A S 2O 2- 8/ZrO 2 Al 2O 3 type solid superacid catalyst was prepared from ZrOCl 2·8H 2O, AlCl 3· 6H 2O and (NH 4) 2S 2O 8 by coprecipitation, maceration and calcination processes. Their crystal structures and acidities were determined by XRD and Hammett method, respectively. The activity of the catalyst was studied as function of Al 2O 3 content, calcination temperature and time in the esterification of acetic acid with butanol, and a conversion of 96 5% was obtained. The catalyst gave also higher yields in syntheses of ketals and acetals: cyclohexanone ethylene ketal(86 2%), acetophenone ethylene ketal(78 5%), acetylacetic ester ketal(88 5%), benzaldehyde glycol acetal(76 3%). The chemical structures of the products were confirmed by IR spectra.
Effects of aqueous salt solutions on the absorbency of superabsorbents synthesized by inverse suspension copolymerization of acrylic acid with acrylamide were studied. The results showed that the water absorbency of superabsorbents in the salt solutions decreased with increase in the ionic strength of the salt. For the same ionic strength of chloride salt solutions, the water absorbency had the following tendency: Na +>Ca 2+ >Fe 3+ ,Li +>Na +>K +, and Mg 2+ >Ca 2+ >Ba 2+ . The influences of anion valency of salts with a common cationic ion(Na +) on the water absorbency were the order of mononalent
The chromatographic behavior of twenty three amino acids on the silica gel thin layers using sodium dodecylsulfate(SDS)/ n butyl alcohol/ n hexane/water microemulsion as a developer have been studied. The results showed that the W/O microemulsion and the bicontinuous microemulsion composed of the mentioned components appeared suitable developers for TLC analysis of amino acids.
