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Adsorption and desorption of phosphate and nitrate ions using quaternary (polypropylene-g-N,N-dimethylamino ethylmethacrylate) graft copolymer منال فوزي أبوطالب
Study has been made on the preparation of functionalized copolymer by grafting N,N- (dimethylaminoethyl) methacrylate (DMAEMA) onto polypropylene (PP) films using -irradiation technique. The effect of monomer concentration and irradiation dose on the grafting yield was studied. It was found that grafting yield increases with increasing the monomer concentration and irradiation dose. Subsequent quaternization of the amine group of PDMAEMA graft chain using different reagents, 1-bromo octadecane, methyl iodide and benzyl chloride, to improve their ionic character was carried out. The grafted PP films were characterized by IR spectroscopy, and mechanical and thermal properties. During the adsorption of phosphate (PO4 3−) and nitrate (NO3−) ions, the rate of adsorption, pH effect, desorbability and initial feed concentration effect were investigated. It was found that the adsorption of PO4 3− and NO3− ions increases with increasing the adsorption time up to 10 h and decreases with increasing the pH of medium. The desorbability is ranging from 18 to 30%, and it is relatively difficult to desorb PO4 3− and NO3− ions from the functionalized grafted copolymers. Results showed good possibility for the use of such functionalized grafted film in the field of removal of some anions such as PO4 3− and NO3− from their media. ...
Radiation Synthesis of Polyampholytic and Reversible pH-Responsive Hydrogel and Its Application as Drug Delivery System منال فوزي أبوطالب
Graft copolymerization of acrylic acid (AA) and acrylamide (AAm) onto chitosan (CS) was carried out using gamma irradiation. Their swelling behavior was investigated. The hydrogels before and after alkaline hydrolysis were confirmed by FTIR spectroscopic studies. The hydrogels show ampholytic and reversible pHresponsiveness characteristics. The swelling variations were explained according to swelling theory based on the hydrogel chemical structure. The ability of the prepared copolymer to be used as gastric antibiotic delivery system was estimated using amoxicillin trihydrate as a model drug. Release of amoxicillin trihydrate from these investigated hydrogels was studied. For non-ionized drugs, such as amoxicilin trihydrate, the electrostatic polymer/ polymer interactions take place between the cationic groups from CS and the anionic ones from PAA resulting in entrapping the drug into the mesh space of the hydrogel. The non-ionized amoxicillin release was controlled by the swelling/eroding ratio. ...
Metal sorption and swelling characters of acrylic acid and sodium alginate based hydrogels synthesized by gamma irradiation منال فوزي أبوطالب
Hydrophilic hydrogels based on poly(acrylic acid) as synthetic polymer and sodium alginates as natural polymer (AG) were prepared by gamma irradiation. The AAc/AG hydrogels were characterized by X-ray diffraction (XRD) and thermogravimetric analysis (TGA). The effect of temperature and pH on the degree of swelling in water was studied. In addition, the metal sorption affinity of the prepared hydrogels for Cu 2, Co 2 and Ni 2 was investigated. The XRD spectroscopic analysis indicates the formation of interpenetrating polymer networks. The TGA study showed that the hydrogels based on AAc/AG hydrogels at different ratios displayed lower thermal stability than PAAc hydrogel. The kinetic study of swelling in water showed that PAAc and AAc/AG hydrogels reached the equilibrium swelling state after five hours. However, AAc/AG hydrogels showed degree of swelling in water greater than PAAc hydrogel. The degree of swelling of AAc/AG hydrogels was affected by temperature, it increases within the temperature range 25–40 C and displayed pH sensitivity within the range 5.5–9 depending on composition. The metal sorption study showed that PAAc hydrogel possessed higher affinity for Cu 2 ions than AAc/AG hydrogels, whereas AAc/AG hydrogels showed higher affinity for Co 2 and Ni 2 ions than PAAc hydrogel. ...
