Long chain dicationic ammonium salts (1a-1c), easily prepared from tert-amines and dihaloalkanes, were successfully used as efficient phase-transfer catalysts in the Michael addition reaction of various active methylene compounds to 2-cyclohexenone without solvent under ultrasonic irradiation. The investigated dicationic salts were more effective than monocationic tetrabutylammonium bromide, with short reaction times and high yields. This methodology was established under phase-transfer catalytic conditions and ultrasonic effects with many advantages, including the easy and cost-effective synthesis of the catalyst, mild reaction conditions, short reaction times, good yields, simple work-up procedures, and environmental friendliness.
Physico-biochemical studies on cationic gemini surfactants: Role of spacer
作者:Kushan Parikh、Bhavesh Mistry、Sarmita Jana、Sarita Gupta、Ranjitsinh V. Devkar、Sanjeev Kumar
DOI:10.1016/j.molliq.2015.01.055
日期:2015.6
spacers) of cationicgeminisurfactants have been synthesized and their critical micelle concentrations (CMC) and surface properties are determined by conductometry and tensiometry. Ester based geminis are having lower CMCs than polymethylene spacer based ones. Interaction of geminis with plasmid DNA (pEGFP-N1) has been studied using agarose gel electrophoreses to optimize lipoplex (surfactant + DNA) composition
Surface‐Active Properties and Antimicrobial Study of Conventional Cationic and Synthesized Symmetrical Gemini Surfactants
作者:Ketan Kuperkar、Jigisha Modi、Keshav Patel
DOI:10.1007/s11743-011-1269-0
日期:2012.1
as well as on the ionic nature of the surfactant (cationic), alkyl chain length (m = 12, 16) and spacer length (s = 2, 4, 6) of the synthesized compounds. Geminisurfactants such as 12‐2‐12 and 12‐4‐12 were found to be weakly active whereas 16‐2‐16 and 16‐4‐16 compounds proved to be the most potent antimicrobial surface‐active agents among the synthesized gemini homologues.
已合成了通常称为“ m – s – m ”的阳离子系列α,ω-烷二基双(二甲基溴化铵)的对称双子表面活性剂。进行光谱分析以确认化合物的结构和纯度。电导率和表面张力测量可更好地了解胶束化过程。还详细讨论了它们在水溶液中的自组装行为。通过细菌和真菌生长抑制来测量抗微生物功效,所述细菌和真菌生长抑制表示为针对代表性微生物群的五种菌株的最小抑制浓度值。枯草芽孢杆菌,金黄色葡萄球菌,肺炎克雷伯菌,副伤寒沙门氏菌B和黑曲霉。所有合成的表面活性剂均显示出对它们的抗菌活性,但取决于它们的结构,其含量不同。具有更长烷基链(更疏水的环境)的表面活性剂表现出更好的抗菌功能。发现抗菌效力取决于代表性的目标微生物(革兰氏阳性细菌>真菌>革兰氏阴性细菌),以及表面活性剂的离子性质(阳离子),烷基链长(m = 12、16 )和垫片长度(s= 2,4,6)的合成化合物。发现双子星座表面活性剂(如12-2-12和12-4-
Micellization and interfacial properties of cationic gemini surfactant (12–4–12) in the presence of additives in aqueous electrolyte solution: A tensiometric study
作者:Farah Khan、Umme Salma Siddiqui、Malik Abdul Rub、Iqrar Ahmad Khan、Kabir-ud-Din
DOI:10.1016/j.molliq.2013.11.022
日期:2014.3
The surfactant concentration required to reduce the surface tension of solvent by 20 mN m− 1, C20, ratio of C20 and CMC, maximum surface excess concentration at the air/solution interface, Γmax, and minimum area per surfactant molecule, Amin, were evaluated. The interaction parameters βσ (for mixed monolayer formation at the solution/air interface), βm (for mixed micelle formation in aqueous medium)
阳离子双子表面活性剂butanediyl-1,4-双(二甲基十二烷基溴化铵)与添加剂(伯线性醇(丁醇,戊醇,己醇)和伯线性胺(丁胺,戊胺,己胺))的临界胶束浓度(CMC)在本研究中,无机盐硝酸钾是通过在303 K下的表面张力测量来测量的。双子星座的CMC值随添加剂浓度的增加而降低,并且观察到的影响程度依次为:C 6 OH> C 5 OH> C 4 OH;C 6 NH 2 > C 5 NH 2 > C 4 NH 2。表面活性剂浓度要求为20mN米,以减少溶剂的表面张力- 1,Ç 20,的比值Ç 20和CMC,最大表面过量浓度在空气/溶液界面,Γ最大和最小面积每个表面活性剂分子,甲min,进行了评估。相互作用参数β σ(用于在溶液/空气界面的混合单层的形成),β米(对于在含水介质中混合胶束形成)和˚F 1米,˚F 2米(活性系数)也有报道。从相互作用参数可以明显看出,在胶束和界面处均观察到
Analysis of Mixed Micellar Behavior of Promazine
Hydrochloride with Surfactants in Aqueous Medium at Different
Temperatures and Compositions
作者:Malik Abdul Rub、Abdullah M. Asiri、Naved Azum、Anish Khan、Aftab Aslam Parwaz Khan、Sher Bahadar Khan、Mohammed M. Rahman、Dileep Kumar、Abdulrahman O. Al-Youbi
DOI:10.1524/zpch.2013.0360
日期:2013.12.1
Abstract
Mixed micellization behavior of an amphiphilic phenothiazine
drug promazine hydrochloride (PMZ) in the presence of conventional
dodecyltrimethylammonium bromide (DTAB) as well as gemini
1,4-bis(N-dodecyl-N,N-dimethylammonium)butane
bromide (12-4-12) cationic surfactants has been studied at four
different fixed temperatures and compositions by conductometric
technique. The experimental data have been analysed by considering
different theoretical models of Clint, Rubingh, Motomura and
Rodenas. The cmc and cmcid values indicate mixed
micelle formation between the components and strong synergism is
observed in the mixed systems. The micellar (actual) mole
fractions of surfactants
(χ1Rub,
χ1M,
χ1Rod and
χ1id), calculated on the
basis of different theoretical proposed models used in the present
study, show greater contribution of surfactants in mixed
micelles. Activity coefficients (f1
and f2) are always less than unity
indicating nonideality in the systems. Thermodynamic parameters
are also evaluated and discussed which suggest that at higher
temperatures dehydration of hydrophobic part of the drug takes
place.