Modified gelatin with quaternary ammonium salts containing epoxide groups

An EPDDMAC-GE polymer （hydrophilic molecule） has been synthesized based on epoxypropyl dodecyl dimethyl ammonium chloride （EPDDMAC） and gelatin. A DEEPSAC-GE polymer （hydrophobic molecule） has been synthesized based on diethyl-2,3-epoxypropyl-[3-methyldimethoxyl] silpropyl ammonium chloride （DEEPSAC） and gelatin. Compared with initial gelatin, the gelatin modified with quaternary ammonium salts containing epoxide groups exhibits stronger antibacterial activity.     

Effects of ion association of lipophilic quaternary ammonium salts in ion-exchange and potentiometric selectivity

It has been found experimentally and substantiated theoretically that the anion-exchange selectivity in water—lipophilic quaternary ammonium salts (QAS) toluene solutions systems as well as the potentiometric selectivity of plasticized PVC membranes containing QAS, are strongly influenced by ion association. In particular, it has been demonstrated that varying the steric accessibility of QAS exchange center is a powerful tool for the selectivity control. The experimental values of the selectivity change caused by variations in the QAS exchange center steric accessibility were about 3 orders of magnitude when the single-charged ions were exchanged for the single-charged ones and more than seven orders when double-charged ions were exchanged for the single-charged. The above effects have also been observed for the potentiometric selectivity of QAS-based PVC membranes and, to some extent, for the potentiometric selectivity of the neutral anion carrier-based membranes doped by QAS to provide anion permselectivity. This fact is of immediate practical interest for the development of ISE with improved selectivity. The obtained results allow to revise the generally accepted idea of QAS as “nonselective” ion-exchangers and to suggest specific ways for controlling the ion-exchange and potentiometric selectivity using the ion association as a tool.     

The antibacterial finish of cotton via sols containing quaternary ammonium salts

The sols containing quaternary ammonium salts were prepared via sol-gel process. The effects of the molar rate of HCl, H₂O and EtOH to TEOS on the sol viscosity were investigated in detail. Cetyltrimethylammonium bromide (CTAB), Octadecyl dimethyl benzyl ammonium chloride (DC) and Ethylene-Bis (Octadecyl trimethyl ammonium chloride) [E-Bis(OTAC)]were added in the sols and applied to cotton samples by treated. The antibacterial activities of the samples were assessed against both Escherichia coli and Staphylococcus aureus bacteria. The samples treated by E-Bis(OTAC) sol exhibited the satisfactory antibacterial activity that resulted from the more microorganism adsorption and hydrophobicity. The antibacterial activities were still excellent after 10 times washings comparison with the control samples.     

Synthesis of fulleropyrrolidines through the reaction of [60]fullerene with quaternary ammonium salts and amino acids

The reactions of [60]fullerene with amino acids and quaternary ammonium salts in toluene afforded two fulleropyrrolidine derivatives. One fulleropyrrolidine derivative contained a RCH moiety originating from quaternary ammonium salts through C–N bond cleavages and other fulleropyrrolidine derivatives contained a PhCH moiety originating from toluene through C–H bond cleavage. By using chlorobenzene instead of toluene as solvent, only one fulleropyrrolidine derivative containing a RCH moiety was obtained in the reactions.     

二甲基烯丙基胺/溴代烷烃系列季铵盐的合成与表征

以溴代烷与二甲基烯丙基胺(DMAA)为原料合成了二甲基烯丙基类季铵盐;探讨了反应温度、原料配比、反应时间及溶剂对反应产率的影响,确定了最佳合成条件;并采用红外光谱仪、核磁共振谱仪(1 H NMR)及质谱仪表征了产物的结构.     

An experimental and theoretical study of the catalytic effect of quaternary ammonium salts on the oxidation of hydrocarbons

The enhancement in the autoxidation of ethylbenzene by molecular oxygen in the presence of quaternary ammonium salts (QAS) was investigated from the experimental and theoretical points of view. The primary effect of the addition of QAS to the reaction medium was an increase in ethylbenzene conversion. Quantum chemical calculations, using B3LYP hybrid functional, revealed a weakening of C-O and O-H bonds of the hydroperoxide. These effects favor the formation of ethylbenzenyl and peroxyl radicals, respectively, both of which are involved in the propagation reaction that leads to the formation of hydroperoxide, the desired final product.     

