Microgravity processing applications

Frazier, D. Paley, M. Penn, B. Abdeldayem H. Smith, D. Microgravity Processing and Photonic Applications of Organic and Polymeric Materials. In MSFC Center Director s Discretionary Fund Final Report, Project No.95-26, NASA Technical Memorandum 108533,1997. 

In the next paper Surfactants Effects on Mass Transfer in Liquid-Liquid Systems Dr Alcina Mendes (Imperial College, UK) reviews the work done by herself and co-workers on the effect of surfactants on mass transfer in binary and ternary liquid-liquid systems. The selected organic-aqueous interfaces has been visualised during the mass transfer process in the presence of ionic and non-ionic surfactants. Results obtained in laboratory and under microgravity conditions are reported. The most significant finding is that surfactants in some cases can induce or increase convection. The latter enhance the mass transfer rate as compared to the Pick s law. The latter means that surfactants can be used to manipulate interfacial stability and particularly in space applications. 

Considering chemical application problems, a large number of them yields mathematical models that consist of initial-value problems (IVPs) for ordinary differential equations (ODEs) or of initial-boundary-value problems (IBVPs) for partial differential equations (PDEs). Special problems of this kind, which we have treated, are diffusion-reaction processes in chemical kinetics (various polymerizations), polyreactions in microgravity environment (photoinitiated polymerization with laser beams) and drying procedures of hygroscopic porous media. 

The study of gas phase and cluster polymerization is an important intellectual and technological frontier which promises unique results not only for a fundamental understanding of polymerization reactions, but also for the development of new materials with unique properties. In the past it has been almost impossible to study gas phase chain polymerization because the involatile product molecules condensed out of the gas phase. The application of microgravity to the study of gas phase polymerization is expected to result in a better control of the process and may also lead to important technological advances. 

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