The surface tension of diethanolamine (DEA) aqueous solution is the basic data of carbon dioxide alkanolamine absorption process. The paper "Research on the Surface Tension of Diethanolamine Aqueous Solution" by Fu Dong and other four scholars from North CHINA Electric Power University introduced the use of ZBY-1 automatic Surface Tensiometer to measure the surface tension of DEA aqueous solution in the temperature range of 25 ~ 82 ℃, and used The experimental data were correlated by the empirical formula, and the correlation results were in good agreement with the experimental values. The relationship between the thermodynamic properties such as surface entropy and surface enthalpy, temperature and solution concentration is studied by using the correlation formula.
Experimental results
The surface of DEA aqueous solution was measured with ZBY-1 automatic Surface Tensiometer in the temperature range of 25 ～ 82 ℃ and DEA mass fractions were 0, 0.09, 0.18, 0.27 , 0.36 , 0.45 , 0.54 , 0.63 , 0.72 and 1 . tension. Experimental results show that ,At a given temperature, the surface tension of the solution decreases monotonically with the increase of the mass fraction of DEA; at a given mass fraction of DEA , the surface tension of the solution decreases with the increase of the temperature. In the experimental temperature range, it can be assumed that the surface tension of the aqueous solution is a linear function of temperature at a given mass fraction of DEA , and this linear function can accurately fit the experimental data. From the relationship between surface tension and temperature , the relationship between thermodynamic properties such as surface entropy and surface enthalpy and temperature and solution concentration can be obtained. Surface entropy is only related to solution concentration (independent of temperature) , while surface enthalpy is related to both temperature and solution concentration.
