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壳聚糖季铵盐的合成及结构表征 总被引:39,自引:4,他引:39
用异相法合成了水溶性壳聚糖季铵盐衍生物,并用红外光谱及核磁共振谱进行结构表征。结果表明:在中性反应条件下,壳聚糖分子的季铵盐衍生化反应主要发生于亲该中心C2位的氨基上,所合成的壳聚糖季铵盐衍生物可直接溶解于水。其水溶液可以任意比例与乙醇、丙二醇、甘油等混溶。 相似文献
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季铵盐型Gemini表面活性剂诱导囊泡结构改变机理研究 总被引:2,自引:1,他引:1
用动态光散射技术以及荧光探针方法, 研究了不同连接基长度的季铵盐型Gemini表面活性剂对卵磷脂囊泡结构改变的影响, 并借助理论模型和临界堆积参数理论探索了Gemini表面活性剂诱导囊泡结构改变的机理. 实验结果表明, 表面活性剂诱导囊泡结构改变的主要原因是表面活性剂嵌入到囊泡的双分子层中, 从而改变了囊泡的表面电荷强度以及嵌入后的表面活性剂在囊泡双分子层中分布的不均匀性. 此外, 表面活性剂分子的结构也会对其产生影响, 不同连接基长度的季铵盐型Gemini表面活性剂对囊泡结构改变的影响不完全相同, 但会呈现出一定的规律性. 相似文献
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手性季铵盐作为相转移催化剂(Phase-transfer catalysts ,PTC) 能使非均相反应在温和条件下进行,操作简单,反应速率加快,产率明显提高,因此这一技术在有机合成中具有广泛的应用.这些季铵盐主要是以金鸡钠生物碱衍生的[1,2],近年来出现了一些其它类型的季铵盐[3],但是它们的制备一般比较困难,大多数催化效果不是很理想;并且这些季铵盐的结构有一定局限,改造比较困难.同时这些季铵盐大都是 C-手性的,很少有N-手性的[4,5];在以前的不对称反应中,有意识地构建N-手性季铵盐及N-手性在不对称反应中的作用鲜有报道[6]. 相似文献
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聚(4-乙烯基吡啶季铵盐-丙烯酰胺)的抗菌性能与机理研究 总被引:2,自引:0,他引:2
季铵盐型阳离子聚合物具有絮凝、缓蚀与杀菌等多种功能,据此,我们通过分子设计,先将丙烯酰胺与4-乙烯基吡啶(4-VP)进行共聚合,然后使用季铵化试剂硫酸二甲酯使共聚物阳离子化,制备了吡啶季铵盐型阳离子聚丙烯酰胺(QPAV),本文报道QPAV的抗菌性能,并探讨其抗菌机理,结果表明,吡啶季铵盐型阳离子聚丙烯酰胺具有很强的抗菌性能,且其抗菌机理是基于杀菌而不仅仅是抑菌。 相似文献
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芳氧亚甲基咪唑啉季铵盐的合成及缓蚀性能评价 总被引:1,自引:1,他引:0
合成了苯氧亚甲基咪唑啉季铵盐(POAI)和萘氧亚甲基咪唑啉季铵盐(NOAI),通过失重法、电化学方法研究了二者在1 mol/L HCl中对A3钢的缓蚀性能,并对二者在A3钢表面的吸附行为进行了探讨。 结果表明,二者在1 mol/L HCl中对A3钢均有较好的缓蚀作用,其中NOAI对A3钢的缓蚀性能优于POAI的缓蚀性能;两化合物均为混合型缓蚀剂。 缓蚀性能随缓蚀剂浓度和温度的增大而增大;二者在A3钢表面的吸附过程吸热,是化学吸附,符合Langmuir吸附等温式。 相似文献
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A poly(vinyl chloride) matrix membrane ion-selective electrode for the determination of the denatonium ion based on the denatonium salt of tetraphenylborate is described. The response characteristics of the electrode for the denatonium ion and for several quaternary ammonium compounds were studied. The potentiometric determination of denatonium benzoate in rapeseed oil in the range 1-10 ppm agreed to within +/-5% of the spiked amounts. The application of the electrode to the titrimetric determination of several quaternary ammonium compounds using sodium tetraphenylborate as the titrant is also described. 相似文献
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以二乙醇胺、丁二酸酐为原料,合成端羟基超支化大分子;用环氧丙基三甲基氯化铵进行末端基团改性,引入季铵盐阳离子基团制备了一种新型季铵盐抑制剂HBP-TAC,其结构经红外光谱、核磁和元素分析表征。考察了端基取代度与浓度对抑制膨润土水化膨胀性能影响,并对滚动回收率及与钻井液配伍性进行了评价、实验结果表明:该类抑制剂对膨润土的水化膨胀有一定抑制作用,加入1%多取代HBP-T2,抑制效果能达到95.31%;在高温130℃条件下,页岩滚动回收的一次回收率为91.8%,二次回收率为80.1%;抑制剂与水基钻井液体系相容性较好,并对滤失性有一定改善效果。
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用戊酸、羊蜡酸、油酸、二乙烯三胺、氯化苄和硫脲为原料,合成了6种咪唑啉季铵盐化合物。 采用静态失重法和极化曲线法,比较了硫脲基烷基咪唑啉型季铵盐和烷基咪唑啉型季铵盐在80 ℃、1 mol/L的HCl溶液中对碳钢的缓蚀性能,研究了这两类缓蚀剂与无机阴离子和阴离子表面活性剂的协同作用。 结果表明,硫脲基烷基咪唑啉季铵盐类的缓蚀效果明显优于烷基咪唑啉季铵盐类,硫脲基羊脂酸咪唑啉缓蚀剂的缓蚀率可达98.3%。 当以羊脂酸、二乙烯三胺、氯化苄和硫脲为原料合成的硫脲基烷基咪唑啉型季铵盐化合物与I-质量比为1∶1复配时,缓蚀效果最佳,比单独使用硫脲基烷基咪唑啉季铵盐化合物的缓蚀率提高了1.5%。 相似文献
