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Ratanasuda Waranyoupalin Sumpun Wongnawa Malinee Wongnawa Chaveng Pakawatchai Pharkphoom Panichayupakaranant Panit Sherdshoopongse 《Central European Journal of Chemistry》2009,7(3):388-394
Complex formation between curcumin and Hg(II) ion MeOH/H2O (1: 1 v/v) was investigated and monitored by the spectrophotometric method. The absorption peak of unreacted curcumin which
was close and overlapped with that of the complex, was removed by calculation using Microsoft Excel, thereby, allowing determination
of the stoichiometry of the complex by the mole-ratio and the Job’s continuous variation methods. Both methods indicated that
a 1:1 complex of curcumin and Hg(II) was formed in solution. The formation constant of the 1:1 Hg(II) complex was obtained
from two methods, the equilibrium concentration calculation and the linear plot of Benesi-Hildebrand equation, as log K =
4.44 ± 0.16 and 4.83 ± 0.02, respectively. The structure is proposed as a tetrahedral complex of Hg(II) with one curcumin
and two chloride ions as ligands.
Electronic Supplementary Material Supplementary material is available for this article at and is accessible for authorized users. 相似文献
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Apinpus Rujiwatra Malinee Phueadpho Kate Grudpan 《Journal of Physics and Chemistry of Solids》2005,66(6):1085-1090
A selective synthesis of zeolitic material, phillipsite, employing calcium hydroxide under mild chemical conditions is reported. This is to provide a potential method in reducing the amount of the waste from lignite power plant and the addition of economical value to the material. The fly ash was first activated by calcination at high temperature, and then fused with calcium hydroxide. The water was then added to the solid mixture before curing under saturated water vapour at low temperature. The treatment of as-received fly ash with either calcium hydroxide or a mixture of calcium and sodium hydroxide following as-described preparative procedure of phillipsite, but without prior calcination was also conducted, and led to the formation of Hibschite hydrogarnet, which was also evidentially selective. The following parameters, i.e. type and amount of alkali reagent, the amount of added water, fusion temperature and reaction time were investigated. Powder X-ray diffraction was used to identify type of crystalline solid products, and scanning electron microscope was employed to follow the alteration of solid morphologies. X-ray fluorescence (XRF) was used to trace the chemical composition of the solids. The heavy metal cation removal abilities toward lead ion of the prepared phillipsites were also investigated. 相似文献
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Hollingsworth N Kanna M Kociok-Köhn G Molloy KC Wongnawa S 《Dalton transactions (Cambridge, England : 2003)》2008,(5):631-641
Reaction of the amino-alkoxides HOCH(CH(2)NMe(2))(2) (Hbdmap) and HOC(CH(2)NMe(2))(3) (Htdmap) with [Ti(OR)(4)] yields a series of heteroleptic titanium alkoxides [Ti(OR)(4-n)(L)(n)] (L = bdmap, tdmap). Substitution of the monodentate alkoxide with the chelating alkoxides becomes progressively more difficult, with homogeneous products being obtained only for n = 1, 2. The structure of [Ti(OEt)(3)(bdmap)](2), a mu-OEt bridged dimer, has been determined. Hydrolysis of [Ti(OR)(2)(L)(2)], by adventitious moisture affords the dimeric oxo-alkoxides [Ti(O)(L)(2)](2), both of which have been characterised crystallographically. These two compounds have also been prepared by reaction of [Ti(NMe(2))(2)(L)(2)] with the hydrated metal salts [Zn(acac)(2).2H(2)O] and [Zn(OAc)(2).2H(2)O] using the intrinsic water molecules in these salts to react with the labile amido groups, though the former also produces Me(Me(2)N)C=C(H)C(O)Me from reaction of liberated HNMe(2) with the coordinated acac ligand, while the latter also affords the ligand exchange product [Zn(OAc)(bdmap)]. In neither case does the free dimethylamino group of [Ti(O)(L)(2)](2) coordinate a second metal. The dimeric structure of [Zn(OAc)(bdmap)](2) has been established, and the structure of the tetrameric oxo-alkoxide [Ti(O)(OPr(i))(OCH(2)CH(2)NMe(2))](4) is reported for comparison with others in this study. [Ti(OEt)(3)(bdmap)](2) has been used as a precursor in AACVD (Aerosol-Assisted Chemical Vapour Deposition) to generate amorphous TiO(2) films on glass at 440 degrees C, and TiO(2)@C nanoparticles of approximate diameter 350 nm with a carbon coating of width ca. 75 nm on heating in a sealed container at 700 degrees C. 相似文献
