Open Access Short Research Article

N,N’-Dialkylimidazolium Dimethyl Phosphates – Promising Media and Catalysts at the Same Time for Condensation Reactions

S. Brica, L. Freimane, L. Kulikovska, A. Zicmanis

Chemical Science International Journal, Page 1-9
DOI: 10.9734/CSJI/2017/34482

The objective of the current work is the elaboration of an alternative method for synthesis of N,N’-dialkylimidazolium dimethyl phosphates – ionic liquids useful both as media and catalysts for condensation reactions in organic synthesis. The proposed method consists of alkylation of 1-substituted imidazoles with 1-alkyl chlorides in a closed steel cylinder followed by treating of obtained imidazolium chlorides with trimethyl phosphate. Data of qualitative analyses made by 1H NMR, quantitative analysis made by potentiometric titration, and thermal stability measured by thermogravimetry of these elaborated advanced materials are presented. Two successful examples of their use in the Knoevenagel condensation reactions are demonstrated.

Open Access Original Research Article

Effective Microporosity for Enhanced Adsorption Capacity of Cr (VI) from Dilute Aqueous Solution: Isotherm and Kinetics

Lloyd Mukosha, Maurice S. Onyango, Aoyi Ochieng, John Siame

Chemical Science International Journal, Page 1-12
DOI: 10.9734/CSJI/2017/34082

The adsorbent pore structure significant to enhanced adsorption capacity of Cr (VI) from dilute aqueous solution is evaluated. As reference, low-cost micro-mesoporous activated carbon (AC) of high basicity, mesoporosity centred about 2.4 nm, and effective microporosity centred about 0.9 nm was tested for removal of Cr (VI) from dilute aqueous solution in batch mode. At pH 2 the low-cost AC exhibited highly improved Langmuir Cr (VI) capacity of 115 mg/g which was competitive to high performance commercial AC. A Comparison with treated characterization results of literature adsorbents/ACs showed that moderate to high effective micropore volume of average pore-size about 0.9 ± 0.1 nm is critical for increased adsorption capacity of Cr (VI) from dilute aqueous solutions. The mesostructure of the tested low-cost AC was associated with rapid kinetics that was fitted by the Pseudo-second kinetics model. While Biot numbers suggested slight significant contribution of intraparticle diffusion. It is hoped that this study may be a useful contribution to development of effective adsorbents for the efficient abatement of toxic Cr (VI) from wastewater and water.

Open Access Original Research Article

Comparative Analysis of Some Digestion Methods Used in the Determination of Metals in Soil and Sediments

Innocent Joseph, H. M. Maina, Pigweh Amos Isah, J. E. Eneche

Chemical Science International Journal, Page 1-4
DOI: 10.9734/CSJI/2017/34652

Analytical study was carried in order to compare the accuracy of three (3) frequently used digestion methods, in the determination of metals in soil and sediments. Samples of soil and sediments were taken from three different locations namely; Bakalchi, Batare, and Anguwan Honna in Girei Local Government Area in Adamawa State Nigeria. Sample matrix was formed from the three samples and the three digestion methods was carried out on each of the sample matrix formed, the methods are, Method I: Roast before digestion using aqua regia as used by Ehi-Eromosele and coworkers [1], Method II: Air dried and digest using Aqua-regia similar to the work of Saxena [2], and Method III; Roast using ammonium chloride before digestion with aqua regia similar to the work of Voica et al [3]. The metal elements Calcium and Iron were chosen because of their relative abundance in natural soil and sediments. Results obtained shows that the soil and sediment samples contain the metal element calcium and Iron which were used to examine the frequently used digestion methods. Based on the result obtained from the analysis, method III (Roast with NH4Cl and digest with aqua regia) appears to be the most promising, given the higher concentration of the elements in all the matrix samples examined.

Open Access Original Research Article

Synthesis and Characterization of Cellular Polyurethane as Redox Catalyst

Misbah Sultan, Yashfa Nazar, Aumera Khursheed, Muhammad Imran, Yusra Safa

Chemical Science International Journal, Page 1-7
DOI: 10.9734/CSJI/2017/34270

Dyes are coloring materials used extensively in common consumer products. A large amount of dye effluent is produced mainly by textile industry. These dye effluents need remediation as they are damaging water bodies and biological organisms including human beings. Polyurethane is one of the potential materials which can be used to solve this problem. In this study, polyurethane was synthesized by a simple method using toluene diisocyanate (TDI), Polyethylene glycol (PEG; 1000 g/mol) and Butanediol (BDO). The synthesis was confirmed by the FTIR bands of –NH, C=O, C–N and C–O–C at 3390 cm-1, 1735 cm-1, 1420 cm-1 and 1094 cm-1, respectively. This synthesized material was applied in degradation of Methylene blue dye through reduction reaction which was monitored by UV-Vis spectroscopy. The color of the dye was removed 100% in just 7 min. Where, more than 70% dye was reduced in just first 3 mins. Consequently, synthesized material can be a potential catalyst in reduction processes.

Open Access Original Research Article

Binary Complexes of Aspartic Acid with Some Metal Ions in Aqueous Solution and Water-dioxane Mixtures

Ebrahim Ghiamati, Maliheh Baniasadi, Alireza Farrokhi

Chemical Science International Journal, Page 1-15
DOI: 10.9734/CSJI/2017/34611

The reaction between amino acids and metal ions has been used as a model for transferring the metallic ions to body tissues. How stable these complexes are formed is our concern. The stability constants of the complexes between L-aspartic acid (Asp) and Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and Ce(III) metal ions were determined by potentiometric titrations in aqueous solution and in 25-75%(v/v) of water-dioxane mixtures(I = 0.1 M, NaNO3) at 15, 20, 25,  35, and 45°C.The observed increasing stability order for the corresponding complexes in water and water-dioxane mixtures were as follows:

 

Kf Cd (II)-Asp< Kf Zn (II)-Asp < Kf Co (II)-Asp< Kf Ni (II)-Asp < Kf Ce(III)-Asp< Kf Cu(II)-Asp

 

Mixed solvents such as water-dioxane provide a better model for in vivo reactions. It was observed that with increase in the percentage of dioxane, the stability constants were elevated. The results showed that the reactions were exothermic and spontaneous.