Comparative Review on Structure,Properties, Fabrication Techniques,and Relevance of Polymer Nanocomposites Reinforced with Carbon Nanotube and Graphite Fillers

Owing to their remarkable electrical, mechanical, thermal, catalytic, and optical properties as well as their unique structure, carbon nanotubes and graphite have been exploited to produce high performance and multifunctional composites. The resultant composites are differentiated on the basis of their properties to meet various applications. In the framework of this review article, we have mainly focused on the preparation, structure, and properties of two families of composite materials with an emphasis on the differences between them. Moreover, the current challenges, future prospectives, and applications of carbon nanotubes- and graphite-based materials in sensors and in photovoltaic and energy storage devices (Li-ion battery) have been discussed.     

On the importance of specific interface area in clay nanocomposites of PMMA filled with synthetic nano-mica

In clay nanocomposites, the specific interface area is the key factor determining potential improvements of properties. Nevertheless, in most systematic studies of nanocomposites little emphasis is put on assuring and characterizing dispersion quality. To probe the influence of dispersion quality, we compare nanocomposites filled with two layered silicates which were made by melt compounding and solution blending, respectively. Poly(methyl methacrylate) (PMMA) is chosen here as a thermoplastic model matrix which was compounded with a synthetic nano-mica (O-hect) and commercial Bentone with typical diameters of 5–7 μm and <300 nm, respectively.     

Evaluation of Microwave Activity on Starch-Based Nanocomposites Reinforced at Different Loading Fraction Organic-to-Inorganic Nanofillers

When subjected to microwave ageing, the microwave-induced improvement in properties is more significant for sample containing higher loading fraction of cellulose nanofiller. This is due to cellulose nanofiller has greater reactivity to microwave energy through activation of dipole–dipole interaction at the polar interface. The strengthening effects on interface were observed to magnify as a function of microwave power and irradiation time. Nevertheless, the higher montmorillonite fraction tended to inhibit such improvement effect due to the occurrence of intramolecular repulsion between montmorillonite and polysaccharides with insufficient irradiation time, facilitating the water absorption and uneven stress transfer.     

Tangible nanocomposites with diverse properties for heart valve application

Abstract

Cardiovascular disease claims millions of lives every year throughout the world. Biomaterials are used widely for the treatment of this fatal disease. With the advent of nanotechnology, the use of nanocomposites has become almost inevitable in the field of biomaterials. The versatile properties of nanocomposites, such as improved durability and biocompatibility, make them an ideal choice for various biomedical applications. Among the various nanocomposites, polyhedral oligomeric silsesquioxane-poly(carbonate-urea)urethane, bacterial cellulose with polyvinyl alcohol, carbon nanotubes, graphene oxide and nano-hydroxyapatite nanocomposites have gained popularity as putative choices for biomaterials in cardiovascular applications owing to their superior properties. In this review, various studies performed utilizing these nanocomposites for improving the mechanical strength, anti-calcification potential and hemocompatibility of heart valves are reviewed and summarized. The primary motive of this work is to shed light on the emerging nanocomposites for heart valve applications. Furthermore, we aim to promote the prospects of these nanocomposites in the campaign against cardiovascular diseases.     

Supercritical carbon dioxide–assisted synthesis of stimuli-responsive magnetic poly(N-isopropylacrylamide)–ferrite biocompatible nanocomposites for targeted and controlled drug delivery

Supercritical carbon dioxide–assisted synthesis of poly(N-isopropylacrylamide)–ferrite nanocomposites was carried out by polymerization reaction of N-isopropyl acrylamide monomer in the presence of ferrite nanoparticles. They were characterized by Fourier transform infrared, X-ray diffraction, transmission electron microscopy, atomic force microscopy, and vibrating sample magnetometry analysis. Drug loading and release profiles were studied. Nanomaterials showed pH-dependent drug release profile. Polymer nanocomposites in comparison to ferrite nanoparticles showed impressive drug release activity, with a release percent of 20.98–76.54%, and greater biocompatibility in breast cancer cells, with a cell viability of 81–93%. This pH-dependent drug release activity and magnetic property of polymer nanocomposites can be used for controlled and targeted drug delivery.     

Enhancement of energy storage density in antiferroelectric PbZrO3 films via the incorporation of gold nanoparticles

In this work, antiferroelectric Au–PbZrO₃ (Au–PZO) nanocomposite thin films were prepared by chemical solution deposition (CSD), and the effects of Au concentration on the antiferroelectric properties and the recoverable energy density were investigated. The results showed that the optimal Au concentration in the Au–PZO nanocomposite thin films was about 1 mol% for structural and electric properties. In the Au–PZO nanocomposite thin films with 1 mol% Au, Au nanoparticles (NPs) were distributed uniformly in the perovskite PZO matrix. Moreover, the recoverable energy density was 10.8 J/cm³ at 600 kV/cm, which is 42% higher than that of the pure PZO films. The results demonstrate that adding an appropriate amount of noble metal NPs in antiferroelectric thin films is an effective method to improve the energy storage properties.     

Friction and wear behavior of alumina-based graphene and CNFs composites

Alumina – carbon nanofibers (CNF) and alumina – graphene oxide (GO) composites were prepared by spark plasma sintering using freeze-dried powders prepared from optimized suspensions of the mixtures. The tribological behavior was studied using the ball-on-disk technique in dry sliding at ambient conditions and compared to a monolithic alumina used as a reference. At low loads there was little difference between friction and wear behavior, whereas at moderate loads the composites showed a noticeable reduction in wear rate over monolithic alumina, five and 2.5 times for the GO and the CNF composite respectively; the friction coefficient slightly decreased for the alumina – GO material. This behavior is related to the presence of a carbon-rich protecting tribofilm. The film present in the alumina – GO showed better tribological performance due to the absence of coalescence of cracks that led to delamination events in the case of the alumina – CNF composite.