Separation Technology,
R. Bakhshi; M. Moraveji; A. Parvareh
Abstract
The polysulfone mixed matrix membranes (MMM) with different concentrations of graphene oxide (0, 0.25, 0.5 wt % of the polymer) are fabricated by a phase separation method. The cross-sectional structures and their upper surface were assessed by the (SEM) surface roughness of the membranes assessed by ...
Read More
The polysulfone mixed matrix membranes (MMM) with different concentrations of graphene oxide (0, 0.25, 0.5 wt % of the polymer) are fabricated by a phase separation method. The cross-sectional structures and their upper surface were assessed by the (SEM) surface roughness of the membranes assessed by (AFM). The mechanical and thermal stability of the fabricated membranes were evaluated as well. The separation of Carbon dioxide, nitrogen and methane from natural gas was considered. Also, by increasing the concentration of graphene oxide in the polymer matrix, the thickness of the spongy structure increases and the holes of the finger-like membranes are also destroyed. From the cross-sectional images of the outer surface of the MMM, it was concluded that an active selector layer was created on the lower surface of the membrane. The membrane tensile strength and the length of the membrane at fracture point increased slightly with an increase in the concentration of graphene oxide. Transition Glass temperature of the membrane increased by the addition of graphene oxide to the structure. From TGA analysis, in the presence of graphene oxide, the thermal stability improved. From the gas permeation test, by the addition of 0.25 % of graphene oxide to the polymer, CO2 permeability was increased from 61.22 GPU to 76.04 GPU, while the addition of 0.5 wt % resulted in a lower permeability (69.55 GPU). The Nitrogen gas permeation flux of membranes decreased from 10.93 GPU to 3.91 GPU by the addition of 0.50 wt % of graphene oxide. The Methane gas permeation flux is reduced from 11.31 GPU to 6.95 GPU and 4.92 GPU by the addition of 0.25 % and 0.50 % of graphene oxide respectively. In conclusion, an increase in the concentration of graphene oxide increased the carbon dioxide selectivity.
Biomedical and Biotechnology,
Y. Beygi-Khosrowshahi; S. Zakhireh
Abstract
Bone tissue engineering requires approaches to provide a suppression/promotion environment for the bone growth. Scaffold biomaterials have profound regulatory effects on the functionality of mesenchymal stem cells (MSCs). In the present study, the three-component bioceramic of selenium/reduced graphene ...
Read More
Bone tissue engineering requires approaches to provide a suppression/promotion environment for the bone growth. Scaffold biomaterials have profound regulatory effects on the functionality of mesenchymal stem cells (MSCs). In the present study, the three-component bioceramic of selenium/reduced graphene oxide/hydroxyapatite (Se/RGO/HA) was developed and its performance to repair bone defects was compared to that of HA. The Se/RGO/HA nanocomposite scaffold was synthesized using the chemical bath technique, characterized by the X-ray diffraction spectra, field emission scanning electron microscopy, energy dispersion X-ray spectrometery, and Fourier transform infrared spectroscopy analyses. Human adipose-derived MSCs (hAD-MSCs) were used to investigate the in-vitro osteogenic properties of the Se/RGO/HA scaffold. The effect of the combined scaffold on the cell proliferation was analyzed by the MTT assay. Cell adhesion behaviors were evaluated using the optical microscopy and SEM. The osteogenic properties of the Se/RGO/HA scaffold were examined by the measurement of the alkaline phosphatase (ALP) activity and western blotting technique. The hAD-MSCs proliferation for HA and the Se/RGO/HA nanocomposite were 2 ± 0.1 and 1.1 ± 0.05 respectively. The Se/RGO/HA nanocomposite had cytotoxic effects on the KHOS-240S cancer cells. Additionally, good cell attachment and osteoblast-like morphology were characterized on the designed scaffold. The ALP activity and mineralization potential of cells seeded on Se/RGO/HA were higher than those seeded on HA. The Osteocalsin protein for Se/RGO/HA and HA were 64 ± 1 and 12 ± 0.1 respectively. Furthermore, the expression of Osteocalcin, a bone-specific protein, was synergistically increased by the incorporation of Se and RGO into HA. In conclusion, the presence of RGO inside Se could significantly increase the positive effects of HA on the osteogenic potential of hAD-MSCs.
Polymer Engineering and Technology,
F. Ader; E. Sharifzadeh
Abstract
In this study, the main purpose has been to investigate the behavior of the nanoparticles with different structures and similar based materials in polymer nanocomposites. To this end, different samples, containing PS as the matrix, and layered graphene oxide (GO) and/or hollow graphene oxide nanoparticles ...
Read More
In this study, the main purpose has been to investigate the behavior of the nanoparticles with different structures and similar based materials in polymer nanocomposites. To this end, different samples, containing PS as the matrix, and layered graphene oxide (GO) and/or hollow graphene oxide nanoparticles (HGO), were prepared via the melt mixing process and were subjected to heat conduction and tensile tests. To evaluate all features of the interaction between the polymer phase and the nanoparticles, a thermal/mechanical analytical model was proposed and the results were used to simulate the behavior of specific geometrical structures, corresponding to the real samples, under different thermal/mechanical conditions. The results showed good agreement between the obtained experimental data and simulation/analytical model interpretations. In addition, it was found that the HGO nanoparticle had such a good performance in enhancing the thermal and mechanical properties of the nanocomposite, due to its unique structure.
Materials synthesize and production
A. jafarizad; H. Hazrati; A.M. Jabbari
Volume 16, Issue 2 , June 2019, , Pages 95-102
Abstract
In this work, for eliminating the (RR1346), considered to be a waste in wastewater from dye industries electrochemical advanced oxidation process has been used. Graphene oxide coated carbon cloth (GO/CC) and Fe3O4 /GO coated carbon cloth (Fe3O4/GO/CC) electrodes has been fabricated by synthesized GO ...
Read More
In this work, for eliminating the (RR1346), considered to be a waste in wastewater from dye industries electrochemical advanced oxidation process has been used. Graphene oxide coated carbon cloth (GO/CC) and Fe3O4 /GO coated carbon cloth (Fe3O4/GO/CC) electrodes has been fabricated by synthesized GO and Fe3O4 nanoparticles. Characteristic properties such as surface morphology as the main reason of utilizing Fe2O3/GO/CC as electrodes has been investigated determined by various instrumental analysis including, Atomic Force Microscopy (AFM), Field Emission Scanning Electron Microscopy (FESEM), Cyclic Voltammetry (CV), Cathodic polarization, and also for investigating the process yield by utilization of mentioned electrodes, UV-vis spectrophotometric analysis has been used to determine dye concentration in sample waste water, after comparing fabricated electrodes removal efficiency in same time intervals, by determining the concentration of RR1346 dye in samples after oxidation process in different time intervals, results indicated better removal efficiency Fe3O4/GO/CC fabricated electrode than the other two electrodes, which this conclusion was proved by AFM,FESEM and UV-vis results.