Hypoxia/Temperature/pH Triple Stimuli–Responsive Block Copolymers: Synthesis,Self-Assembly,and Controlled Drug Release

The amphiphilic block copolymer poly(methacrylic acid-co-2-nitroimidazole acrylate)-b-poly(2-(N,N-dimethylamino)ethyl methacrylate) (P(MAA-co-NIMA)-b-PDMAEMA) with the hypoxia/temperature/pH triple responsiveness is synthesized by reversible addition-fragmentation chain transfer polymerization (RAFT), hydrolysis, and 3-(3-dimethylaminopropyl)-1-ethylcarbodiimide (EDC) reactions, and successfully self-assembled into micelles. The hypoxia response in vitro is realized, and then the sensitivity of the self-assembled micelles to the hypoxia condition is studied by controlling the grafting amount of aminated 2-nitroimidazole. Because 2-(N,N-dimethylamino) ethyl methacrylate (DMAEMA) is a typical material sensitive to temperature and pH conditions, the self-assembled micelles are also responsive to temperature and different acidic/basic conditions. In addition, the cumulative release rate of doxorubicin (DOX) at 42 °C, pH = 6.0, and hypoxic conditions increases significantly, and verifies the synergistic promotion effect of the above stimulations. This intelligent polymer with triple response mechanism improves the controllability and efficiency of drug release, and is expected to be a drug carrier for cancer treatment.     

DEDS-10双子表面活性剂的性能研究

合成了一种新型的DEDS-10双子表面活性剂,用红外光谱对所合成化合物的结构进行了初步表征。DEDS-10的临界胶束浓度cm c为0.47 mmol/L,γcm c为34.5 mN/m,A lC l3、CaC l2和NaC l可以使γcm c降低3.6~1.1 mN/m,其cm c值大约为纯水溶液cm c值的1/5~1/3;加入乙醇,可增加其表面活性,在乙醇的浓度为0.22 mol/L时,其表面张力为30 mN/m左右。与阳离子表面活性剂DTAB和非离子表面活性剂曲拉通X-100复配,可以大幅度地降低cm c和γcm c值,与阴离子表面活性剂TLS复配时,cm c降低,cγm c略有增加。     

p－（N，N－二甲氨基）肉桂酸乙酯在分子聚集体中的光化学行为

本文报道了ｐ－（Ｎ，Ｎ－二甲氨基）肉桂酸乙酯（ＤＭＡＣ）在十二酸（ＬＡ）聚集体中的光谱和光化学性质．这种肉桂酸衍生物的吸收和发射光谱表现出典型的分子内电荷转移的特征，在十二酸存在下，观察到ＤＭＡＣ激基缔合物荧光，荧光强度随ＤＭＡＣ浓度增加而增加，与普通溶液中的反应相比，十二酸聚集体中的ＤＭＡＣ具有较大的光二聚反应速度．用荧光光谱跟踪反应的结果表明，ＤＭＡＣ激基缔合物具有较ＤＭＡＣ单体更高的光化学活性。     

Surface activity of quaternary ammonium salts derived from jojoba oil

A number ofcis andtrans quatenary ammonium salts were synthesized from jojoba oil. All derivatives were found to be surface active agents, i.e., they reduced the surface tension to 35 dynes/cm⁻¹, at very low concentrations. The relationship between the surface activity and the molecular structure is discussed.     

硫代磷酸/伯胺N1923协同萃取锌和镉的机理

有机硫代磷酸/伯胺N1923协同萃取锌、镉的萃取率随pH的变化较为反常，可能因伯胺N1923与硫酸作用进而聚为反向胶束. 实验表明，如以(N1923)n.H2SO4表示反向胶束的实验式，N1923与H2SO4比值n多为3左右，可能与空间效应相关. 萃取机理为: M2+(a) +2BHA(o) + (2/n)SO42–(a) = MA2(o) + (2/n)(Bn.H2SO4)(o) + 2(1–2/n)H+(a)， n=3, 4, 5.     

