Abdel Salam Hamdy Makhlouf

A comparative study on the basis of adsorption capacity between CNTs and activated carbon as adsorbents for removal of noxious synthetic dyes: a review

Rapid removal of noxious synthetic dyes from wastewater is of great concern in the scientific research field, this is due to the expansion of harmful effects of synthetic dyes traces in water streams on the environment and human health with the exponential rise in concentration of synthetic dye globally and demand in various industries that coincided with the implantation of more stringent water quality standards. Various technologies have been applied for the removal of synthetic dye from wastewater, including adsorption technology, which has a great potential in treating varieties of synthetic dyes. This article comprehensively reviews the latest progress in the development of carbon nanotubes (CNTs) and their applications for the removal of synthetic dyes from wastewater, including functionalized of CNTs and their researched counterparts. The emerging trends in the development of alternative adsorbents with different substrates, morphologies, and functional groups are also elucidated.

Novel, Facile, Single-Step Technique of Polymer/TiO2 Nanofiber Composites Membrane for Photodegradation of Methylene Blue

Novel photocatalyst membrane materials were successfully fabricated by an air jet spinning (AJS) technique from polyvinyl acetate (PVAc) solutions containing nanoparticles (NPs) of titanium dioxide (TiO2). Our innovative strategy for the production of composite nanofibers is based on stretching a solution of polymer with a high-speed compressed air jet. This enabled us to rapidly cover different substrates with TiO2/PVAc interconnected nanofibers. Surprisingly, the diameters of the as-spun fibers were found to decrease with increasing amount of NPs. Our results showed that AJS PVAc-based fibrous membranes with average fiber diameters of 505-901 nm have an apparent porosity of about 79-93% and a mean pore size of 1.58-5.12 μm. Embedding NPs onto the as-spun fibers resulted in increasing the tensile strength of the obtained composite fiber mats. The photodegradation property of TiO2 membrane mats proved a high efficiency in the decomposition of methylene blue dye. The novel fiber spinning technique discussed in this paper can provide the capacity to lace together a variety of types of polymers, fibers and particles to produce interconnected fibers layer. Our approach, therefore, opens the door for the innovation in nanocomposite mat that has great potential as efficient and economic water filter media and as reusable photocatalyst.

Recent Advances in Nanocomposite Coatings for Corrosion Protection Applications

Nanocomposite coatings have shown increasing interest in recent years in many strategic industries such as automotive, aerospace, petroleum, and electronics. Nanocomposite coatings are engineered to provide attractive and cost-effective functional surface coatings with superior properties for anticorrosion, antimicrobial, antifogging, and adhesive applications. The unique characteristics of nanocomposite coatings include enhanced mechanical strength, weight reduction, improved barrier properties, and increased heat, wear, and scratch resistance for lifelong performance. Compared to the traditional anticorrosive composite coatings, the superior performance of their nanocomposite counterparts is mostly attributed to the improved morphology with nanoscale phase-separated domains. The simplest approach for the preparation of anticorrosive nanocomposite coatings is through the direct mixing of inorganic nanoparticle additives with the organic coating matrix. However, the recent advanced nanotechnologies are based on designing and functionalization of nanoparticles prior to their incorporation into the nanocomposite coatings to enable them to provide effective and continuous corrosion protection functionality. These include self-healing nanocomposite coatings, stimuli-responsive layer-by-layer nanocomposite coatings, organic-inorganic hybrid nanocomposite coatings, electroactive nanocomposite coatings based on electrically conductive polymers, and various carbon nanostructures. This chapter highlights these emerging nanotechnologies and presents the most recent achievements in this area.

