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Objective: Photooxidation of pharmaceutical drugs like benzyl penicillin and streptomycin by singlet molecular oxygen, both of which are antibacterial and antibiotic drugs. Methods: Methylene blue was added to the drug solutions and then irradiated with a light source and air was continuously bubbled in the reaction mixture. Effect of various factors like triplet energy of sensitizer, nature of solvent and singlet molecular oxygen scavenger on the yield of photoproduct was also observed. Results: After completion of photooxidation reaction, photoproduct was isolated and characterized by physical, chemical and spectral data. A tentative mechanism for the photooxidation has been proposed involving singlet molecular oxygen as an oxidizing species. Conclusion: The results of this study demonstrate that benzyl penicillin and streptomycin could efficiently photooxidized by singlet molecular oxygen. [ABSTRACT FROM AUTHOR]

The article deals with a study which successfully synthesized and characterized an in situ sodium-activated and organomodified bentonite clay/styrene-butadiene rubber nanocomposites using a latex blending method. Based on X-ray diffraction data, it was found that the in situ sodium activation has helped increase the intergallery distance from 1.28 to 1.88 nanometers. The in situ sodium-activated compound also exhibited a substantial improvement in physical properties.

The photochromic behavior of potassium hexacyanoferrate (II) - fuchsin basic and potassium hexacyanoferrate (II) - malachite green systems was investigated in detail. The effect of variation of various parameters, like pH, light intensity, concentration of dyes, and concentration of potassium hexacyanoferrate(II), on the rates of forward and backward reactions of these systems has been observed. Based on experimental data, a tentative mechanism has also been proposed. [ABSTRACT FROM AUTHOR]

A fast and facile procedure for the synthesis of pyridomercaptotriazole 4a-e and pyridothiazolidinone 5a-e is being reported starting from dihydropyridine 1a-e. Subsequent oxidation with nitrating mixture (HNO3/H2SO4) produced the anticipated 2,6-dimethylpyridine derivatives 2a-e, which were subsequently condensed with thiosemicarbazide in ethanol to produce the key intermediate 2,2'-[4-(4-substituted phenyl)- 2,6-dimethylpyridine-3,5-diyl]dicarbonyldihydrazine carbothioamides 3a-e. In the final step pyridomercaptotriazole derivatives 4a-e were synthesized by treating 3a-e in alkaline media. In parallel pyridothiazolidinone derivatives 5a-e were obtained by the reaction of 3a-e with ClCH2COOH/CH3COONa. All the reactions were carried out on microwave irradiation in good yield with short time. The structures of all the compounds have been confirmed on the basis of their analytical, IR, 1H NMR, and Mass spectral data (Table I and Table II). The potent antimicrobial effects of the synthesized compounds were also investigated. [ABSTRACT FROM AUTHOR]

Different methods of wastewater treatment are being used for the removal of dyes from their solution, but in most of the cases, either homogeneous catalysts or different adsorbents are used. These methods have their own merits and demerits. In the present work, antimony trisulphide was used as a heterogeneous catalyst. The effects of different parameters on the rate of the reaction were observed, such as pH, concentration of dye, amount of semiconductor and light intensity. A tentative mechanism is proposed in which the role of hydroxyl radical as an active oxidizing species is shown for degradation of Naphthol green B. [ABSTRACT FROM AUTHOR]

Chitosan–polyaniline–copper(II) oxide (Ch–PANI–CuO) nanocomposite has been synthesized using batch adsorption method. It was characterized using UV–Vis, scanning electron microscopy (SEM), X-ray diffraction and Fourier transform infrared (FTIR) and transmission electron microscopy (TEM). The SEM and TEM showed that the surface of the nanocomposite was rough and porous with pleats, which is probably responsible for better dye adsorption. The maximum percentage of dye degradation was found to be 94.6% for methyl orange dye. The desorption study and FTIR results confirmed the presence of hydroxyl and amino functional groups. The results clearly indicate that the polymer matrix could be used as an adsorbent for the removal of methyl orange from aqueous solution. [ABSTRACT FROM AUTHOR]

Abstract: In-situ sodium activated organo modified bentonite clay was also used for partial replacement of the carbon black (N330). Detailed study with the black filled compound revealed that, with slight modification of the curing package, up to 10 phr of the carbon black replacement is possible. At equivalent loading of 5 and 10 phr of in-situ sodium activated organo modified bentonite clay exhibited better properties in comparison to carbon black filled compound. [Copyright &y& Elsevier]

Abstract: This paper presents a detailed characterization and rheometric property study of in-situ sodium activated, organomodified bentonite clay – styrene-butadiene rubber (SBR) nanocomposite. It was found that around 10phr loading was the optimum level for maximum effect of the organo clay. The WAXD data indicated that at higher loading there was formation of agglomerations in the matrix. It was found that organo clay compound exhibited lower maximum torque in comparison to equivalent amount of carbon black loaded compound. The nanocomposites were also used for partial replacement of N330 carbon black in a highly black loaded compound. Part replacement of the carbon black with nano-clay reduced the maximum rheometric torque in comparison to the control compound. Detail study revealed that with slight modification of the curing package, similar rheometric properties can be obtained. [Copyright &y& Elsevier]

The present study describes the photochemical degradation of phenol-red using photo-Fenton reaction. The progress of the reaction has been monitored spectrophotometrically. The effect of various organic additives e.g. hydroquinone, resorcinol and catechol on the rate of photodegradation has been observed. The effect of variation of various parameters such as pH, concentration of dye, Fe3+ ion and additives, amount of H2O2, and light intensity on the rate of photodegradation was also observed. A tentative mechanism of the reaction has been proposed. [ABSTRACT FROM AUTHOR]

Abstract: Solar desalination is gradually emerging as a successful renewable energy source of producing fresh water from seawater or brackish water by utilizing the greenhouse effect of solar energy. To enhance the overall efficiency of conventional basin type solar still, different semiconducting oxides like CuO, PbO2 and MnO2 have been utilized as photocatalysts. It is observed that metal oxides not only improve the efficiency of the process but the rate of production of desalinated water was also increased to a remarkable extent. The water quality for its various parameters like pH, TDS, etc. are analyzed (for raw and desalinated water). [Copyright &y& Elsevier]

• Chitosan-polyaniline-NiO nanocomposite was prepared using batch adsorption method. • FT-IR, XRD, XPS, SEM and TEM were used for characterization. • The BE at 854.6, 861.1, 864.2 eV for +2 and 856.9 eV for +3 form of Ni was measured. Chitosan-polyaniline-nickel (II) oxide nanocomposite was synthesized in the presence of acetic acid and the resulting nanocomposite was characterized by various analytical techniques such as FTIR, SEM, TEM, XRD, and XPS. The peak at 511 cm−1 indicated the Ni-O stretching frequency of NiO present in the nanocomposite. The size of the NiO nanoparticles wrapped in Ch-PANI composite is approximately 34 nm, analyzed by TEM and XRD. The percentage of composition present at the surface of nanocomposite for C, O, N and Ni are 22.1, 48.7, 3.7, and 21.9 respectively, from the XPS analysis. The binding energies of 854.6, 856.9, 861.1 and 864.2 eV are attributed to oxyhydroxide in +3, oxyhydroxide in +2, hydroxide of nickel, and oxide of nickel, which are present on the surface of the nanocomposite, respectively. This material could be a potential candidate for advanced applications in biomedical sciences. [ABSTRACT FROM AUTHOR]