Effect Of Alcohol On Properties Of Alkylimidazole Gemini Surfactant

Compared to traditional surfactants,Gemini surfactants have shown a more superior performance,in which alkylimidazole Gemini surfactant is a class of highly efficient new surfactant,and alcohol is the most commonly used surfactant additives in the fields of industry and daily cosmetics.In recent years,the effect of alcohol on the surface activity and aggregation behavior of Gemini surfactants has also been studied.The study of effects of different structure of alcohol on the surface activity and micellization behavior of alkylimidazole Gemini surfactants is of great importance in promoting the development and practical application of alkylimidazole Gemini surfactant.At the same time it will help to select the appropriate alcohol additives to regulate the surface and solution properties of alkylimidazole Gemini surfactants,thereby promoting the development of alkylimidazole Gemini surfactants and the practicality application in the fields of daily life and fine chemicals.In this paper,two alkylimidazole Gemini surfactants[C_n-4-C_nim]Br₂?n=12?14?are synthesized by the method of hydrophobic chain addition.The reaction of which is carried out in two steps.IR spectroscopy,element analysis and nuclear magnetic resonance are used to characterize the structure and composition of products.The results show that the synthesized products were consistent with the theory.The thermogravimetric analysis and differential thermal analysis of alkylimidazolium Gemini surfactants are carried out by thermogravimetric analyzer.The TG curves,DTG curves and DTA curves of the two surfactants at different heating rates are investigated.The results show that the melting point of the two surfactants is very low,which possessing the typical characteristics of the ionic liquid.With the increase of the reaction rate,the pyrolysis reaction of the surfactant is delayed and the time required for the pyrolysis reaction is increased.By comparing the activation energy and frequency factors of the two surfactants,we can see that the activation energy and frequency factors are increased with the increase of the carbon chain,which indicate that the pyrolysis reaction is more difficult.The effects of three short-chain alcohols?ethanol,n-propyl alcohol,n-butyl alcohol?on the surface activity and micellization behavior of alkylimidazole Gemini surfactants are studied by a variety of methods.In the surface tension experiment,the short chain alcohol can significantly reduce the surface tension of the surfactant solution,increase the CMC of the solution,and have a great influence on the adsorption parameters such as?_cmc??_max?A_min?The effects of short chain alcohols on the CMC,?,?G_m,?H_m and?S_m of surfactants are studied by conductivity.It turns out that the effects of the three short-chain alcohols on the?and K of the surfactant solution have no obvious regularity.At room temperature and atmospheric pressure,all systems are thermodynamically stable systems.The micellization process is spontaneous process.The results suggest that all systems are process of entropy driven at low temperature,entropy-enthalpy driven at high temperature.Fluorescence spectra and fluorescence quenching spectroscopy are used to study the effect of alcohols on the CMC and micelle of surfactant.Results indicate that the short chain alcohol can reduce the average number of micelles.The longer the carbon chain of short chain alcohol is,the more obvious the effects are.The effect of short chain alcohols on the water and kinetic radius of surfactants is determined by dynamic light scattering method.The short chain alcohols can also obviously increase the average micelle size.In the experiment of interface expansion rheology,the?and?_d of two surfactants increase gradually with the increase of the concentration of surfactant solution,and then gradually decrease and finally remain unchanged.The trend of?and?_d increases with the increase of the expansion frequency,and this trend is not obvious.In the process of increasing the frequency of expansion,?_d appears a maximum value.The addition of short chain alcohols increases with?,?_d and?_d in different degrees,and the longer the hydrophobic chain of short chain alcohols is,the greater the increase of?,?_d and?_d is.But they do not change the overall trend.