Microwave discharge electrodeless lamps (MDEL)

摘要: A novel mercury-free Dewar-like (double-walled structure) microwave discharge thermally-insulated electrodeless lamp (MDTIEL) was fabricated and its performance evaluated using the photo-isomerization of trans-urocanic acid (trans-UA) in aqueous media as a test process driven by emitted UV light when ignited with radiation. The processes trans-UA → cis-UA were re-visited from conventional high-pressure Hg source examined for influence irradiance solution temperature; temperature dependence trans cis displayed negative activation energy, Ea = −1.3 cal mol−1. To control urocanic heat usually dissipated (single-walled MDEL), it necessary to suppress microwave-initiated heat. For comparison, gas-fill MDEL lamp, which typically consists mixture Ar, changed more eco-friendly N2 gas MDTIEL device. dynamics wavelengths N2-MDTIEL compared those single-walled N2-MDEL Hg/Ar-MDEL sources, used irradiate, via fiber optic, photoreactor located wave-guide apparatus. heating efficiency double-walled Advantages are described comparison on basis unit surface area power consumption. considerably lower external should make attractive carrying out photochemical reactions that may be heat-sensitive such photothermochromic system.