Research Journal of Chemistry and Environment

Indexed in SCOPUS, Chemical Abstracts Services, UGC, NAAS and Indian Citation Index etc.

Research Journal of Chemistry and Environment

Fabrication and Properties of PPC/PEO/TiO2 Composite Polymer Electrolyte for Lithium-ion Battery

Yu Xiao-Yuan, Xiao Min, Wang Shuang-Jin and Meng Yue-Zhong

PEO/PPC/x%TiO2 composite polymer electrolytes (CPEs) have been prepared by solution casting technique using poly(propylene carbonate) (PPC) and poly(ethylene oxide) PEO as polymer matrices, nano-TiO2 as filler. The thermal performance, crystallinity, ionic conductivity, lithium ion transference number and electrochemical stability of the PEO/PPC/x%TiO2 CPEs were then investigated. SEM images show that nano-TiO2 particles disperse well in polymer matrix. DSC and XRD experimental results of all PEO/PPC/x%TiO2 composite polymer electrolytes indicate that the crystallinity of PEO decreases with increasing nano-TiO2 amount. Therefore, the results show that the addition of nano-TiO2 particles can enhance the lithium ion transference number and the ionic conductivity of PEO/PPC/10%LiClO4 composite polymer electrolytes. The maximum ionic conductivity of 1.4×10-5 S cm-1 at room temperature, 8×10-3 S cm-1 at 80 oC and the electrochemical stability window of 4.5V (vs Li/Li+) were recorded when the content of nano-TiO2 was 3%. The Lithium ion transference numbers of PEO/PPC/x%TiO2 composite polymer electrolyte increase first and then decrease with increasing nano-TiO2 content. The highest lithium ion transference number (TLi+) was 0.62 for PEO/PPC composite polymer electrolyte with 10% nano-TiO2. The PEO/PPC/3%TiO2 composite polymer electrolytes possess good interfacial stability with the lithium electrode, making it possible of PEO/PPC/x%TiO2 as the electrolyte materials for all solid-state rechargeable lithium ion batteries.

Full Text

Enzyme-catalyzed Removal of Bisphenol A by Using Herseradish Peroxidase Immobilized on Magnetic Silk Fibroin Microspheres

Jing Dong, Zhang Kun, Tiantian Tang and Shiyun Ai

The catalytic removal of bisphenol A (BPA) from aqueous solution with horseradish peroxidase (HRP) immobilized on Silk Fibroin magnetic microspheres was investigated. To introduce HRP onto the magnetic microsphere, silk fibroin and poly(amido amine) (PAMAM) were covalently bonded onto the magnetic Fe3O4 nanoparticles to give an aminated magnetic silk fibroin microsphere. HRP was immobilized onto the aminated microsphere via glutaraldehyde coupling reaction. Upon immobile-zation, the enzyme showed a broader pH, higher temperature and excellent storage stability. The optimum condition for the removal of BPA with immobilized HRP was that immobilized HRP reacted with BPA solution under the temperature of 20~40 C with pH value of 6 for 120 min. Under optimized operational conditions, the degradation efficiencies of BPA using the native enzyme and immobilized enzyme method were 50% and 64% respectively. After 4 repeated uses, the immobilized enzyme still retained about 82% of its initial activity. The results show that the silk–fibroin–PAMAM modified magnetic micros¬pheres are a promising support for the treatment of wastewaters contaminated by phenolic compounds.

Full Text

Alumina supported Manganese Oxide doped Noble Metal Oxides for Catalytic Methanation Reaction of Simulated Natural Gas

Wan Abu Bakar W.A., Ali R., Kadir A. A. A., Abd Rahim H.F. and Jue L. C.

Manganese oxide doped noble metal supported on alumina was prepared for methanation reaction by doping the manganese oxide based catalyst with noble metals namely ruthenium and palladium via impregnation method. All the catalysts were calcined at 400ºC and 1000ºC for 5 hours separately. In-house-built micro reactor with Fourier Transform Infra Red (FTIR) detector and Gas Chromatography (GC) were used to study the percentage of carbon dioxide (CO2) conversion and also the percentage of methane (CH4) formation. It was found that the catalyst with Ru:Mn(25:75)-Al2O3 calcined at 1000oC showed 60.21% formation of CH4 at 200oC. FESEM illustrated that catalyst surface is covered with small and dispersed particles with undefined shape. The X-Ray Diffraction (XRD) analysis revealed that the catalyst is crystalline. Moreover, Nitrogen Gas Adsorption (NA) analysis showed that both fresh and spent catalysts are of mesoporous material with type III isotherm and type H3 hysteresis loop. Furthermore, fresh catalyst has 84.887 Ǻ pore diameter which is bigger than used catalyst which is 79.053Ǻ.

