Measurement of Nanoparticles Release during Drilling of Polymer Nanocomposites

Nanomaterials are one of the promising technologies of this century. The Project on Emerging Nanotechnologies [1] reports more than 1600 consumer products based on nanotechnology that are currently on the market and advantages link to the reinforcement of polymeric materials using nano-fillers are not to demonstrate anymore. However, the concerns about safety and its consumer perception can slow down the acceptance of nanocomposites. Indeed, during its life-cycle, a nanotechnology-based product can release nano-sized particles exposing workers, consumers and environment and the risk involved in the use and disposal of such particles is not well known. The current legislation concerning chemicals and environment protection doesn’t explicitly cover nanomaterials and changes undergone by nanoparticles during the products’ life cycle. Also, the possible physio-chemical changes that the nanoparticles may undergo during its life cycle are unknown. Industries need a standard method to evaluate nanoparticles release during products’ life cycle in order to improve the knowledge in nanomaterials risk assessment and the legislation, and to inform customers about the safety of nanomaterials and nanoproducts. This work aims to propose a replicable method in order to assess the release of nanoparticles during the machining of nanocomposites in a controlled environment. For this purpose, a new experimental set-up was implemented and issues observed in previous methods (background noise due to uncontrolled ambient environment and the process itself, unrepeatable machining parameters) were solved. A characterisation and validation of the chamber used is presented in this paper. Also, preliminary testing on drilling of polymer-based nanocomposites (Polyamide-6/Glass Fibre reinforced with nano-SiO2) manufactured by extrusion and injection moulding were achieved

Morphological, optical and thermal characterisation of aerogel-epoxy composites for enhanced thermal insulation

The present work explores the possibility of introducing aerogel at different stages of the epoxy resin cure to identify the most effective method that ensures minimal destruction of the aerogel particles. The aerogel particles are added at 0.5 h, 1 h and 1.5 h after the resin and the hardener are mixed together. Additionally, the effect of a wetting agent that improves the interface between the aerogel and the resin is also investigated. The different materials are characterised using optical images and ESEM-EDX to determine the most effective processing route. Additional data are also provided by determining the different material’s optical transmittance and reflective characteristics. From the experimental results, it is observed that the addition of aerogel at the 1-h mark proves to be the most efficient route to follow. In addition, the wetting agent displays a negligible effect on the samples in the study; hence, its usage is advocated due to its influence on the interface strength. Therefore, the aerogel/epoxy/wetting agent sample with the aerogel added at the 1 h mark looks promising. A 13.3% decrease in thermal conductivity when compared with the pure resin/hardener sample along with the damage coefficient value of 0.183 demonstrates the material’s potential for thermal insulation applications

PEO-based polymer blend electrolyte for composite structural battery

High mechanical strength and ionic conductivity of solid-state electrolyte (SSE) are currently conflicting targets that are very difficult to achieve. Polyethylene oxide (PEO) is one of the most common polymers adopted for SSE because of its very high ionic conductivity, but its mechanical strength is very low. This work discusses the manufacturing and testing of PEO blends using polysulfone (PSf) and Lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) to assess the mechanical response under microtensile testing and the ionic conductivity with electrochemical impedance spectroscopy (EIS). Mechanical tests demonstrated a beneficial effect of LiTFSI with significant increase in maximum stress and ductility measured as strain at failure. The blending of PEO and PSf showed promising conductivity values at room temperature with the 90–10 PEO-PSf composition achieving the highest value (1.06 × 10−6 S/cm) and for the 70–30 composition achieving the highest maximum stress (3.5 MPa) with a conductivity of 3.12 × 10−7 S/cm

Numerical investigation and fluid-structure interaction (FSI) analysis on a double-element simplified Formula One (F1) composite wing in the presence of ground effect

This research paper focuses on a novel coupling of the aerodynamic and structural behaviour of a double-element composite front wing of a Formula One (F1) vehicle, which was simulated and studied for the first time here. To achieve this goal, a modified two-way coupling method was employed in the context of high performance computing (HPC) to simulate a steady-state fluid-structure interaction (FSI) configuration using the ANSYS software package. The front wing plays a key role in generating aerodynamic forces and controlling the fresh airflow to maximise the aerodynamic performance of an F1 car. Therefore, the composite front wing becomes deflected under aerodynamic loading conditions due to its elastic behaviour which can lead to changes in the flow field and the aerodynamic performance of the wing. To reduce the uncertainty of the simulations, a grid sensitivity study and the assessment of different engineering turbulence models were carried out. The practical contribution of our investigations is the quantification of the coupled effect of the aerodynamic and structural performance of the wing and an understanding of the influence of ride heights on the ground effect. It was found that the obtained numerical surface pressure distributions, the aerodynamic forces, and the wake profiles show an accurate agreement with experimental data taken from the literature

Surface damage in woven carbon composite panels under orthogonal and inclined high-velocity impacts

The present research is aimed at the study of the failure analysis of composite panels impacted orthogonally at a high velocity and with an angle. Woven carbon-fibre panels with and without external Kevlar layers were impacted at different energy levels between 1.2 and 39.9 J. Sharp and smooth gravels with a mass from 3.1 to 6.7 g were used to investigate the effects of the mass and the contact area on the damage. Optical microscopy and thermography analyses were carried out to identify internal and surface damage. It was identified that sharp impactors created more damage on the impacted face of the panels, while the presence of a Kevlar layer increased the penetration limit and reduced the damage level in the panel at a higher energy

Nanomaterials Life Cycle Analysis: Health and Safety Practices, Standards and Regulations – Past, Present and Future Perspective

A new technology always raises new issues with its introduction on the market. Nanotechnology is not an exception. The advantages of nanomaterials use are not to demonstrate anymore and so, the commercialization of consumer products based on nanotechnology doesn’t stop increasing. The introduction on the market of nanoproducts also involves some uncertainties. Risks regarding the environment and human health are not well known by the scientist, and the legislation doesn’t cover health and safety aspects related to nanomaterials. Especially, fate of nanoparticles during the life-cycle of nanoproducts is not fully experienced due the large variety of nanomaterials existing and their diverse applications. It is safe to say that, given the explosive R&D and commercial uptake of nanomaterials unsurprisingly, the regulations governing the use and disposal of nanomaterials during its life cycle is behind the curve. The wide acceptance of nanotechnology by the consumers depends on alleviating the perceived safety related concerns. This paper aims to review the state of the art about exposure to nano-sized particles during life-cycle of nanomaterials. Also, future challenges and necessary work to ensure the success of nanotechnologies will be reviewed in this paper