Papers by Morteza Sadeghi
The effect of TiO 2 nanoparticles on the gas separation properties of polyurethane has been inves... more The effect of TiO 2 nanoparticles on the gas separation properties of polyurethane has been investigated. Polyurethane was synthesized using hexamethylene diisocyanate (HDI) and 1,4-butanediol (BDO) as hard segment and poly(tetramethylene glycol) (PTMG, 2,000 g/mol) as soft segment. The synthesized polymer was in a 1 : 2 : 1 molar ratio of polyol : diisocyanate : chain extender through bulk two-step polymerization. PU membranes were prepared by thermal phase inversion method. Scanning electron microscopy (SEM), X-ray diffraction and Fourier Transform Infrared (FTIR) analyses characterized the prepared membranes. FTIR and SEM results indicate the good interaction between particles and polymer matrix and also the nanoscale dispersion of TiO 2 particles in polymer matrix. Gas permeation properties of PU-TiO 2 nanocomposite membranes with TiO 2 contents up to 30 wt% were studied for N 2 , O 2 , CH 4 and CO 2 gases at 10 bar and 25 o C. Results suggest a decrease in permeability of studied gases and increase in gas selectivities as TiO 2 content increases.
Iranica Journal of Energy and Environment, 2013
n this research, the effect of fiber surface treatment and matrix modification on interfacial she... more n this research, the effect of fiber surface treatment and matrix modification on interfacial shear strength (IFSS) was investigated. In this study, ultra-high-molecular-weight polyethylene (UHMWPE) fibers were treated with chemical grafting of glycidyl methacrylate (GMA). The 5 % GMA was grafted on the surface of UHMWPE fibers and the epoxy matrix was modified by addition of functionalized nonoporous MCM-41 particles simultaneously. A series of epoxy matrixes with different loadings of these particles consisting 0.35, 0.7 and 1 wt% were prepared. Microbond tests were carried out to evaluate the effect of fiber and matrix modification on interfacial shear strength. The result of microbond measurements showed that the nanocomposite with 0.35 wt.% concentration of functionalized nano porous MCM-41 particles has the highest interfacial shear strength (IFSS) among these mentioned concentrations.
Korean Journal of Chemical Engineering, 2014
The effect of TiO 2 nanoparticles on the gas separation properties of polyurethane has been inves... more The effect of TiO 2 nanoparticles on the gas separation properties of polyurethane has been investigated. Polyurethane was synthesized using hexamethylene diisocyanate (HDI) and 1,4-butanediol (BDO) as hard segment and poly(tetramethylene glycol) (PTMG, 2,000 g/mol) as soft segment. The synthesized polymer was in a 1 : 2 : 1 molar ratio of polyol : diisocyanate : chain extender through bulk two-step polymerization. PU membranes were prepared by thermal phase inversion method. Scanning electron microscopy (SEM), X-ray diffraction and Fourier Transform Infrared (FTIR) analyses characterized the prepared membranes. FTIR and SEM results indicate the good interaction between particles and polymer matrix and also the nanoscale dispersion of TiO 2 particles in polymer matrix. Gas permeation properties of PU-TiO 2 nanocomposite membranes with TiO 2 contents up to 30 wt% were studied for N 2 , O 2 , CH 4 and CO 2 gases at 10 bar and 25 o C. Results suggest a decrease in permeability of studied gases and increase in gas selectivities as TiO 2 content increases.