Full Text

The Effect of Light on the Transformations of Bisphenol AP in Water

Peng Zhange

Bisphenol AP (4, 4’-(1-Phenyle­thyli­dene) bisphenol, BPAP) is a member of the bisphenol family and is structurally close to bisphenol A which is a kind of suspected endocrine disruptors. These compounds could be a threat to the aquatic ecosystems and human health, so its transformation fate in natural environment was important. In this work, experiments were conducted to study the transformation of BPAP induced by three kinds of freshwater algae under light. Results showed that the freshwater algae are capable of promoting the degradation of BPAP under irradiation. The degradation efficiency of BPAP was increasing with algae concentration increasing. For example, in the Chlorella vulgaris suspensions, the photodegradation rate of BPAP was increased from 17% to 25% with algae concentration ranging from 2.0 × 109 cells•L-1 to 6.0 × 109 cells•L-1. Results showed that the light had an important role in the chemical transformation of BPAP. Oxidative photodegradation is a decomposition fate of BPAP in water. The research provides some references for the fate of phenolic endocrine disruptors in natural water.

Full Text

Removal of Fluoride Ions from Aqueous Solution in a One-Step Process

Huang Ruihua

A novel technology for wastewater treatment was proposed based on simultaneously synthesis of N-2- hydroxypropyl trimethyl ammonium chloride chitosan (HTCC)-bentonite and removal of fluoride ions (F-) in a one-step process. The bentonite modified in the process was characterized by X-ray diffraction (XRD) and Fourier transforming infrared (FTIR) spectroscopy. The effects of contact time, temperature, pH and initial concentrations on the removal of F- were investigated. The removal efficiencies achieved were 84.5 % and 86.3 % within 30 min for F- solutions with initial concentrations of 20 mg/L and 40 mg/L respectively. The HTCC-bentonite regenerated with deionized water still retained a high adsorption capacity for F-. Therefore, the one-step bentonite process could provide a simple, efficient and economical alternative for removal of high levels of F- from contaminated water.

Full Text

Demulsification of Triton X-100, Low-Sulfur Wax Residue (LSWR), Sorbitan Monooleate (Span 83) and Sodium Dodecyl Sulfate (SDS)-Stabilized Petroleum Emulsions with a Microwave Separation Method

Abdulbari Hayder A., Abdurahman N.H., Rosli Y.M. and Azhari N.H.

The formation of emulsions during oil production and processing is a costly problem both in terms of chemicals used and production losses. For economic and operational reasons, it is necessary to separate the water completely from crude oils before transporting or refining them. Experimental data are presented to show the influences of Triton X-100, low-sulfur wax residue (LSWR), sorbitan monooleate (Span 83) and sodium dodecyl sulfate (SDS) on the stability and microwave demulsification of petroleum emulsions. It was found that emulsion stability was related to several parameters including the surfactant concentration, water-to-oil phase ratio (10–90%), temperature and agitation speed. Based on this study, a possible emulsion-minimization approach utilizing microwave irradiation is suggested, which could be implemented in refineries. Compared with conven¬tional heating the use of microwave heating can significantly enhance the demulsification rate, reaching over 90 v/v% for the emulsions studied in this work.

Full Text

Phytochemical and Bioactivity Studies of Zingiber amaricans Blume

Riyanto S., Sukari M. A., Rahmani M., Ali A. M. and Shaharudin N.

Phytochemical studies on the rhizomes of Zingiber amaricans afforded zerumbone1 as the major constituent, together with sterol mixtures containing, stigmasterol2, β-sitosterol3, cholesterol4 and campes¬terol5. The structures of the isolated compounds were elucidated using spectroscopic methods. The crude extracts and isolated pure compounds were examined for their bioactivity against phatogenic microbes and cancer cell lines. Zerumbone1 shows moderate cytotoxic activity against human lymphoblastic T leukemia cell.

