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Papers by Khaled Mezghani

Journal of Polymer Engineering, 2001

In this study we have investigated the effects of mixing parameters on the extent and structural ... more In this study we have investigated the effects of mixing parameters on the extent and structural morphology of the nanoclay dispersion and distribution in the epoxy matrix. Two mixing methods namely, sonication mixing and high shear mixing were used to disperse organically modified Nanomer I.30E nanoclay within Diglycidyl ether of Bisphenol A (DGEBA) epoxy resin. Mixing by sonication was performed for periods ranging from 5 to 60 minutes, whereas high shear mixing (HSM) was performed at mixing speeds ranging from 500 to 8000 rpm and mixing durations of 15 to 90 minutes. Differential Scanning Calorimetry (DSC), X-ray diffraction (XRD) and Scanning Electron Microscope (SEM) techniques were employed to examine the effects of sonication time and HSM speed and time on the extent of dispersion and structural morphology of the nanocomposite. The results show that under the same optimal curing conditions, the mixing parameters play a significant role in determining the degree and structural...

RSC Adv.

Graphene oxide/MIL-100(Fe) composites synthesized using covalent chemistry present an attractive ... more Graphene oxide/MIL-100(Fe) composites synthesized using covalent chemistry present an attractive strategy to develop adsorbents with high uptakes as well as heat transfer rates.

For decreasing greenhouse gas (mainly CO2) emissions, several approaches have been evaluated and ... more For decreasing greenhouse gas (mainly CO2) emissions, several approaches have been evaluated and reviewed for capturing CO2 in the utility industry, namely Carbon Capture and Storage technology (CCS). As a promising CCS technology, oxy-fuel combustion can be used in existing and new power plants. There are two main approaches available to utilize the oxy-combustion technology, one of them is the use of air separation units to separate O2 which can be used in the combustion process in any conventional combustion system auch as gas turbine. The other approach is the application of oxyfuel combustion in ion transport membrane (ITM) reactors. The objective of this work is to study in details the above mentioned two approaches for applications of oxy-fuel combustion technology.

Energy, 2015

A combined experimental and numerical study is performed on a button-cell LNO-ITM reactor. A semi... more A combined experimental and numerical study is performed on a button-cell LNO-ITM reactor. A semi-empirical model for oxygen permeation is considered, ABn model, and the values of the empirical constants are calculated based on the fitting of the available experimental data in the literature. A validation study for the present model is performed using the present experimental data. A detailed numerical study is presented on an LNO-ITM button-cell reactor under oxy-fuel combustion conditions. CH4 is used as the working fuel forming a mixture with CO2 at the permeate side inlet. The model results showed reasonable agreements under different operating conditions. The effect of reactivity in the permeate side of the membrane on oxygen permeation flux is considered. It is found that the oxygen permeation flux is increased by about 50% for the case of reacting flow as compared to the case of non-reacting flow. Distinct behavior of oxygen permeation flux values through the present button-cell ITM reactor is encountered while varying the operating conditions as compared to other reactors in the literature. This may be attributed to the complicated design of the flow path close to the membrane surface which maximizes the effects of flow momentum on the oxygen flux.

A co-rotating twin screw extruder with 3 zones of mixing elements was used to produce nanocomposi... more A co-rotating twin screw extruder with 3 zones of mixing elements was used to produce nanocomposite fibers of polyethylene terapthalate (PET) and carbon nanotubes. The PET and the CNT materials were fed using two separately controlled feeders. The polymer was fed at the first entrance to the extruder; whereas, the CNT was fed at three different positions located along the extruder barrel. The results showed that an addition of 1 wt% CNT enhanced the mechanical properties of PET/CNT nanocomposite fibers. The yield strength, tensile strength, and toughness were increased by 80%, 51%, and 134%, respectively, in contrast to the mechanical properties of pristine PET fibers. The scanning electron microscope (SEM) images showed that the feeding position with three mixing zones gives the most uniform distribution of CNT and the best spinnability of the PET/CNT fibers.

ABSTRACT Reasonably high oxygen permeation fluxes, similar to 4 x 10(-2) mu mol.cm(-2).s(-1), wer... more ABSTRACT Reasonably high oxygen permeation fluxes, similar to 4 x 10(-2) mu mol.cm(-2).s(-1), were obtained from surface decoration with La0.8Sr0.2CoO3-delta (LSC113) or LaSrCoO4 +/-delta (LSC214) on La0.8Sr0.2Ga0.8Mg0.115Co0.085O3-delta (LSGMC) and Ce0.8Sm0.2O2-delta (SDC) membranes at 700 degrees C. Promoting surface exchange kinetics at the feed side of LSGMC and SDC membranes, which was found rate-limiting, is needed to further enhance oxygen permeation of these membranes. This work demonstrates the possibility of reducing the amount of noble metal usage for membranes based on the concept of short-circuited ion conductors and shows promise for the development of noble-metal-free permeation membranes.

