Ionic liquid-based surfactants chain

A new one phase method for the synthesis of uniform monodisperse crystalline Ag nanoparticles in aqueous systems was developed by using newly synthesized mono and dihydroxylated ionic liquids and cationic surfactants based on 1,3-disubstituted imidazolium cations and halogens anions. The hydroxyl functionalized ionic liquids and hydroxyl functionalized cationic surfactants simultaneously act both as the reducing and protective agent. By changing the carbon chain length, alcohol structure and anion of the hydoxy-functionalized 1,3-imidazolium based ionic liquids and the hydroxyl functionalized cationic surfactants the particle size, uniformity and dispersibility of nanoparticles in aqueous solvents could be controlled (Dorjnamjin et al, 2008). 

If metal salts are heated in a solvent or solvent mixtures in the presence of thiourea, then metal sulfides are accessible. Based on this idea, thiourea has been widely used as a sulfur source in nonaqueous syntheses of ternary and quaternary metal chalcogenides [139-142]. Ai and Jiang presented the synthesis of hierarchical porous Cu2FeSnS4 hollow chain microspheres via a surfactant-assisted microwave-solvothermal approach using ben2yl alcohol [143]. Ionic liquids have also been used as solvents for the formation of metal sulfides MS (M = Cd, Zn, and Pb) by the reaction of thioacetamide with metal acetates in imidazolium-based ionic liquids [144]. 

Surfactants have a unique long-chain molecular structure composed of a hydrophilic head and hydrophobic tail. Based on the nature of the hydrophilic part surfactants are generally categorized as anionic, non-ionic, cationic, and zwitter-ionic. They all have a natural tendency to adsorb at surfaces and interfaces when added in low concentration in water. Surfactant absorption/desorption at the vapor-liquid interface alters the surface tension, which decreases continually with increasing concentrations until the critical micelle concentration (CMC), at which micelles (colloid-sized clusters or aggregates of monomers) start to form is reached (Manglik et al. 2001 Hetsroni et al. 2003c). 

A surfactant was defined in Chapter 8 as an agent, soluble or dispersible in a liquid, which reduces the surface tension of the liquid [1]. It is helpful to visualise surfactant molecules as being composed of opposing solubility tendencies. Thus, those effective in aqueous media typically contain an oil-soluble hydrocarbon-based chain (the hydrophobe) and a smaller water-solubilising moiety which may or may not confer ionic character (the hydrophile). The limitations of space do not permit a comprehensive detailed treatment of the chemistry of surfactants. The emphasis is therefore on a broad-brush discussion of the principal types of surfactant encountered in textile preparation and coloration processes. Comprehensive accounts of the chemistry and properties of surfactants are available [2-13]. A useful and lucid account of the chemistry and technology of surfactant manufacturing processes is given by Davidsohn and Milwidsky [ 14] ... 

Very recently, the self-assembly of poly(y-benzyl-i,-glulamalc)-fo-poly(i,-lysine) rod-coil copolypeptide via ionic complexation was reported by Ikkala, Hadjichristidis and coworkers [65]. Complexation between the anionic surfactants dodecyl benzenesulfonic acid and the cationic poly(L-lysine) chains occurs via proton transfer from the acid group to the base, resulting in electrostatically bonded comb-like structures, and fluid-like liquid crystalline structures at room temperature due to efficient plasticization of dodecyl benzenesulfonic acid. 

Generally, amphiphilic molecules self-assemble to form micelle, microemulsion, lyotropic liquid crystal and vesicle. Moreover, long-chain ILs can act as ionic surfactants and form similar self-assembly in water or oil. Qiu et al. summarized the studies of IL based microemulsions from the p>erspective of the role of ILs (Qiu Texter, 2008). ILs participated in the formation of the microemulsions, in which ILs replaced oil, water or surfactants. Hao et al. reviewed the self-assembled structures (such as micelles, microemulsions, liquid crystals and vesicle) in ILs, which acted as the solvent (Hao Zemb, 2007). In this p>art, we summarized the IL based organized assemblies, in which IL participated in the formation of micelles, microemulsions, vesicles and liquid crystals rather than acted as solvents. 

Gavach et al. were probably the first to apply liquid membrane-based ion-selective electrodes (ISEs) for the titration of long chain alkyl methyl ammonium salts with sodium tetraphenyl borate. Birch et al." were also among the first researchers to use liquid ion-exchange electrodes responsive to ionic surfactants in 1972. 

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