Sayed M. Badawy

Radiation-induced grafting of glycidyl methacrylate onto cotton fabric waste and its modification for anchoring hazardous wastes from their solutions.

Ion exchange adsorbents based on cellulosic fabric wastes carrying sulfonic acid and amine functional groups were synthesized by radiation-induced graft polymerization of glycidyl methacrylate (GMA) with subsequent chemical modification of the epoxy groups of poly-GMA graft chains with sodium sulfite/H(2)SO(4) and triethylamine, respectively. The conversion of epoxy groups into the functional groups was investigated. Factors affecting on grafting process such as radiation dose, monomer concentration and solvent were studied. The synthesized adsorbent and its applications in the removal of different types of hazardous pollutants e.g. acidic dye, cobalt, dichromate and phenols from aqueous solution were also studied.

Uranium isotope enrichment by complexation with chelating polymer adsorbent

Abstract Polyacrylamidoxime (PAO) granules prepared by radiation-induced polymerization of acrylonitrile and introduction of amidoxime groups by reaction with hydroxylamine are used for separation of 235 U and 238 U in solution by utilizing the small difference of stability constant of the complex between polymer ligand and metal ions. An isotope ratio of 0.00763 is obtained by single-column experiment. This value is 5% higher than that of the feed solution. The coordination of PAO with metal ions, Cu 2+ , was investigated by FT-IR, XRD and ESR analysis.

Chemical reactive filter paper prepared by radiation-induced graft polymerization—I

Abstract Chelating filter papers with chemically bonded amidoxime groups were synthesized by radiation-induced grafting of acrylonitrile onto filter paper (W3) followed by chemical treatment with hydroxylamine. The effect of grafting conditions such as absorbed dose, dose rate, monomer concentration and filter paper thickness on the grafting yield was studied. It was found that the degree of grafting increases with increasing absorbed dose and dose rate, and then tends to level off at high doses. The order of the dependence of the initial grafting rate on the dose is found to be of 0.33. An increasing monomer concentration was accompanied by a significant increase in grafting. At high monomer concentration the initial rate of grafting is fast followed by a slow rate. The rate of grafting is controlled by the filter paper thickness and the diffusion of monomer into the interior of the filter paper. Mechanical properties of the prepared filter paper were improved over the ungrafted paper. The amidoxime filter papers were examined for adsorption of uranium concentration ranging between 10–100 ppm.

Direct pyrolysis mass spectrometry of acrylonitrile–cellulose graft copolymer prepared by radiation-induced graft polymerization in presence of styrene as homopolymer suppressor

Abstract Graft polymerization of acrylonitrile onto cellulosic filter paper competing with the homopolymerization by mutual irradiation technique was studied in the presence of homopolymer suppressors. Addition of FeCl 3 decreased both homopolymerization and graft polymerization, whereas inclusion of a low ratio of styrene monomer with acrylonitrile leads to successful grafting of acrylonitrile with little homopolymer formation. Chemical structure and thermal behavior of the produced graft copolymers were investigated by gradual heating in the solid probe of a mass spectrometer equipped with a GCMS data system. The resulting total ion current (TIC) showed that the degradation of graft copolymers follows two-step pyrolysis. The presence of a low ratio of styrene comonomer increased thermal stability of the prepared acrylonitrile–cellulose graft copolymer. The pyrolysis products have mass spectra characteristic of the copolymer composition; they contain the repeating unit of the oligomers. Total ion current and spectrum subtractions were used to separate and measure spectra of graft copolymers at distinctly different temperatures.

Chelating polymer granules prepared by radiation-induced homopolymerization. I—Kinetic study of radiation polymerization process

Chelating polymer granules containing amidoxime chelating groups were synthesized by radiation-induced homopolymerization of acrylonitrile monomer. The chemical reactive intermediate polyacrylonitrile was treated with hydroxylamine solution to convert the chemical active cyano groups into the amidoxime groups. Kinetic study of the effects of monomer concentration, radiation dose, dose rate, and temperature on the polymerization process was investigated. It was found that at low monomer concentration, the rate of polymerization is roughly independent on the initial monomer concentration, while at high monomer concentration, 35–65%, a marked acceleration on the rate was observed. The order of the dependence of the initial rate of polymerization on the dose rate is 0.77, which deviates from the classical square-root law due to the precipitation of the formed polymer. The conversion percent and molecular weight of the produced polymer are inversely proportional to dose rate at constant radiation dose. The activation energy was found to be 2.7 kcal/mol, and the rate constant of initiation is independent of temperature. The effect of type of solvent on the polymerization was studied. DMF solvent of the closest solubility parameter to the solubility parameter of polyacrylonitrile is the best solvent for the polymerization process.

