The Experts below are selected from a list of 111 Experts worldwide ranked by ideXlab platform

Ubirajara P. Rodrigues-filho - One of the best experts on this subject based on the ideXlab platform.

  • Photoactive layer-by-layer films of Cellulose Phosphate and titanium dioxide containing phosphotungstic acid
    Applied Surface Science, 2013
    Co-Authors: Sajjad Ullah, J. J. S. Acuña, André A. Pasa, Sara A. Bilmes, María Elena Vela, Guillermo Benítez, Ubirajara P. Rodrigues-filho
    Abstract:

    A versatile layer-by-layer (LbL) procedure for the preparation of highly dispersed, adherent and porous multilayer films of TiO2 nanoparticles (NPs) and phosphotungstic acid (HPW) on a variety of substrates at room temperature was developed based on the use of Cellulose Phosphate (CP) as an efficient and non-conventional polyelectrolyte. UV/vis absorption spectroscopy confirmed the linear and regular growth of the films with the number of immersion cycles and a strong adsorption ability of CP towards TiO2 NPs. FTIR spectroscopy showed that HPW binds to the surface of TiO2 through the oxygen atom at the corner of the Keggin structure. XPS results showed that the interaction between TiO2 and CP is through Ti–O–P linkage. A model is proposed for the TiO2–HPW interaction based on XPS and FTIR results. FEG/SEM study of the surface morphology revealed a porous film structure with a homogenous distribution of the TiO2 NPs induced by CP. HRTEM studies showed that the resulting composite films consist of crystalline anatase and rutile phases and poly-nano-crystalline HPW with a semi-crystalline TiO2–HPW interface. These CP/TiO2 and CP/TiO2/HPW LbL films showed good photoactivity against both saturated and unsaturated species, for instance, stearic acid (SA), crystal violet (CV) and methylene blue (MB) under UV irradiation. The CP/HPW films formed on bacterial Cellulose (BC) showed good photochromic response which is enhanced in presence of TiO2 due to an interfacial electron transfer from TiO2 to HPW. This simple and environmentally safe method can be used to form coatings on a variety of surfaces with photoactive TiO2 and TiO2/HPW films.

Sherif M.a.s. Keshk - One of the best experts on this subject based on the ideXlab platform.

  • Novel synthesis of flame-retardant magnetic nanoparticles/hydroxy acid Cellulose-6-Phosphate composite
    Materials Research Express, 2019
    Co-Authors: Sherif M.a.s. Keshk, Adel A. El-zahhar, Ayman M. S. Youssef, Samir Bondock
    Abstract:

    In the present paper, an eco-friendly synthesis route is proposed to produce fire-retardant magnetic nanoparticles (MNPs; Fe3O4)/hydroxyl acid Cellulose Phosphate (HACP) composite. Dialdehyde Cellulose Phosphate (DACP) experienced an intramolecular Cannizzaro reaction during the in situ preparation of MNPs and produced HACP. The (Fe3+/Fe2+) co-precipitation method was employed to prepare the MNPs/HACP composite from DACP. The microstructural properties of the produced composite were assessed through FT-IR, Raman spectroscopy, x-ray diffraction (XRD), SEM, TGA, and DTA. The XRD analysis revealed a significant change in the DACP phase of the MNPs/HACP composite, and SEM images confirmed a homogenous distribution of MNPs in hydroxyl acid. Furthermore, DSC and TGA proved that char yield increased from 8% in DACP to 25% in the composite in the temperature range of 600 °C–800 °C; hence, it indicates that MNPs significantly increased the flame retardancy of the composite as compared to Cellulose Phosphate (CP) and DACP.

  • novel synthesis of flame retardant magnetic nanoparticles hydroxy acid Cellulose 6 Phosphate composite
    Materials Research Express, 2019
    Co-Authors: Sherif M.a.s. Keshk, Ayman M. S. Youssef, Samir Bondock, Adel A Elzahhar
    Abstract:

    In the present paper, an eco-friendly synthesis route is proposed to produce fire-retardant magnetic nanoparticles (MNPs; Fe3O4)/hydroxyl acid Cellulose Phosphate (HACP) composite. Dialdehyde Cellulose Phosphate (DACP) experienced an intramolecular Cannizzaro reaction during the in situ preparation of MNPs and produced HACP. The (Fe3+/Fe2+) co-precipitation method was employed to prepare the MNPs/HACP composite from DACP. The microstructural properties of the produced composite were assessed through FT-IR, Raman spectroscopy, x-ray diffraction (XRD), SEM, TGA, and DTA. The XRD analysis revealed a significant change in the DACP phase of the MNPs/HACP composite, and SEM images confirmed a homogenous distribution of MNPs in hydroxyl acid. Furthermore, DSC and TGA proved that char yield increased from 8% in DACP to 25% in the composite in the temperature range of 600 °C–800 °C; hence, it indicates that MNPs significantly increased the flame retardancy of the composite as compared to Cellulose Phosphate (CP) and DACP.