Radiation synthesis and characterization of polyamidoamine dendrimer macromolecules with different loads of nickel salt for adsorption of some metal ion منال فوزي أبوطالب
Graft copolymer networks of poly(methacrylic acid-g-polyamidoamine dendrimer) with different loads of nickel salt were synthesized by gamma radiation-induced copolymerization of polyamidoamine dendrimer and methacrylic acid (MAA). Nickel release and metal adsorption from the polymeric systems, and their thermal stability were analyzed. A high percentage of the nickel loaded was released, although strong interactions between the polymeric matrices and the nickel ion was established since a total nickel release did not take place. The higher the concentration of the loading Ni2þ, the higher were the adsorption capacities obtained. The metal release and uptake by such prepared hydrogels was determined by using atomic absorption technique. On the other hand, the presence of nickel salt induced an evident thermal instability in the polymeric matrices, although all the polymeric systems can be considered thermally stable. ...
Removal of phenolic compounds using (2-hydroxyethyl methacrylate/acrylamidopyridine) hydrogel prepared by gamma radiation منال فوزي أبوطالب
Hydrophilic copolymers of 2-acrylamidopyridine (AP) and 2-hydroxyethylmethacrylate (HEMA) with different molar ratios were prepared by gamma irradiation-induced copolymerization using 60Co gamma rays of 20 wt.% aqueous solutions of monomer mixtures. The prepared polymers were characterized by FTIR, NMR and TGA analysis. The capacities for the adsorption of phenolic compounds onto the copolymers were found to be 26.7, 12.5 and 8.5 mg/g polymer for phenol, 2,6-dimethylphenol (DMP) and 2,6-di-t-butylphenol (DBP), respectively, using 20% AP copolymer. When the ratio of AP increased to 50% in the copolymer composition the amount of the above mention phenols retained increased significantly to be 35.1, 30.1 and 17.2 mg/g polymer for phenol, 2,6-dimethylphenol (DMP) and 2,6-di-t-butylphenol (DBP), respectively. Increasing the pH of the medium resulted in increasing of the amount of adsorbed phenols by the polymers. The kinetics of the adsorption at different concentration was also investigated. ...
Adsorption and controlled release of Chlortetracycline HCl by using multifunctional polymeric hydrogels منال فوزي أبوطالب
Adsorption and controlled release of Chlortetracycline HCl to and from multifunctional polymeric materials (HEMA/ MAA) hydrogels were investigated. P(HEMA/MAA) hydrogels were synthesized by gamma radiation-induced copolymerization of 2-hydroxyethylmethacrylate (HEMA) and methacrylic acid (MAA) in aqueous solution. The influence of copolymer composition and pH value of the surrounding medium on the type of water diffusion into the glassy polymer were discussed. Drug, Chlortetracycline HCl containing hydrogels, with different drug concentration to polymer ratios, was loaded by direct adsorption method. The influence of MAA content in the gel on the adsorption capacities of hydrogel was studied. Chlortetracycline HCl adsorption capacity of hydrogels was found to increase from 8 to 138 mg Chlortetracycline HCl per gram dry gel with increasing amount of MAA in the gel system and drug concentration. The effect of pH on the releasing behavior of Chlortetracycline HCl from gel matrix was investigated. In vitro drug release studies in different buffer solutions show that the basic parameters affecting the drug release behavior of hydrogel are the pH of the solution and MAA content of hydrogel. ...
Radiation Synthesis and Characterization of 2-Hydroxyethyl-methacrylate-Based Hydrogels Containing Di- and Tri-Protic Acid and Its Application on Wastewater Treatment منال فوزي أبوطالب
Radiation-crosslinked 2-hydroxyethylmethacrylate/ citric acid (HEMA/CAc), 2-hydroxyethylmethacrylate/ tartaric acid (HEMA/TA), and 2-hydroxyethylmethacrylate/ succinic acid (HEMA/Sc) copolymers were prepared by using 60Co g-rays. The gel fraction yield and the swelling behavior of the prepared hydrogels were studied. It was shown that increasing irradiation doses was accompanied by an increase in yield of gel fraction and a decrease in swelling degree. The parameters of equilibrium swelling, maximum swelling, initial swelling rate, swelling exponent, and diffusion coefficient of the hydrogels were determined by studying the swelling behavior of the hydrogels prepared. It was seen that the equilibrium swelling degree increases as the content of acid increases, as a result of introducing more hydrophilic groups. When the hydrophilic polymer (acids) varies in the content range of 40–80 mg, swelling exponents (n) decreases, thereby indicating a shift in the water-transport mechanism from the anomalous (non-Fickian)-type to the Fickian-type. Characterization and some selected properties of the prepared hydrogels were studied, and accordingly the possibility of its practical use in the treatment of industrial wastes such as dyes and heavy metals (Fe, Ni, Co, and Cu) were also studied. The effect of treatment time, pH of feed solution, initial feed concentration, and temperature on the dye and heavy metals uptake was determined. The uptake order for a given metal was HEMA/TA hydrogel > HEMA/ CAc > HEMA/Sc hydrogel. ...
