Ayman Yousef

Activated carbon/silver-doped polyurethane electrospun nanofibers: Single mat for different pollutants treatment

AbstractAdsorption ability and antibacterial activity could be created in a single electrospun nanofiber mat. Activated carbon/silver-doped polyurethane electrospun nanofiber mats have been introduced as a novel multifunction nanostructural material. Production of the introduced mat could be achieved by electrospinning of a colloidal solution from polyurethane containing activated carbon nanoparticles and silver nitrate. The high electric field and the presence of N,N-dimethylformamide, which is used as a solvent, led to reduced silver precursor in the silver nanoparticles. The introduced mat revealed good adsorption ability toward methylene blue dye. The presence of silver nanoparticles resulted in good antibacterial activity for the introduced mat since a piece of the mat could completely eliminate Escherichia coli bacteria. Overall, according to the utilized physiochemical characterizations, the introduced mat can be used as a mask or filter media.

Preparation and characterization of nylon-6/gelatin composite nanofibers via electrospinning for biomedical applications

Easy fabrication, porosity, good mechanical properties, and composition controllable of the electrospun nanofiber mat make this material a promising candidate for wound dressing applications. In the present study, nylon6/gelatin electrospun nanofiber mats are introduced as novel wound dressing materials. The introduced mats were synthesized by electrospinning of nylon6 and gelatin mixtures, three mats containing different gelatin content were prepared; 10, 20 and 30 wt%. Interestingly, addition of the gelatin did not affect the mechanical properties of the nylon 6, moreover the mat containing 10 wt% gelatin revealed higher mechanical properties due to formation of spider-net like structure from very thin nanofibers (∼10 nm diameter) bonding the main nanofibers. Biologically study indicates that gelatin incorporation strongly enhances the bioactivity performance as increasing the gelatin content linearly increases the MC3T3-E1 cell attachment. Overall, the obtained results recommend exploiting the introduced mats as wound dressing material.

Low Temperature Synthesis of Cobalt–Chromium Carbide Nanoparticles-Doped Carbon Nanofibers

Electrospinning has been used to synthesize cobalt-chromium carbide nanoparticles (NPs)-doped carbon nanofibers (CNFs) (Composite). Electrospun mat comprising of cobalt acetate, chromium acetate and poly(vinyl alcohol) (PVA) has been carbonized at low temperature (850 °C) for 3 h under argon atmosphere to produce the introduced composite. The process was achieved at low temperature due to the presence of cobalt as an activator. Field emission scanning electron microscope (FE-SEM), X-ray diffractometry (XRD), and transmission electron microscopy (TEM) equipped with EDX techniques were used to determine the products characteristics. The results indicated the formation of pure cobalt (Co), Cr7C3 NPs and crystalline CNFs. The Co and Cr7C3 NPs were covered with CNFs. Overall, the proposed NFs open new avenue to prepare different metals-metal carbides-carbon NFs at low temperature and short reaction time.

In-Situ Synthesis of Amorphous Co Nanoparticles Supported onto TiO2 Nanofibers as a Catalyst for Hydrogen Generation from the Hydrolysis of Ammonia Borane

Co0 nanoparticles supported on TiO2 nanofibers (nanocomposite) were prepared using a simple electrospinning technique and In-Situ chemical reduction. The synthesized nanocomposite was used to generate hydrogen from ammonia borane (AB). Standard characterization techniques revealed dense distribution of Co0 nanoparticles (Co NPs) onto the TiO2 nanofibers (TiO2 NFs) in the prepared nanocomposite. The introduced nanocomposite has been showed a good catalytic activity as compared to those unsupported Co NPs. As, the hydrogen evolutions for the nanocomposite and Co NPs were 3 mol in 23 min and 47 min, respectively. Furthermore, both the nanocomposite concentration and the temperature have a significant catalytic activity in the AB dehydrogenation. The nanocomposite also showed low effective activation energy of ~26.03 KJ · mol-1.