Recently, cyclopentyl methyl ether (CPME) has found use as a commercially available solvent for various applications. As CPME shows better properties such as more hydrophobicity, less solublity in water, less volatility, and more stablity compared with typical ethereal solvents, it could be used as a diluent or an extractant in liquid-liquid extraction systems. In the present study, CPME was found to be useful for the extraction of Au(III) in hydrochloric acid media. Extraction of Au(III) increased with as increase in the hydrochloric acid concentration. Au(III) was selectively extracted using CPME from other precious metal ions and base metal ions. From the result of the dependency of the Au(III) concentration, CPME can load at least 0.93 g/dm 3 Au(III). Extracted Au(III) was quantitatively stripped from CPME using 0.1 M aqueous thiourea solution. As the solubility of water into CPME is much smaller than that into alcohols such as 1-hexanol, CPME is more favorable as an extractant for Au(III) in hydrochloric acid media.

In vitro biomimetic mineralization by means of nanotechnology allows the formation of calcium carbonate polymorphs at low temperatures (<25 degrees C) under a CO(2) atmosphere of 500-1500 ppm. A two-dimensional zinc-ion ordered array (zinc array), which acts as an active-site mimic of carbonic anhydrase, has been prepared by immersing the self-organized monolayer of 3-(2-imidazolin-1-y)propyltriethosilane on mica (ImSi substrate) into aqueous zinc solution. The zinc array mounted on the ImSi substrate catalyzed the conversion from CO(2) to HCO(3) (-), and accelerated the formation of calcium carbonate. In situ X-ray diffraction data of the formed calcium carbonate on the poly(L-aspartate)-coated chitin substrate (pAsp substrate), with calcium ion-recognition sites, demonstrated that the interaction between the zinc array and pAsp substrates formed both vaterite and calcite at low temperature (15 degrees C) and mainly vaterite at 25 degrees C; this interaction also controlled the morphology of calcium carbonate formed on pAsp substrate.

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The cooperation between carbonic anhydrase (CA) or some biomimetic zinc model compound as a catalyst for the conversion from CO2 to HCO3− and poly(l-aspartate) as calcium ion recognition sites induced the aragonite formation of calcium carbonate. The higher CA-arising activity promoted the calcium carbonate production amount.