Entity

Time filter

Source Type


Polyaniline (PAni) nanocomposites were prepared via in situ emulsion polymerization using dodecylbenzene sulfonic acid (DBSA) as an emulsifier and doping agent in the presence of titanium dioxide nanowires (TiO 2-NWs). Firstly, TiO2 nanoparticles (P25) were converted to TiO2 nanowires through a hydrothermal process using 10% NaOH, subsequently the TiO2-NWs were dispersed in a DBSA solution. After, the aniline monomer was added and the polymerization occurred on the addition of ammonium persulfate as an initiator in the absence of any added acid. The ratio of TiO2-NWs in the nanocomposites varied from 5 to 15 wt%. The tubular morphology and crystalline structure of the prepared PAni/TiO2 nanocomposites were analysed using scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD). Furthermore, the prepared nanocomposites have been characterized using different spectroscopic methods such as UV-visible spectroscopy and gel permeation chromatography (GPC). The thermal stability of the nanocomposites was characterized using thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC). In addition, the AC-conductivity of the prepared PAni/TiO2 nanocomposites was evaluated. The prepared nanocomposites can be used as conductive packaging materials. © 2014 The Royal Society of Chemistry. Source


Rashad A.M.,National Research Center of Egypt
Construction and Building Materials | Year: 2013

The development of new binders, as an alternative to Portland cement (PC), by alkaline activation, is a current researchers interest. Alkali-activated metakaolin (AAMK), belongs to prospective materials in the field of Civil Engineering. This paper presents a comprehensive overview of the previous works carried out on the use of MK in alkali activation. © 2013 Elsevier Ltd. All rights reserved. Source


Rashad A.M.,National Research Center of Egypt
Construction and Building Materials | Year: 2013

Kaolin can satisfy the world demand for filler, paper and ceramic industries. Kaolin converts to a pozzolan material named metakaolin (MK) after suitable thermal treatment. MK can be used in mortar and concrete to improve their properties. In addition, MK can be used as a source of cementing materials in alkali activation or geopolymer. This part presents a comprehensive overview of the previous works carried out on kaolin history, MK sources, production and composition. © 2012 Elsevier Ltd. All rights reserved. Source


Youssef A.M.,National Research Center of Egypt
Polymer - Plastics Technology and Engineering | Year: 2013

Polymer nanocomposites markedly improved packaging properties due to their nanometer size dispersion. These enhancements include increased modulus and strength, decreased gas permeability, and increased water resistance. Additionally, biologically active ingredients can be added to impart the desired functional properties to the resulting packaging materials. Accordingly, polymer-based nanocomposites packaging materials with bio-functional properties have a huge potential for application in the active food packaging industry. In this review, recent advances in the preparation and characterization of polymer nanocomposites, and their potential use in packaging applications are addressed. © 2013 Copyright Taylor and Francis Group, LLC. Source


Rashad A.M.,National Research Center of Egypt
Construction and Building Materials | Year: 2014

Application of nano-SiO2 (NS) in cementitious materials has drawn much attention, due to the increased demand for new materials with attractive properties. Traditional cementitious materials based on Portland cement (PC) and alkali-activated fly ash (AAFA) systems were improved by applying NS aiming to develop a novel, smart and environment. This paper presents an overview of the previous works carried out on using NS into the traditional cementitious materials based on PC and AAFA. Heat of hydration, workability, setting time, strength, abrasion resistance, freeze-thaw resistance, fire resistance, drying shrinkage, resistance to aggressive environmental, leaching, water absorption, chloride penetration and permeability of PC-based materials modified with NS as well as comparison between NS and other nano types have been reviewed. In addition, previous works curried out on setting time, compressive strength and permeability of AAFA-based materials modified with NS have been reviewed. © 2013 Elsevier Ltd. All rights reserved. Source

Discover hidden collaborations