Accession Number : ADA315585

Title :   Novel Materials and Devices From Self-Assembled Periodic Structures.

Descriptive Note : Final technical rept. 1 Oct 92-30 Sep 95,

Corporate Author : PITTSBURGH UNIV PA DEPT OF CHEMISTRY

Personal Author(s) : Asher, Sanford A.

PDF Url : ADA315585

Report Date : 30 SEP 1996

Pagination or Media Count : 118

Abstract : The research program developed novel mesoscopically periodic materials for use in novel optical devices such as optical limiters (OL) and switches. These materials are fabricated using the crystalline colloidal array (CCA) self assembly motif. We developed methods to polymerize CCA into hydrogel matrices to form rugged mesoscopic periodic arrays. We developed novel strategies to incorporate monodisperse CdS quantum dots in monodisperse ca. 100 nm colloidal spheres of SiO2 to form nonlinear materials for use in OL. This work also resulted in new high surface area porous SiO2 colloids with voids and chambers which should be useful in applications such as catalysis. We also developed a synthesis of monodisperse polymethylmethacrylate (PMMA) colloids containing covalently bound dye. These colloids form CCA which we polymerized in a hydrogel matrix. We matched the real part of the medium refractive index to that of the PMMA particles to form a periodic array which shows variations only in the imaginary part of the refractive index. We are utilizing this material for optical switching devices.

Descriptors :   *OPTICAL SWITCHING, REFRACTIVE INDEX, ARRAYS, POLYMETHYL METHACRYLATE, MATRIX MATERIALS, CRYSTALS, NONLINEAR OPTICS, COLLOIDS, GELS, LIMITERS.

Subject Categories : Electrooptical and Optoelectronic Devices

Distribution Statement : APPROVED FOR PUBLIC RELEASE