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  • 1.
    Ashour, Radwa M.
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik.
    Abdelhamid, Hani Nasser
    Abdel-Magied, Ahmed F.
    Abdel-Khalek, Ahmed A.
    Ali, M. M.
    Uheida, Abdusalam
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Material- och nanofysik, Funktionella material, FNM.
    Muhammed, Mamoun
    Zou, Xiaodong
    Dutta, Joydeep
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Material- och nanofysik, Funktionella material, FNM.
    Rare Earth Ions Adsorption onto Graphene Oxide Nanosheets2017Inngår i: Solvent extraction and ion exchange, ISSN 0736-6299, E-ISSN 1532-2262, Vol. 35, nr 2, s. 91-103Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Graphene oxide (GO) was synthesized and used as a coagulant of rare earth elements (REEs) from aqueous solution. Stability and adsorption capacities were exhibited for target REEs such as La(III), Nd(III), Gd(III), and Y(III). The parameters influencing the adsorption capacity of the target species including contact time, pH, initial concentration, and temperature were optimized. The adsorption kinetics and thermodynamics were studied. The method showed quantitative recovery (99%) upon desorption using HNO3 acid (0.1 M) after a short contact time (15 min).

  • 2.
    Mohamed, A.
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Material- och nanofysik. Cairo University, Egypt; Akhbar El Yom Academy, Egypt.
    Yousef, S.
    Ali Abdelnaby, M.
    Osman, T. A.
    Hamawandi, Bejan
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Material- och nanofysik.
    Toprak, Muhammet S.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Material- och nanofysik.
    Muhammed, Mamoun
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Material- och nanofysik. Alexandria University, Egypt.
    Uheida, Abdusalam
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Material- och nanofysik.
    Photocatalytic degradation of organic dyes and enhanced mechanical properties of PAN/CNTs composite nanofibers2017Inngår i: Separation and Purification Technology, ISSN 1383-5866, E-ISSN 1873-3794, Vol. 182, s. 219-223Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This work describes the enhanced mechanical properties of the composite nanofibers and the photodegradation of two organic dyes using PAN/CNTs under UV irradiation at different volume concentration (0.05, 0.1, 0.2, and 0.3 wt.%). The composite nanofibers was performed with polyacrylonitrile (PAN), and carbon nanotubes (CNTs) by electrospinning process. The composite nanofibers structure and morphology is characterized by XRD, FTIR, SEM, and TEM. The result indicates that with increasing CNTs content, the mechanical properties of the composite nanofibers was enhanced, and became more elastic, and the elastic modulus increased drastically. The results of mechanical properties exhibit improvements in tensile strengths, and elastic modulus by 38% and 84% respectively, at only 0.05 wt.% CNTs. Moreover, photocatalytic degradation performance in short time and low power intensity was achieved comparison to earlier reports.

  • 3.
    Mohamed, Alaa
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Material- och nanofysik. Akhbar El Yom Academy, Egypt.
    Osman, T. A.
    Toprak, Muhammet S.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Material- och nanofysik, Funktionella material, FNM.
    Muhammed, Mamoun
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Material- och nanofysik.
    Yilmaz, E.
    Uheida, Abdusalam
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Material- och nanofysik, Funktionella material, FNM.
    Visible light photocatalytic reduction of Cr(VI) by surface modified CNT/titanium dioxide composites nanofibers2016Inngår i: Journal of Molecular Catalysis A: Chemical, ISSN 1381-1169, E-ISSN 1873-314X, Vol. 424, s. 45-53Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In this work we report a highly efficient photocatalytic reduction of Cr(VI) based on PAN-CNT/TiO2-NH2 composite nanofibers fabricated by using electrospinning technique followed by chemical crosslinking of surface modified TiO2 NPs functionalized with amino group. The structure and morphology of the fabricated composite nanofibers were characterized by FTIR, SEM, TEM, TGA, and XPS. The results indicate that the composite nanofibers possess excellent photoreduction performance for Cr(VI) under visible light (125 W) after 30 min, which is much faster than previous reports. The effects of various experimental parameters such as catalyst dose, irradiation time, initial concentration of Cr(VI), and pH on the photoreduction efficiency of Cr(VI) were investigated. The highest photoreduction efficiency of Cr (VI) was obtained at low acidity and low amount of TiO2/CNT photocatalyst. The kinetic experimental data was attained and fitted well with a pseudo-first-order model. The UV–vis spectrophotometer and XPS analyses proved that chromate Cr(VI) was reduced to Cr(III). In addition, it can be concluded that the addition of the phenol enhances the photocatalytic reduction of Cr(VI). Furthermore, the photoreduction mechanism has also been discussed. Finally, the fabricated composite nanofibers were found to be stable after at least five regeneration cycles.

