Study on Foaming Properties and Dynamic Surface Tension of Sodium Branched-alkyl Benzene Sulfonates |
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Authors: | Xiao-Chun Wang Lei Zhang Qing-Tao Gong Lu Zhang Lan Luo Zhen-Quan Li |
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Institution: | 1. Technical Institute of Physics and Chemistry, Chinese Academy of Sciences , Beijing , P. R. China xiaochun.sunny@yahoo.com.cn;3. Technical Institute of Physics and Chemistry, Chinese Academy of Sciences , Beijing , P. R. China;4. Geological Scientific Research Institute, Shengli Oilfield Company of SINOPEC , Dongying , Shandong , China |
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Abstract: | Foaming properties and the dynamic surface tension (DST) were carried out with aqueous solutions of sodium branched-alkyl benzene sulfonates to elucidate the relationship between foaming properties and surfactant structures. The parameters of the DST (t*, n, R 1/2 ) are correlated with the foaming ability for alkyl benzene sulfonates with benzene ring substituting at positions 2, 4, and 8 of hexadecane. The parameters of the DST (t*, n, R 1/2 ) are correlated with the foaming ability of the same surfactant solutions. The results indicated that the molecular diffusion in the solution, adsorption, and arrangement at the air/water interface were changed with different molecular structures: changing the substituted position of benzene ring from 2 to 8 of hexadecane, the value of t* and n decrease, and the value of R 1/2 increases, which lead to the high dynamic surface activity and high foam volume. The foam stability is correlated with the high surface dilational elasticity and the strength of surface monolayer: changing the substituted position of benzene ring from 2 to 8 of hexadecane, the branched-alkyl chain becomes more flexible, which is characterized by densely packed adsorbed molecules and high film elasticity of the adsorption film. Therefore, the foam stability increases. |
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Keywords: | Dynamic surface tension foaming properties molecular structure sodium branched-alkyl benzene sulfonates |
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