离子对分离和抑制电导检测法测定四乙基铵和四丁基铵根离子

建立了季铵盐的离子色谱分析方法.采用Dionex DX-500 型离子色谱仪,C18柱,电导检测器,以30%乙腈和10 mmol/L甲烷磺酸混合溶液为流动相,流量为1.00 mL/min.四乙基溴化铵和四丁基溴化铵的质量浓度和峰面积的相关系数分别为0.9996和0.9994;线性范围分别为10～80 mg/L和20～120 mg/L;检出限分别为0.28和0.76 mg/L;RSD分别为1.3%、 2.5%.该方法可用于分析水溶液中季铵盐的含量.     

基于链状氨基酸N-手性季铵盐合成中的取代反应研究

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].     

Mixed ternary ion associate formation between xanthene dye, cinchona-alkaloid and quaternary ammonium ion and its application to the determination of trace amounts of quaternary ammonium salts in pharmaceuticals

Xanthene dyes such as eosin and tetraiodofluorescein form 1:2 ion associates with quaternary ammonium ions at pH 7-9; however, the development of color in the organic solvent is poor. When a quaternary ammonium salt is added in the extractable 1:2 associate formed between a xanthene dye and a cinchona-alkaloid in the neutral media, a mixed ternary ion associate (xanthene dye:cinchona-alkaloid:quaternary ammonium ion=1:1:1) is formed. Its extractability is enhanced due to the more bulky associate formation. The ion association caused by addition of cinchona-alkaloids is unique. Of the cinchona-alkaloids, quinidine and cinchonidine with tetraiodofluorescein show excellent effects on sensitivity and extractability. Eosin and tetraiodofluorescein are useful as ion association reagents in the ion associate formation. The apparent molar absorptivities are about 1×10⁵ l mol⁻¹ cm⁻¹ and the calibration range for quaternary ammonium salt is from 2.5×10⁻⁷ to 1.5×10⁻⁶ M. The proposed method is applicable to the selective and sensitive determination of cetylpyridinium chloride, berberine chloride and benzethonium chloride in pharmaceuticals.     

Heterocyclization of amino alcohols into saturated cyclic quaternary ammonium salts

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Imparting durable antimicrobial properties to cotton fabrics using quaternary ammonium salts through 4-aminobenzenesulfonic acid-chloro-triazine adduct

A 4-aminobenzenesulfonic acid-chloro-triazine adduct was successfully synthesized in a laboratory scale and treated with cotton fabrics in order to increase the anionic sites and thereby % exhaustion of cationic compounds. Two Quaternary Ammonium Salts (QAS) was investigated namely, Cetylpyridinum chloride (CPC) and Benzyldimethylhexadecyl ammonium chloride (BDHAC) which are widely accepted as strong antimicrobial agents. The reaction mechanism involved in the synthesis of the reactive adduct as well its application to cotton fabric were demonstrated in detail. The effects of application parameters, namely pH, temperature and liquor ratio were examined. The reaction efficiency was determined through monitored % exhaustion of the adduct by cotton fabric. Antimicrobial activity of the treated cotton sample was studied against Staphylococcus aureus according to AATCC test method 100-1999. Results obtained show that the treated fabric shows higher antimicrobial activity compared with the untreated fabric. The results depict also that % exhaustion decreases as the pH, temperature and liquor ratio increase. Moreover, the appropriate predictable empirical models were developed using Excel solver function incorporating interaction effects of all variables to predict the % exhaustion and the satisfactory results (R² > 0.98) were obtained.     

