Fiber and film formation by self-assembly of colloidal silicalite-1 and copper coated silicalite-1 nanocrystals

Silicalite-1 nanocrystals with sizes of 20 and 74 nm were synthesized and stored as colloidal solutions in water or ethanol. The self-assembly of the colloidal silicalite-1 nanocrystals into thin films and transparent, rectangular fibers was monitored. Monodispersed and binary colloidal silicalite-1 nanocrystals both formed rectangular fibers through close packing of the nanocrystals. The formation of fibers or thin films was controlled by varying the concentration of the colloidal solutions. At higher concentration, fibers were formed, while very diluted colloidal solutions resulted in thin films. Calcination of the fibers or thin films did not damage the zeolite structures. Two methods were developed to coat copper metal onto the silicalite-1 nanocrystals. Silicalite-1 fibers and films coated with copper were conductive materials.