Thiourea single crystals have been grown from aqueous solution by slow cooling technique. The stability of the saturated solutions of different pH values has been assessed by measuring the metastable zone width (MSZW) by a nucleation method. MSZW has been enhanced by the influence of pH of thiourea solution. The growth rate of the thiourea crystal along the c-direction [001] was found faster fo...

An in-situ reactor was elaborately designed for O-alkylation of chitosan in an ionic liquid ([BMIM]Cl) solvent, using N, N'-carbonyldiimidazole as bonding agent. The original chitosan and the modified chitosan were characterized by FT-IR and XRD analysis. FT-IR spectra revealed that the alkylation of chitosan selectively occurred at hydroxyl groups, with unprotected amino groups untouched. It w...

Six mixtures, containing 10, 20 and 30% w/w ibuprofen and isomalt, were compacted by a traditional or ultrasound-assisted machine and analysed by means of thermal (DSC and TGA) and micro-spectrometry (Raman and FT-IR) techniques. Ultrasound discharge causes melting of ibuprofen powder, transforming into a paste that could not assume the shape of a tablet; when in mixture with isomalt, thermal e...

5-aminosalicylic acid (5-asa) is currently prepared by electrochemical reduction of 5-nitrosalicylic acid (5-nsa) in acidic media. in this work, electrolytic reduction of 5-nsa in alkaline media is presented. reactionconditions and parameters such as anode and cathode electrodes, electrolyte type, reaction time, temperature,current, and the ph for isolation of product are investigated. the yiel...

Th e chemical composition and sensory characteristics vary signifi cantly within different honey types. In order to determine botanical origin of honey, it is necessary to conduct rather complicated and time consuming analytical methods. IR spectroscopy has not yet been experimentally explored for honey analysis in Croatia, so the aim of this study was to determine claimed botanical origin of h...

In order to improve the gelling properties of agarose, we modified it by methylation. The agarose was prepared from Gracilaria asiatica, G. bailinae, and G. lemaneiformis with alkaline, treated with diatomaceous earth and activated carbon, and anhydrous alcohol precipitation. The methylation reaction process of agarose was performed with dimethyl sulfate while the chemical structure of low-gell...

The need for the identification of compounds present in complex gaseous mixture or after separation by gas chromatography (GC) using vapor-phase infrared (VPIR) spectrometry is becoming increasingly important. This is primarily due to advances in Fourier transform infrared (FT-IR) spectrometry allowing the acquisition of complete spectra in a few tenths of a second with detection limits of less...

Transition metal ions doped NaCaAlPO4F3 phosphors have been synthesized using a solid state reaction method. The prepared samples are characterized by powder XRD, SEM, optical absorption, EPR, PL and FT-IR techniques. The XRD studies confirm the crystal structure of prepared phosphor samples as monoclinic system. SEM images show nanoclusters. Optical absorption and EPR spectra of TM ions doped ...