Personal protective equipment | EPFL Graph Search

Personal protective equipment (PPE) is protective clothing, helmets, goggles, or other garments or equipment designed to protect the wearer's body from injury or infection. The hazards addressed by protective equipment include physical, electrical, heat, chemicals, biohazards, and airborne particulate matter. Protective equipment may be worn for job-related occupational safety and health purposes, as well as for sports and other recreational activities. Protective clothing is applied to traditional categories of clothing, and protective gear applies to items such as pads, guards, shields, or masks, and others. PPE suits can be similar in appearance to a cleanroom suit. The purpose of personal protective equipment is to reduce employee exposure to hazards when engineering controls and administrative controls are not feasible or effective to reduce these risks to acceptable levels. PPE is needed when there are hazards present. PPE has the serious limitation that it does not elimin

Exploration of auxetics materials in sport

Thibault Antoine Marie Joseph Ghesquière-Diérickx, Nicolas Tireford

A special property of auxetic materials is their negative Poisson’s ratio : this material shortens or lengthen in all directions when subjected respectively to a compressive or tensile force. This unusual characteristic opens up new perspectives in many fields. Sport is one of the fields where these properties can be well exploited. Already studied and already used for protective equipment, their properties could also prove themselves useful with other application such as grips. The goal of this paper is to study the properties of a sole cell, modelled to exhibit the auxetic behaviour, although the material itself is not auxetic. 3D modelling will allow both parametric finite element studies and the possibility of making 3D prints for testing friction especially.

2021

Modified full-face snorkel masks as reusable personal protective equipment for hospital personnel

Nitin Arora, Patrick Gerber, Mélanie Thérèse Marie Hannebelle

Here we adapt and evaluate a full-face snorkel mask for use as personal protective equipment (PPE) for health care workers, who lack appropriate alternatives during the COVID-19 crisis in the spring of 2020. The design (referred to as Pneumask) consists of a custom snorkel-specific adapter that couples the snorkel-port of the mask to a rated filter (either a medical-grade ventilator inline filter or an industrial filter). This design has been tested for the sealing capability of the mask, filter performance, CO2 buildup and clinical usability. These tests found the Pneumask capable of forming a seal that exceeds the standards required for half-face respirators or N95 respirators. Filter testing indicates a range of options with varying performance depending on the quality of filter selected, but with typical filter performance exceeding or comparable to the N95 standard. CO2 buildup was found to be roughly equivalent to levels found in half-face elastomeric respirators in literature. Clinical usability tests indicate sufficient visibility and, while speaking is somewhat muffled, this can be addressed via amplification (Bluetooth voice relay to cell phone speakers through an app) in noisy environments. We present guidance on the assembly, usage (donning and doffing) and decontamination protocols. The benefit of the Pneumask as PPE is that it is reusable for longer periods than typical disposable N95 respirators, as the snorkel mask can withstand rigorous decontamination protocols (that are standard to regular elastomeric respirators). With the dire worldwide shortage of PPE for medical personnel, our conclusions on the performance and efficacy of Pneumask as an N95-alternative technology are cautiously optimistic.

PUBLIC LIBRARY SCIENCE2021

TiO2- based ceramics, from basic science to applications

Lidia Rossi

Nanomaterials and nanoparticles are nowadays used in a wide range of applications; from sunscreens, paint and food industry to catalytic processes, lighting, TV's and displays, their presence is percolating in our daily life. New applications rise every day, pushing forward the technology limits with increasing efforts and funding for nanomaterial science and applications. Among different nanomaterials, titanium dioxide (TiO2) continues to attract considerable theoretical and experimental attention because of its technological relevance in applications such as environmental purification, solar energy harvesting, memristors, catalysis, advanced ceramic materials and more. Different allotropes and morphologies of the compound are being examined, in particular nanoparticles and nanofilaments (nanowires and nanotubes) in titanate (H2Ti3O7), anatase or rutile phase. In this dissertation, we have deeply investigated the behavior of titanium-oxide based nanowires (TiO2 NWs), which, thanks to their larger specific surface area than bulk or polycrystalline counterparts, are very promising for photocatalysis. The TiO2 NWs are very suitable for such nanofilamentary applications since they have an ideal form for assembling themselves into nanoporous aerogel membranes. Our nanowires can be used directly in both 2D and 3D architecture, and they can serve as ideal support (reducing Ostwald ripening and coarsening in general) for various metal nanoparticles. H2Ti3O7 NWs are equally important, indeed, both as active components, for example in case of very sensitive humidity sensors and efficient catalysts and as reinforcement fibers in composites or as metal nanoparticles support for advanced CO oxidation catalysis. The NW behavior in titanate, anatase and rutile phase has been studied and the phase transition temperature determined, finding out that the strong surface effects, in the 2D system, result in unexpected stabilization of the metastable anatase phase and the absence of rutile phase above 900 °C. However, the classical Ostwald ripening particle coarsening is observed in sintered pellets, accompanied by a typical anatase to rutile phase transition at 900 °C. Mechanical measurements and nanoscopic observations both on bulk and on individual nanowire have allowed determining the mechanical moduli and the hardness. In particular, for the first time, the shear modulus of individual nanowire in titanate phase has been directly measured and its relatively low value of 1.5±0.8 GPa confirms the layered structure with a relatively weak bond between layers. The elastic modulus is within the expected range of about 70 GPa for titanate and above 100 GPa for anatase. Functionality and potential impact of TiO2 NWs for a few specific catalytical applications have been explored. The photocatalytic effectiveness of titania nanowires for destroying DNA chains after a suitable exposition to UV light (elimination of pollutants) was established. Finally, I investigated the application of our TiO2 NWs in the form of paper filters for viruses and bacteria, like the current SARS-CoV-2. I demonstrated the concept of novel personal protective equipment (PPE), that TiO2 NWs based-facial mask is may be very effective stopping the virus or bacteria, but also that it is easily regenerated with simple UV exposition, cutting down the economical and environmental cost of a future product.

EPFL2020

TiO2- based ceramics, from basic science to applications

Lidia Rossi

EPFL2020