mohammad shahadat | King AbdulAziz University (KAU) Jeddah, Saudi Arabia (original) (raw)

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Papers by mohammad shahadat

Journal of Developing Areas, 2011

... Volume 45, Single Issue, Fall 2011. E-ISSN: 1548-2278 Print ISSN: 0022-037X. Estimating an Et... more ... Volume 45, Single Issue, Fall 2011. E-ISSN: 1548-2278 Print ISSN: 0022-037X. Estimating an Ethical Index of Human Wellbeing. Masudul Alam Choudhury Sultan Qaboos University, Oman. Mohammad Zakir Hossain Sultan Qaboos University, Oman. ...

Chemical Engineering Journal, 2011

A new amorphous composite cation exchange material has been synthesized at pH 1.0 by sol-gel meth... more A new amorphous composite cation exchange material has been synthesized at pH 1.0 by sol-gel method. The experimental parameters such as mixing volume ratio, concentration and pH were established for the synthesis of the material. Exchange capacity of the composite material was determined for alkali and alkaline earth metals. The exchanger was characterized on the basis of FTIR, XRD, SEM, TGA and CHNO analysis. This composite material exhibits improved ion-exchange capacity, chemical and thermal stability. It can withstand up to 300 • C with 98% of initial ion-exchange capacity retained. The distribution coefficient studies of metal ions on the composite material were performed in non-ionic, cationic and anionic surfactants systems of varying concentrations. On the basis of distribution coefficient values, the material was found to be selective for Pb(II), Hg(II), Bi(III) and Zr(IV) ions. The limit of detection (LOD) and the limit of quantification (LOQ) for Pb(II) metal ion was found to be 0.85 and 2.85 g L −1 . Some analytically important, selective separations of metal ions have been successfully applied for the analysis of industrial effluent and natural water on the columns of this exchanger.

Chemical Engineering Journal

A semi-crystalline stable composite cation exchange adsorbent for the treatment of heavy metal io... more A semi-crystalline stable composite cation exchange adsorbent for the treatment of heavy metal ions has been synthesized at pH 1.0 by sol-gel method which was characterized by FTIR, XRD, SEM, TGA and TEM analysis. Ion exchange capacity, pH titration, elution behavior and distribution studies were also carried out to determine the primary ion-exchange characteristics of the material. The material shows exchange capacity of 1.47 meq g − 1 (for Na + ions). The composite material exhibits improved ion-exchange capacity, chemical and thermal stability. It can be used up to 200°C with 88% retention of initial ion-exchange capacity. pH titration data reveal its bifunctional behavior. The distribution coefficient values (K d ) of metal ions have been determined in various solvent systems. On the basis of K d values the material was selective for Ba(II), Hg(II), and Pb(II) ions. The limit of detection (LOD) and the limit of quantification (LOQ) for Pb(II) was found to be 0.97 and 2.93 μg L − 1 , respectively. A number of important and analytically difficult quantitative separations of metal ions have been achieved using columns packed with this exchanger. The composite cation exchanger is applied for the treatment of sewage water and synthetic mixture successfully and can be used as a conducting material.

Colloids and Surfaces B-biointerfaces, 2011

Polymer nanocomposites (NSPANI/AuNP/GR) based on nanostructured polyaniline, gold nanoparticles (... more Polymer nanocomposites (NSPANI/AuNP/GR) based on nanostructured polyaniline, gold nanoparticles (AuNP) and graphene nanosheets (GR) have been synthesized using in situ polymerization. A series of nanocomposites have been synthesized by varying the concentration of GR and chloroauric acid to optimize the formulation with respect to the electrochemical activities. Out of these series of NSPANI/AuNP/GR nanocomposites, it has been found that only one particular nanocomposite has the best electrochemical properties, as analyzed by cyclic voltammetry (CV) and differential pulse voltammetry and conductivity. The best nanocomposite has been characterized by Fourier transform infrared Raman spectroscopy, UV-vis spectroscopy, X-ray diffraction studies, transmission electron microscopy, scanning electron microscopy and atomic force microscopy. The CV of the best nanocomposites show the well-defined reversible redox peaks characteristic of polyaniline, confirming that the polymer maintains its electro activity in the nanocomposites. Another nanocomposite has been prepared with identical composition (as found with the best nanocomposite) by mixing of presynthesized nanostructured polyaniline with chloroauric acid and graphene dispersion in order to predict the mechanism of in situ polymerization. It is inferred that the nanocomposite prepared by blending technique loses its property within 48 h indicating phase separation whereas the nanocomposite prepared by in situ technique is highly stable.