Full Text

The effect of the pH value on the growth and properties of chemical bath deposited SnS thin films

Anuar Kassim*, Ho Soon Min, Atan Shariff and Md Jelas Haron Department of Chemistry, Faculty of Science, Universiti Putra Malaysia, 43400 Serdang, Selangor, MALAYSIA

Thin films of semiconductors were commonly used for the fabrication of inexpensive solar cells. The aim of the present study was to investigate the influence of pH (pH 1.5, 2.5 and 3.5) on the properties of chemical bath deposited SnS thin films. The differences in the morphological properties of the films were investigated using atomic force microscopy, meanwhile the optical properties were studied using UV-Visible spectrophotometer. We observed that the grain size was relatively uniform, good coverage and thicker films could be obtained at lower pH value such as pH 1.5. The band gap values were found to be 1.2-1.6 eV for the films deposited under various pH values.

Full Text

Multianalytical characterization of silica-rich megabreccias from the proposed natural area of Richat (Sahara desert, Mauritania)

Martinez Frias Jesus, Rull Pérez Fernando, Martín-Redondo M.Paz, Huertas Antonio Delgado, Sampedro Fernández M.Teresa, García-Talavera Francisco, López-Vera Fernando, Rodriguez-Losada J. Antonio and Salván César Menor

Some terrestrial areas have favourable environmental features that allow the preservation and scientific study of processes which can be used as geomarkers. The crater-like Richat structure (Sahara desert, Mauritania) is a recently proposed protected natural area, which can be considered as one of these sites. Volcanic, hydrothermal and arid environments merge together, making easy their investigation in the field and their later characterization by the use of a set of geochemical and mineralogical techniques (XRD, transmitted and reflected light microscopy, SEM-EDX, laser-Raman spectroscopy, XRF, ICP-MS and stable isotope spectroscopy). The study presented here focuses on the spectacular silica-rich megrabreccias which crop out, as a large and thick lenticular body, at the centre of the Richat structure. Based on paragenetic relationships, six types of silica-rich megabreccias were identified. The link between the geochemical and mineralogical characteristics was established, from macro to micro scale, showing the existence of: a) variable distributions of the major, minor and trace elements; b) polymorphic phases; c) micrometric cataclastic features and d) different textural intergrowths and degrees of crystallinity of some minerals.The oxygen and carbon isotopic signatures of the carbonates, within the silica-rich megabreccias, point out a meteoric (low-temperature hydrothermal) origin for the source waters.

Full Text

Voltammetric determination of Pb (II) ions by Carbon Paste Electrode modified with Lemon grass powder

Rajawat D. S. and Satsangee S. P. USIC Remote Instrumentation Lab, Dayalbagh Educational Institute, Agra 282110, INDIA

Lemon grass powder contains materials with functional groups which have the ability to bind with metal ions. Lemon grass powder was used as modifier of carbon paste electrode for voltammetric determination of lead ions in aqueous samples. Different parameters like electrode composition, different electrolytes, electrolyte concentration, pH value, deposition time and deposition potential were optimized for application of lemon grass powder modified electrodes. The use of 0.2M HCl as supporting electrolyte and 10% (w/w) modifier, deposition time 300 sec, deposition potential -1100 mV and pH 6 gave an optimum current response for lead (II) solution. Results showed that the fabricated electrode can determine lead with better sensitivity in aqueous solutions.

Full Text

Catalytic-Kinetic Determination of Manganese (II) by Spectrophotometric Method in Aqueous Acetate Medium

Gazala Mohamed H. Ben Hander Faculty of Science, Chemistry Department, Al-Tahadi University, Serit, LIBYA

A simple and sensitive spectrophotometric method is reported for the determination of manganese(II) based on its catalytic effect on the oxidation of nitrilotriacetatocobalt(II)-benzoate complex by periodate in acetate medium. The increase in absorbance of Co(III)-product was monitored at 580 nm, pH = 4.99, I = 0.5 M and T = 25 oC. The kinetics studied have been investigated under pseudo first order condition by taking large excess of oxidant. The various variables affect on sensitivity were studied and optimized and a study of interfering ions was also carried out. The calibration graph was linear in the range of 0.050–0.50 mol dm-3 acetate and (3.0 – 15.0) x10-5 mol dm-3 Mn(II). Mn(I1) in tap water, ground water and an industrial waste water has been successfully determined by the proposed method.