Identification of Some Polymeric Materials by Low-Temperature Pyrolysis Mass Spectrometry

The application of low-temperature pyrolysis mass spectrometry to the identification of some commercial and synthetic polymers using a direct insertion probe and electron ionization has been studied. The polymers were analyzed directly in the solid probe of a mass spectrometer within the ion source at 70 eV electron impact. The quadrupole mass spectrometer, equipped with gas chromatogram software and a library of low molecular weight compounds, was used to characterize the polymers by measuring the chemical structure of the repeat units and the end groups and to examine the thermal degradation pathways. The polymers investigated show different degradation pathways. Investigation of sequences and determination of the composition of co-polymers were studied. Total ion pyrogram and spectrum subtractions were used to separate and measure spectra of pyrolysis steps at distinctly different temperatures.

Adsorption of direct green 26 onto fix 3500 treated sawdust: equilibrium, kinetic and isotherms

AbstractCationized sawdust (CSD) was prepared by the reaction of sawdust (SD) with cationizing agent. Three levels of CSD having different nitrogen content were prepared. The CSD samples were characterized by estimation of nitrogen content. The feasibility of CSD to remove C.I. Direct Green (DG 26) dye from aqueous solutions was examined. The impacts of several operating parameters such as adsorbent dose, adsorption time, and adsorbate concentration on the adsorption capacity were investigated. The CSD was effectively used in adsorption of DG 26 dye from aqueous solutions. In order to determine the best fit isotherm, the experimental equilibrium data were analyzed using eight adsorption isotherm models including Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich (two parameter models), Redlich–Peterson, Toth, Sips and Khan (three parameter models) using non-linear regression technique. Tempkin and Sips isotherms were found to best represent the data for DG 26 dye than other isotherms. The kinetics of ...

Structural characterization of gallbladder stones using energy dispersive x-ray spectroscopy (EDS) and x-ray diffraction (XRD)

AIM AND OBJECTIVE Formation of the gallbladder stones is a common disease and a major health problem. The present study aimed to identify the structures of the most common types of gallbladder stones using X-ray spectroscopic techniques, which provide information about the process of stone formation. MATERIAL AND METHOD Phase and elemental compositions of pure cholesterol and mixed gallstones removed from gallbladders of patients were studied using energy-dispersive X-ray spectroscopy combined with scanning electron microscopy analysis and X-ray diffraction. RESULTS The crystal structures of gallstones which coincide with standard patterns were confirmed by X-ray diffraction. Plate-like cholesterol crystals with laminar shaped and thin layered structures were clearly observed for gallstone of pure cholesterol by scanning electron microscopy; it also revealed different morphologies from mixed cholesterol stones. Elemental analysis of pure cholesterol and mixed gallstones using energy-dispersive X-ray spectroscopy confirmed the different formation processes of the different types of gallstones. CONCLUSION The method of fast and reliable X-ray spectroscopic techniques has numerous advantages over the traditional chemical analysis and other analytical techniques. The results also revealed that the X-ray spectroscopy technique is a promising technique that can aid in understanding the pathogenesis of gallstone disease.

Application of Acacia modesta and Dalbergia sissoo gums as green matrix for silver nanoparticle binding

Abstract A low-cost, efficient, and ecofriendly method for the synthesis of silver nanoparticles (AgNPs) using gums as reducing agent was performed. The obtained nanoparticles were characterized by UV-visible spectroscopy. The antibacterial activity of the prepared nanoparticles was tested against Gram-negative and Gram-positive bacteria. The in vitro toxicity was evaluated by performing hemolytic analysis. The mutagenic activity was evaluated using Ames test. The prepared nanoparticles possessed high antibacterial potential and also inhibited the biofilm formation. Under the conditions of this study, it is concluded that the prepared AgNPs were nontoxic and nonmutagenic and possessed pharmaceutical applications.

Sesbania sesban L. biomass as a novel adsorbent for removal of Pb(II) ions from aqueous solution: non-linear and error analysis

Abstract In the present study, we reported the feasibility of the Sesbania sesban L. as a biosorbent to remove Pb(II) from aqueous solutions. The ability of S. sesban L. to adsorb Pb(II) was investigated by using batch adsorption procedure. Such effects as pH, contact time, adsorbate concentration, and biosorbent dosage on the adsorption capacity were studied. The experimental data were analyzed using various adsorption kinetic models, namely, pseudo-first-order model, the pseudo-second-order model, Batacharia-Venkobachar, the Elovich equation, the intraparticle diffusion model, and Bangham equation. Results show that the pseudo-second-order equation provides the best correlation for the biosorption process. To determine the best fit isotherm, the experimental equilibrium data were analyzed using two-parameter (Langmuir, Freundlich, Dubinin-Radushkevich, and Tempkin) and three-parameter isotherms (Redlich-Peterson, Sips, Khan, and Toth). The examination of error analysis methods showed that the Langmuir isotherm model and Redlich-Peterson models provide the best fit for experimental data than other isotherms. Sebania sesban L. is found to be inexpensive and effective adsorbent for removal of Pb(II) from aqueous solutions.