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Hashemian S.,Islamic Azad University at Yazd
Main Group Chemistry | Year: 2011

The adsorption of Acid Red 151 (AR151) from water was determined for kaolin, MnFe2O4 and MnFe2O4/kaolin magnetic nano-composite. MnFe2O4 and MnFe 2O4/kaolin were prepared using a simple chemical co-precipitation procedure. The MnFe2O4/kaolin composite was prepared with Mn: Fe: kaolin mass ratios of 1: 1: 10, 1: 1.5: 10 and 1: 2: 10. The adsorption capacity increased in 1: 2: 10 Mn: Fe: kaolin. Powder XRD and SEM were used to characterize the sorbents. The spinel magnetic phase is present in the MnFe2O4. The AR151 adsorption is strongly dependent on pH and increases with increasing acidity with a maximum at pH 2. The adsorption capacity of the composite is greater than that of natural kaolin and MnFe2O4. The adsorption was not affected by the presence of chloride, but was significantly affected by sulfate. The adsorption kinetics of AR151 on kaolin and ferrite powder are similar, but the adsorption of AR151 on the MnFe2O4/kaolin composite is much more rapid and occurs within 2-5 min of contact. The adsorption process follows pseudo-second order kinetics. The solid magnetic composite could be conveniently recovered after adsorption. © 2011 - IOS Press and the authors. All rights reserved. Source

Background: Various water clusters including hexamers, heptamers, octamers, decamers and 1D or 2D infinite water chains in a number of organic and inorganic-organic hybrid hosts, have been reported.Results: {[Cu(pydc)(amp)].3H 2O} nhas been hydrothermally synthesized and characterized by elemental analysis and by IR spectroscopy. A wide range of hydrogen bonds (of the O-H...O, N-H...O and N-H...N type) are present in the crystal structure. Hydrogen bond interactions between the co-crystallized water molecules led to formation of six-membered rings with chair conformation.Conclusion: In {[Cu(pydc)(amp)].3H 2O} n, there are three uncoordinated water molecules. Thermal methods confirm number of co-crystallized water molecules in polymer. Hydrogen bond interactions between the co-crystallized water molecules led to the formation of a six-membered ring with the chair conformation. These rings are part of a 1D chain containing six-membered O6 rings, which are alternately made from (H 2O) 6and [(H 2O) 4O 2] rings. [(H 2O) 4O 2] rings are also in chair conformation. © 2010 Tabatabaee et al. Source

Hashemian S.,Islamic Azad University at Yazd
African Journal of Biotechnology | Year: 2010

Magnetic MnFe2O4/bentonite nanocomposite was synthesized by chemical co-precipitation method. The product was characterized by X-ray diffraction (XRD) and Scanning electron microscope (SEM). XRD results indicated the presence of free quartz in bentonite. The magnetic ferrite MnFe2O4 has spinel structure. It is also found that the presence of bentonite in the magnetic composite has not made any changes in the spinel structure of MnFe2O4. SEM images of the sorbent shows nanocomposite with a uniform structure and nanochannels from 0.3 to 0.8 mμ in diameter having a surface area of 130 m2 g-1. The results also revealed that the composite has much higher catalytic activity than the bentonite. The process confirmed very fast kinetic and pseudo-second-order model for acid red 138 (AR138) from aqueous solutions. The adsorption of AR138 was strongly dependent on the pH of the medium, where the removal efficiency increased as the pH decreased in pH 2. © 2010 Academic Journals. Source

Nazari A.,Islamic Azad University at Yazd
Journal of the Textile Institute | Year: 2014

In this research, protease pretreated wool fabric (PWF) was treated with butane tetra carboxylic acid (BTCA), citric acid (CA), and nano TiO2 (NTO) to produce fabric with enhanced durable antimicrobial and ultraviolet (UV) protection properties. However, treatment of proteases enzymatic wool with NTO/CA/BTCA has not been informed. The NTO particles were stabilized on the enzymatic wool surface using CA/BTCA cross-linking agents. In order to create optimum UV protection (UP) based on (ΔE*) and bacteria reduction against gram-positive and gram-negative bacteria, the appropriate models were obtained based on Design-Expert software. The roles of CA, BTCA, and NTO concentrations in UP and antimicrobial properties of the PWF were investigated using response surface methodology. Overall, the protease pretreatment of the wool fabrics made the improvement of the antimicrobial activity against Staphylococcus aureus and Escherichia coli bacteria, and also caused the remarkable enhancement of UP properties as compared with control samples. Also, reflectance spectra analyses (200-400 nm) and scanning electron microscopy were employed to confirm the NTO particles on the pretreated wool surface. © 2013 © 2013 The Textile Institute. Source

Hashemian S.,Islamic Azad University at Yazd
International Journal of Physical Sciences | Year: 2011

The adsorption of methylene blue (MB) dye onto activated rice bran and CuFe 2O 4/rice bran (CRB) composite was investigated. Activated rice bran was prepared by treating with NaCl. The CuFe 2O 4/rice bran was prepared by chemical co-precipitation method. The adsorbents were characterized by XRD and SEM analyses. The adsorption of MB was strongly dependent on the pH (pH 12). The process was very fast initially and maximum adsorption was attained within 60 min of contact time. The specific surface area (BET method) of rice bran, activated rice bran and CuFe 2O 4/ rice bran were 0.44, 35 and 68 m 2 g -1, respectively. The adsorption isothermal data could be well interpreted by the Langmuir isotherm model. The adsorption process follows pseudo second-order kinetics and rate constant 0.112 for ARB and 0.17 for CRB (g mg -1 min -1). Thermodynamic parameters were evaluated. ©2011 Academic Journals. Source

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