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RISS 인기검색어
- 검색키워드
- 저자 : Nabel A. Negma (검색결과 4 건)
- 무료
- 기관 내 무료
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Nabel A. Negma,Ali A. Abd-Elaal,Dalia E. Mohamed,Ahmed. F. El-Farargy,Sara Mohamed 한국공업화학회 2015 Journal of Industrial and Engineering Chemistry Vol.24 No.-
Silver nanoparticles loaded by three Gemini cationic surfactants having different spacer chain length were prepared and characterized using ultraviolet–visible (UV–vis) absorption spectroscopy and transmission electron microscope (TEM) analysis. TEM analysis showed the homogeneity and stability of the formed silver nanoparticles in the presence of the Gemini surfactants. The results showed increased activity of the silver nanoparticles in the presence of the Gemini cationic surfactants. Antimicrobial results of inhibition zone diameter and minimum inhibitory concentration were correlated to Gemini surfactants and their nanoparticles including surface activity and tendency toward adsorption at interfaces
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Characterization, surface properties and biological activity of some synthesized anionic surfactants
Nabel A. Negma,AHMED SALAH MAHMOUD TAWFIK 한국공업화학회 2014 Journal of Industrial and Engineering Chemistry Vol.20 No.6
In this study, esterification reaction between four different fatty alcohols (octyl, dodecyl, hexdecyl andoctadecyl alcohol) and phosphoric acid was performed. The produced compound was reacted withpolyethylene glycol-400. Then, the reaction product was quenched using sodium hydroxide to form thedesired anionic gemini surfactants. The chemical structures of the synthesized surfactants wererecognized by FT-IR and 1H NMR spectroscopy. The synthesized surfactants showed higher surfaceactivity. The emulsion stability measurements showed the applicability of these surfactants asemulsifying agents. The foaming power measurements showed the synthesized surfactants have lowability to foam formation. The thermodynamic parameters showed their tendency toward adsorption atthe interfaces and also micellization in the bulk of their solutions. The studied surfactants wereevaluated as antimicrobial agents against pathogenic bacteria using inhibition zone diameters. Thesynthesized surfactants showed good antimicrobial activities against the tested microorganismsincluding Gram positive, Gram negative as well as fungi. The promising inhibition efficiency of thesecompounds against the pathogenic bacteria facilitates them to be applicable in the petroleum field asnew categories of biocides.
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Nabel A. Negma,Salah M. Tawfik,Ali A. Abd-Elaal 한국공업화학회 2015 Journal of Industrial and Engineering Chemistry Vol.21 No.1
Here in, the new gemini anionic surfactants with different alkyl chain length were synthesized (C8A,C12A, C16A and C18A). The chemical structure of the synthesized surfactants was confirmed using infraredspectroscopy (IR) and proton nuclear magnetic resonance spectroscopy (1H NMR). Silvernanoparticles colloidal solution of 20–25 nm diameters was prepared using trisodium citrate asreducing agent. The nanostructure of the synthesized surfactant with silver nanoparticles withdiameters ranging from 6.3 to 23.2 nm was prepared and characterized using ultra violetspectrophotometer (UV), transmission electron microscope (TEM), dynamic light scattering (DLS)and energy dispersive X-ray (EDX). The results declare formation and stabilization of silver nanoparticleusing synthesized anionic surfactants. Antimicrobial activity of the synthesized anionic surfactants andtheir nanostructure with silver nanoparticles were evaluated against pathogenic bacteria and fungi. Theantimicrobial activity showed the enhancement in the antimicrobial activity of the synthesized geminianionic surfactants in the nanostructures form.
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Treatment of industrial wastewater containing copper and cobalt ions using modified chitosan
Nabel A. Negma,Ragaa El Sheikh,Ahmed. F. El-Farargy,Hassan H.H. Hefni,Mahmoud Bekhit 한국공업화학회 2015 Journal of Industrial and Engineering Chemistry Vol.21 No.1
Chitosan was extracted and characterized using several analyses. The produced chitosan was reacted byglycine and chloroacetic acid. Chemical structures of biosorbents were confirmed. Adsorptionefficiencies of the two biosorbents in neutral and alkaline medium at 25 8C were determined usingatomic absorption spectroscopic analysis. Adsorption capacity ofmodified biosorbents toward Cu(II) andCo(II) ions was determined and compared to virgin chitosan. The biosorbents showed lower adsorptionefficiency toward copper and cobalt ions compared to virgin biosorbent. Furthermore, adsorptioncapacity of glycine–chitosan was higher than chloroacetic acid–chitosan biosorbents, which attributedto chelating of amino groups than chloro-substituted polymer. Thermodynamic studies showed thespontaneous behavior of the adsorption process of metal ions under the studied conditions. Entropychanges indicate that the adsorption of the metal ions are endothermic process, and lower values of DS8indicate the affinity toward metal ions by the biosorbents at different degrees depending on theirchemical structures.
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