Standard Research Institute SRI

Karaj, Iran

Standard Research Institute SRI

Karaj, Iran
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Nemati M.,Arak University | Hosseini S.M.,Arak University | Shabanian M.,Standard Research Institute SRI
Journal of Hazardous Materials | Year: 2017

In the present work a novel heterogeneous cation exchange membrane (CEM) composed of poly vinyl chloride (PVC) and 2-acrylamido-2-methylpropane sulfonic acid based hydrogel (AMAH) was prepared. The membranes were fabricated with different fractions of AMAH to optimize the performance in desalination. The hydrogel was characterized by FT-IR to prove the successful synthesis. The membrane properties such as permselectivity, ionic permeability, flux, water content, electrical resistance, morphology, contact angle and dimensional stability were evaluated. Modified membranes showed acceptable dimensional stabilities, more hydrophilic surface, higher water content and porosity. SEM images revealed the formation of a more porous membrane structure. Membrane permselectivity and transport number showed a relatively constant then decreasing trend in Na+ and Ba2+ solutions. The experimental results showed that the incorporation of AMAH into the PVC matrix obviously improved ionic permeability and flux of Na (∼9%) and Ba (∼23%). Membrane electrical resistance was declined about 36% by adding AMAH in the membrane structure. Membranes’ performance in potassium and heavy metal ions removal showed a remarkable separation capacity of K+ (99.9%), Pb2+ (99.9%) and Ni2+ (96.9%). Membranes showed desirable potential for scaling removal. © 2017 Elsevier B.V.

Raeisi A.,Arak University | Faghihi K.,Arak University | Shabanian M.,Standard Research Institute SRI
Carbohydrate Polymers | Year: 2017

The easy migration of di(2-ethylhexyl) phthalate (DEHP) from the plasticized PVC (P-PVC) poses a serious threat to human health and the ecosystems. Thus, its control migration from the P-PVC products is very important. In this work, a poly(β-cyclodextrin-ester) network (β-CDP) was synthesized via reaction of β-cyclodextrin with 3,3′,4,4′-benzophenone tetracarboxylic dianhydride. As a potential inhibitor for reduction of the DEHP migration, the β-CDP was grafted to Fe3O4 nanoparticles. Poly(β-cyclodextrin-ester) functionalized Fe3O4 nanoparticles (MNP-CDP) has been used in PVC/DEHP system as a reactive nano-inhibitor to reduce DEHP migration. Thermal stability and mechanical properties of obtained films were investigated. DEHP migration tests of the P-PVC films were also carried out by using Gas chromatography. It was found that by incorporating the small amounts of nano-inhibitor in PVC/DEHP system, the migration of DEHP effectively reduced from the P-PVC samples about 65% without any serious changes in mechanical and thermal properties of the P-PVC films. © 2017 Elsevier Ltd

Kord B.,Standard Research Institute SRI | Roohani M.,Standard Research Institute SRI
Journal of Composite Materials | Year: 2017

The physical, mechanical, thermal, and flammability properties of high-density polyethylene/old corrugated container composites reinforced with carbon nanotubes are presented in this study. High-density polyethylene/old corrugated container composites with different loadings of carbon nanotube (0, 1, 3, and 5 phc) were prepared by melt compounding followed by injection molding. Results indicated that the incorporation of carbon nanotube into high-density polyethylene, significantly improved the mechanical properties of the composites. The tensile and flexural properties achieved the maximum values when 3 phc carbon nanotube was added. Meanwhile, the impact strength of the composites progressively decreased with increasing carbon nanotube content. Furthermore, the water absorption and thickness swelling of the samples remarkably reduced with the addition of carbon nanotube. From thermogravimetric analysis data, the presence of carbon nanotube could enhance the thermal stability of the composites, especially the maximum weight loss rate temperature and also the better char residual was obtained at high loading level of carbon nanotube. Simultaneous differential scanning calorimetry thermograms revealed that the thermal degradation temperatures for the samples with carbon nanotube were much higher than those made without carbon nanotube. Moreover, it was found that the addition of carbon nanotube results in a significant enhancement in flame retardancy of the composites. Morphological observations showed that the nanoparticles were predominantly dispersed uniformly within the high-density polyethylene matrix. © 2016, © The Author(s) 2016.

