Synthesis of free-standing chabazite-type films

An optimized synthesis procedure is reported for synthesis of free-standing chabazite-type films on walls of polypropylene reaction bottles. The optimum synthesis procedure involved a step heating procedure, in which the reaction composition is heated to 90 degrees C for 40 h, followed by a rapid heating to 103 degrees C, which is maintained for 2 h, and then the completion of the synthesis at 90 degrees C for one more hour. The rapid heating co 103 degrees C introduces thermally induced currents and particles from the settled gel move up from the bottom into solution by convection. This process promotes rapid film formation by releasing nuclei/aluminosilicate colloids into the solution. The films formed are typically 10 mu m thick and made up of 4-5 mu m spherical particles. It is malleable when wet and can be calcined. Relatively large pieces (cm(2)) can be readily peeled off from the walls of the polypropylene bottle. (C) 2000 Elsevier Science B.V. All rights reserved.