Full Text

Photoremoval of Malachite Green (MG) using Advanced Oxidation Process

Fouad F. Mohamed*, Puazi Md. Abdul Allah , Asmma Mehdi and Mohamed Baseem

Removal of a commercial dye Malachite Green (MG) from its aqueous solution over TiO2 suspension and under UV irradiation has been investigated. The absorption spectra of MG dye indicated that the maximum wavelength 617 nm, almost kept the same. The process of photodegradation was carried out in aqueous solutions containing the dye in the presence of TiO2 (Degussa p – 25) upon UV irradiation (high pressure mercury lamp Radium 125 W). The photocatalytic process used the photogenerated holes at the surface of TiO2 and hydroxyl radicals at the solution bulk as oxidizing species for the dyes. Different parameters affecting the photocatalytic degradation process such as initial dye concentration, TiO2 dosages and amount of H2O2 were investigated .Results obtained revealed that the dye removal % is inversely proportional to its concentration but the dye removal % is directly proportional to H2O2. Study of kinetics has been investigated and the reactions were first order kinetic.

Full Text

Influence of Heavy Metals and Surfactants on the Adsorption of Tetracyclines to Sediment

Jinhua Li, Baoxue Zhou, Bai Xue, Qiulei Mo and Weimin Cai

The widely utilization of pharmaceutical and personal care products (PPCPs) in the pharmaceutical therapies and agricultural husbandry has led to the world pollution. Thus, it is of great interest to study the mobility and fate of PPCPs in the environment. The aim of this study was to investigate the influence of heavy metal Pb(II), anionic surfactant sodium dodecylbenzenesulfonate (SDBS), nonionic surfactant Triton X-100 (TX-100) on the adsorption of representative PPCPs (tetracycline (TC) and oxytetracycline (OTC) on two types of adsorbents. Results showed that the adsorption isotherms of TC and OTC on two sediments were in good comparison with Freundlich equation. However, compared to the sediment B without organic matter (OM), the sediment A with higher OM exhibited the higher adsorption affinity to TC and OTC. The presence of Pb (II) caused a significant increase on the TC and OTC adsorption to sediment A due to the formation of ternary complex between OM ligand groups and tetracycline ligand groups. However, the influence of Pb (II) on TC and OTC adsorption on sediment B was minimal. The presence of SDBS increased TC and OTC adsorption on two sediments, which could be due to the significantly increasing OM content of two sediments via the SDBS adsorption. In contrast, the nonionic surfactant TX-100 caused a slight reduction on TC and OTC adsorption on two sediments even at high concentration.

Full Text

Toxic Assessment of Potassium Nitrate in Charles Foster Rats with Emphasis on Histopathology of Vital Organs

Saxena Abhilasha, Dubey Chetan, Gupta Rakhi, Singh Poonam, Bansode F.W., Rawat S.K., Singh R. P. and Singh R.K.

Potassium nitrate is a white, powdery compound naturally present in many leafy green vegetables. Nitrate itself is comparatively non-toxic but its metabolites may cause a number of health hazards such as nitrite caused methemoglobinemia. This research work was concerned with the study of midterm (14 days intoxicant) potassium nitrate exposure to Charles foster (CF) rats at the doses of 0, 45, 90 and 135 mg/kg of body weight. Under these conditions, the body weights were investigated with special emphasis on the histopathology of vital organs of rats. No such adverse effect on vital organs was seen which could be related to nature or dose of potassium nitrate.

Full Text

Pyrazoles as Potential Anti-Obesity Agents

Gupta Girish Kumar, Kumar Vikas and Kumar Vinod

Pyrazoles are an important class of heterocycles for new drug development that attracted much attention in the field of medicinal chemistry. In literature several pyrazole derivatives have been reported as target structures and evaluated for their biological activities. This review focuses on the development of various pyrazole derivatives up to 2010 that possess anti-obesity activity.

Full Text