Direct coagulation casting

Direct Coagulation Casting. In this NEAR NET SHAPE technique for forming complex shapes, an aqueous electrostatically stabilized suspension of low viscosity is cast into a non-porous mould and then coagulated by changing the pH or by a delayed reaction catalyzed by enzymes, to form a stiff, wet green body. 

Si WJ, Graule TJ, Baader EH, Gauckler LJ. Direct coagulation casting of silicon carbide components. J Am Ceram Soc 1999 82 1129-1136. 

Immediately after the casting solution came out of the spinneret, the inner surface of the hollow fiber was brought into contact with an internal coagulant (water), and the solvent/nonsolvent (water) exchange started to take place. In this process, the stream of water entering the hollow fiber wall would form a whirlpool around the nodules, which may have resulted in the stress in the angular direction. 

Here poly(ethyl aerylate) (PEA)/clay nanocompsite as the first example of rubbery polymer/elay nanocomposite synthesized by in situ emulsion polymerization is reported. The clay used is bentonite having extremely strong swelling characteristies in water. The resulting nanocomposite emulsion is directly cast to form film without coagulation process. This study focuses on microstructure, thermal and meehanical properties, and gas barrier permeability of the final PEA/clay nanoeomposites. 

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