Chemical Engineering Journal, 2011

Polyaniline-carboxylic acid functionalized multi-walled carbon nanotube (PAni/c-MWNT) nanocomposi... more Polyaniline-carboxylic acid functionalized multi-walled carbon nanotube (PAni/c-MWNT) nanocomposites were prepared in sodium dodecyl sulfate (SDS) emulsion. First, the c-MWNTs were dispersed in SDS emulsion then the aniline was polymerized by the addition of ammonium persulfate in the absence of any added acid. SDS forms the functionalized counterion in the resulting nanocomposites. The content of c-MWNTs in the nanocomposites varied from 0 to 20 wt%. A uniform coating of PAni was observed on the c-MWNTs by field-emission scanning electron microscopy (FESEM). The PAni/c-MWNT nanocomposites have been characterized by different spectroscopic methods such as UV-Visible, FT-Raman, and FT-IR. The UV-Visible spectra of the PAni/c-MWNT nanocomposites exhibited an additional band at around 460 nm, which implies the induced doping of the MWNTs by the carboxyl group. The FT-IR spectra of the PAni/c-MWNT nanocomposites showed an inverse intensity ratio of the bands at 1562 and 1480 cm S1 as compared to that of pure PAni, which reveals that the PAni in the nanocomposites is richer in quinoid units than the pure PAni. The increase in the thermal stability of conductivity of the nanocomposites was due to the network structure of nanotubes and the charge transfer between the quinoid rings of the PAni and the c-MWNTs.

Toxicological & Environmental Chemistry, 2012

A heteropolyacid Zr(IV) tungstate-based cation exchanger has been synthesized. An amorphous sampl... more A heteropolyacid Zr(IV) tungstate-based cation exchanger has been synthesized. An amorphous sample, prepared at pH 1.2 and having a Na+ ion exchange capacity of 0.92 meq g−1, was selected for further studies. Its physicochemical properties were determined using Fourier transform infrared spectrometer, X-ray diffraction, thermogravimetric, and scanning electron studies. To understand the cation exchange behavior of the material, distribution coefficients (K d) for metal ions in various solvent systems were determined. Some important binary separations of metal ions, namely Mg2+–Bi3+, Cd2+–Bi3+, Fe3+–Bi3+, Th4+–Bi3+, and Fe3+–Zn2+, were achieved on such columns. The practical utility of these separations was demonstrated by separating Fe3+ and Zn2+ ions quantitatively in commercial pharmaceutical formulation. The cation exchanger has been successfully applied also for the treatment of industrial wastewater and a synthetic mixture. All the results suggests that Zr(IV) tungstate has excellent potential for the removal of metals from aqueous systems using packed columns of this material.

Journal of Developing Areas, 2011

... Volume 45, Single Issue, Fall 2011. E-ISSN: 1548-2278 Print ISSN: 0022-037X. Estimating an Et... more ... Volume 45, Single Issue, Fall 2011. E-ISSN: 1548-2278 Print ISSN: 0022-037X. Estimating an Ethical Index of Human Wellbeing. Masudul Alam Choudhury Sultan Qaboos University, Oman. Mohammad Zakir Hossain Sultan Qaboos University, Oman. ...

Chemical Engineering Journal, 2011

A new amorphous composite cation exchange material has been synthesized at pH 1.0 by sol-gel meth... more A new amorphous composite cation exchange material has been synthesized at pH 1.0 by sol-gel method. The experimental parameters such as mixing volume ratio, concentration and pH were established for the synthesis of the material. Exchange capacity of the composite material was determined for alkali and alkaline earth metals. The exchanger was characterized on the basis of FTIR, XRD, SEM, TGA and CHNO analysis. This composite material exhibits improved ion-exchange capacity, chemical and thermal stability. It can withstand up to 300 • C with 98% of initial ion-exchange capacity retained. The distribution coefficient studies of metal ions on the composite material were performed in non-ionic, cationic and anionic surfactants systems of varying concentrations. On the basis of distribution coefficient values, the material was found to be selective for Pb(II), Hg(II), Bi(III) and Zr(IV) ions. The limit of detection (LOD) and the limit of quantification (LOQ) for Pb(II) metal ion was found to be 0.85 and 2.85 g L −1 . Some analytically important, selective separations of metal ions have been successfully applied for the analysis of industrial effluent and natural water on the columns of this exchanger.

Chemical Engineering Journal

A semi-crystalline stable composite cation exchange adsorbent for the treatment of heavy metal io... more A semi-crystalline stable composite cation exchange adsorbent for the treatment of heavy metal ions has been synthesized at pH 1.0 by sol-gel method which was characterized by FTIR, XRD, SEM, TGA and TEM analysis. Ion exchange capacity, pH titration, elution behavior and distribution studies were also carried out to determine the primary ion-exchange characteristics of the material. The material shows exchange capacity of 1.47 meq g − 1 (for Na + ions). The composite material exhibits improved ion-exchange capacity, chemical and thermal stability. It can be used up to 200°C with 88% retention of initial ion-exchange capacity. pH titration data reveal its bifunctional behavior. The distribution coefficient values (K d ) of metal ions have been determined in various solvent systems. On the basis of K d values the material was selective for Ba(II), Hg(II), and Pb(II) ions. The limit of detection (LOD) and the limit of quantification (LOQ) for Pb(II) was found to be 0.97 and 2.93 μg L − 1 , respectively. A number of important and analytically difficult quantitative separations of metal ions have been achieved using columns packed with this exchanger. The composite cation exchanger is applied for the treatment of sewage water and synthetic mixture successfully and can be used as a conducting material.

