Marwa Sherief

National Research Center, Egypt | NRC · Department of Inorganic Chemistry

This work aims to develop a new kind of ethylene propylene diene rubber (EPDM) to be utilized as insulator in electrical cables. This type was incorporated with Al(OH) 3 , Al 2 O 3 , and graphene oxide (GO) to decrease the flammability of the rubber. Al 2 O 3 nanoparticle was synthesized via Sol-Gel route. The produced nano Al 2 O 3 powder was char...

Background The objective of the study was to prepare and assess novel remineralizing oral films loaded with fluorapatite powder and composed of a combination of hydroxyethyl cellulose (HC) and cellulose nanofibers (CF). Methods Three concentrations of the prepared nano-fluorapatite were tried and tested after loading in the cellulose blends and fi...

Copper-doped ZnO nanoparticles with the formula Zn1−x(Cu)O, where x = 0.0, 0.03, 0.05, and 0.07 were produced using the co-precipitation process. Physical, chemical, and structural properties were properly examined. Powdered X-ray diffraction (P-XRD) patterns revealed the formation of hexagonal wurtzite crystal structure in all samples, through ato...

Background and Aim Yeasts are common contaminants in the cheese industry, which frequently arise from raw milk, the surrounding environment, and equipment, resulting in economic losses in addition to health hazards. This study aimed to compare the antifungal effect of chitosan and nano-chitosan as natural preservatives with a commonly used chemical...

The main purpose of this work was to boost the surface and adsorption characteristics of diatomite (D) through chemical modifications with chitosan (DC), chitosan/titanium isopropoxide (DCTi), or chitosan/ graphene oxide (DCGr), respectively. Physicochemical characteristics of the prepared samples were investigated using SEM, TEM, XRD, FTIR, TGA, a...

Conversion of industrial wastes to valuable products has become a global requirement to reduce the pollution of environment. This study intended to utilize the solid waste of calcium hydroxide fouled with gases which produced from smokestacks of glass industry by using low-cost and simple procedure. In the current work, this waste was converted to...

Marine microalgae (Diatoms, DE) acting as a cost-effective natural source of silicon have been used in a large variety of applications in several biotechnology sectors. Adding silver nanoparticles onto the diatom surface, could be motivated to obtain Ag-DE/NPs. Marine algae derivatives are promising as innovative applicants in antibacterial drug di...

The aim of this work is recovery the chromium content from the tannery wastewater to decrease the environmental pollution. Also, benefit the extracted chromium compound by study their electrical behavior to be used as humidity sensor device. The chromium content was extracted as a solid power by using MgO for precipitation. The prepared dry powder...

To study the effects of the precursor materials on the structure, the morphology, and the thermal stability of Mg(OH) 2 particles, five samples were prepared by using the same method. The produced powder was characterized by using FTIR, XRD, SEM, and TEM, and the thermal stability was studied by using the thermogravimetric analysis. This study aims...

This study reports the influence of zinc oxide (ZnO) on the bioactivity and antimicrobial properties of nano-hydrxoyapatite. Nanoparticles of hydroxyapatite (HA) were prepared by a sol-gel method. The dried prepared particles were mixed with different percentages of ZnO (25, 50 and 75% wt. %). The produced samples were characterized by Fourier tran...

Fire performance of polypropylene (PP) containing different percentages of ammonium polyphosphate (APP) with montmorillonite (Mt) or treated montmorillonite (MtT) was carried out by using the cone calorimeter test (CCT). Different samples from ammonium polyphosphate and montmorillonite were mixed with 90% polypropylene. The characterization of the...

This paper aims at preparation of disordered mesoporous silicates from the diatomite ore as a natural resource of silica. Studying the morphological, chemical and textural properties of the prepared silicate samples was evaluated by field-emission scanning electron microscope (FE-SEM) combined with energy dispersive spectroscopy (EDS), high-resolut...

THIS WORK is a continuation of the previous works by the authors to increase the efficiency of ammonium polyphosphate (APP) as flame retardant for polypropylene(PP). In this work a more abundant kaolin was used. Also to improve the efficiency of kaolin, an acid modification by sulfuric acid was used. XRD, XRF, IR, SEM and BET were used to character...

Due to the bioactivity and the excellent properties of the rare earth elements, the effects of adding different amounts of La and Ce to the familiar base glass materials were studied. Different samples with and without rare earth elements were tested without farther calcinations. X-ray diffraction and IR spectrum were used to characterize the produ...

To evaluate the effects of nano hydroxyapatite (NHAP) and amorphous calcium phosphate (ACP) remineralizing agents on the surface roughness of bleached bovine enamel. A total of 25 bovine anterior teeth were prepared for this study. They were randomly divided into two main groups the control group (n=5) and the experimental group (n=20) which receiv...

The flammability of a mixture of (APP/DE)/PP was studied by using both the thermogravimetric analysis and the cone- calorimeter test. In this study the (APP/DG)/PP system was characterized by using the IR spectra, the X-ray diffraction and the morphology of their mixture. The IR spectra indicate that there are incorporate of DE into the APP structu...

Phosphogypsum (PG) derived from the manufacturing of phosphoric acid by wet process method was converted to nano-particle hydroxyapatite (HAP). Also, the effects of the calcination temperature and the doping with some rare earth elements (La and/or Ce) on the structure of the produced HAP particles were studied. The produced samples were characteri...