  • Synthesis and characterization of novel Schiff’s bases derived from dialdehyde Cellulose-6-Phosphate
    Cellulose, 2019
    Co-Authors: Sherif M.a.s. Keshk, Adel A. El-zahhar, Samir Bondock, Mohammad Abu Haija
    Abstract:

    In this study, the effects of replacing a hydroxyl group on C-6 of Cellulose by a Phosphate group, as in Cellulose-6-Phosphate, on the aldehyde content and the reactivity of dialdehyde Cellulose Phosphate were explored. Cellulose-6-Phosphate ( 1 ) was efficiently oxidized by using an aqueous solution of potassium periodate to obtain dialdehyde Cellulose Phosphate (DACP) ( 2 ). The condensation of DACP with two aromatic amines, sulfanilamide ( 3 ) and sulfathiazole ( 4 ) produced the respective Schiff bases, namely (Cellulose-6-phoshate-2,3-bis-[(4-methylene-amino)-benzene-sulfonamide] ( 5 ) and Cellulose-6-phoshate-2,3-bis-[(4-methylene-amino)- N -(thiazol-2-yl) benzene sulfonamide] ( 6 ). Fourier transform infrared spectra, scanning electron microscope (SEM), X-ray diffraction (XRD), and thermal gravimetric analysis (TGA) were used to characterize the synthesized biopolymers. For compounds 2 , 5 , and 6, the aldehyde content of was found to be 95%, 20.1%, and 11.2%, respectively. The highest reactivity of DACP toward sulfa drugs was displayed due to aldehyde content values. Significant changes in the d -spacing with decreasing crystallinity index (46.9%) were observed in the XRD of Cellulose-6-Phosphate and its Schiff’s base. In SEM images, a fibrous structure and a rough surface were observed in the samples with slight variations. The results of TGA showed a delay in the major degradation step for DACP, Cellulose-6-Phosphate-2,3-bis[(4-methyleneamino)- N -(thiazol-2-yl)-benzen sulfonamide] and Cellulose-6-Phosphate-2,3-bis-[(4-methyleneamino)-benzene sulfonamide] compared to Cellulose Phosphate.

  • synthesis and characterization of novel schiff s bases derived from dialdehyde Cellulose 6 Phosphate
    Cellulose, 2019
    Co-Authors: Sherif M.a.s. Keshk, Samir Bondock, Adel A Elzahhar, Mohammad Abu Haija
    Abstract:

    In this study, the effects of replacing a hydroxyl group on C-6 of Cellulose by a Phosphate group, as in Cellulose-6-Phosphate, on the aldehyde content and the reactivity of dialdehyde Cellulose Phosphate were explored. Cellulose-6-Phosphate (1) was efficiently oxidized by using an aqueous solution of potassium periodate to obtain dialdehyde Cellulose Phosphate (DACP) (2). The condensation of DACP with two aromatic amines, sulfanilamide (3) and sulfathiazole (4) produced the respective Schiff bases, namely (Cellulose-6-phoshate-2,3-bis-[(4-methylene-amino)-benzene-sulfonamide] (5) and Cellulose-6-phoshate-2,3-bis-[(4-methylene-amino)-N-(thiazol-2-yl) benzene sulfonamide] (6). Fourier transform infrared spectra, scanning electron microscope (SEM), X-ray diffraction (XRD), and thermal gravimetric analysis (TGA) were used to characterize the synthesized biopolymers. For compounds 2, 5, and 6, the aldehyde content of was found to be 95%, 20.1%, and 11.2%, respectively. The highest reactivity of DACP toward sulfa drugs was displayed due to aldehyde content values. Significant changes in the d-spacing with decreasing crystallinity index (46.9%) were observed in the XRD of Cellulose-6-Phosphate and its Schiff’s base. In SEM images, a fibrous structure and a rough surface were observed in the samples with slight variations. The results of TGA showed a delay in the major degradation step for DACP, Cellulose-6-Phosphate-2,3-bis[(4-methyleneamino)-N-(thiazol-2-yl)-benzen sulfonamide] and Cellulose-6-Phosphate-2,3-bis-[(4-methyleneamino)-benzene sulfonamide] compared to Cellulose Phosphate.

