Experimental And Model For The Surface Tensions And Viscosities Of Ionic Liquids Promoted Alkylol Amine Aqueous Solutions

The surface tensions and viscosities of 1-butyl-3-methylimidazolium tetrafluoroborate（[Bmim][BF₄]）, 1-butyl-3-methylimidazolium bromide（[Bmim][Br]）, N-methyldiethanolamine（MDEA）-[Bmim][BF₄] and MDEA-[Bmim][Br] aqueous solutions were measured by using the BZY-1 surface tension meter and NDJ-5S rotational viscometer, respectively. The temperature ranged from 293.2 to 323.2 K. The mass fraction of MDEA ranged from 0.30 to 0.45. Thermodynamic equations were proposed to model the surface tensions and viscosities of MDEA- ionic liquids（ILS） aqueous solutions and the calculated results agreed well with the experiments. The effects of temperature, mass fractions of MDEA and ILS on the surface tensions and viscosities were demonstrated on the basis of experiments and calculations. Our results showed that:（1）The increase of the temperature tends to decrease both the surface tensions and viscosities of MDEA-ILS aqueous solutions;（2） At a given mass fraction of MDEA, the increases of the mass fractions of ILS respectively decrease the surface tension and increase the viscosity of MDEA aqueous solutions;（3） The proposed models correctly capture the effects of temperature, mass fractions of ILS on the surface tensions and viscosities.