水-短链醇二元溶液的表面吸附  

Surface Adsorption of Water-alcohol Binary Solutions

作　　者：于先超 亓文帅 邓全花 侯万国[1,3] YU Xianchao;QI Wenshuai;DENG Quanhua;HOU Wanguo(Key Laboratory of Colloid&Interface Chemistry,Ministry of Education,2.School of Chemistry and Chemical Engineering,3.National Engineering Technology Research Center of Colloidal Materials,Shandong University,Jinan 250100,China)

机构地区：[1]山东大学胶体与界面化学教育部重点实验室,济南250100 [2]山东大学化学与化工学院,济南250100 [3]山东大学国家胶体材料工程技术研究中心,济南250100

出　　处：《高等学校化学学报》2023年第11期82-90,共9页Chemical Journal of Chinese Universities

基　　金：国家自然科学基金(批准号:22272088)资助。

摘　　要：基于表面聚集吸附(SAA)模型和Gibbs吸附微分方程,建立了二元液体混合物Gibbs表面过剩(Γ_(2))和吸附层厚度(τ)代数方程,可在全浓度范围内预测Γ_(2)和τ随体相组成(如组分2的摩尔分数x_(2,b))的变化.采用所建立的模型,研究了水(组分1)-短链醇(组分2)二元溶液的表面吸附行为,其在水表面的吸附趋势按甲醇、乙醇、异丙醇、正丙醇和叔丁醇的顺序依次增强,与其疏水性增强趋势一致,且其Γ_(2)和τ在低x_(2,b)区均依次增大,而在高x_(2,b)区均依次减小,是短链醇间吸附趋势和分子尺寸的差异所致.对于给定的短链醇体系,随着x_(2,b)的增大,Γ_(2)先急剧增大然后降低,呈现一个最大值,而其τ持续降低.Algebraic equations of the Gibbs surface excess( Γ_(2))and adsorption layer thickness(τ)were developed for binary liquid mixtures based on the surface aggregation adsorption(SAA)model and the Gibbs differential equation,which can predict the change of Γ_(2) andτwith the bulk composition(such as the molar fraction of component 2,x_(2,b))in the whole concentration range.The model equations were used to investigate the surface adsorption of water(1)-alcohol(2)binary solutions.The alcohols involved include methanol(MeOH),ethanol(EtOH),iso-propanol(iPrOH),n-propanol(nPrOH),and tert-butanol(tBuOH).It was found that their adsorption trend on the water surface increases in turn,consistent with the enhancement trend of their hydrophobicity.Their Γ_(2) andτincrease in turn in the low x_(2,b) region,while decrease in turn in the high x_(2,b) region,which arise from the differences in adsorption trend and molecular size between alcohols.In addition,for a given alcohol system,with an increase in x_(2,b) from 0 to 1,its Γ_(2) initially sharply increases and then decreases,showing a maximum,but itsτexhibits a continuous reduction.This work provides a better understanding of the surface adsorption behavior of water-alcohol liquid mixtures.

关 键 词：液体混合物 表面吸附 表面聚集 吸附层厚度 热力学模型 

分 类 号：O647[理学—物理化学]