溴化苄基取代吡啶类季铵盐的制备和抗菌性能

抗菌材料和抗菌制品的研究与应用一直是世界各国研究的重要课题~([1-3]),其中有机抗菌剂占据主要地位.季铵盐是研究比较多的一类有机抗菌剂,它们表现出良好的物理性质,如胶束浓度低,黏弹性好和溶解性强~([4]),同时此类抗菌剂具有强效的抗菌作用~([5]),引起了人们的极大兴趣.季铵盐广泛应用于医药、卫生、食品、饲料工业、农业、纺织、塑料、橡胶、造纸、水处理、油田开采、涂料、日常生活等多种领域~([6-10]).     

Study of ring cleavage in quaternary ammonium salts of 1,3-diazaadamantane

A series of quaternary ammonium salts of 5,7-dimethyl-1,3-diazaadamantan-6-one bearing aryl and alkyl substituents was synthesized. On treatment with aqueous KOH, these compounds undergo ring cleavage to give 3,7-diazabicyclo[3.3.1]nonane derivatives. The product structure was confirmed by ¹H and ¹³C NMR and IR spectroscopy. Dedicated to Academician V. A. Tartakovsky on occasion of his 75th birthday. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1496–1501, August, 2007.     

Antibacterial membranes based on chitosan and quaternary ammonium salts modified nanocrystalline cellulose

Etherification of nanocrystalline cellulose (NCC) with three kinds of quaternary ammonium salts epoxypropyltrimethylammonium chloride, N,N‐dimethyl‐N‐dodecyl‐N‐(1,2‐epoxypropyl) ammonium chloride (DMDEPAC), and N,N‐dimethyl‐N‐octadecyl‐N‐(1,2‐epoxypropyl) ammonium chloride (DMOEPAC) was successfully performed via a nucleophilic addition reaction. The synthesized DMDEPAC and DMOEPAC were characterized by nuclear magnetic resonance. The modified NCC particles, NCC epoxypropyltrimethylammonium chloride, NCC‐DMDEPAC, and NCC‐DMOEPAC, were characterized by energy dispersive spectrometer. Nanocomposite films based on chitosan (CS) containing quaternary ammonium salts modified NCC were prepared with nanoparticle loadings of 5.0, 7.5, and 10.0%, respectively. The effect of nanoparticle content on the tensile strength of composite films was studied. The results indicated that the films with 5.0% nanoparticle loading exhibited the biggest increase in tensile strength. Surface morphology, smoothness, and antibacterial properties of composite films containing 5% modified NCC were also studied. CS/NCC‐DMDEPAC‐5.0 and CS/NCC‐DMOEPAC‐5.0 displayed excellent biocidal abilities against both Gram‐positive Staphylococcus aureus (ATCC 6538) and Gram‐negative Escherichia coli O157:H7 (ATCC 43895). The bio‐based nanocomposite films with increased mechanical strength and excellent antibacterial properties show great potential as food packaging materials. Copyright © 2017 John Wiley & Sons, Ltd.     

Nonstabilized azomethine ylides in the synthesis of aryl cucurbitine derivatives

Nonstabilized azomethine ylides react with 4-arylidene-2-phenyloxazol-5(4H)-ones to form diazaspiro[4.4]nonenes, which were hydrolyzed to aryl cucurbitine derivatives in 35–67% overall yield.     

Measuring quaternary ammonium cleaning agents with ion selective electrodes

Data for coated-wire, ion selective electrodes (ISEs) are presented for cationic surfactant ions found in common cleaners including benzyldimethyltetradecylammonium, benzyldimethyldodecylammonium, and benzyldimethylhexadecylammonium. The ion exchangers dinonylnaphthalene sulfonic acid, tetraphenyborate, and tetrakis(4-chlorophenyl)borate are examined, showing dinonylnaphthalene sulfonic acid to be the favored species. The ISEs exhibit approximately Nernstian behavior down to the 10⁻⁶ M limit of detection with lifetimes in excess of 50 days when used continuously, and a shelf life of over 100 days. Reaching the upper detection limit at the critical micelle concentration requires use of polymeric-membrane reference electrodes including a new membrane cocktail, which allow response measurements of an order of magnitude higher than the traditional fritted-glass reference electrode. The surfactant ISEs show excellent selectivity over the common metal ions Na⁺, K⁺, Mg²⁺, Ca²⁺, and Cu²⁺ with selectivity coefficients less than 10^−5.3. The ISEs are also selective over the lower molecular weight quaternary ammonium ions tetradecyltrimethylammonium, dodecyltrimethylammonium, benzyldimethyl(2-hydroxyethyl)ammonium, and tetrabutylammonium with selectivity coefficients ranging from 10^−1.7 to 10^−5.5. Use of a single electrode to determine accurately the total cationic surfactant concentration in common cleaning solutions is accomplished with information about concentration dependent interferences and a modified Nikolsky–Eisenman model. Finally, quaternary ammonium surfactants have a deleterious effect on the measurements of pH and common ions like K⁺, Mg²⁺ and Ca²⁺ with polymeric ISEs. This makes it critical to include surfactant electrodes in a detector array when cleaning agents are present.     