Mohammad Abu Haija - One of the best experts on this subject based on the ideXlab platform.

  • Synthesis and characterization of novel Schiff’s bases derived from dialdehyde Cellulose-6-Phosphate
    Cellulose, 2019
    Co-Authors: Sherif M.a.s. Keshk, Adel A. El-zahhar, Samir Bondock, Mohammad Abu Haija
    Abstract:

    In this study, the effects of replacing a hydroxyl group on C-6 of Cellulose by a Phosphate group, as in Cellulose-6-Phosphate, on the aldehyde content and the reactivity of dialdehyde Cellulose Phosphate were explored. Cellulose-6-Phosphate ( 1 ) was efficiently oxidized by using an aqueous solution of potassium periodate to obtain dialdehyde Cellulose Phosphate (DACP) ( 2 ). The condensation of DACP with two aromatic amines, sulfanilamide ( 3 ) and sulfathiazole ( 4 ) produced the respective Schiff bases, namely (Cellulose-6-phoshate-2,3-bis-[(4-methylene-amino)-benzene-sulfonamide] ( 5 ) and Cellulose-6-phoshate-2,3-bis-[(4-methylene-amino)- N -(thiazol-2-yl) benzene sulfonamide] ( 6 ). Fourier transform infrared spectra, scanning electron microscope (SEM), X-ray diffraction (XRD), and thermal gravimetric analysis (TGA) were used to characterize the synthesized biopolymers. For compounds 2 , 5 , and 6, the aldehyde content of was found to be 95%, 20.1%, and 11.2%, respectively. The highest reactivity of DACP toward sulfa drugs was displayed due to aldehyde content values. Significant changes in the d -spacing with decreasing crystallinity index (46.9%) were observed in the XRD of Cellulose-6-Phosphate and its Schiff’s base. In SEM images, a fibrous structure and a rough surface were observed in the samples with slight variations. The results of TGA showed a delay in the major degradation step for DACP, Cellulose-6-Phosphate-2,3-bis[(4-methyleneamino)- N -(thiazol-2-yl)-benzen sulfonamide] and Cellulose-6-Phosphate-2,3-bis-[(4-methyleneamino)-benzene sulfonamide] compared to Cellulose Phosphate.

  • synthesis and characterization of novel schiff s bases derived from dialdehyde Cellulose 6 Phosphate
    Cellulose, 2019
    Co-Authors: Sherif M.a.s. Keshk, Samir Bondock, Adel A Elzahhar, Mohammad Abu Haija
    Abstract:

    In this study, the effects of replacing a hydroxyl group on C-6 of Cellulose by a Phosphate group, as in Cellulose-6-Phosphate, on the aldehyde content and the reactivity of dialdehyde Cellulose Phosphate were explored. Cellulose-6-Phosphate (1) was efficiently oxidized by using an aqueous solution of potassium periodate to obtain dialdehyde Cellulose Phosphate (DACP) (2). The condensation of DACP with two aromatic amines, sulfanilamide (3) and sulfathiazole (4) produced the respective Schiff bases, namely (Cellulose-6-phoshate-2,3-bis-[(4-methylene-amino)-benzene-sulfonamide] (5) and Cellulose-6-phoshate-2,3-bis-[(4-methylene-amino)-N-(thiazol-2-yl) benzene sulfonamide] (6). Fourier transform infrared spectra, scanning electron microscope (SEM), X-ray diffraction (XRD), and thermal gravimetric analysis (TGA) were used to characterize the synthesized biopolymers. For compounds 2, 5, and 6, the aldehyde content of was found to be 95%, 20.1%, and 11.2%, respectively. The highest reactivity of DACP toward sulfa drugs was displayed due to aldehyde content values. Significant changes in the d-spacing with decreasing crystallinity index (46.9%) were observed in the XRD of Cellulose-6-Phosphate and its Schiff’s base. In SEM images, a fibrous structure and a rough surface were observed in the samples with slight variations. The results of TGA showed a delay in the major degradation step for DACP, Cellulose-6-Phosphate-2,3-bis[(4-methyleneamino)-N-(thiazol-2-yl)-benzen sulfonamide] and Cellulose-6-Phosphate-2,3-bis-[(4-methyleneamino)-benzene sulfonamide] compared to Cellulose Phosphate.

Sajjad Ullah - One of the best experts on this subject based on the ideXlab platform.

