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One-step synthesis of Co-TiC-carbon composite nanofibers at low temperature
Yousef, Ayman,Brooks, Robert.M.,Abutaleb, Ahmed,El-Newehy, Mohamed H.,Al-Deyab, Salem S.,Kim, Hak Yong Elsevier 2017 CERAMICS INTERNATIONAL Vol.43 No.7
<P><B>Abstract</B></P> <P>Cobalt-titanium carbide-carbon composite nanofibers (Co-TiC-CNFs [nanocomposite]) were prepared using one-step electrospinning of a sol-gel consisting of titanium(IV) isopropoxide, polyvinylpyrroliodine and cobalt acetate tetrahydrate. Dried electrospun nanofiber mats were sintered in an argon (Ar) atmosphere at 850°C, i.e. at a lower temperature compared to literature data. The synthesized nanocomposite showed good electrical conductivity and could be used in various applications. The TiC preparation method used in this study could open the way for synthesizing different nanocomposite based metal carbides.</P>
Yousef, Ayman,Barakat, Nasser A.M.,EL-Newehy, Mohamed H.,Ahmed, M.M.,Kim, Hak Yong Elsevier 2015 Colloids and surfaces. A, Physicochemical and engi Vol.470 No.-
<P><B>Abstract</B></P> <P>Cu(0) nanoparticles supported on TiO<SUB>2</SUB> nanofibers (Cu-decorated TiO<SUB>2</SUB> NFs) are introduced as an effective photocatalyst for hydrolytic dehydrogenation of ammonia borane (AB) under solar radiation. The introduced Cu-decorated TiO<SUB>2</SUB> NFs were prepared using electrospinning followed by hydrothermal treatment as a novel route for preparation of metal-decorated metal oxide nanofibers. Interestingly, the utilized physicochemical characterizations showed that the prepared nanocatalyst composed of core TiO<SUB>2</SUB> NFs decorated by Cu(0) NPs. A strong photocatalytic activity for catalytic hydrolysis of AB under solar radiation using the introduced nanocatalysts was observed. The results reveal that high rate of hydrogen release from ammonia borane (2.75 equivalent moles) as compared to undecorated TiO<SUB>2</SUB> NFs (1.6 equivalent moles) and pristine Cu NPs (1.2 equivalent moles). The obtained high hydrogen production, in case of the introduced Cu-decorated TiO<SUB>2</SUB> NFs, is attributed to the dual effect of counter parts. Furthermore, the introduced nanofibers could be utilized for three successive cycles with the same efficiency which reflects high stability. Moreover, the photocatalytic activity of the introduced NFs was further confirmed by photodegradation of methylene blue (MB) under solar radiation; complete removal was observed after 120min.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Cu(0) nanoparticles covered surface of titanium dioxide nanofibers. </LI> <LI> High catalytic activity in hydrogen release from ammonia borane. </LI> <LI> Prepared photocatalyst can be reused with the same activity. </LI> </UL> </P>
Preparation and Characterizations of Anisotropic Chitosan Nanofibers via Electrospinning
R. Nirmala,Baek Woo Il,R. Navamathavan,Mohamed H. El-Newehy,김학용 한국고분자학회 2011 Macromolecular Research Vol.19 No.4
We report the preparation of anisotropic chitosan nanofibers prepared using an electrospinning technique. The effect of electrospinning on the formation of nanofibers was examined from results of bulk chitosan. The morphological, structural characterizations and thermal properties of the chitosan bulk and electrospun nanofibers were analyzed by field-emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), differential scanning calorimetry (DSC), thermogravimetry (TGA), Fourier transform infrared (FTIR), and Raman spectroscopy. Matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) was performed to accurately characterize the high aspect ratio nanofiber structure by the direct identification of mass resolved chains. FE-SEM showed that the electrospun chitosan nanofibers had diameters ranging from 10 to 1,200 nm with an anisotropic nature. MALDI-TOF revealed the presence of lower mass group protonated amino groups, which was the main constituent for the formation of the ultrafine nanofibers in chitosan.
Gehan M.K. Tolba,나지르,A.M. Bastaweesy,E.A. Ashour,Wael Abdelmoez,Mohamed H. El-Newehy,Salem S. Al-Deyab,김학용 한국공업화학회 2015 Journal of Industrial and Engineering Chemistry Vol.29 No.-
Amorphous nanosilica separated from rice-husk at yield of 81% by hydrothermal technique is introducedas effective and reusable adsorbent for the organic pollutants. The prepared nanosilica is spheroid with aparticle size of 10–50 nm. As adsorbent, the results indicated that the nanosilica could remove 65% fromthe methylene blue dye (10 ppm) within the first minute. The calculated thermodynamic parametersindicated that the adsorption of MB is spontaneous and endothermic. Interestingly, regeneration of theintroduced material by caclination at 450 8C enhanced the adsorption process as the removingpercentage was linearly depending on the number of the successive cycles.
Single-nozzle Core-shell Electrospun Nanofibers of PVP/Dextran as Drug Delivery System
Meera Moydeen A.,Syed Ali Padusha M.,Badr M. Thamer,Anis Ahamed N.,Abdullah M. Al-Enizi,Hany El-Hamshary,Mohamed H. El-Newehy 한국섬유공학회 2019 Fibers and polymers Vol.20 No.10
Ciprofloxacin-loaded poly(vinylpyrrolidinone) (PVP) and dextran sulfate (Dex) (PVP/Dex) nanofibers wereprepared using the emulsion electrospinning method. The physical and morphological characteristics of the preparednanofibers were evaluated by conducting a Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy(SEM) and thermogravimetric analysis (TGA). The polymer-polymer and polymer-drug interactions were determined usingdifferential scanning calorimetry (DSC). Moreover, the formation of the core-shell structure was confirmed by transmissionelectron microscopy (TEM) and confocal laser microscopy. The sustained release behavior was evaluated using ultravioletvisible(UV-vis) spectroscopy, and its kinetic mechanism was investigated using Korsmeyer-Peppas, Peppas-Sahlin, andWeibull models by a non-linear regression equation. The antibacterial properties were evaluated using the disc diffusionmethod with respect to several wound gram-positive (Methicillin-resistant Staphylococcus aureus (MRSA), Staphylococcusepidermidis, Staphylococcus aureus, and Klebsiella pneumoniae) and gram-negative bacteria (Pseudomonas aeruginosa,Salmonella typhimurium, and Proteus vulgaris). In general, the release behavior of Ciprofloxacin from PVP/Dex is controlledby diffusion in the delivery system.