Kord B.,Standard Research Institute SRI | Roohani M.,Standard Research Institute SRI
Composites Part B: Engineering | Year: 2017

This study mainly focused on investigating the effect of carbon nanotubes (CNTs) on the long-term hygroscopic behavior of composites based on old corrugated container (OCC) and high density polyethylene (HDPE). Composite profiles were made by melt compounding and then injection molding. For CNT as a reinforcing agent, different loading levels of 0, 1, 3 and 5 phc was used. The amount of HDPE and coupling agent was fixed at 50 wt% and 2 phc for all formulations, respectively. The governing kinetic behavior of water transport in the studied composites was examined by immersing them in water at room temperature for several weeks, and water diffusion coefficients were also calculated by evaluating the water absorption isotherms. In addition, a predictive model for determining the thickness swelling rate of the samples was developed by Shi and Gardner model. Results indicated that the composites filled with CNT had considerably lower water absorption compared with those samples without ones. The absorption processes for all families of composites were found to exhibit Fickian diffusion behavior. It was found that that equilibrium thickness swelling and also shorter equilibrium time (the time to reach the equilibrium thickness swelling) decreased with increase of CNT loading. Furthermore, the swelling model provided a good predictor of the hygroscopic thickness swelling process of HDPE/OCC/CNT hybrid composites. Also, a good linear relationship was fit between swelling rate parameter (KSR) and CNT contents. The minimum KSR values were observed in composites made of 5 phc CNT. © 2017

Hajibeygi M.,Kharazmi University | Shabanian M.,Standard Research Institute SRI | Khonakdar H.A.,Islamic Azad University at Tehran
Applied Clay Science | Year: 2015

A new series of polyamide/Zn-Al layered double hydroxide (LDH) nanocomposites (PANC) was prepared by solution intercalation technique under ambient condition in dimethylformamide as solvent. The polyamide (PA) containing pyridine ring and imide group was synthesized using direct polycondensation reaction with good solubility and desired molar mass. Organo-modified Zn-Al LDH (OLDH) was produced by one-step method and used to improve mechanical, thermal and flame properties of PA. The extent of dispersion of OLDH sheets was quantified by X-ray diffraction (XRD) and transmission electron microscopy (TEM) and the results showed a good dispersion for OLDH in the PA matrix. According to the results of mechanical tests, the tensile strength and the Young's modulus of PANC enhanced with increasing OLDH content. Thermal properties of PANC were studied by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The thermal property results in both nitrogen and air atmospheres showed that the addition of OLDH resulted in a substantial increase in the thermal stability and char yields of PANC as compared to the neat PA. Significant improvements in flame retardancy performance were observed for PANC from microscale combustion calorimeter (MCC) (reducing both the heat release rate and the total heat released). © 2015 Elsevier B.V.

Aminifar M.,Standard Research Institute SRI | Emam-Djomeh Z.,University of Tehran
Journal of Agricultural Science and Technology | Year: 2014

In this study, the effect of addition of three different levels of microbial lipase (0, 4, and 8.0 g lipase in 100 kg milk) was investigated on the physiochemical properties, free fatty acids, textural properties, and microstructure of Lighvan cheese during ripening. The addition of lipase did not significantly affect pH, acidity, moisture, and salt content of Lighvan cheese, but increased its free fatty acid content considerably. It also increased hardness and decreased the brittleness of Lighvan cheese in all stages of ripening. The number and the mean diameter of fat globules, which were entrapped in casein network, were affected by all levels of the added lipase. Following the addition of lipase to Lighvan cheese and after 90 days of ripening, individual fat globules or their aggregates totally disappeared and some fingerprints of fat were observed. Disappearance of fat globules along with increase in protein matrix junctions leads to uniform structure of casein consisting voids which are produced from fermentation.

