Chiang Mai, Thailand
Chiang Mai, Thailand

Time filter

Source Type

Trisuwan K.,Center for Innovation in Chemistry | Rukachaisirikul V.,Center for Innovation in Chemistry | Sukpondma Y.,Center for Innovation in Chemistry | Phongpaichit S.,Natural Products Research Center | And 2 more authors.
Tetrahedron | Year: 2010

Nine new fungal metabolites, penicisochromans A-E, penicipyrone, penicipyranone, peniciphenol, and penicisoquinoline, were isolated from the sea fan-derived fungus Penicillium sp. PSU-F40 together with five known compounds. Their structures were determined by spectroscopic analysis. Their antibacterial activity against the standard Staphylococcus aureus ATCC 25923 and methicillin-resistant S. aureus was evaluated. © 2010 Elsevier Ltd. All rights reserved.


Phuruangrat A.,Chiang Mai University | Thongtem T.,Center for Innovation in Chemistry | Thongtem S.,Chiang Mai University
Current Applied Physics | Year: 2010

Lead molybdate and lead tungstate nanoparticles were successfully synthesized by a sonochemical method for 1 h. XRD patterns showed the body-centered tetragonal structures of PbMoO4 and PbWO4, and were in accordance with those of the simulation and JCPDS software. Calculated lattice parameters are a = b = 5.4233 Å and c = 12.1253 Å for PbMoO4, and 5.4570 Å and 12.0995 Å for PbWO4. They are in accordance with those of the corresponding JCPDS software. TEM images show that the particles were 29.09 ± 5.22 nm and 21.05 ± 2.68 nm for PbMoO4 and PbWO4, respectively. Raman and FTIR vibrations were investigated to identify a definite existence of the structures. © 2009 Elsevier B.V. All rights reserved.


Chindaprasirt P.,Khon Kaen University | Rattanasak U.,Center for Innovation in Chemistry
Waste Management | Year: 2010

In this paper, synthesis of geopolymer from fluidized bed combustion (FBC) ash and pulverized coal combustion (PCC) fly ash was studied in order to effectively utilize both ashes. FBC-fly ash and bottom ash were inter-ground to three different finenesses. The ashes were mixed with as-received PCC-fly ash in various proportions and used as source material for synthesis of geopolymer. Sodium silicate (Na2SiO3) and 10 M sodium hydroxide (NaOH) solutions at mass ratio of Na2SiO3/NaOH of 1.5 and curing temperature of 65 °C for 48 h were used for making geopolymer. X-ray diffraction (XRD), scanning electron microscopy (SEM), degree of reaction, and thermal gravimetric analysis (TGA) were performed on the geopolymer pastes. Compressive strength was also tested on geopolymer mortars. The results show that high strength geopolymer mortars of 35.0-44.0 MPa can be produced using mixture of ground FBC ash and as-received PCC-fly ash. Fine FBC ash is more reactive and results in higher degree of reaction and higher strength geopolymer as compared to the use of coarser FBC ash. Grinding increases reactivity of ash by means of increasing surface area and the amount of reactive phase of the ash. In addition, the packing effect due to fine particles also contributed to increase in strength of geopolymers. © 2009 Elsevier Ltd. All rights reserved.


Thongsuriwong K.,Center for Innovation in Chemistry | Amornpitoksuk P.,Center for Innovation in Chemistry | Suwanboon S.,Prince of Songkla University
Journal of Physics and Chemistry of Solids | Year: 2010

The potential of using encapsulation by MEA, DEA and TEA to control the morphology of ZnO powders was investigated. The crystallite and particle size decreased as a function of aminoalcohol concentration. We found that aminoalcohols can inhibit the crystal growth of ZnO along the c-axis. A steric effect by TEA more strongly influenced the formation of different ZnO shapes than did MEA and DEA. The value of the band gap was dependent on the crystallite size, particle size and particle shape. © 2010 Elsevier Ltd. All rights reserved.


Watchasit S.,Center for Innovation in Chemistry | Kaowliew A.,Center for Innovation in Chemistry | Suksai C.,Center for Innovation in Chemistry | Tuntulani T.,Chulalongkorn University | And 2 more authors.
Tetrahedron Letters | Year: 2010

Mono- and dinuclear Cu(II) complexes of p-tert-butylcalix[4]arene (CuL1 and CuL2, respectively) were synthesized, and their anion recognition abilities were explored. Recognition is efficiently signaled through the displacement of pyrocatechol violet bound to the receptor. For CuL2, recognition selectivity is ascribed to the tuning of the distance between donor atoms of anion guests and their ability to encompass the Cu2+-Cu2+ distance within the cleft of CuL2. In addition, the preorganization of calix[4]arene in the cone conformation and steric hindrance of two bulky tripodal amine moieties are important factors in controlling the Cu2+-Cu2+ distance. These factors caused CuL2 to recognize pyrophosphate selectively with respect to other inorganic anions in 80/20 (v/v%) MeCN/H2O solution buffered with 10 mM HEPES at pH 6.4. © 2010 Elsevier Ltd. All rights reserved.