  • Photoactive layer-by-layer films of Cellulose Phosphate and titanium dioxide containing phosphotungstic acid
    Applied Surface Science, 2013
    Co-Authors: Sajjad Ullah, J. J. S. Acuña, André A. Pasa, Sara A. Bilmes, María Elena Vela, Guillermo Benítez, Ubirajara P. Rodrigues-filho
    Abstract:

    A versatile layer-by-layer (LbL) procedure for the preparation of highly dispersed, adherent and porous multilayer films of TiO2 nanoparticles (NPs) and phosphotungstic acid (HPW) on a variety of substrates at room temperature was developed based on the use of Cellulose Phosphate (CP) as an efficient and non-conventional polyelectrolyte. UV/vis absorption spectroscopy confirmed the linear and regular growth of the films with the number of immersion cycles and a strong adsorption ability of CP towards TiO2 NPs. FTIR spectroscopy showed that HPW binds to the surface of TiO2 through the oxygen atom at the corner of the Keggin structure. XPS results showed that the interaction between TiO2 and CP is through Ti–O–P linkage. A model is proposed for the TiO2–HPW interaction based on XPS and FTIR results. FEG/SEM study of the surface morphology revealed a porous film structure with a homogenous distribution of the TiO2 NPs induced by CP. HRTEM studies showed that the resulting composite films consist of crystalline anatase and rutile phases and poly-nano-crystalline HPW with a semi-crystalline TiO2–HPW interface. These CP/TiO2 and CP/TiO2/HPW LbL films showed good photoactivity against both saturated and unsaturated species, for instance, stearic acid (SA), crystal violet (CV) and methylene blue (MB) under UV irradiation. The CP/HPW films formed on bacterial Cellulose (BC) showed good photochromic response which is enhanced in presence of TiO2 due to an interfacial electron transfer from TiO2 to HPW. This simple and environmentally safe method can be used to form coatings on a variety of surfaces with photoactive TiO2 and TiO2/HPW films.

Samir Bondock - One of the best experts on this subject based on the ideXlab platform.

  • Novel synthesis of flame-retardant magnetic nanoparticles/hydroxy acid Cellulose-6-Phosphate composite
    Materials Research Express, 2019
    Co-Authors: Sherif M.a.s. Keshk, Adel A. El-zahhar, Ayman M. S. Youssef, Samir Bondock
    Abstract:

    In the present paper, an eco-friendly synthesis route is proposed to produce fire-retardant magnetic nanoparticles (MNPs; Fe3O4)/hydroxyl acid Cellulose Phosphate (HACP) composite. Dialdehyde Cellulose Phosphate (DACP) experienced an intramolecular Cannizzaro reaction during the in situ preparation of MNPs and produced HACP. The (Fe3+/Fe2+) co-precipitation method was employed to prepare the MNPs/HACP composite from DACP. The microstructural properties of the produced composite were assessed through FT-IR, Raman spectroscopy, x-ray diffraction (XRD), SEM, TGA, and DTA. The XRD analysis revealed a significant change in the DACP phase of the MNPs/HACP composite, and SEM images confirmed a homogenous distribution of MNPs in hydroxyl acid. Furthermore, DSC and TGA proved that char yield increased from 8% in DACP to 25% in the composite in the temperature range of 600 °C–800 °C; hence, it indicates that MNPs significantly increased the flame retardancy of the composite as compared to Cellulose Phosphate (CP) and DACP.

  • novel synthesis of flame retardant magnetic nanoparticles hydroxy acid Cellulose 6 Phosphate composite
    Materials Research Express, 2019
    Co-Authors: Sherif M.a.s. Keshk, Ayman M. S. Youssef, Samir Bondock, Adel A Elzahhar
    Abstract:

    In the present paper, an eco-friendly synthesis route is proposed to produce fire-retardant magnetic nanoparticles (MNPs; Fe3O4)/hydroxyl acid Cellulose Phosphate (HACP) composite. Dialdehyde Cellulose Phosphate (DACP) experienced an intramolecular Cannizzaro reaction during the in situ preparation of MNPs and produced HACP. The (Fe3+/Fe2+) co-precipitation method was employed to prepare the MNPs/HACP composite from DACP. The microstructural properties of the produced composite were assessed through FT-IR, Raman spectroscopy, x-ray diffraction (XRD), SEM, TGA, and DTA. The XRD analysis revealed a significant change in the DACP phase of the MNPs/HACP composite, and SEM images confirmed a homogenous distribution of MNPs in hydroxyl acid. Furthermore, DSC and TGA proved that char yield increased from 8% in DACP to 25% in the composite in the temperature range of 600 °C–800 °C; hence, it indicates that MNPs significantly increased the flame retardancy of the composite as compared to Cellulose Phosphate (CP) and DACP.

