulsion, and the growth inhibitory effect test to appraise the cytotoxicity on human normal cells. Results show that W/O microemulsion forms when water content below 50% in the microemulsion system. The microemulsion region decreases slightly with the increase of temperature, salinity and the decrease of pH. However, the viscosity measurements along certainly selected dilution lines to the microemulsion indicate that no phase invert occurred. Diameter of microemulsion particle increases with the addition of INS, and the increase is sharp in the first 5 days then very slightly at 68.6 nm within a month. The INS loaded W/O microemulsion possesses eminent sustaining release efficiency and the cytostatic as well as cytotoxic assays illustrate that the microemulsion can be used as drug delivery at small dosage. 相似文献
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A novel class of conjugated linoleic acid (CLA)-in-water microemulsion based on Tween80, EL-35, ethanol, and n-octanol was investigated as potential food delivery systems. The influences of pH on the microemulsion region were considered. The microemulsion structural transition was divided into water-in-oil (W/O), bicontionuous, and oil-in-water (O/W) microemulsion by conductivity and viscosity method. The microemulsion size and polydispersity were determined by dynamic light scattering (DLS). The size of O/W microemulsion droplets depends strongly on the contents of surfactants and CLA, and the diameter ranges from 22.1 to 30.7 nm and from 18.3 to 32.8 nm, respectively. All samples keep a remarkable stability in the experiments of 30 days. The stability of CLA in microemulsion and ethanol solution was determined by ultraviolet-visible spectrophotometry, the results revealed that the stability of the CLA in the microemulsion was increased remarkably. 相似文献
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影响反相微乳液导电性能的因素 总被引:1,自引:0,他引:1
分别以聚乙二醇辛基苯基醚(Triton X-100)或十六烷基三甲基溴化铵(CTAB)为表面活性剂, 与正己烷、正己醇和水构成反相微乳液. 研究了水相H+浓度、表面活性剂、助表面活性剂等对微乳液导电性能的影响. 结果表明, 增加水相H+浓度可大幅度提高反相微乳液的导电能力, 当H+浓度由1.0 mol•L-1增加到10 mol•L-1时, 微乳液的电导率可提高1~2个数量级. 当水相H+浓度为10 mol•L-1时, 微乳液的电导率随溶水量的增大而增大, 水油体积比为3:10时, 两种体系的电导率均达到3200 μS•cm-1. Triton X-100浓度对微乳液的电导率影响较大, 电导率随其浓度增加而增大;而CTAB浓度对微乳液电导率的影响较小, 电导率随其浓度增加略有减小;助表面活性剂正己醇使非离子型反相微乳液的电导率下降, 而使阳离子型反相微乳液的电导率先增大, 然后减小, 呈骆峰状变化. 相似文献
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十二烷基硫酸钠多相微乳液的研究 总被引:2,自引:0,他引:2
十二烷基硫酸钠(SDS)/正丁醇-异丙醇/庚烷/盐水体系可形成多相微乳液,研究了盐浓度、温度对相态的影响,并用小角X衍射、NMR和ESR技术对多相微乳液的结构进行了研究,比较了四相微乳液中两个富表活剂相的区别。结果认为该体系在合适条件下可形成三相及四相微乳液,微乳液中伴随有层状液晶存在。四相微乳液中的两个富表活剂相组成及结构均不同,表现为ESR中TEMPO探针所检测到的微环境不同,以及^2HNMR反映出其组成和H~2O分子所在位置处分子平均有序性也不同。 相似文献
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HA( 2-乙基己基膦酸 2-乙基己基酯 )是一种性能优良的萃取剂,经皂化形成微乳液后,能大大提高萃取率 .许多学者对含有中长链醇等助表面活性剂的 HA碱皂微乳液的物理化学性质进行了深入的研究 [1- 4]. 本文报导了用 NaOH皂化不含任何助表面活性剂的 HA煤油溶液,当体系中的 NaOH与 HA数量比达到一定值时,会形成稳定的 W/O型微乳液 .不同的 nNaOH:nHA形成的微乳液的状态可能有所不同 .对这种不含助表面活性剂的微乳液的相行为、电导、溶水量等物理化学性质进行了初步研究 .1实验部分 ( 1) 仪器和试剂 DDS-11A型电导率仪,上… 相似文献
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Barbosa DA Paschoal CW Louzeiro HC Mendonça KK Maciel AP Silva FC de Oliveira HP 《Colloids and surfaces. B, Biointerfaces》2011,84(2):766-328
In this work it was investigated the microemulsion formation using impedance spectroscopy analysis. The results indicated that the microemulsion formation is clearly observed on the impedance complex plane. The phase transition related with microemulsion formation is characterized by a time relaxation distribution. In the condition of the microemulsion formation, the impedance spectra are characterized by a single relaxation time. 相似文献
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用紫外-可见吸收光谱和荧光发射光谱研究了蒽在不同组成和结构的十二烷基硫酸钠(SDS)/苯甲醇(BA)/H20微乳液中的光谱特征,探讨了微乳液组成和结构对蒽光谱特征的影响,阐述了蒽在微乳液中的定位。结果表明,蒽位于O/W微乳液的膜相和油核;在SDS/BA/H2O W/O微乳液中,蒽定位于油连续相。 相似文献