• Journal of Conservation Science
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• v.26 no.1
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• pp.85-94
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• 2010

Color stable hydrogenated bisphenol-A (HBA) epoxy adhesives containing organic-inorganic hybrid nanocomposites were prepared and investigated the properties. Isophorone-diamine (IPDA) was used as a hardener and polyhedral organomeric silsesquioxanes (POSS; EP0408 and EP0409) having epoxy function groups were used to tailor adhesives in the nanoscale range. The dependence of the concentration of different nano materials were studied since the large surface area of the nanosized particles can cause significant changes in properties of adhesives. HBA-IPDA adhesives containing different amount of nanomaterials have been applied to the fresh Namsan granite and compared with those of commercial adhesives, which have problems of color change as well as a high viscosity. The mechanical properties of HBA-IPDA containing POSSs are consistent with those of commercial adhesives in addition to the low viscosity.

• New Physics: Sae Mulli
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• v.68 no.11
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• pp.1208-1214
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• 2018

The one-step spin coating method is reported as an excellent thin film process because it can be easily used to fabricate high-quality methyl-ammonium lead tri-iodide ($MAPbI_3$) perovskite layers. One of the important things in the one-step spin coating method towards obtaining high-quality $MAPbI_3$ layers is the anti-solvent (AS) engineering, which consists of an one-step deposition of the $MAPbI_3$ film and dripping of the AS. The properties of the $MAPbI_3$ layer were found to be strongly influenced by the amount, dispensing speed, and spraying time of the AS solution. The $MAPbI_3$ solution was prepared by dissolving lead iodide and methyl-ammonium iodide in N,N-dimethylformamide and adding N,N-dimethyl sulfoxide. Diethyl ether (DE) was used for the AS solution. The results indicate that a $MAPbI_3$ layer appropriately sprayed with DE is beneficial for improving film quality and device efficiency because nucleation of $MAPbI_3$ layer is affected by the characteristics of DE, which affect the film's crystallinity, density, and surface morphology. The $MAPbI_3$ layer, which was optimized by using 0.7 mL of DE, a 3.03 mL/sec dispensing speed, and a 7 second time to spray after spinning showed the best efficiency of 13.74%, which was reproducible.