Advanced Materials Research, 2013

Epoxy-clay nanocomposites were prepared by high shear mixing method using Nanomer I.30E nanoclay ... more Epoxy-clay nanocomposites were prepared by high shear mixing method using Nanomer I.30E nanoclay as nano-reinforcement in diglycidyl ether of bisphenol A (DGEBA). The effect of mixing speed and time on the nature and degree of clay dispersion were investigated by varying the mixing speed in the range of 500-8000 RPM and mixing time in the range of 15-90 minutes. The effect of degassing temperature on the morphology of the resultant nanocomposites was also studied. Scanning and transmission microscopy (SEM & TEM) along with x-ray diffraction (XRD) have been used to characterize the effect of shear mixing speed, mixing time and degassing temperature on the structure of the resultant nanocomposites. The SEM, TEM and XRD examinations demonstrated that the degree of clay dispersion was improved with increasing the high shear mixing speed and mixing time. The results showed that the optimum high shear mixing speed and mixing time were 6000 rpm and 60 min, respectively. It was observed tha...

Key Engineering Materials, 2011

Epoxy resin is one of the most applied thermoset polymers as a matrix for Glass Fiber Reinforced ... more Epoxy resin is one of the most applied thermoset polymers as a matrix for Glass Fiber Reinforced Pipes (GFRP). Curing process of epoxy resin is important for the integrity of the GFRP. The present work has been conducted to determine the proper pre-curing and post-curing temperatures and duration to develop epoxy-clay nanocomposite. During this study a differential scanning calorimeter (DSC) was used to determine the glass transition temperature and hence the degree of curing. Several samples of epoxy were prepared at different pre-curing and post-curing temperatures and durations. Pre-curing temperatures ranging from 80 to 150°C and post-curing temperatures ranging from 150 to 200°C were studied. The results show that the optimum pre-curing and post-curing temperatures are 100 and 170°C, respectively. Regarding the effect of curing duration, several specimens were prepared at the same pre-curing and post-curing temperatures with different curing durations of 1, 2, and 3 hours. It w...

International Polymer Processing, 2012

In the present study, blown films of h-LLDPE, LDPE, and their blends were produced using a twin s... more In the present study, blown films of h-LLDPE, LDPE, and their blends were produced using a twin screw extruder. The tear properties of all films were determined in the machine direction (MD) and the transverse direction (TD). On one hand, similar values of the MD tear-resistance for the two virgin polymers, h-LLDPE and LDPE, were measured to be 100 and 120 kN/m, respectively. On the other hand, the TD tear-resistance value of h-LLDPE was 180 kN/m, four times higher than that of LDPE, 45 kN/m. It was observed that small additions of LDPE (5 to 20 wt.%) to h-LLDPE produced blends with better TD tear-resistance films, 400 kN/m. The main reason for this large increase in tear-resistance was attributed to the morphological changes induced by the addition of the LDPE polymer, as shown by SEM, FTIR, and birefringence techniques.

... A particular focus will be placed on oxy-combustion in a subsequent section. ... They estimat... more ... A particular focus will be placed on oxy-combustion in a subsequent section. ... They estimated the emissions from natural gas com-bined cycle (CC) and pulverized coal plants, equipped ... turbine power plants, namely (1) post-combustion separation of CO2 from exhaust gas of a ...

Journal of Thermoplastic Composite Materials, May 1, 2012

Multi-walled carbon nanotubes (CNTs) were functionalized on treatment with nitric acid and the su... more Multi-walled carbon nanotubes (CNTs) were functionalized on treatment with nitric acid and the surface-modified CNT was characterized using Fourier transform infrared spectroscopy (FTIR). Isotactic polypropylene (iPP)/CNT composites at different CNT loadings (ie, 0.1, 0.25, 1.00, and 5.00 wt%) were prepared by melt blending in a mini blender. The differential scanning calorimetric (DSC) studies showed the nucleating effect of CNTs on the crystallization behavior of iPP. Results of X-ray diffraction studies are in ...

Journal of the Electrochemical Society, 2013

Journal of Plastic Film and Sheeting, 2012

Ceramics International, 2015