  • Synthesis and characterization of novel Schiff’s bases derived from dialdehyde Cellulose-6-Phosphate
    Cellulose, 2019
    Co-Authors: Sherif M.a.s. Keshk, Adel A. El-zahhar, Samir Bondock, Mohammad Abu Haija
    Abstract:

    In this study, the effects of replacing a hydroxyl group on C-6 of Cellulose by a Phosphate group, as in Cellulose-6-Phosphate, on the aldehyde content and the reactivity of dialdehyde Cellulose Phosphate were explored. Cellulose-6-Phosphate ( 1 ) was efficiently oxidized by using an aqueous solution of potassium periodate to obtain dialdehyde Cellulose Phosphate (DACP) ( 2 ). The condensation of DACP with two aromatic amines, sulfanilamide ( 3 ) and sulfathiazole ( 4 ) produced the respective Schiff bases, namely (Cellulose-6-phoshate-2,3-bis-[(4-methylene-amino)-benzene-sulfonamide] ( 5 ) and Cellulose-6-phoshate-2,3-bis-[(4-methylene-amino)- N -(thiazol-2-yl) benzene sulfonamide] ( 6 ). Fourier transform infrared spectra, scanning electron microscope (SEM), X-ray diffraction (XRD), and thermal gravimetric analysis (TGA) were used to characterize the synthesized biopolymers. For compounds 2 , 5 , and 6, the aldehyde content of was found to be 95%, 20.1%, and 11.2%, respectively. The highest reactivity of DACP toward sulfa drugs was displayed due to aldehyde content values. Significant changes in the d -spacing with decreasing crystallinity index (46.9%) were observed in the XRD of Cellulose-6-Phosphate and its Schiff’s base. In SEM images, a fibrous structure and a rough surface were observed in the samples with slight variations. The results of TGA showed a delay in the major degradation step for DACP, Cellulose-6-Phosphate-2,3-bis[(4-methyleneamino)- N -(thiazol-2-yl)-benzen sulfonamide] and Cellulose-6-Phosphate-2,3-bis-[(4-methyleneamino)-benzene sulfonamide] compared to Cellulose Phosphate.

  • synthesis and characterization of novel schiff s bases derived from dialdehyde Cellulose 6 Phosphate
    Cellulose, 2019
    Co-Authors: Sherif M.a.s. Keshk, Samir Bondock, Adel A Elzahhar, Mohammad Abu Haija
    Abstract:

    In this study, the effects of replacing a hydroxyl group on C-6 of Cellulose by a Phosphate group, as in Cellulose-6-Phosphate, on the aldehyde content and the reactivity of dialdehyde Cellulose Phosphate were explored. Cellulose-6-Phosphate (1) was efficiently oxidized by using an aqueous solution of potassium periodate to obtain dialdehyde Cellulose Phosphate (DACP) (2). The condensation of DACP with two aromatic amines, sulfanilamide (3) and sulfathiazole (4) produced the respective Schiff bases, namely (Cellulose-6-phoshate-2,3-bis-[(4-methylene-amino)-benzene-sulfonamide] (5) and Cellulose-6-phoshate-2,3-bis-[(4-methylene-amino)-N-(thiazol-2-yl) benzene sulfonamide] (6). Fourier transform infrared spectra, scanning electron microscope (SEM), X-ray diffraction (XRD), and thermal gravimetric analysis (TGA) were used to characterize the synthesized biopolymers. For compounds 2, 5, and 6, the aldehyde content of was found to be 95%, 20.1%, and 11.2%, respectively. The highest reactivity of DACP toward sulfa drugs was displayed due to aldehyde content values. Significant changes in the d-spacing with decreasing crystallinity index (46.9%) were observed in the XRD of Cellulose-6-Phosphate and its Schiff’s base. In SEM images, a fibrous structure and a rough surface were observed in the samples with slight variations. The results of TGA showed a delay in the major degradation step for DACP, Cellulose-6-Phosphate-2,3-bis[(4-methyleneamino)-N-(thiazol-2-yl)-benzen sulfonamide] and Cellulose-6-Phosphate-2,3-bis-[(4-methyleneamino)-benzene sulfonamide] compared to Cellulose Phosphate.