Recent Innovations in Chemical Engineering - Volume 10, Issue 1, 2017

Background: There is an enormous growth in the epoxidation base on vegetable oils in recent years due to the rising demand for eco-friendly epoxides to replace petrochemical resources. Objective: The aim of this review is to give an insight on the articles on epoxidation of various vegetable oils published in scientific journals major proceedings and books. The major area research have been identified and discussed based on available literature in each research topic. Result: It was observed that most of these articles were published during the recent years with the number of articles increasing yearly. Review on optimization and kinetics study of epoxidized vegetable oils are found to be the leading topics in this area. Conclusion: The methodologies followed and analytical techniques employed by the researches to attain their objectives have been discussed.

Background and Objective: Li3InBr6-yXy (X=F, I) was synthesized and the substitution effect on ionic conductivity was investigated. Method: An all solid state secondary battery was fabricated using Li3InBr6-yXy (X=F, Cl, I) and evaluated. Li3InBr6-yFy was single phase at y ≤ 3. The lattice constants for both compounds were decreased with an amount of F. The conductivity of Li3InBr6-yFy was decreased with y and electrochemical stability was improved by the substitution. The conductivity in Li3InBr6-yIy(y ≤ 3) was changed with y and Li3InBr3I3 showed the highest value in these compounds to be 3 x 10-3 Scm-1 at 333 K. 7Li NMR spectra in Li3InBr6-yIy was sharp and it was confirmed the diffusion of Li ion was fast at room temperature. Batteries using Li3InBr5F could be stably charged and discharged for 10 cycles. Results and Conclusion: The discharge capacity increased in the first few cycles and the maximum value of 81 mAhg-1 was obtained in the fourth cycle.

Background and Objective: In this work, the precipitation combined with vacuum drying and supercritical CO2 drying was applied in the preparation of Mg(OH)2 which was thermally decomposed to MgO. Results: Results showed that the constant dropping rate of Mg(NO3)2 solution into NaOH aqueous solution under 90°C with a relatively high pH of 10.1 led to the MgO powder with high specific surface area and large pore volume with both vacuum drying and supercritical drying. Among the produced MgO, the pore volume1.45 cm3/g from the vacuum drying was the highest, and the bulk density 0.0247 g/ml from the supercritical drying was the lowest in the reported literature. Conclusion: Particularly, the MgO produced from the supercritical drying showed high adsorption of Pb2+ (as high as 3635 mg/g at pH=6 and 25°C) and Mn2+ (as high as 861 mg/g at pH=6 and 25°C). The adsorption isotherms and kinetics of Pb2+ and Mn2+ on the produced MgO were fitted well to the Langmuir model and pseudo-second order model.

Objective: Aim of this paper is to investigate the interactions between industrial-grade polycarboxylate ether (PCE) polymers and ordinary Portland cement to assess whether is possible to draw structure/performance relations for impure, yet fully characterized, polymers. Method: To this end thirteen PCE polymers were synthesised in industrial fashion, deeply analyzed and tested in cement paste. Chemical stability and adsorption behaviour have been evaluated through gel permeation chromatography technique, leading to insights regarding the plasticization timing and the adsorption control. Results: All the results were interpreted and critically discussed by invoking the characteristics of initial dispersers and workability retainers; furthermore a comprehensive description has been attempted through the Gay and Raphael conformation plot, based on the establishment of which molecular feature affects each step of the PCE's working mechanism. Conclusion: The results confirm many of the findings despite the imperfect nature of the chosen polymers and show that common impurities, such as unreacted side chains, do not noticeably interact with the binder. In particular it is clear that the limiting stage of the entire action lies on adsorption rate and occurrence, which seems to be ruled by the absolute value of charge per chain and by the conformation regime.

Objective: In this work, the synthesis of polycarboxylate ethers (PCE) via partial esterification of acrylic copolymers has been experimentally carried out with the aim of obtaining results useful to the development of a reliable kinetic model. Method: Experimental tests were conducted starting from monomethyl ether polyethylene glycol (MPEG) as side chain, and two acrylic backbones of different constitution. The reactions were carried out in a 350 mL batch reactor made of glass. Thirteen PCE polymers have been produced varying the target esterification degree (15–45%), reaction temperature (150–180°C) and time (60–460 min). Results: The results of degree of MPEG conversion, obtained through gel permeation chromatography, have been fitted with different kinetic models through a devoted software and procedure. The model resulting in a very satisfying fitting was based on a kinetic equation of pseudo 1st-order with respect to the MPEG concentration, and pure 1st-order with respect to the concentration of carboxylic groups. Once the kinetic parameters have been determined, the model has been validated against experimental data obtained under different and additional operating conditions in terms of esterification degree and operating temperature. Conclusion: The good fitting with the experimental data of MPEG conversion under the new operating conditions witnesses the soundness of the proposed approach.

Background: In the current study, nanocrystalline thin films of TiO2:xSiO2 (x: mole percentage) with high photocatalytic activity were grown on glass surfaces using sol-gel method. The films were then treated under high temperature of 500°C for the crystal growth. The synthesized films presented high photocatalytic activity when they were in contact with methyl orange (MO) solution and UV irradiation. Due to complexity and nonlinearity photocatalytic features of TiO2 films doped by SiO2, Artificial Neural Network (ANN) and Fuzzy Logic (FL) models have been applied to predict and calculate the MO concentration variations with SiO2 concentration and MO degradation time. Results: The simulations have resulted in accurate and reliable predictive models since the squared correlation coefficient (R2) and the standard squared error (SSE) have been R2>0.99, 0.004, R2 >0.96, and 0.14 for ANN and FL models, respectively. The reported figures have shown that the independent predicted values of MO concentration are extremely close to their corresponding experimental data. Conclusion: The results of simulations have shown that ANN and Fuzzy models are reliable predictive models to study the photocatalytic activity of TiO2 thin film doped by SiO2.