Effects of Spacers on Surface Activities and Aggregation Properties of Anionic Gemini Surfactants

Abstract

This present article employs four anionic Gemini surfactants with different spacer groups and investigates their physicochemical and aggregation properties. The critical micelle concentration (CMC), surface tension at CMC (c CMC ) and C 20 of these surfactants have been investigated using the du Nouy ring method. The aggregation number (N) was determined with intrinsic fluorescence quenching method using pyrene as a fluorescence probe and benzophenone as a quencher. Results show that these anionic Gemini surfactants have lower CMC and C 20 values compared with those conventional ones and show higher surface activity. As expected, the spacer plays an important role in the aggregation properties of Gemini surfactants. Under experimental conditions, Gemini B-D with an alkoxylated group as spacer has a lower CMC and a higher aggregation number than Gemini A with methylene as spacer. For Gemini B-D, the CMC and aggregation number values decrease with the increasing flexible spacer length. The micropolarity also affects the aggregation of the present anionic Gemini surfactants. The micropolarity of micelle becomes low when the concentration of surfactants increases. Aggregation numbers of surfactants increase and fluorescence intensities decrease with the increasing concentration of NaCl. These results will help us to understand the relationship between the architectures of Gemini surfactants and their various properties in aqueous solution.

Aggregation behavior of anionic sulfonate gemini surfactants with dodecylphenyl tails

“…In addition, for gemini surfactants with four oxyethylene units in the spacer, the CMC decreased with an increase in alkyl tail length from 8 to 12 hydrocarbon units. Cao et al [30] observed that anionic sulfonate gemini surfactants with one, two and three oxyethylene groups as a spacer exhibited a lower CMC and a higher aggregation number than a surfactant with a spacer formed by one ethylene unit.…”

“…The values of the CMC, γCMC and C20 of the gemini surfactants and data corresponding to their conventional analog SDBS [30] are summarized in Table 4.…”

Influence of Spacer Nature on the Aggregation Properties of Anionic Gemini Surfactants in Aqueous Solutions

“…The spacer plays an important role in the aggregation properties of gemini surfactants [12,13], and the nature of the spacer (flexible or rigid, hydrophobic, or hydrophilic) has a great effect on the aggregation properties of gemini surfactants [2,4,10,11]. Therefore, the effect of the spacer chain on the aggregation properties of anionic gemini surfactants has been investigated in our present work.…”

Recent Advances in the Synthesis of Sulfonate Gemini Surfactants

“…In 2010, Cao, Li, and Song () and Li, Hu, Zhu, and Zhao () prepared 2,2′‐{6,6′‐[ethyl‐1,2‐diimino‐bis(4‐alkyl amine)‐1,3,5‐triazine‐2,6‐dialkyl]diimino}bis ethyl sulfonate (2C n ‐SCT). 4‐Chloro‐6‐alkyl amine‐1,3,5‐triazine was first synthesized using cyanuric chloride and aliphatic amine as raw materials.…”