Amount Of Zinc Acetate Research Articles

Synthesis and characterization of resorcinol–formaldehyde resin chars doped by zinc oxide

Polycondensation polymerization of resorcinol–formaldehyde (RF) mixtures in water with addition of different amounts of zinc acetate and then carbonization of dried gels are studied to prepare ZnO doped chars. Zinc acetate as a catalyst of resorcinol–formaldehyde polycondensation affects structural features of the RF resin (RFR) and, therefore, the texture of chars prepared from Zn-doped RFR. The ZnO doped chars are characterized using thermogravimetry, low temperature nitrogen adsorption/desorption, Raman spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), and high resolution transmission electron microscopy (HRTEM). At a relatively high content of zinc acetate (1mol per 10–40mol of resorcinol) in the reaction mixture, the formation of crystallites of ZnO (zincite) occurs in a shape of straight nanorods of 20–130nm in diameter and 1–3μm in length. At a small content of zinc acetate (1mol per 100–500mol of resorcinol), ZnO in composites is XRD amorphous and does not form individual particles. The ZnO doped chars are pure nanoporous at a minimal ZnO content and nano-mesoporous or nano-meso-macroporous at a higher ZnO content.

Transesterification of NDC with EG: Effects of Reaction Conditions on NDC Conversion

Transesterification of dimethyl 2,6-napthalene dicarboxylate with ethylene glycol over metal salts catalyst was empolyed as probe reation. The effects of reaction temperature, reaction time, the molar ratio of ethylene glycol to dimethyl 2,6-napthalene dicarboxylate, N2 flowrate, kind of metal salt on the conversion of dimethyl 2,6-napthalene dicarboxylate have been investigated. The results showed that the sequence of influence was as follows: reaction temperature > reaction time > ethylene glycol/dimethyl 2,6-napthalene dicarboxylate molar ratio > amount of the catalyst. The optimum reaction conditions were 210 oC of reaction temperature, 240 min of reaction time, 2.8 molar ratio of ethylene glycol to dimethyl 2,6-napthalene dicarboxylate, 60 ml/min of N2, amount of zinc acetate being 0.08 % / mole of dimethyl 2,6-napthalene dicarboxylate.

Preparation of ZnO Films on Sapphire (0001) Substrates by Alternate Supply of Zinc Acetate and H2O

Abstract ZnO films have been prepared by alternate supply of zinc acetate and H2O. A rate of film growth is nearly equal to an ideal rate expected for atomic layer epitaxy when both zinc acetate and H2O are sufficiently supplied. The morphology of ZnO films is affected by amount of zinc acetate and H2O per cycles.