Studies on organic binders with high infrared transparency

This paper reports that two kinds of polymers with high infrared transparency and good mechanical and physical properties have been prepared.An internal standard method is used to evaluate the infrared transparency of the binders.The physical and mechanical properties of the binders are measured according to corresponding standards. The results show the absorbance of polymer A in 8-14 μm range is 26% that of the ethylene-vinyl acetate copolymer （EVA）,and polymer B is 9% that of the EVA correspondingly.The film of polymer A shows good flexibility of above 1 mm,a hardness of grade 1,and adhesion of grade 2.The film of polymer B shows good flexibility of above 1 mm,a hardness of grade 1,and adhesion of grade 1.

Glass formation and physical properties of Sb_(2)S_(3)–CuI chalcogenide system

Novel chalcogenide glasses of pseudo-binary(100-x)Sb_(2)S_(3-x)CuI systems were synthesized by traditional meltquenching method.The glass-forming region of Sb_(2)S_(3)-CuI system was determined ranging from x=30 mol% to 40 mol%.CuI acts as a non-bridging modifier to form appropriate amount of [SbSI] structural units for improving the glass-forming ability of Sb_(2)S_(3).Particularly,as-prepared glassy sample is able to transmit light beyond 14 μm,which is the wider transparency region than most sulfide glasses.Their physical properties,including Vickers hardness(Hv),density(ρ),and ionic conductivity(σ) were characterized and analyzed with the compositional-dependent Raman spectra.These experimental results would provide useful knowledge for the development of novel multi-spectral optical materials and glassy electrolytes.

Influence of La3+ ion in the yttria matrix in improving the microhardness of infrared transparent nano LaxY2-xO3 sintered via hybrid heating

In the present work, hybrid sintering technique which couples the resistive heating and microwave heating is employed to sinter infrared transparent La0.15Y1.85O3 to 99.2% of the theoretical density for the first time to the best of our knowledge. The presence of La3+ in the yttria matrix improves the hardness properties to a greater extent without affecting the transmittance properties, but there is a deterioration in the thermal properties of the sample. So we have limited our studies to La0.15Y1.85O3 which shows better optical, thermal, and hardness properties. The pellets fabricated from the ultra-fine nano powder with average particle size of ~12 nm synthesized by combustion technique and sintered at 1430 ℃ with an average grain size of 0.22 μm show ~80.1% transmittance in the UV–visible region and 81% in mid infrared region. For a comparative study of the optical, mechanical, and thermal properties, two other variants of sintering strategies namely conventional sintering and microwave sintering are also employed. A comprehensive analysis on the hardness reveals that the hardness of the pellets sintered via hybrid heating is 9.73 GPa and is superior to the pellets sintered using the other two techniques. The thermal conductivity of the sample is also analyzed in detail. The results clearly indicate that the La0.15Y1.85O3 ultra-fine nano powder synthesised by the single-step combustion method and sintered via microwave hybrid heating shows better transmittance properties without compromising the mechanical properties, and can be used very effectively for the fabrication of infrared transparent windows and domes.