  • 4. Mohamed, Alaa
    et al.
    Osman, T. A.
    Toprak, Muhammet Sadaka
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap.
    Muhammed, Mamoun
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Material- och nanofysik, Funktionella material, FNM.
    Uheida, Abdusalam
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Material- och nanofysik, Funktionella material, FNM.
    Surface functionalized composite nanofibers for efficient removal of arsenic from aqueous solutions2017Inngår i: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 180, s. 108-116Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A novel composites nanofiber was synthesized based on PAN-CNT/TiO2-NH2 nanofibers using electrospinning technique followed by chemical modification of TiO2 NPs. PAN-CNT/TiO2-NH2 nanofiber were characterized by XRD, FTIR, SEM, and TEM. The effects of various experimental parameters such as initial concentration, contact time, and solution pH on As removal were investigated. The maximum adsorption capacity at pH 2 for As(III) and As(V) is 251 mg/g and 249 mg/g, respectively, which is much higher than most of the reported adsorbents. The adsorption equilibrium reached within 20 and 60 min as the initial solution concentration increased from 10 to 100 mg/L, and the data fitted well using the linear and nonlinear pseudo first and second order model. Isotherm data fitted well to the linear and nonlinear Langmuir, Freundlich, and Redlich-Peterson isotherm adsorption model. Desorption results showed that the adsorption capacity can remain up to 70% after 5 times usage. This work provides a simple and an efficient method for removing arsenic from aqueous solution.

  • 5. Mohamed, Alaa
    et al.
    Salama, Ahmed
    Nasser, Walaa S.
    Uheida, Abdusalam
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik.
    Photodegradation of Ibuprofen, Cetirizine, and Naproxen by PAN-MWCNT/TiO2-NH2 nanofiber membrane under UV light irradiation2018Inngår i: Environmental Sciences Europe, ISSN 2190-4707, E-ISSN 2190-4715, Vol. 30, artikkel-id 47Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background: In this study, the photodegradation of three pharmaceuticals, namely Ibuprofen (IBP), Naproxen (NPX), and Cetirizine (CIZ) in aqueous media was investigated under UV irradiation. The photocatalyst used in this work consists of surface functionalized titanium dioxide (TiO2-NH2) nanoparticles grafted into Polyacrylonitrile (PAN)/multi-walled carbon nanotube composite nanofibers. Surface modification of the fabricated composite nanofibers was illustrated using XRD, FTIR, and SEM analyses. Results: Sets of experiments were performed to study the effect of pharmaceuticals initial concentration (5-50 mg/L), solution pH (2-9), and irradiation time on the degradation efficiency. The results demonstrated that more than 99% degradation efficiency was obtained for IBP, CIZ, and NPX within 120, 40, and 25 min, respectively. Conclusions: Comparatively, the photocatalytic degradation of pharmaceuticals using PAN-CNT/TiO2-NH2 composite nanofibers was much more efficient than with PAN/TiO2-NH2 composite nanofibers.

  • 6.
    Sallam, Ahmed
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik. Aswan Univ, Fac Archaeol, Aswan, Egypt..
    Hemeda, Sayed
    Cairo Univ, Fac Archaeol, Conservat Dept, Cairo 12613, Egypt..
    Toprak, Muhammet
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik.
    Muhammed, Mamoun
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik.
    Hassan, Moustapha
    Karolinska Inst, Dept Lab Med, S-14186 Stockholm, Sweden..
    Uheida, Abdusalam
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik.
    CT Scanning and MATLAB Calculations for Preservation of Coptic Mural Paintings in Historic Egyptian Monasteries2019Inngår i: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 9, artikkel-id 3903Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Investigations of Coptic mural paintings in historic churches and monasteries demand a deep understanding of the micro structure of the mural painting layers. The main objective of the present study is to study the efficiency of new avenues of computed X-ray tomography (CT Scan) and MATLAB in the analysis of Coptic mural paintings, either in the form of images or videos made to collect information about the physical characteristics of the material structure of the layers of mural paintings. These advanced techniques have been used in the investigation of samples of Coptic mural paintings dating back to the V-VIII century A.D, which have been collected from several locations in the Coptic monasteries in Upper Egypt. The application of CT-scanning is a powerful non-destructive tool for imaging and investigation which can be applied to the preservation of monuments made from many different materials. The second stage of research will be to characterize the materials through analytical techniques including XRD, XRF, EDX and FTIR to confirm the findings of CT scanning and to provide additional information concerning the materials used and their deterioration processes. This paper presents the results of the first pilot study in which CT scan and MATLAB have been utilized in combination for the non-destructive evaluation and investigation of Coptic mural paintings in Upper Egypt. The examinations have been carried out on mural painting samples from three important Coptic monasteries in Upper Egypt: the Qubbat Al Hawa Monastery in Aswan, the Saint Simeon Monastery in Aswan and the Saint Matthew the Potter Monastery in Luxor. This multi-stranded investigation has provided us with important information about the physical structure of the paintings, grains dimensions, grain texture, pore media characterization which include the micro porosity, BET and TPV, surface rendering, and calculation of the points in the surface through calculations completed using MATLAB. CT scanning assisted in the investigation and analyses of image surface details, and helped to visualize hidden micro structures that would otherwise be inaccessible due to over painting.

