ATR FT-IR absorption enhancement of a thin film under the photon-tunneling condition

A simple, yet very powerful technique for the spectral acquisition of an extremely thin film with enhanced absorption was explored. An infrared absorption of an extremely thin film confined between media of high refractive indices was greater than that of its bulk when the spectrum was acquired under the attenuated total reflection (ATR) condition with parallel (p) polarized radiation. The absorption enhancement was not observed under perpendicular (s) polarized radiation. Theoretical investigations indicated that the absorption enhancement was proportional to the integration of the mean square evanescent field within the film. The field integration under p-polarized radiation increased, while that under s-polarized radiation decreased as the thickness of the confined film became thinner. The maximum enhancement was observed when the film was sufficiently thinner than the penetration depth. The phenomena were experimentally investigated, and the results agreed very well with theoretical predictions.<br /

Effect of Thermal Treatment on Nano- and Micro-Copper Particles for Jewelry Making

Copper nanoparticles are being applied in the biosensors, engineering, electronic devices, and technology fields. A key advantage of nanomaterials is that their properties differ from their bulk with the same composition. However, the application of nano-copper particles for jewelry and artwork has not yet been revealed. We discovered and compared the application of nano-sized copper particles in jewelry fabrication with micro-copper particles. The nano- and micro-sized copper particles were synthesized and mixed with the same organic binders and water content to produce an alternative clay-like material for creating handmade jewelry and artwork. The article addresses the effects of thermal treatment on thermal behavior and the development of physical properties of differently sized copper particles. Their physical properties depend strongly on the size of the starting copper particles and heating conditions. We investigated the influence of thermal treatment, heating rate, firing temperature, and holding time to optimize the firing conditions for jewelry fabrication and wearing