CRYSTAL GROWTH FROM COLLOIDAL SPHERES IN SUSPENSION

摘要

PCT No. PCT/GB89/00532 Sec. 371 Date Dec. 18, 1990 Sec. 102(e) Date Dec. 18, 1990 PCT Filed May 17, 1989 PCT Pub. No. WO89/11555 PCT Pub. Date Nov. 30, 1989.The invention is a method of producing oriented, essentially perfect colloidal crystals by subjecting a suspension of colloidal spheres, which is contained betwen two narrowly spaced substantially parallel surfaces, to oscillating motion. This motion must have a frequency greater than the Brownian motion of the spheres and an amplitude approximately equal to the thickness of the surface's separation. This method is suitable for monosized spheres of radii between about 0.1 and 1 micron. The suspension of colloidal spheres must have a volume fraction greater than 0.49. This method produces colloidal crystals with a uniform face centered cubic structure, which are suitable for use as notch optical filters, high strength ceramics, or thin film dielectric materials.