Effects of HEMA on water evaporation from water–HEMA mixtures

Objectives: The aims of this research were: (1) to determine the relative rates of evaporation of water and HEMA, and (2) to determine the effects of increasing concentrations of HEMA on the rate of evaporation of water from water and HEMA mixtures. Methods. Ten microliters of each solution (100% H 2O, 75% H 2O–25% HEMA, 50% H 2O–50% HEMA, 25% HEMA, 100% HEMA) were placed on the pan of a thermogravimetric analysis instrument held at 37°C. The rate of spontaneous weight loss was measured as a function of time and relative humidity (RH) and compared statistically using ANOVA and Scheffé F test. Results. The rate of evaporation of pure water was 32-fold higher than that of 100% HEMA. Addition of HEMA to water lowered the rate of evaporation of water from the water–HEMA mixtures in a manner that was proportional to its effect on lowering the vapor pressure of water ( p