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Pimpaporn Sriprang Sumpun Wongnawa Orawan Sirichote 《Journal of Sol-Gel Science and Technology》2014,71(1):86-95
Amorphous TiO2, synthesized from TiCl4 and diluted NH3 solution, was characterized by X-ray diffraction spectrometry, UV–Vis diffused reflectance spectroscopy, Fourier-transformed infrared spectroscopy, and scanning electron microscopy. The powder exhibited high specific surface area at 508 m2/g as measured by the Brunauer-Emmett-Teller method. The pH at point of zero charge of the as-prepared amorphous TiO2 was determined by the pH drift method to be 6.8. The product was studied for its sorption efficiency using two dyes—crystal violet (CV) and malachite green (MG). Studies on the effects of various sorption parameters (contact time, TiO2 dosage, pH of solution, and initial concentration of dye) were carried out in order to find the optimum adsorption conditions for which the results were: contact time ~30 min, TiO2 dosage ~0.05–0.1 g, pH 7–9, and initial concentration <1 × 10?4 M. The adsorption data were analyzed and fitted better with the Langmuir model than the Freundlich model. The maximum adsorption capacities obtained from the Langmuir model were 0.4979 and 0.4075 mmol dye/g TiO2 for CV and MG dye, respectively. In addition, the regeneration and the recyclability of the prepared amorphous TiO2 were also studied. The used adsorbent should be regenerated 10–12 h before reuse in the next cycle for the best result. 相似文献
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Miki Kanna Sumpun Wongnawa Supat Buddee Ketsarin Dilokkhunakul Peerathat Pinpithak 《Journal of Sol-Gel Science and Technology》2010,53(2):162-170
Decolorization of dye solutions, crystal violet and congo red, were investigated using the synthesized amorphous titanium
dioxide and compared with commercial titanium dioxides: Degussa P25 and anatase. Results showed that amorphous TiO2 had good adsorptivity that could decolorize the dye polluted water effectively mainly by adsorption. Decolorization by photocatalytic
property was also detected but was very low. Concentrations of dye solutions used in this work were about ten times higher
than normally used in other reports. After use, the particle surface was completely covered with dye molecules but this could
be regenerated and the cleaned particles could be reused several times. Hydrogen peroxide and ultraviolet irradiation were
used in the regeneration process. 相似文献
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Mixed amorphous and anatase-type titania particles were synthesized using non-ionic triblock copolymer as surfactant template and TiOSO4 as inorganic precursor through sol–gel process. The as-prepared materials were characterized by X-ray diffraction spectroscopy, scanning and transmission electron microscopy, specific surface area, Fourier-transformed infrared spectroscopy, and diffuse reflectance ultraviolet–visible spectroscopy. The template material could be easily removed by extracting with dichloromethane and was confirmed by infrared spectroscopy. X-ray diffraction pattern reveals the crystalline part of as-prepared product as a framework of anatase phase. From the N2 adsorption–desorption analysis, the as-prepared sample has a surface area of 301 m2/g with pore size distribution narrowly centered around 6 nm. The photodegradation of indigo carmine including kinetics, effect of pH, and recyclability of the product were investigated. The photocatalytic results showed that the as-synthesized titania could efficiently degrade indigo carmine under ultraviolet irradiation and showed higher photocatalytic activity than the commercial Degussa P25–TiO2. 相似文献
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Uraiwan Sirimahachai Nicholas Ndiege Ramesh Chandrasekharan Sumpun Wongnawa Mark A. Shannon 《Journal of Sol-Gel Science and Technology》2010,56(1):53-60
Nanosized TiO2 and nano-anatase TiO2 decorated on SiO2 spherical core shells were synthesized by using a sol–gel method. The synthesized pure TiO2 nano particle and TiO2 grafted on SiO2 sphere with various ratios have been characterized for their structure and morphologies by X-ray diffraction (XRD), X-ray
photoelectron spectroscopy (XPS), Fourier transform infrared spectrophotometry (FTIR) and transmission electron microscopy
(TEM). Their surface areas were measured using the BET method. The photocatalytic activity of all nanocomposites was investigated
using methylene blue as a model pollutant. The synthesized TiO2/SiO2 particles appeared to be more efficient in the degradation of methylene blue pollutant, as compared to pure TiO2 particles. 相似文献