Colloids and Surfaces B-biointerfaces, 2011

Polymer nanocomposites (NSPANI/AuNP/GR) based on nanostructured polyaniline, gold nanoparticles (... more Polymer nanocomposites (NSPANI/AuNP/GR) based on nanostructured polyaniline, gold nanoparticles (AuNP) and graphene nanosheets (GR) have been synthesized using in situ polymerization. A series of nanocomposites have been synthesized by varying the concentration of GR and chloroauric acid to optimize the formulation with respect to the electrochemical activities. Out of these series of NSPANI/AuNP/GR nanocomposites, it has been found that only one particular nanocomposite has the best electrochemical properties, as analyzed by cyclic voltammetry (CV) and differential pulse voltammetry and conductivity. The best nanocomposite has been characterized by Fourier transform infrared Raman spectroscopy, UV-vis spectroscopy, X-ray diffraction studies, transmission electron microscopy, scanning electron microscopy and atomic force microscopy. The CV of the best nanocomposites show the well-defined reversible redox peaks characteristic of polyaniline, confirming that the polymer maintains its electro activity in the nanocomposites. Another nanocomposite has been prepared with identical composition (as found with the best nanocomposite) by mixing of presynthesized nanostructured polyaniline with chloroauric acid and graphene dispersion in order to predict the mechanism of in situ polymerization. It is inferred that the nanocomposite prepared by blending technique loses its property within 48 h indicating phase separation whereas the nanocomposite prepared by in situ technique is highly stable.

Chemical Engineering Journal, 2011

Polyaniline-carboxylic acid functionalized multi-walled carbon nanotube (PAni/c-MWNT) nanocomposi... more Polyaniline-carboxylic acid functionalized multi-walled carbon nanotube (PAni/c-MWNT) nanocomposites were prepared in sodium dodecyl sulfate (SDS) emulsion. First, the c-MWNTs were dispersed in SDS emulsion then the aniline was polymerized by the addition of ammonium persulfate in the absence of any added acid. SDS forms the functionalized counterion in the resulting nanocomposites. The content of c-MWNTs in the nanocomposites varied from 0 to 20 wt%. A uniform coating of PAni was observed on the c-MWNTs by field-emission scanning electron microscopy (FESEM). The PAni/c-MWNT nanocomposites have been characterized by different spectroscopic methods such as UV-Visible, FT-Raman, and FT-IR. The UV-Visible spectra of the PAni/c-MWNT nanocomposites exhibited an additional band at around 460 nm, which implies the induced doping of the MWNTs by the carboxyl group. The FT-IR spectra of the PAni/c-MWNT nanocomposites showed an inverse intensity ratio of the bands at 1562 and 1480 cm S1 as compared to that of pure PAni, which reveals that the PAni in the nanocomposites is richer in quinoid units than the pure PAni. The increase in the thermal stability of conductivity of the nanocomposites was due to the network structure of nanotubes and the charge transfer between the quinoid rings of the PAni and the c-MWNTs.

Toxicological & Environmental Chemistry, 2012

A heteropolyacid Zr(IV) tungstate-based cation exchanger has been synthesized. An amorphous sampl... more A heteropolyacid Zr(IV) tungstate-based cation exchanger has been synthesized. An amorphous sample, prepared at pH 1.2 and having a Na+ ion exchange capacity of 0.92 meq g−1, was selected for further studies. Its physicochemical properties were determined using Fourier transform infrared spectrometer, X-ray diffraction, thermogravimetric, and scanning electron studies. To understand the cation exchange behavior of the material, distribution coefficients (K d) for metal ions in various solvent systems were determined. Some important binary separations of metal ions, namely Mg2+–Bi3+, Cd2+–Bi3+, Fe3+–Bi3+, Th4+–Bi3+, and Fe3+–Zn2+, were achieved on such columns. The practical utility of these separations was demonstrated by separating Fe3+ and Zn2+ ions quantitatively in commercial pharmaceutical formulation. The cation exchanger has been successfully applied also for the treatment of industrial wastewater and a synthetic mixture. All the results suggests that Zr(IV) tungstate has excellent potential for the removal of metals from aqueous systems using packed columns of this material.