Polymerization in microgravity

Pojman, J. A. Khan, A. M. Mathias, L. J. 1997a. Frontal Polymerization in Microgravity Results from the Conquest I Sounding Rocket Flight, Microg. Set. 

This Chapter is dedicated to the memory of the authors dear friends and colleagues V. Leont ev and A. Mashinsky who initiated and took an active part in the studies on polymerization in microgravity. 

Briskman, V. Kondyurin, A. Kostarev, K. Leont ev, V. Levkovich, M. Mashinsky, A. Nechitailo, G. Yudina, T. Polymerization in microgravity as a new process in space technology. IAA-97-1AA 12.1.07 48th International Astronautical Congress, 1997. 

Ainsworth, W. Pojman, J. A. Chekanov, Y. Masere, J. Bubble Behavior in Frontal Polymerization Results from KC-135 Parabolic Flights in Polymer Research in Microgravity Polymerization and Processing ACS Symposium Series No. 793 Downey, J. P. Pojman, J. A., Ed. American Chemical Society Washington, DC, 2001 pp 112-125. 

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 example of polyreactions in microgravity environment mentioned in Section 1 yields similar results. Here, it is additionally necessary to use variable reaction rates, which characterize the photoinitiated polymerization. Summarizing, we have found that the described numerical algorithm is an effective procedure for different applications of the prescribed kind, e.g. in chemical kinetics. It is planned to extend the algorithm to problems, which require the solution of differential-algebraic equations. 

Briskman, V.A. (2001) in Polymer Research in Microgravity Polymerization and Processing, Acs Symposium Series No. 793 (eds J.P. Downey and J.A. Pojman), American Chemical Society, Washington, DC, pp. 97-110. 

Sturm, D. Muller, R. Rath, M.-J. Photoinitiated Radical Polymerization of Liquid Monomers in Microgravity, Vlllth European Symposium on Materials and Fluid Sciences in Microgravity, 1992, 895-899. 

In our laboratory, we have recently conducted gelation studies of silica nanopardcles in microgravity during the STS-95 space shuttle mission (28). Stable silica nanoparticle dispersions may be form either by polymerization of silicic acids in an aqueous system or through hydrolysis and condensation of silicon alkoxides (the sol-gel or Stober route). Comparison of small-angle x-ray scattering (SAXS) measurements of Ludox, a commercial aqueous silicate with acid- and base-catalyzed alkoxides shows that only aqueous silicate sols are uniform, whereas alkoxides generate fractal particles. As Brinker and Scherer point out (29), these results illustrate that sols derived from aqueous silicates are... 

Prospects for the Study of Gas-Phase Polymerization and the Synthesis of Polymers Containing Nanoparticles in Microgravity... 

In this chapter, we describe few examples of gas phase and intracluster oligomerization reactions for the study of the early stages of polymerization and present methods for the synthesis of polymeric materials containing ultrafine and nanoparticles. We also discuss several approaches and opportunities to study gas phase polymerization and synthesize novel polymeric materials in microgravity. 

Development of Impedance Spectroscopy to Study Polymerization Processes in Microgravity... 

Because of the high cost of microgravity research, it is important to develop techniques that can continuously monitor the polymerization process in space. Impedance spectroscopy is one technique, which is being developed to complement other techniques used to study polymerization reactions. Impedance spectroscopy has been used successfully to study the photopolymerization of diacetylene both in solution and at the surface. There are distinct differences between the measurements of the solution and surface polymerization processes. In addition, the effect of convection on the polymerization process was observed using this technique. Impedance spectroscopy can potentially become a useful tool for monitoring polymerization processes in microgravity. 

Polymer research in microgravity polymerization and processing / James Patton Downey, John A. Pojman, editors. 

Third, microgravity virtually eliminates sedimentation. In emulsion polymerization and dispersion polymerization polymer particles are formed with a higher density than the surrounding medium and tend to settle. The same sedimentation issues arise with polymer production in living cells. Microgravity allows a researcher to create colloids and dispersions with stabilities not normally achievable on the ground. 

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. 

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