(513e) Microwave Synthesis of Nthu-4 and Related Materials
AIChE Annual Meeting
2006
2006 Annual Meeting
Materials Engineering and Sciences Division
Novel Catalytic Materials
Thursday, November 16, 2006 - 9:55am to 10:15am
Recently, a zinc gallophosphate molecular sieve designated as NTHU-4 was prepared using 4,4-trimethyllenedipyridene (tmdp) as a template. The structure of NTHU-4 is composed of corner shared tetrahedra of GaO4, ZnO4 and PO4/HPO4. The 1.3 nm elliptical pores are defined by 14 membered rings (14MR). An interesting feature of NTHU-4 is the emission of white light when excited below 400nm. Generally, multiple phosphors are combined to generate white light for solid state lighting. Therefore, an intrinsic white light emitting phosphor would be an advance. The emission and color arises because of MO4 and HPO4 disorder sites in the channels. The hydrothermal synthesis normally takes 7 days at 160oC. In contrast, we can prepare NTHU-4 in 5 hours or less using microwaves. The emission observed for NTHU-4 is thought to arise from defect sites stemming from the structural disorder. There is also evidence for partial reduction of zinc. So we have examined the effect of microwaves on the NTHU-4 structure as well as the substitution of gallium by zinc and boron. An attempt to correlate the photoemission properties with microwave synthesis conditions and framework composition will be described.