Wanichacheva N.,Silpakorn University | Prapawattanapol N.,Chulalongkorn University | Sanghiran Lee V.,University of Malaya | Grudpan K.,Center for Innovation in Chemistry | Petsom A.,Chulalongkorn University
Journal of Luminescence | Year: 2013

A novel fluorescent sensor bearing two naphthalimide fluorophores based on 2-(3-(2-aminoethylsulfanyl)propylsulfanyl)ethanamine, 1, was readily synthesized for the recognition of Hg2+. The sensitive and selective binding behaviors of 1 were investigated by fluorescence spectroscopy. Sensor 1 selectively binds Hg2+ by exhibiting OFF-ON fluorescence enhancement behaviors of the monomer and excimer bands. The sensor provides excellent Hg2+-selectivity in the presence of high concentrations of competitive ions, particularly Cu2+ and Pb2+ as well as Na+, K+, Mn2+, Cd2+, Ni 2+, Ca2+, Li+, Zn2+ and Co 2+, with an available detection limit of 2.1×10-7 M or 42 ppb. © 2012 Elsevier B.V. All rights reserved.


Bunkoed O.,Prince of Songkla University | Bunkoed O.,Center for Innovation in Chemistry | Davis F.,Cranfield University | Kanatharana P.,Prince of Songkla University | And 3 more authors.
Analytica Chimica Acta | Year: 2010

We report the development of transparent sol-gels with entrapped sensitive and selective reagents for the detection of formaldehyde. The sampling method is based on the adsorption of formaldehyde from the air and reaction with β-diketones (for example acetylacetone) in a sol-gel matrix to produce a yellow product, lutidine, which was detected directly. The proposed method does not require preparation of samples prior to analysis and allows both screening by visual detection and quantitative measurement by simple spectrophotometry. The detection limit of 0.03 ppmv formaldehyde is reported which is lower than the maximum exposure concentrations recommended by both the World Health Organisation (WHO) and the Occupational Safety and Health Administration (OSHA). This sampling method was found to give good reproducibility, the relative standard deviation at 0.2 and 1 ppmv being 6.3% and 4.6%, respectively. Other carbonyl compounds i.e. acetaldehyde, benzaldehyde, acetone and butanone do not interfere with this analytical approach. Results are provided for the determination of formaldehyde in indoor air. © 2009 Elsevier B.V. All rights reserved.


Lowmunkhong P.,Center for Innovation in Chemistry | Ungthararak D.,Center for Innovation in Chemistry | Sutthivaiyakit P.,Center for Innovation in Chemistry
Corrosion Science | Year: 2010

The inhibitor effect of tryptamine on the corrosion of mild steel in 0.5 M hydrochloric acid at 30 °C was investigated using linear polarization, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. The inhibition efficiency increases with an increase in concentration of tryptamine. At 500 ppm tryptamine the inhibition efficiency calculated by these techniques is around 97%. Cathodic and anodic polarization curves of mild steel in the presence of different concentrations of tryptamine at 30 °C reveal that it is a mixed type inhibitor. Tryptamine follows Langmuir adsorption with adsorption free energy of -35.07 kJ mol-1. © 2009 Elsevier Ltd. All rights reserved.


Satienperakul S.,Maejo University | Phongdong P.,Maejo University | Liawruangrath S.,Center for Innovation in Chemistry
Food Chemistry | Year: 2010

A simple pervaporation flow injection chemiluminescence (PFI-CL) procedure was utilised as an on-line separation for the analysis of contaminated sulphite in food samples. The method involves the injection of standard and/or sulphite sample solutions into a 0.20 M sulphuric acid donor stream. Sulphite is converted to sulphur dioxide and transported to the donor chamber of a pervaporation module. The sulphur dioxide gas then evaporates into the headspace and diffuses across a semi-permeable PTFE membrane into an acceptor stream containing 0.75% (m/v) sodium hexametaphosphate and 1.0 mg L-1 rhodamine B in 0.02 M H3PO4, which functions as a carrier solution for the chemiluminescence detection. The sulphur dioxide in the acceptor stream merges at a T-piece with a reagent stream consisting of potassium permanganate (8.0 × 10-5 M) prepared in the acidic sodium hexametaphosphate carrier solution. The elicited chemiluminescence intensity of the resulting reaction mixture was measured at a red sensitive photomultiplier tube operated at a voltage of 1.00 kV. Optimal experimental conditions for an on-line determination of sulphite were investigated. The second-order polynomial calibration curve was developed over the concentration range of 0.5-10.0 mg L-1 sulphite with a resulting equation of I = -0.239C2 + 4.846C - 1.64, r2 = 0.9997. The detection limit was found to be 0.2 mg L-1 with a sampling frequency of 30 h-1. The effects of common anionic and cationic interferences were also investigated. The proposed PFI procedure was successfully applied to the determination of sulphite in different food samples. The PFI data was validated versus standard differential pulse polarography. © 2010 Elsevier Ltd. All rights reserved.


Samaele N.,Center for Innovation in Chemistry | Amornpitoksuk P.,Center for Innovation in Chemistry | Suwanboon S.,Prince of Songkla University
Materials Letters | Year: 2010

Biprism, rugby cone and triangle-like shapes of ZnO particles were synthesized directly from an aqueous zinc acetate dihydrate solution in the presence of poly(ethylene oxide)-b-poly(propylene oxide) copolymer and sodium hydroxide at a pH of 8, 10 and 12, respectively. The particle sizes of their ZnO particles decreased with an increase of pH values. Furthermore, it had been found that the estimated band gap value and the emission peak in the UV region showed a blue shift as a dependence on their particle sizes. © 2009 Elsevier B.V.

Loading Center for Innovation in Chemistry collaborators
Loading Center for Innovation in Chemistry collaborators