Electrical Heaters for Anti/De-Icing of Polymer Structures.

The problem of icing for surfaces of engineering structures requires attention more and more every year. Active industrialization in permafrost zones is currently underway; marine transport in Arctic areas targets new goals; the requirements for aerodynamically critical surfaces of wind generators and aerospace products, serving at low temperatures, are increasing; and fiber-reinforced polymer composites find wide applicability in these structural applications demanding the problem of anti/de-icing to be addressed. The traditional manufacturing approaches are superimposed with the new technologies, such as 3D printers and robotics for laying heat wires or cheap and high-performance Thermal Sprayed methods for metallic cover manufacturing.

A Review of Electrospun Nanofiber Interleaves for Interlaminar Toughening of Composite Laminates.

Recently, polymeric nanofiber veils have gained lot of interest for various industrial and research applications. Embedding polymeric veils has proven to be one of the most effective ways to prevent delamination caused by the poor out-of-plane properties of composite laminates. The polymeric veils are introduced between plies of a composite laminate, and their targeted effects on delamination initiation and propagation have been widely studied.

Negative Temperature Coefficient of Resistance in Aligned CNT Networks: Influence of the Underlying Phenomena.

Temperature dependence of electrical conductivity/resistivity of CNT networks (dry or impregnated), which is characterised by a temperature coefficient of resistance (TCR), is experimentally observed to be negative, especially for the case of aligned CNT (A-CNT). The paper investigates the role of three phenomena defining the TCR, temperature dependence of the intrinsic conductivity of CNTs, of the tunnelling resistance of their contacts, and thermal expansion of the network, in the temperature range 300-400 K. A-CNT films, created by rolling down A-CNT forests of different length and described in Lee et al.

Separating Curing and Temperature Effects on the Temperature Coefficient of Resistance for a Single-Walled Carbon Nanotube Nanocomposite.

The temperature coefficient of resistance () determines the electrical performance of materials in electronics. For a carbon nanotube (CNT) nanocomposite, change of resistivity with temperature depends on changes in CNT intrinsic conductivity, tunnelling thresholds and distances, matrix' coefficient of thermal expansion, and other factors. In our study, we add one more influencing factor-the degree of cure.

Uncertainties in Electric Circuit Analysis of Anisotropic Electrical Conductivity and Piezoresistivity of Carbon Nanotube Nanocomposites.

Electrical conductivity and piezoresistivity of carbon nanotube (CNT) nanocomposites are analyzed by nodal analysis for aligned and random CNT networks dependent on the intrinsic CNT conductivity and tunneling barrier values. In the literature, these parameters are assigned with significant uncertainty; often, the intrinsic resistivity is neglected. We analyze the variability of homogenized conductivity, its sensitivity to deformation, and the validity of the assumption of zero intrinsic resistivity.

Influence of the Nanostitch Sensor Embedment on the Fibrous Microstructure of Glass Fiber Prepreg Laminates.

Changes in the fibrous microstructure in glass fiber/epoxy prepreg quasi-isotropic laminates after the introduction of embedded sensors in the form of "nanostitch" as interleaves are investigated using 3D imaging with synchrotron radiation computer tomography (SRCT). Nanostitch interfaces are created by aligned carbon nanotubes (CNTs) with two different morphologies. The laminates are fabricated using an autoclave.

Scalable Fabrication of Thermally Conductive Layered Nacre-like Self-Assembled 3D BN-Based PVA Aerogel Framework Nanocomposites.

In this study, three-dimensional (3D) polyvinyl alcohol (PVA)/aligned boron nitride (BN) aerogel framework nanocomposites with high performance were fabricated by a facile strategy. The boron nitride powder was initially hydrolyzed and dispersed with a chemically crosslinked plasticizer, diethyl glycol (DEG), in the PVA polymer system. The boron nitride and DEG/PVA suspensions were then mixed well with different stoichiometric ratios to attain BN/PVA nanocomposites.

Multiscale Numerical Modeling for Prediction of Piezoresistive Effect for Polymer Composites with a Highly Segregated Structure.

In this work, the piezoresistive effect for a polymer nanocomposite with a highly segregated distribution of conductive filler was investigated. As a base polymer for the investigated nanocomposites, ultrahigh-molecular-weight polyethylene, processed in a solid state (below melting point), was used. Multiwalled carbon nanotubes (MWCNTs) were used as a nanofiller forming a highly segregated structure in between polymer particles.