Yamini Y.,Tarbiat Modares University | Faraji M.,Standard Research Institute SRI
Journal of Pharmaceutical Analysis | Year: 2014

A simple, rapid and sensitive method termed as magnetic solid phase extraction (MSPE) combined with high-performance liquid chromatography- ultraviolet detector (HPLC-UV) has been proposed for the determination of trace amounts of chlorpromazine (CPZ) in water, urine and plasma samples. The separation and determination was performed on a C18 column under the optimal chromatographic conditions. Several factors influencing the extraction efficiency of CPZ, such as pH, surfactant and adsorbent amounts, ionic strength, extraction time, sample volume and desorption conditions, were studied and optimized. Under the optimal MSPE conditions, the extraction percentage of CPZ was 74%, 27% and 16% in water, urine and plasma samples, respectively. The limits of detection (LODs) of the proposed approach were 0.1, 5.0 and 10 ng/mL in water, urine and plasma samples, respectively. The relative standard deviations (RSDs) based on five replicate determinations at 10 ng/mL level of CPZ was 1.2%. Good linear behaviors over the investigated concentration ranges (0.25-300 ng/mL) with good coefficient of determination, R2>0. 9998, were obtained. Good spike recoveries with relative errors less than 9.0% were obtained when applying the proposed method to water, urine and plasma samples. © 2014 Xi'an Jiaotong University. Production and hosting by Elsevier B.V. All rights reserved.

Kord B.,Standard Research Institute SRI | Hosseinihashemi S.K.,Islamic Azad University at Karaj
Mechanics of Composite Materials | Year: 2014

The influence of fungal decay on the hygroscopic thickness swelling rate of lignocellulosic filler-polyolefin biocomposites has been investigated. Composites based on polypropylene (PP), bagasse fiber (BF), and a coupling agent (PP-g-MA) were made by melt compounding and injection molding. The weigt ratio of BF to PP was controlled at 60/40 for all blends. The amount of coupling agent was fixed at 2% for all formulations. The samples obtained were exposed to the action of brown-rot (Coniophora puteana) and white-rot (Trametes versicolor) fungi for 8, 12, and 16 weeks according to the Kolle-flask method. The thickness swelling of the samples was evaluated by immersing them in water at room temperature for several weeks. The morphology of the composites was characterized using the scanning electron microscopy (SEM). The results indicated that the fungal decay had an adverse affect on the dimensional stability of BF/PP composites due to an increase in the thickness swelling rate. The thickness swelling of white-rotted samples was higher than that of brown-rotted ones and control samples. Also, the thickness swelling of BF/PP composites increased with increasing time of fungal decay. In addition, after 16 weeks of exposure to white-rot fungi, the composites exhibited a higher parameter of swelling rate K SR than control samples. The K SR of the composites was influenced both by the type of rooting and the exposure time. Furthermore, the SEM micrographs showed that the extent of degradation increased with growing exposure time to fungi. © 2013 Springer Science+Business Media New York.

Hafezi B.,Standard Research Institute SRI | Majidi M.R.,University of Tabriz
Analytical Methods | Year: 2013

A fast, sensitive and accurate electrochemical sensor based on copper nanostructures for electrocatalytic determination of nitrate has been developed. Cyclic voltammetry and hydrodynamic amperometry were employed to characterize the response of the sensor to nitrate that changes linearly in the concentration range from 1 to 35 μM. The repeatability of measurements for nitrate was evaluated as 2.3% (N = 15) and the limit of detection of the method was found to be 0.59 μM (S/N = 3). The content of nitrate in foodstuffs and mineral water samples was determined by the proposed and the reference method based on Griess protocol at the 95% confidence level. No interferences were observed from nitrite ions on the nitrate analysis. The interference from chloride ions was also examined. © 2013 The Royal Society of Chemistry.

A green, convenient and efficient procedure is reported for the synthesis of S-aryl dithiocarbamates by a simple one-pot three component Ullmann-type condensation of an amine, carbon disulfide and an aryl iodide. Magnetically separable and reusable copper oxide (Fe3O4-CuO) nanoparticles are used as a heterogeneous catalyst under base- and solvent-free conditions. Nanoparticles with an average size of 10-20 nm has been successfully prepared by a simple precipitation method in aqueous medium from readily available inexpensive starting materials. The catalyst could be easily separated from the reaction mixture by using an external magnet and recycled four times without significant loss in its activity. © 2016 The Royal Society of Chemistry.

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