稀土三元催化体系ZnO/SiO2负载化及季铵盐催化CO2与环氧丙烷合成高分子量聚碳酸酯

由环氧丙烷(PO)和CO2交替共聚合成脂肪族聚碳酸亚丙酯,CO2利用率高, 所得产物具有一定的力学性能和生物降解性能, 具有广泛应用前景. 目前, 用于CO2和环氧化合物共聚的催化体系主要包含锌、钴、镉、铬、铝和稀土等金属活性中心, 结构、活性各异的催化剂体系, 其催化性能和产物性能也各具特色. 其中, 稀土三元催化剂(ZnEt2-甘油-三氯乙酸钇)因合成聚碳酸酯产物的分子量高、碳酸酯单元含量高、聚醚及环碳酸酯副产物少的特点而受到关注. 但是由于催化剂催化效率低, 聚合时间长, 产品成本高, 使得工业化规模生产受到限制.本文基于稀土三元催化体系, 将催化剂负载于硅胶及锌改性硅胶, 优化了其制备条件, 同时考察了添加季铵盐对催化CO2/环氧丙烷共聚合成聚碳酸酯性能的影响. 结果表明, 在1 L聚合釜中, 于3.5 MPa和70 oC反应条件下, ZnO担载量及ZnO/SiO2添加量对反应性能均有影响. 当3 wt% ZnO/SiO2的添加量为5 g时, 稀土三元催化体系的活性为4845.2 g/molZn..所得聚合物经过多次纯化处理后, 能够有效提高材料的热学性能, 即有效除去产物中的ZnO对聚合物的热稳定性有重要作用. 添加含有不同阴离子(F- , Cl- 和Br- )的季铵盐可显著影响稀土三元催化剂的活性. 其中, 仅四甲基氟化铵可以明显提高反应活性乃至聚合物分子量. 在3 wt% ZnO/SiO2载体和四甲基氟化铵的协同作用下, 稀土三元催化体系的共聚性能明显提 升, 活性最高可达5223.0 g/molZn. 聚合物结构分析表明, 在载体和四甲基氟化铵存在下, 聚合物分子量明显提高, 可达到20万以上, 分子量分布明显变窄, 且聚合物结构如碳酸酯的单元含量、副产物含量以及聚合物产品玻璃化温度基本不变, 后者均保持在40-41 ?C. 基于此, 我们提出了在ZnO改性硅胶载体及四甲基氟化铵存在下稀土三元催化体系催化CO2/环氧丙烷共聚的反应机理: ZnO/SiO2载体有利于稀土三元催化体系的分散, 而四甲基氟化铵则有利于吸附在ZnEt2上的环氧丙烷开环.     

Measurement of thermophysical properties of ammonium salts in the solid and molten states

The thermal conductivity, specific heat capacity and thermal diffusivity of solid and molten ammonium thiocyanate, ammonium formate, ammonium acetate and ammonium nitrate were measured in the temperature range 80–190C, including the solid and liquid phases, by using the AC-heated strip (wire) technique. The results indicate that the thermal conductivities depend on the type of the ammonium salt. It was found that the mechanism of heat transfer is due to phonons in the region below the melting points of the salts, while above this region the main mechanism is due to conduction.