Effect of Long‐Chain Length on the Surface Activities of Zwitterionic Imidazolium‐Based Surfactants: 1‐Carboxymethyl‐3‐alkylimidazolium Inner Salts

Abstract

Zwitterionic imidazolium‐based surfactants, namely 1‐carboxymethyl‐3‐alkyl imidazolium inner salts (CnimCM, n = 10, 12, and 14), were synthesized. Their molecule structures were characterized by means of electrospray ionization mass spectrometry (ESI–MS), 1H nuclear magnetic resonance (1H NMR) and elemental analysis. Compared to the structurally related N‐alkylbetaines (CnH2n+1N+(CH3)2CH2COO−), the CMCs of CnimCM are smaller than those of N‐alkylbetaines. The effect of the long‐chain length on the typical physicochemical properties of CnimCM was studied. It is found that the lengthening of the long‐chain enhances the surface activity of CnimCM. The tendency for CnimCM surfactants is similar to the case of the structurally related traditional zwitterionic N‐alkylbetaines.

Synthesis and Surface Properties of Novel Carboxylic Ester‐Containing Imidazolium‐Based Zwitterionic Surfactants: Monoalkyl 2‐(3‐Methylimidazolium‐1‐yl) Succinate Inner Salts

“…(6) is 0.5, which means that addition of two methyl groups to the long hydrocarbon chain decreases the CMC of C n MimSU (n = 8, 10, 12 and 14) by a factor of approximately 10. These results show that the relationship between log CMC and n c is similar to those of traditional zwitterionic ones [3]. That is, zwitterionic surfactants C n MimSU pack more closely at the air-water interfaces with the hydrophobic chain length (n C ) increasing [35,36].…”

“…In recent years, new classes of amphiphilic molecules have emerged and drawn the attention of various industrial and academic research groups [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16]. One of these classes is the zwitterionic surfactants, which contain both cationic and anionic active groups as their hydrophilic groups.…”

“…However, because of their high production cost and complex synthetic route, zwitterionic surfactants are far less investigated than anionic, cationic and nonionic surfactants. During the past years, the synthesis of imidazolium-based zwitterionic surfactants, such as ImS 3 -14 [1], CMDim [2] and C n imCM (n = 10, 12, 14) has been reported [3].…”

Reversible-Tuning Krafft Temperature of Selenium-Containing Ionic Surfactants by Redox Chemistry

“…20 For zwitterionic surfactants, the addition of an electrolyte always decreases the K T . 5,21 In addition, neutral polymers, 22,23 foam boosters of amides, 24 and aromatic solutes 25 also change the K T of ionic surfactants in various degrees. The K T versus composition curves observed in binary surfactant mixtures could be classified into two groups: one group having a minimum K T at a certain composition and the other group experiencing monotonical variations in the K T with changes in the composition.…”

Alkyl Xylosides: Physico‐Chemical Properties and Influence on Environmental Bacteria Cells

“…Moreover, the alkyl chain length of a surfactant can affect its foaming properties [21]. The lengthening of the alkyl-chain enhances the surface activity of zwitterionic imidazoliumbased surfactants [22]. The interfacial dilational properties of several hydroxy-substituted alkyl benzenesulfonates with different alkyl chain lengths were tested by Wu et al [23].…”