The review renders a short background on the research work carried out on epoxy clay nanocomposites Clays are one of the ideal nano reinforcements for polymers because of their high intercalation chemistry and aspect ratio Epoxy clay nanocomposites are finding vast applications in various industries like aerospace, defense, automobile, etc The physical and chemical properties of the epoxy systems are influenced by the processing techniques, clay modifier and curing agents used for the preparation of nanocomposites The clay morphology (intercalation/exfoliation) of the nanocomposites is also depended on the above parameters So the emphasis of the present work is to highlight these parameters on morphology and the final mechanical, thermal and barrier properties of the nanocomposites The proposed applications of the epoxy clay nanocomposites are also discussed

Epoxy clay nanocomposites ― processing, properties and applications: A review

Electrospun nanofiber reinforced composites: a review

The fibrillation of pulp fiber was attempted by two methods, a high-pressure homogenizer treatment and a grinder treatment. The grinder treatment resulted in the successful fibrillation of wood pulp fibers into nanofibers. The nanofibers demonstrate promising characteristics as reinforcement material for optically transparent composites. Due to the size effect, the nanofiber-reinforced composite retains the transparency of the matrix resin even at high fiber content such as 70 wt %. Since the nanofiber is an aggregate of semi-crystalline extended cellulose chains, its addition also contributes to a significant improvement in the thermal expansion properties of plastics while maintaining its ease of bending. Cellulose nanofibers have tremendous potential as a future resource since they are produced in a sustainable manner by plants, one of the most abundant organic resources on earth.

Optically transparent composites reinforced with plant fiber-based nanofibers(ABSTRACTS (MASTER THESIS FOR GRADUATE SCHOOL OF AGRICULTURE))

Electrospun polyimide nanofibers and their applications

The re-exploration of the nanostructure production technique known as electrospinning was carried out in the past decade due to its simplicity and uniqueness of producing nanostructures. As nanotechnology is one of the most promising and growing technologies today, a large amount of work is being carried out in an extensive area and shows an extremely huge potential for miraculous works in the fields of medicine and biotechnology. These nanostructures were found to be of great significance because of their inherent properties such as large surface area to volume ratio and the engineered properties such as porosity, stability and permeability. The functionality and applicability of these nanostructures were further improved by incorporating secondary phases either during electrospinning or in the post-processing resulting in the composite nanostructures. These secondary phases may include metal oxides, carbon nanotubes, precious metals, gold nanoparticles and hydroxyapatite. Nanofibrous materials that mimic the native extracellular matrix (ECM) and promote the adhesion of various cells are being developed as tissue-engineered scaffolds for the skin, bone, vasculature, heart, cornea, nervous system and other tissues. The article discusses in detail the applicability of these composite fibers in energy, sensors, filters, biotechnology and details the technological issues, research challenges and future trends.

Electrospun composite nanofibers and their multifaceted applications

Effect of Nylon-66 nano-fiber interleaving on impact damage resistance of epoxy/carbon fiber composite laminates

The concept of electrospun polymer nanofiber fabric interleaving to enhance dynamic properties, impact damage resistance, fracture toughness and resistance, and delamination onset life was evaluated. Polymer nanofabric interleaving increased the laminate thickness and weight by an order of 1%, and its impact on in-plane mechanical properties of the composite laminate would be statistically zero. On the other hand, its influence on interlaminar fracture toughness and resistance, impact damage resistance, and damping is substantial. Results of this study showed that interleaving AS4/3501-6 composite laminate increased the damping by 13%, reduced the impact damage size to one-third, increased fracture toughness and resistance by 1.5 times and one-third, respectively, significantly increased delamination onset life, and increased the fatigue threshold energy release rate by two-thirds. These improvements are comparable to that of the commercial T800H/3900-2 composite but with no thickness increase penalty, loss of in-plane properties, or multiple glass transition temperatures.

Polymer Nanofabric Interleaved Composite Laminates

Air plasma etching followed by scanning electron microscope (SEM) imaging technique for visualizing the inorganic nanofillers in polymeric composites is a promising technique for quick screening of exfoliation and dispersion of nanofillers in nanocomposites in manufacturing and materials development environments. The method was applied to three different nanocomposites, namely, montmorillonite (MMT) clay vinyl ester, carbon nanotube (CNT) vinyl ester and MMT epoxy nanocomposites samples produced using high shear mixing. Results were compared with transmission electron microscope data. The etch rate for 2%MMT/vinyl ester and 1%MMT/epoxy nanocomposites varied from 1 to 2 nm/min.

A method of visualization of inorganic nanoparticles dispersion in nanocomposites

Electrospun High Temperature Polyimide Nanopaper

This paper systematically studies the electrospinning and characteristics of Nylon-66 polymer nanofiber fabrics that were electrospun at two different collector drum speeds of 1.5 m/s and 3.0 m/s. It also evaluates the potential for producing nanofiber fabrics with uniform thickness using single-nozzle and multiple-nozzle electrospinning set-ups. The polymer concentration was varied from 6 – 12% by weight. The influence of collector drum speeds, electrospinning set-ups (single and multiple-nozzle) and polymer concentrations on the morphology, uniformity and mechanical properties of the electrospun nanofiber fabrics is studied in this paper. The nanofiber fabrics electrospun using multiple-nozzle electrospinning set-ups were observed to have more uniform thickness along their width than that electrospun using single-nozzle electrospinning set-up. The morphology characterization of the nanofiber fabrics showed formation of wet polymer (at 6% wt.), beads (at 8% wt.) at lower concentrations of polymer and dry fibers without beads at higher concentration (at 10 and 12% wt.). It was observed that the diameter of the fibers increased as the polymer concentration increased and it decreased as the collector drum speed increased. The diameter of the fibers were in the range of 20-100 nm for 6% Nylon-66 fabric and 120 – 240 nm for 12% Nylon-66 fabric. The mechanical characterization involved the measurement of tensile modulus and strength in the longitudinal (collector drum rotating direction) and transverse directions. The fabrics electrospun at 1.5 m/s had almost same properties in both the directions while the fabrics electrospun at 3.0 m/s had higher properties in the longitudinal direction. This showed that at collector drum speed of 1.5 m/s the nanofibers in the fabrics were randomly oriented and as the speed increased to 3.0 m/s they became directionally oriented (or partially aligned) towards the drum rotating direction. Finally, the mechanical properties of the fabrics measured in the present work are compared with that of literature data and commercial Nylon-66. It was observed that the present results are better than the literature data and comparable to some of the properties of commercial bulk Nylon-66.

Shivalingappa Lingaiah

Papers

Effect of Nylon-66 nano-fiber interleaving on impact damage resistance of epoxy/carbon fiber composite laminates

Polymer Nanofabric Interleaved Composite Laminates

A method of visualization of inorganic nanoparticles dispersion in nanocomposites

Electrospun High Temperature Polyimide Nanopaper

Electrospinning of Nylon-66 Polymer Nanofabrics