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Sadayuki Koizumi T. Imato Nobuhiko Ishibashi 《Analytical and bioanalytical chemistry》1997,357(1):37-43
Potentiometric selectivities of a plasticized poly(vinyl chloride) (PVC) membrane containing a hydrophobic quaternary ammonium
salt and triphenyltin chloride (TPTCl) for several inorganic anions were evaluated by measurements of the membrane potential
of a bi-ionic system (the so-called bi-ionic membrane potential). The addition of TPTCl to the plasticized PVC membrane containing
a quaternary ammonium salt gave rise to selectivity patterns different from the Hofmeister anion series, which is observed
for a membrane containing only the quaternary ammonium salt. The change in the selectivity pattern from the Hofmeister to
the non-Hofmeister was observed under conditions where the TPTCl concentration was higher than the quaternary ammonium salt
in the membrane. Response mechanisms and the selectivity of the TPTCl-based electrode are discussed with respect to the concentration
dependence of TPTCl and quaternary ammonium salt in the membrane.
Received: 6 July 1995/Revised: 2 February 1996/Accepted: 6 February 1996 相似文献
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H. J. Veith 《Journal of mass spectrometry : JMS》1976,11(6):629-633
The field desorption mass spectra of salts such as quaternary ammonium and carbenium salts with organic cations in addition to high cation intensities show signals for cluster ions composed of the salt cation + salt molecule, i.e. [C + nM]+, n = 1–5, thus allowing determination of the molecular weights of salts. In some cases cluster ions of the type [nM – 1]+ are detected. Conditions for the formation of cluster ions are discussed. 相似文献
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The cycloaddition of epoxides with carbon disulfide proceeds effectively by using a binary catalyst system of tetradentate Schiff‐base aluminum complexes (designated as salenAlX) as Lewis acid in connection with a nucleophilic co‐catalyst, such as quaternary ammonium salt. The steric factor of the substituent groups on the aromatic rings of salenAlX and the anion of quaternary ammonium salt all have significant effects on the activity of the binary catalyst system, as well as the selectivities of the resultant cyclic products. The effects of temperature, time and the molar ratio of reactants were also investigated in detail with regard to propylene oxide with carbon disulfide, and a plausible mechanism was proposed. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献