Study On Mass Transfer Characteristics Of Fatty Alcohol Monolayers At The Gas/Liquid Interfac

Water is one of the most important resources in our country. But the loss of water evaporation is so enormous, especially in arid region. The most feasible method to inhibit water evaporation is to spread water evaporation retardants over the water surface. Water evaporation retardants are a kind of highly biological safety surfactants, which can form an insoluble film spontaneously over the water surface to reduce water evaporation.However, during the application in actual, the monolayers were found many shortcomings for they can not withstand the conditions such as temperature changes, moderate winds and impurities and so on. Such failure of practical use eventually led to a reduction in research effort. The possibility of resisting natural environment motivated us to try to make a new kind of water evaporation retardants.Combination of existing theories, the permeability of monolayers over water surface and the capacity of monolayers inhabiting concentrated hydrochloric acid and ammonia volatilization, were studied from the mass transfer point of view. And the stability of monolayers was tested through the MDC method. Meanwhile the study on biodegradation of film-forming substance of monolayers was carried out.The homogeneity systems were prepared by dissolve method, and the heterogeneous systems were prepared by emulsion method in this paper. The results showed that the water evaporation retardants did not affect the mass transfer of oxygen and carbon dioxide essentially, and the homogeneous system was for the best. While the petroleum ether as spreading solvent, the mass transfer coefficient could be up to3.42x110-4m/min, at the room temperature. The non-homogeneous liquid film had a good anti-environmental interference capability, that under0-4grade wind, the inhibition of the film on concentrated hydrochloric acid and ammonia volatilization would not be affected. For the substrate of the film such as cetyl alcohol and the liquid film, the degradation rate could be reach87.92%and86.81%after4hr and3hr respectively, which would not cause environmental pollution. It provided necessary theoretical basis for the next mechanism study and application of water evaporation retardants.