This study aimed to prepare nanostructured hydroxyapatite (nHAp) by sol-gel method and assess the influence of its incorporation with different concentrations into a dental resin composite. The prepared nHAp powder was characterized by X-ray diffraction (XRD), infrared spectrum (IR), and scanning electron microscopy (SEM). nHAp was added to a comme...

This study aimed to prepare nanostructured hydroxyapatite (nHAp) by sol-gel method and assess the influence of its incorporation with different concentrations into a dental resin composite. The prepared nHAp powder was characterized by X-ray diffraction (XRD), infrared spectrum (IR), and scanning electron microscopy (SEM). nHAp was added to a comme...

The purpose of this study was to prepare amorphous nano-hydroxyapatite fillers by sol-gel method and incorporating the prepared fillers into traditional PMMA bone cement to test the compressive strength of amorphous nHA/PMMA composite. The prepared fillers were characterized by XRD, FT-IR andTEM. We prepared composite specimens containing 20 wt% am...

The prepared nanosized ammonium polyphosphates (APP) from ammonium dihydrogen phosphate and urea in the presence of ammonia solution was evaluated as flame retardant for polypropylene (PP). The results of study show that negligible change has occurred on the mechanical properties with APP addition. Both the thermogravimetric analysis (TG and DTA) a...

The aim of this work is stydying the removal of some divalent cations, Cd, Cu, and Co from their aqueous solutions by using the natural materials, diatomite. The diatomite material was characterized by the chemical analysis, IR, X-ray and TEM also the surface area was calculated. The results of characterization indicate that diatomite consist mainl...

Diatomite (DE), Ferrihidrite- modified diatomite (DFe) and microemulsion modified diatomite (DEM) were used for removal of phosphate ions from their aqueous solutions. The diatomite (DE) and the modified diatomite [DFe and DEM] were characterized by X-ray, IR and SEM also surface area was estimated. The results of characterization indicated that, t...

Ammonium polyphosphate (APP) had been prepared from ammonium dihydrogen phosphate, urea, and ammonia solution. The produced sample was dried and characterized by using IR, XRD, TG, and DTA. The morphology of the product was examined by using TEM and SEM. The results of characterization indicate that the produced APP has a structure belong to form I...

The aim of this work is stydying the removal of some divalent cations, Cd, Cu, and Co from their aqueous solutions by using the natural materials, diatomite. The diatomite material was characterized by the chemical analysis, IR, X-ray and TEM also the surface area was calculated. The results of characterization indicate that diatomite consist mainl...

Fast proton conductors could be chemicovectrially prepared by introducing a large amount of water into magnesium metaphosphate. When fine-sized magnesium metaphosphate powders (MP) were contacted with distilled water (DW), hydrogelation started resulting in formation of magnesium polyphosphates with high viscosity. Different hydrated glass samples...

Y PO4 and Mg2P2O7 mixed ceramic semiconductor samples were prepared and investigated to be used as humidity sensors. The samples were characterized using XRD. Surface area, SEM, and electrical conductivity under the effect of humidity at room temperature were measured and discussed. X-ray patterns showed the formation of YPO4 in tetragonal phase an...

Fast proton conductors could be chemicovectrially prepared by introducing a large amount of water into magnesium metaphosphate. When fine–sized magnesium metaphosphate powders (MP) were contacted with distilled water (DW), hydrogelation started resulting in formation of magnesium polyphosphates with high viscosity. Different hydrated glass samples...

The efficacy of Natural diatomaceous (DE) alone and combined with three fungal pathogens: Beauveria bassiana, Metarhizium anisopliae and Isaria fumosorosea against three moth species, Plodia interpunctella, Ephestia cautella and E. kuehniella was evaluated. Modified diatoms with Calcium hydroxide (Ca-DE) and modified diatoms with Sodium hydroxide (...

Cerium phosphate, CePO4, nanoparticles with hexagonal or monoclinic phase was synthesized by the reaction between Ce(SO4)2.4H2O and two different phosphate sources, H3PO4 and Na2HPO4. The obtained gel was dried and calcined at different temperatures (200, 400, and 800 оC). The effects of the precursor materials and the calcination temperatures on t...

Condensed phosphates are generally prepared from their simple phosphates by heating at high temperature. The formation, structure and the morphology of the resultant condensed phosphates depend on the kind of inorganic cations as well as the conditions of preparation, temperature, heating time, and cooling rate of the melt. Condensed sodium phospha...

Two samples of rare earth cuprates, RE2CuO4 (RE =La, Eu, Nd) were prepared by using sol-gel method. The first sample was prepared by mixing RECl3 and CuCl2 with molar ratio 1:1 in presence of ethylene oxide gas as gelating agent. The product was dried at 120°C The second one was prepared from RECl3 and CuCl2 and using citric acid and ethylene glyco...

The objective of this work is to study the feasibility of two raw materials, calcite and dolomite, as adsorbent for phosphate removal from wastewater. The natural ores were characterized by using both chemical analysis and x-ray diffraction. The results indicate that the calcite sample having the chemical formula CaCO3(99 %Ca) and the dolomite is C...