Radiation Synthesis of Copolymers for Adsorption of Dyes from Their Industrial Wastes منال فوزي أبوطالب

Copolymer hydrogels were prepared by γ-radiation copolymerization of N-vinyl-2-pyrrolidone (NVP) and methylmethacrylate (MMA) or acrylonitrile (AN). The effect of NVP/MMA and NVP/AN compositions and irradiation dose on the gel fraction yield in the prepared hydrogels was determined. It was found that as the content of NVP increased, the gel fraction yield decreased. The increase in irradiation dose resulted in increasing the crosslinked network structure and, consequently, the gel percentage increased. The thermal stability and swelling properties were also investigated as a function of comonomer composition. The nitrile groups (–CN) in the prepared copolymer were converted into their respective amidoxime groups by treating with NH2OH-hydrochloride. Such a process resulted in improving both the swelling behavior and adsorption capacity. Characterization and some selected properties of the prepared hydrogels were studied and accordingly the possibility of its practicable use in the treatment of industrial waste dyes was determined. The thermodynamic parameters for the adsorption process were calculated. The effect of treatment time, pH of feed solution, effect of initial feed concentration, and temperature on the dye uptake was also investigated. The maximum uptake for investigated dyes was higher for treated NVP/AN hydrogel than that for untreated NVP/AN and NVP/MMA ones.

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Radiation Synthesis and Characterization of Poly(N-vinyl- 2-pyrrolidone/acrylic acid) and Poly(N-vinyl-2-pyrrolidone/ acrylamide) Hydrogels for Some Metal-Ion Separation منال فوزي أبوطالب
Two different hydrogels, prepared from N-vinyl-2-pyrrolidone/acrylic acid (NVP/AAc) and N-vinyl- 2-pyrrolidone/acrylamide (NVP/AAm), were studied for the separation and extraction of some heavy-metal ions from wastewater. The hydrogels were prepared by the -radiation- induced copolymerization of the aforementioned binary monomer mixtures. Further modification was carried out for the NVP/AAc copolymer through an alkaline treatment to improve the swelling behavior by the conversion of the carboxylic acid groups into its sodium salts. The thermal stability and swelling properties were also investigated as functions of the N-vinyl-2-pyrrolidone content. The characterization and some selected properties of the prepared hydrogels were studied, and the possibility of their practical use in wastewater treatment for heavy metals such as Cu, Ni, Co, and Cr was investigated. The maximum uptake for a given metal was higher for a treated NVP/AAc hydrogel than for an untreated NVP/AAc hydrogel and was higher for an untreated NVP/AAc hydrogel than for an NVP/ AAm hydrogel. ...
Linear and Nonlinear Waves Propagating in Plasmas رفعت صبرى عبدالوهاب
Nonlinear excitations: solitons, double layers (shocks), blowup/explosive, Rogue Waves, vortices, modulated envelope wave packets, instabilities, ponderomotive coupling effects. Electrostatic and electromagnetic excitations in: pair-ion plasma, electron-positron-ion plasmas, two-electron temperature plasma, two-ion temperature plasma, nonthermal plasma. Beam-plasma interactions: beam-plasma properties, pulse propagation and instabilities. Surface waves (surface plasmon-polaritons): electrostatic and electromagnetic excitations, ponderomotive coupling effect, envelope solitons, and counterstreaming plasmas. Wake potential: test charge properties in multi-component plasma. ...
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