摘要
常压下测定了乙酸乙酯和异丙醇二元系在298.15～323.15K下的黏度和表面张力,计算了黏度偏差、过量流动活化自由能和表面张力偏差,采用Redlich-Kister方程进行了关联。结果表明,黏度偏差、过量流动活化自由能和表面张力偏差均为负值,且显示了相同的变化趋势,随温度降低而偏差增大。利用表面张力数据进一步考察了混合液表面熵和表面焓,并基于扩展的Langmuir模型,计算了异丙醇的疏液性β及其表面组成。β值表明异丙醇对表面有更大的亲和力,其表面组成始终高于在溶液本体中的组成。
The viscosity（η） and surface tension（σ） of ethyl acetate（EA） ＋ isopropanol（IPA） binary mixture were measured over the entire composition range at 298.15—323.15 K and atmospheric pressure using Ubbelohde viscometer and pendant drop method,respectively.Viscosity deviations（Δη）,excess Gibbs energy of activation of viscous flow（ΔG＊E） and surface tension deviations（Δσ） were calculated from the experimental data.The excess thermodynamic properties,Δη,ΔG＊E and Δσ were correlated by the Redlich-Kister equation,and fitted parameters and standard deviations were obtained.The results show that Δη,ΔG＊E and Δσ are negative over the whole mole fraction range in the temperature range studied,and all deviations become larger as temperature decreases.The surface tension values were further used to calculate the surface entropies（Ss） and surface enthalpies（Hs） per unit surface area.The lyophobicity（β） and the surface mole fraction（xs2） of IPA were also derived using the extended Langmuir model.The obtained xs2 values indicate that the surface concentration of IPA is always higher than its bulk concentration and consequently confirm that the surface is enriched with IPA.
出处
《化工学报》
EI
CAS
CSCD
北大核心
2012年第1期18-24,共7页
CIESC Journal
关键词
乙酸乙酯
异丙醇
黏度
表面张力
超额性质
疏液性
ethyl acetate
isopropanol
viscosity
surface tension
excess property
lyophobicity