Separation and Purification Technology, 2015
In this research, the effects of Zeolite 4Å and ZSM-5 on the separation of C 2 H 6 and C 3 H 8 fr... more In this research, the effects of Zeolite 4Å and ZSM-5 on the separation of C 2 H 6 and C 3 H 8 from CH 4 through polyurethane/zeolite mixed matrix membranes (MMM) are evaluated. Physical properties of synthesized polyurethane and polyurethane/zeolite MMM were investigated by FTIR, XRD, TGA and SEM analyses. Results indicate that phase separation of hard and soft segments in polyurethane would be increased by adding butanediamine (BDA) chain extender in polymer due to the generation of more hydrogen bonds between hard segment domains. The obtained SEM micrographs confirm that the Zeolite is distributed in the polymer matrix homogenously. The results of gas permeation represent that permeability and selectivity of Hydrocarbons are increased by increasing the urea groups in the polymer structure. Moreover, the obtained results of gas permeation of polyurethane-zeolite (4Å) membranes indicate an increase in the permeability of Methane, with the reduction in C 2 H 6 /CH 4 and C 3 H 8 /CH 4 selectivity by increasing the Zeolite 4Å up to 10 wt%. In addition, the results of the gas permeation of polyurethanezeolite (ZSM-5) MMM indicate a significant increment in permeability and selectivity of all Hydrocarbons. The permeability of Propane and its selectivity over Methane is increased from 64.8 Barrer and 2.6 into 117.2 Barrer and 3.64 in with 20 wt% filled PU-ZSM 5 MMM, respectively.
Sensing and Imaging: An International Journal, 2011
Page 1. ORIGINAL PAPER Pull-in Voltage of Electrostatically-Actuated Microbeams in Terms of Lumpe... more Page 1. ORIGINAL PAPER Pull-in Voltage of Electrostatically-Actuated Microbeams in Terms of Lumped Model Pull-in Voltage Using Novel Design Corrective Coefficients Ghader Rezazadeh Mohammad Fathalilou Morteza Sadeghi ...
Korean Journal of Chemical Engineering, 2014
ABSTRACT Researchers have focused on improving the performance of polymeric membranes through var... more ABSTRACT Researchers have focused on improving the performance of polymeric membranes through various methods, such as adding inorganic nanoparticles into the matrix of the membranes. In the present study, the separation of oxygen, nitrogen, methane and carbon dioxide gases by PVC/silica nanocomposite membranes was investigated. Silica nano-particles were prepared via sol-gel method. Membranes were prepared by thermal phase inversion method and characterized using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and thermal gravimetry (TGA) analyses. The FTIR and SEM analyses demonstrated a nano-scale dispersion and good distribution of silica particles in the polymer matrix. According to TGA results, thermal properties of PVC membranes were improved and DSC analysis showed that glass transition temperature of nanocomposite membranes increased by adding silica particles. We concluded that the permeability of carbon dioxide and oxygen increased significantly (about two times) in the composite PVC/silica membrane (containing 30 wt% silica particles), while that of nitrogen and methane increased only 40 to 60 percent. Introducing 30 wt% silica nanoparticles into the PVC matrix, increased the selectivity of CO2/CH4 and CO2 /N2 from 15.9 and 21 to 18.2 and 27.3, respectively. The diffusion and solubility coefficients were determined by the time lag method. Increasing the silica mass fraction in the membrane increased the diffusion coefficients of gases considered in the current study.
Advanced Materials Research, 2009
Desalination, 2014
Heavy metal removal from drinking water with a nanofiltration membrane was studied.
Separation and Purification Technology, 2008
The gas separation properties of ethylene vinyl acetate (EVA) membranes containing 18 and 28 wt% ... more The gas separation properties of ethylene vinyl acetate (EVA) membranes containing 18 and 28 wt% of vinyl acetate (VA) were investigated in this study. The effects of membrane preparation conditions, such as thermal and thermal/wet phase inversion, and the type of solvent on the gas separation properties of EVA membranes were investigated. The permeation of pure O 2 , N 2 , CH 4 , and CO 2 gases at different feed pressures ranging from 2 to 11 bar were examined.
Macromolecular Chemistry and Physics, 2013
A new model for prediction of the effective permeability of gases in mixed matrix membranes (MMMs... more A new model for prediction of the effective permeability of gases in mixed matrix membranes (MMMs), considering the effects of particle shape and the interfacial layer, is presented. The proposed model treats core fi ller particles and interfacial shell layers as complex particles. Moreover, the Bruggman mathematical procedure is used to improve the accuracy of the presented model for high concentrations of fi llers in MMMs. Also, an appropriate uniform criterion is established to make effi cient use of the new model for various experimental data to avoid the need for curve-fi tting procedures. Finally, the proposed model is examined for several sets of experimental data.
