A membrane method for degassing nonaqueous liquids

Degassing of nonaqueous solvents is useful for their applications in chemical synthesis and in maintaining purity (against oxidative degradation) during long term storage. In addition, degassed solvents have been found to be of value in the production of oil and water emulsions. Currently, there are three main methods for degassing solvents. These are the freeze-pump-thaw process, partial degassing using sonication under slight vacuum and purging, where one active gas (usually oxygen) is replaced with an inert gas (e.g., nitrogen). In this work we have demonstrated the potential application of hollow-fibre membranes to efficiently degas water-immiscible, hydrophobic liquids. Mixtures of dodecane and water, separately degassed using membranes, show an enhanced dispersion of dodecane, similar to that previously reported for freeze-thaw degassed mixtures.