Gemini quaternary ammonium salts are synthesized by the one-step method which are GC-BA with a counterion of benzene sulfonate and GC-MA with a counterion of methanesulfonate. Then, the expected structure is proved by FT-IR, ESI-MS, 1 H NMR, and 1 H- 1 H COSY. Most importantly, the adsorption behavior at various interfaces and the aggregation properties in aqueous solutions are investigated. The adsorption circumstances when the equilibrium is reached at the gas/liquid interface are evaluated by surface tension (ST) tests, while the short-term kinetic process is assessed by dynamic surface tension (DST) measurements. The adsorption at the gas/liquid/solid triple-phase is characterized by the contact angle, and the adsorption at the oil/water interface is expressed by oil/water interfacial tension (ITF). Finally, the aggregation properties are illustrated by conductivity measurements. In summary, some basic theoretical data for the new Gemini quaternary ammonium salts with organic counterions can be provided.

以十二烷基二甲基叔胺、环氧氯丙烷和对甲基苯磺酸为原料,合成了一种反离子含有机酸根的异丙醇基双子季铵盐GC-S.通过正交实验优化了合成工艺.利用FTIR、1HNMR和ESI-MS对产物结构进行鉴定.在最佳反应时间为10 h、反应温度100℃、n(十二烷基二甲基叔胺):n(对甲苯磺酸)=2:1.00的条件下,合成的GC-S具有较高的表面活性,临界胶束浓度(CMC)为2.09×10–4 mol/L,平衡表面张力(γCMC)为24.06 mN/m.与以氯为反离子的传统双子季铵盐GC-Cl和单链季铵盐1231相比,GC-S展现出更优的润湿性、起泡性和稳泡性、乳化性.棉布片在GC-S水溶液中的下沉时间最短,为175.2 s.GC-S起始泡沫体积为390 mL,5 min时消泡体积为20 mL;GC-S分出定量水层的时间为317 s.此外,GC-S对大肠杆菌和金黄色葡萄球菌均表现出优异的抑菌活性.

金属纳米团簇由几个至几百个金属原子组成,通常尺寸在1～10 nm.其中,银纳米簇(Silver Nanoclusters,Ag NCs)具有合成方法简单、荧光发射波长可调等优点,已成为纳米簇领域里发展前景最好的材料之一.Ag NCs的聚集诱导发光(AIE)现象可以通过超分子策略将Ag NCs与不同类型的小分子材料相结合来实现.通过吡啶二羧酸(2,6-DPA)诱导原子精确的银(9)纳米团簇(Ag9-NCs)自组装,在多重非共价键作用下,构筑了具有AIE特性的水凝胶,其荧光寿命提高了～574倍,荧光寿命达到1.88μs.透射电子显微镜(TEM)和扫描电子显微镜(SEM)的表征结果证明水凝胶由形状特殊的棱形纳米棒组成.红外光谱(FT-IR)和X射线衍射(XRD)的结果证明水凝胶形成的主要驱动力是氢键和π-π堆积作用.这项工作的开展扩展了原子精确纳米团簇自组装行为的研究,为新型纳米团簇AIE凝胶体系的构筑提供了新的研究思路.

研究了十六烷基三甲基甲酸铵(HTAF)、十六烷基三甲基乙酸铵(HTAA)和十六烷基三甲基丁酸铵(HTAE)的表面活性、抗静电性、耐盐和耐酸碱性、金属腐蚀性、抑菌性和生物降解性,并对HTAF与脂肪醇聚氧乙烯醚硫酸钠(AES)、脂肪醇聚氧乙烯醚羧酸钠(AEC-9Na)和非离子表面活性剂烷基糖苷(APG1214)二元复配体系的抑菌性和去污洗涤效果进行了测试.结果表明:HTAE的临界胶束浓度(cmc)和表面张力(γcmc)皆低于HTAF和HTAA;HTAF和HTAA的抗静电性能与传统抗静电剂十八烷基二甲基羟乙基硝酸铵(SN)处于一个数量级,HTAE的抗静电性较差;三种有机反离子季铵盐对一价Na+和二价Ca2+,Mg2+都具有优良的耐盐性(>200 g/L),并且耐酸碱性能较好;有机反离子季铵盐对金属的腐蚀性明显低于十六烷基三甲基氯化铵(HTAC);三种有机反离子季铵盐的7天初级生物降解度都大于98％;在20 mg/kg含量下,HTAF对金黄色葡萄球菌(S.aureus)和大肠杆菌(E.coli)仍表现出较好的抑菌效果(>95％).二元复配体系表明:AES/HTAF混合体系相比标准洗衣液具有更好的去污效果,但基本无抑菌性能;AEC-9Na/HTAF混合体系兼具优异的抑菌和去污洗涤性能;APG1214/HTAF混合体系抑菌性能较好,但去污效果较差.

The counterions had a particular influence on various physical and chemical properties, which were significantly present in Gemini quaternary ammonium salt. To investigate this contribution three Gemini quaternary ammonium salt with different counterions, GC-S, GC-N and GC-Cl, were synthesized from dodecyl tertiary amines, epichlorohydrin, and corresponding acids. The structures were characterized by FT-IR and H-1 NMR. Critical parameters such as surface tension, minimum interfacial tension, CMC, and maximum adsorption capacity were measured subsequently. The role of counterions on the adsorption properties was discussed with the help of two classical adsorption models. Their aggregation behavior was observed by TEM. The results showed that counterions with larger ionic radii were adsorbed near the cationic head group more easily, which facilitates the arrangement of surface-active molecules by reduced the repulsive force between them on the adsorption layer. Moreover, the diversity of counterions allowed the surfactants to aggregate in solution to form micelles with different aggregation structures. Cationic surfactants with different counterions were studied as corrosion inhibitors, and found to exhibit temperature-dependent inhibition effects. (C) 2021 Published by Elsevier B.V.

Metal nanocluster is a kind of zero dimensional material with excellent photophysical properties and good biocompatibility. The selectivity of ligands to the thermodynamically stabilized products of clusters and the kinetic regulation of reducing agents can be used to synthesize metal nanoclusters with various structures, which show great potential in the fields of optical materials, biomaterials and catalytic materials. However, the instability and weak luminescence of metal nanoclusters limit their practical application. Therefore, the coordinated regulation of aggregation-induced emission effect and supramolecular self-assembly on stability and optical properties of metal nanoclusters can construct metal nanoclusters assembly with controllable structure and luminescent properties, which effectively promotes the practical availability of metal nanoclusters. In this paper, the synthesis of metal nanoclusters protected by different ligands is briefly introduced, and the photoluminescence properties of metal nanoclusters are illuminated. The influence of aggregation-induced emission effect on the photoluminescence properties of cluster supramolecular assemblies is summarized. The existing problems in current research are analyzed and the prospect of future research are proposed.