Journal of Polymer Research, 2012
The diffusion and permeation of sulfuric, perchloric, and phosphoric acids through the polybenzim... more The diffusion and permeation of sulfuric, perchloric, and phosphoric acids through the polybenzimidazole (PBI) membrane were evaluated by using the timelag method. The results showed that the permeation of these acids in the polymeric film is due to normal Fickian diffusion. Increasing the acidity and concentration of each inorganic acid upstream increased the diffusion coefficients. Permeation results confirmed that the dual-mobility model was applicable. The dual-mobility model constants were found by using a least square program via fitting experimental data to dual-mobility equation. The results have indicated that the partial immobilization of Langmuir sorption coefficient, F, decreases with molecular size of acids. Besides, the diffusion coefficient of acid molecules in Henry's law, D D , increases with increasing acidity of the acids studied. Comparison of permeability coefficients of acids in PBI membrane indicates that permeability increases with acidity. Therefore, diffusion is considered the dominant factor in this transport mechanism.
Journal of Polymer Research, 2013
In this study, the effects of various solvents on the structure and permeation properties of poly... more In this study, the effects of various solvents on the structure and permeation properties of polysulfone-silica nanocomposite membranes were investigated. Silica nanoparticles were prepared by the sol-gel method through the hydrolysis and condensation of tetraethyl orthosilicate (TEOS). Polysulfone-silica nanocomposite membranes were prepared by the thermal phase inversion method. N-methyl pyrrolidone (NMP), N,N-dimethyl acetamide (DMAc) and tetrahydrofuran (THF) were used as solvents. Based on the experimental results, it was observed that the CO 2 /N 2 and O 2 / N 2 selectivities increased in the presence of silica nanoparticles in all cases. However, the permeabilities of the applied gases decreased, except for CO 2 . Based on the obtained selectivity data, permeability data, and favorable dispersion of silica nanoparticles in the polymer matrix, the results indicate that NMP is the best solvent for polysulfone-silica membrane preparation. The obtained CO 2 permeability and CO 2 /N 2 selectivity of the polysulfone-silica (5 wt%) membrane prepared using NMP as the solvent were 7 barrers and 35, respectively.
Journal of Membrane Science, 2011
This work presents the structural properties of gas permeation of a group of polyurethane membran... more This work presents the structural properties of gas permeation of a group of polyurethane membranes. All polymers were synthesized using a 1:3:2 molar ratio of polyol:diisocyanate:chain extender. The obtained results from Fourier transform infrared spectrometer (FT-IR) of polymers indicate that by changing the diisocyanate from aromatic to linear aliphatic, the microphase separation of hard and soft segments increases. Study of the differential scanning calorimetery (DSC) and X-ray diffraction (WAXD) patterns confirmed that PTMG and PCL polyols can be arranged in small crystalline structures. Furthermore, a hard ordered segment in crystal phase could be obtained, owing to the high phase separation of the polymer based on HDI. Permeation measurements of polymers revealed that the permeability of gases increases with microphase separation in polymer and selectivity of gases drops down. Polymers based on PPG showed the highest phase separation and permeability. The obtained results revealed more phase mixing of the polymer based on DMPA chain extender in comparison to BDO, which lead to lower permeability and higher selectivity. The solubility and diffusivity of gases indicate solubility domination of gas transport in these membranes. The observed solubility domination increases by phase separation. The results of permeability tests indicate high permeability, up to 186 Barrer (1 Barrer = 1 × 10 −10 [cm 3 (STP) cm/cm 2 s cmHg]), and high selectivity for carbon dioxide with respect to nitrogen (CO 2 /N 2 : 45). Our data sheds light on gas permeation properties of polyurethane membranes.
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Papers by Morteza Sadeghi