Reaction Engineering, Kinetics and Catalysts,
Z. Shojaei; E. Iravani; M.A. Moosavian; M. Torab-Mostaedi
Volume 13, Issue 2 , April 2016, , Pages 3-21
Abstract
Adsorption of Ce(III) from aqueous solution by amino phosphate modified nano TiO2 was investigated. Effects of pH of solution, adsorbent dose, contact time, initial metal concentration and temperature were examined. Experimental data were fitted well by the pseudo second order model. Adsorption was well ...
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Adsorption of Ce(III) from aqueous solution by amino phosphate modified nano TiO2 was investigated. Effects of pH of solution, adsorbent dose, contact time, initial metal concentration and temperature were examined. Experimental data were fitted well by the pseudo second order model. Adsorption was well described by Freundlich isotherm model with a maximum adsorption capacity of 25 mg g-1. According to the obtained thermodynamic parameters, the adsorption was a spontaneous and endothermic process. Effect of interfering cations was studied. The presence of Ca and Mg ions up to 150 mg L-1 showed no considerable effect on the adsorption of Ce(III). Regeneration of adsorbent was performed using HNO3 with efficiency greater than 84%. The quantities of distribution coefficient (Kd), the affinity of metal for retention onto solid phase, was the higher for Ce(III) than La(III). Due to the high sorption capacity, being plentiful and low cost it is concluded that the use of amino phosphate mofified nano titania as an appropriate adsorbent is promising for the removal of lanthanides especially Ce(III) from contaminated sites.
Separation Technology,
Mohammad Reza Moghbeli; Siamak Khoshrou; Ismaeil Ghasemi
Volume 12, Issue 4 , October 2015, , Pages 69-83
Abstract
Polysulfone/carbon nanotubes (PSF/CNTs) nanocomposite membrane was prepared via phase inversion induced by immersion precipitation technique. In addition, the surface of the CNTs were functionalized by polar carboxylic and amine groups to improve the interaction between the CNTs and the polymer matrix. ...
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Polysulfone/carbon nanotubes (PSF/CNTs) nanocomposite membrane was prepared via phase inversion induced by immersion precipitation technique. In addition, the surface of the CNTs were functionalized by polar carboxylic and amine groups to improve the interaction between the CNTs and the polymer matrix. For this purpose, the neat CNTs were chemically treated using sulfuric acid/ nitric acid (H2SO4/HNO3) mixture and an aromatic amine agent, i.e. 1-4-diamino benzene (DABZ), to produce the functional groups on the CNTs surface. The Fourier transform infrared (FTIR) spectra indicated the presence of carboxylic- and amine-functional groups on the nanotubes surface. Asymmetric PSF composite membrane with various levels of the functionalized CNTs were prepared to investigate the effect of functional group type on the morphology and water flux rate of the resulting membranes. The results showed that the incorporation of the functionalized CNTs up to 0.5 wt% increased the pore size and surface roughness of the sheet membranes, while further addition decreased porosity and roughness. Higher water flux rate was observed for the amine-functionalized CNTs (af-CNTs) reinforced PSF membrane when compared with the membranes reinforced with the carboxyl-functionalized CNTs (cf-CNTs). The stronger compatibility between af-CNTs and the PSF matrix caused higher water permeability. The salt rejection performance of these microfiltration composite membranes was evaluated.
Biomedical and Biotechnology,
Volume 12, Issue 4 , October 2015, , Pages 93-100
Abstract
Antioxidants have an important role in control and prevention of dangerous diseases like cancers, but instability and high solubility of the antioxidants are major challenges of pharmaceutical researchers. Thus, using a suitable carrier for an antioxidant can enhance the antioxidant stability and protect ...
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Antioxidants have an important role in control and prevention of dangerous diseases like cancers, but instability and high solubility of the antioxidants are major challenges of pharmaceutical researchers. Thus, using a suitable carrier for an antioxidant can enhance the antioxidant stability and protect it from reacting with the other existing molecules in the blood circulation. Mesoporous silica nanoparticles (MSNs) have been widely used as a carrier for therapeutic applications because of their suitable biological properties. This study attempts to improve the surface properties and increase antioxidant loading by functionaliztion of MSNs with 3-aminopropyltriethoxysilane (AP-MSNs) via post- synthesis grafting method. Synthesized nanoparticles were characterized by Scanning electron microscopy (SEM), Zetasizer and Fourier transform infrared spectroscopy (FTIR). Gallic acid (GA) was loaded into AP-MSNs. To optimize GA loading capacity, two effective parameters: GA concentration and embedding time were investigated. So different concentrations of GA in EtOH (1-50 mg/mL) were prepared and sampling was done in 24 and 48 h. Results showed that the best GA loading capacity was obtained at a concentration of 40 mg/mL in 48 h. The maximum GA loading capacity and entrapment efficiency were obtained 46 and 20%, respectively, determined by spectrophotometry and high-performance liquid chromatography (HPLC) analysis.