  • 7.
    Uheida, Abdusalam
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik.
    Mohamed, Alaa
    Cairo Univ, EGNC, Egypt Nanotechnol Ctr, 6th October City 12588, Egypt.;Akhbar El Yom Acad, Prod Engn & Printing Technol Dept, Giza 12655, Egypt..
    Belaqziz, Majdouline
    Cadi Ayyad Univ, Natl Ctr Study & Res Water & Energy, BP 511, Marrakech 40000, Morocco..
    Nasser, Walaa S.
    Res Inst Med Entomol, Giza 12611, Egypt..
    Photocatalytic degradation of Ibuprofen, Naproxen, and Cetirizine using PAN-MWCNT nanofibers crosslinked TiO2-NH2 nanoparticles under visible light irradiation2019Inngår i: Separation and Purification Technology, ISSN 1383-5866, E-ISSN 1873-3794, Vol. 212, s. 110-118Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In this work the photocatalytic degradation of pharmaceuticals (Ibuprofen, Cetirizine, and Naproxen) was evaluated using surface modified TiO2 nanoparticles immobilized on polyacrylonitrile/multiwall carbon nanotubes composite nanofibers. The photocatalytic degradation was studied under visible light (0.1 W/cm(2)) irradiation. Comparatively, the photocatalytic degradation of pharmaceuticals using PAN-CNT/TiO2-NH2 composite nanofibers was much more efficient than with PAN/TiO2-NH2 composite nanofibers under visible light irradiation. The results obtained showed that the photocatalytic efficiency of the studied pharmaceuticals is pH dependent in which more than 99% degradation was obtained at pH 2. Complete degradation of IBP, CTZ, and NPX was achieved within 200, 50, and 90 min, respectively under visible light.

  • 8.
    Yazdi, Milad Ghadami
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik.
    Ivanic, M.
    Rudjer Boskovic Inst, Div Marine & Environm Res, Zagreb, Croatia..
    Mohamed, Alaa
    Cairo Univ, Egypt Nanotechnol Ctr, EGNC, 6Th October City 12588, Egypt.;Karlsruhe Inst Technol, Inst Funct Interfaces IFG, Membrane Technol Dept, D-76344 Karlsruhe, Germany.;Akhbar El Yom Acad, Prod Engn & Printing Technol Dept, Giza 12655, Egypt..
    Uheida, Abdusalam
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik.
    Surface modified composite nanofibers for the removal of indigo carmine dye from polluted water2018Inngår i: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 8, nr 43, s. 24588-24598Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Surface coated magnetite nanoparticles (Fe3O4 NPs) with 3-mercaptopropionic acid were immobilized on amidoximated polyacrilonitrile (APAN) nanofibers using electrospinning followed by crosslinking. The prepared composite nanofibers were characterized with Scanning Electron Microscopy (SEM), and Fourier Transform Infrared analysis (FTIR). The composite nanofiber was evaluated for the removal of indigo carmine dye from aqueous solutions. The effects of contact time, initial dye concentration, solution pH and adsorption equilibrium isotherms were studied. The adsorption of indigo carmine was found to be greatly affected by solution pH. The maximum loading capacity was determined to be 154.5 mg g(-1) at pH = 5. The experimental kinetic data were fitted well using a pseudo-first order model. The adsorption isotherm studies showed that the adsorption of indigo carmine fits well with the Langmuir model. The reuse of the composite nanofiber was also investigated in which more than 90% of indigo carmine was recovered in 5 min. The results of stability studies showed that the adsorption efficiency can remain almost constant (90%) after five consecutive adsorption/desorption cycles.