A Novel Approach for Facile Synthesis of Biocompatible PVA-Coated PLA Nanofibers as Composite Membrane Scaffolds for Enhanced Osteoblast Proliferation

This chapter discusses a novel approach for facile synthesis of biocompatible poly(vinyl alcohol) PVA-coated polylactide (PLA) as composite membrane scaffolds for enhanced osteoblast proliferation. The composite scaffolds combined from PLA nanofiber-based materials coated with PVA thin layer were fabricated using hydrothermal treatment. The effects of deposition of the hydrophilic PVA on the MC3T3-E1 osteoblast cell attachment and proliferation were investigated by in vitro cell compatibility tests. The morphology, structure, chemical interfacial bonding, and thermal and mechanical properties of the scaffolds were studied. Results showed that PVA thin layer was successfully deposited onto the electrospun PLA fiber surfaces during hydrothermal treatment. The hydrothermal process induced crystalline conformation due to enhanced chain mobility of PLA. The mechanical tests showed that PLA could be turned from rigid to ductile with enhanced tensile strength, due to maximizing the hydrogen bond interaction during the heat treatment and the presence of PVA. The adhesion and proliferation properties of MC3T3-E1 cells on composite scaffolds were significantly higher than on the pristine fibers. The treatment process on PLA and producing composite samples from substrates could contribute to decelerating the rapid acidic phase release from the PLA molecules in the surrounding physiological environment. Based on the experimental results, PVA-coated PLA mats could be of particular interest in bone tissue engineering for tissue regeneration.

Historical development of drug delivery systems: From conventional macroscale to controlled, targeted, and responsive nanoscale systems

Abstract This chapter overviews the historical progress and development in drug delivery systems (DDSs) that based on polymeric carriers over the last 50 years. It discusses the main drug release mechanisms from polymeric carriers via diffusion, chemical, solvent, and responsive (on-demand) control. The breakthrough steps for the development of DDSs from macroscale to microscale and nanoscasle are summarized. Selected examples from successful clinical translations, marketed drugs and the ongoing clinical trials are briefly presented. The general features and the structure-property relationship of the most important polymers for macro-micro and nano-DDSs are highlighted. The evolution of passive and targeted DDSs based on polymeric nanocarriers including liposomes, micelles, protein-drug conjugates, polymer-drug conjugates (polymer prodrugs), polymeric nanoparticles, and on-demand release responsive polymeric nanocarriers, was discussed in detail. The evolution of stimuli-responsive DDSs as an emerging tool for drug design and targeted drug delivery was also discussed. The main aspects of the endogenous triggers (temperature, pH, and redox) and exogenous stimulus (thermo, magnetic, and ultrasound) are introduced with highlighted potential applications as DDSs. The recent status of the clinical trials based on stimuli-responsive nanocarriers is summarized.

History of High-Performance Paints and Coatings of Unique Characteristics

Innovative coatings have been produced by ancient Egyptians. The coating systems that they designed possess unique characteristics and outstanding capability to withstand extreme corrosive environments. The coatings are characterized with smooth structure, brightness, adherence, stability, and durability, which point to their unique technology behind the synthesis of the coating raw materials, surface preparation of the substrates, and the methodology adopted while applying the coatings and paintings over the materials. The ability of such paints and coatings to retain their outstanding appearance and stability for an extremely long time indicates the smart characteristics of the novel materials. These coatings could tune themselves to resist various severe conditions such as corrosion, erosion, abrasion, heat, cold, storms, and radiation. This chapter highlights few examples of coatings produced by ancient Egyptians.

Chapter 18 – Effect of Nano-Additives (Al2O3 and NaF) on the Performance of Ceramic Coatings Formed by Microarc Oxidation on Magnesium Alloys

Abstract This chapter discusses a modified microarc oxidation (MAO) process using two kinds of nano-additives (Al 2 O 3 and NaF) doped in the alkaline electrolyte system in order to improve the performance of MAO ceramic coatings formed on magnesium alloy AMS4429. The surface morphology, phase composition, and elemental composition of the MAO ceramic coating were examined by field electron emission scanning electron microscopy, X-ray diffraction, and energy-dispersive X-ray spectroscopy. electrochemical impedance spectroscopy and potentiodynamic polarization techniques were used to investigate the electrochemical behavior of MAO coatings. Results showed that the ceramic coatings formed are composed of pure MgO with porous surface structures. Nano-additives showed no significant effect on the elemental composition, while they strongly influenced the morphological features and corrosion resistance of the MAO coating formed. The addition of NaF to the electrolyte solution results in the formation of MAO coatings with finer uniform nodules than that of Al 2 O 3 nanoparticles leading to a successful protective MAO coating.