Membrane degumming of crude rice bran oil: Pilot plant study

The procedure for the classical chemical refining of vegetable oils consists of degumming, alkali neutralization, bleaching, and deodorization. Conventional refining of rice bran oil using alkali gives oil of acceptable quality, but the refining losses are very high. A critical work has been carried out to study the application of membrane technology in the pretreatment of crude rice bran oil. Oils intended for physical refining should have a low phosphorus content, and this is not readily achievable by the conventional acid/water degumming process. The application of membrane technology for the pretreatment of rice bran oil has been investigated. The process has already been successfully applied to other vegetable oils. Ceramic membranes, which are important from the commercial point of view, were examined for this purpose. The results showed that the membrane‐filtered oils met the requirements of physical refining, with a substantial reduction in color. It was observed that most of the waxy material was also rejected. Experiments were carried out to establish the relationship between permeate flux and rejection with membrane pore size, trans‐membrane pressure and micellar solute concentration.     

表面活性剂聚集体的流变性质

以流变学基础知识为出发点，系统综述了胶束、微乳液，溶致液晶（层状、六角状、立方状），囊泡、虫状胶束等表面活性剂聚集体的流变性质及其剪切诱导结构转变现象的研究现状，总结了自流变性质的特点和理论模型，对具有黏弹性的表面活性剂活性剂聚集体进行了较为详细的论述，胶束稀溶液和微乳液多为牛顿流体；溶致液晶为非牛顿流体，有应力服价值和较高的黏弹性，囊泡的弹性性质比较突出，；虫状胶束体系具有非线性黏弹性，易形成网络结构；层状液晶、囊泡和虫状胶束等结构在剪切作用下能发生变化。这些结论对指导表面活性剂的研究和应用有重要意义。     

磺酸型Gemini表面活性剂的合成及表面活性

以壬基酚、1,4-二溴丁烷和氯磺酸为主要原料,通过三步反应合成了新型的磺酸型Gemini表面活性剂9BA-4-9BA,讨论了合成反应时间、温度以及催化剂对产物纯度和产率等因素的影响,优化了反应过程。利用核磁共振谱和红外光谱表征了产物结构,并通过DCTA21表面/界面张力仪测试其水溶液中的表面张力。和传统表面活性剂相比,合成的Gemini表面活性剂9BA-4-9BA具有更高的表面活性,其临界胶束浓度和C20分别为6.2×10-4mol/L和1.1×10-5mol/L。     

阳离子型双子表面活性剂的合成及表面活性

合成了一种季铵盐型双子表面活性剂Gem in i 12-3-12,采用红外光谱、元素分析和两相滴定法对其结构和纯度进行了分析,测定了不同浓度表面活性剂水溶液的表面张力,并得到临界胶束浓度(CMC)、饱和吸附量(Γm ax)、单分子饱和吸附面积(Am in)。结果表明,Gem in i 12-3-12的收率为77.2%,纯度为98.4%,它与相应的单尾基十二烷基三甲基溴化铵(DTAB)的表面活性相当,但CMC比DTAB低14倍左右。     

新显色剂4—（2—苯并噻唑偶氮）邻苯二酚—钼（Ⅵ）—OP体系的分光光度研究

在ｐＨ５．０～５．７范围内，新显色剂４－（２－苯并噻唑偶氮）邻苯二酚（ＢＴＡＰＣ）与钼（Ⅵ）和非离子表面活性剂ＯＰ反应，形成稳定的、带负电荷的、紫红色三元胶束配合物。该配合物中Ｍｏ（Ⅵ）与ＢＴＡＰＣ的组成比为１∶２；其λｍａｘ为５６０ｎｍ，对比度（Δλ）为１２８ｎｍ；在２０℃、ｐＨ５．２和μ０．１时，配合物的表观稳定常数为３．０２×１０１０，表观摩尔吸光系数ε５６０为８．１１×１０４Ｌ·ｍｏｌ－１·ｃｍ－１，真实ε５６０为７．６７×１０４Ｌ·ｍｏｌ－１·ｃｍ－１。钼含量在０～０．７２ｍｇ／Ｌ范围内遵从比耳定律。建议了配合物的结构。本法简便、快速、准确，用于合金钢试样中痕量或小量钼的测定，取得了满意的结果。