  • 9.
    Yohai, L.
    et al.
    UNMdP, CONICET, INTEMA, Div Ceram, B7608FDQ, Mar Del Plata, Buenos Aires, Argentina.
    Giraldo Mejía, Hugo
    Procaccini, R.
    Pellice, S.
    Laxman Kunjali, Karthik
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik.
    Dutta, Joydeep
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik.
    Uheida, Abdusalam
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik.
    Nanocomposite functionalized membranes based on silica nanoparticles oss-linked to electrospun nanofibrous support for arsenic(v) sorption from contaminated underground water2019Inngår i: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 9, nr 15, s. 8280-8289Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Nanocomposite functionalized membranes were synthesized using surface functionalized mesoporous silica nanoparticles (MCM-NH2 or MCM-PEI) cross-linked to a modified polyacrylonitrile (mPAN) nanofibrous substrate for the removal of 1 mg L-1 of As(V); a concentration much higher than what has been reported for underground water in Argentina. Adsorption studies were carried out in batch mode at pH 8 with nanoparticles in colloidal form, as well as the nanoparticles supported on the modified PAN membranes (mPAN/MCM-NH2 and mPAN/MCM-PEI). Results indicate a twenty-fold improvement in As(V) adsorption with supported nanoparticles (nanocomposite membranes) as opposed to their colloidal form. The adsorption efficiency could be further enhanced by modifying the nanocomposite membrane surface with Fe3+ (mPAN/MCM-NH2-Fe3+ and mPAN/MCM-PEI-Fe3+) which resulted in more than 95% arsenic being removed within the first 15 minutes and a specific arsenic adsorption capacity of 4.61 mg g(-1) and 5.89 mg g(-1) for mPAN/MCM-NH2-Fe3+ and mPAN/MCM-PEI-Fe3+ nanocomposite membranes, respectively. The adsorption characteristics were observed to follow a pseudo-first order behavior. The results suggest that the synthesized materials are excellent for quick and efficient reduction of As(V) concentrations below the WHO guidelines and show promise for future applications.

  • 10.
    Zohdi, Zeynab
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik. Karolinska Inst, Dept Clin Neurosci, Ctr Psychiat Res, SE-17176 Solna, Sweden ; Univ Bu Ali Sina, Dept Chem, Hamadan 65174, Iran.
    Hashemi, Mahdi
    Univ Bu Ali Sina, Dept Chem, Hamadan 65174, Iran..
    Uheida, Abdusalam
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik.
    Moein, Mohammad Mahdi
    Karolinska Inst, Dept Clin Neurosci, Ctr Psychiat Res, SE-17176 Solna, Sweden..
    Abdel-Rehim, Mohamed
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik. Karolinska Inst, Dept Clin Neurosci, Ctr Psychiat Res, SE-17176 Solna, Sweden Dept Appl Phys, SE-16440 Stockholm, Sweden..
    Graphene Oxide Tablets for Sample Preparation of Drugs in Biological Fluids: Determination of Omeprazole in Human Saliva for Liquid Chromatography Tandem Mass Spectrometry2019Inngår i: Molecules, ISSN 1420-3049, E-ISSN 1420-3049, Vol. 24, nr 7, artikkel-id 1191Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In this study, a novel sort of sample preparation sorbent was developed, by preparing thin layer graphene oxide tablets (GO-Tabs) utilizing a mixture of graphene oxide and polyethylene glycol on a polyethylene substrate. The GO-Tabs were used for extraction and concentration of omeprazole (OME) in human saliva samples. The determination of OME was carried out using liquid chromatography-tandem mass spectrometry (LC-MS/MS) under gradient LC conditions and in the positive ion mode (ESI+) with mass transitions of m/z 346.3 -> 198.0 for OME and m/z 369.98 -> 252.0 for the internal standard. Standard calibration for the saliva samples was in the range of 2.0-2000 nmol L-1. Limits of detection and quantification were 0.05 and 2.0 nmol L-1, respectively. Method validation showed good method accuracy and precision; the inter-day precision values ranged from 5.7 to 8.3 (%RSD), and the accuracy of determinations varied from -11.8% to 13.3% (% deviation from nominal values). The extraction recovery was 60%, and GO-Tabs could be re-used for more than ten extractions without deterioration in recovery. In this study, the determination of OME in real human saliva samples using GO-Tab extraction was validated.

1 - 10 of 10
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