Second degree burns require dressings to heal. The ideal dressing should keep a moist environment, have low cost, be elastic and have a bactericidal effect. The potential of PVA-NaCMC (sodium carboxymethyl cellulose) gels to combine the mechanical and swelling properties of PVA with the flexibility and high water uptake of NaCMC and the antimicrobial characteristics of propolis is investigated. The freeze-thawed gels were characterized by FTIR and DSC. Their swelling behavior, their mechanical response, the delivery of active compounds and their antimicrobial properties were also determined. The main findings of the FTIR analysis were that no chemical bonding occurred between the materials. The DSC analysis revealed that the addition of NaCMC to PVA lowered the PVA crystallinity, as did the addition of propolis, leading to a more deformable gel (as can be observed from the tensile tests results). This also resulted in a higher rate of delivery of active compounds, higher weight loss and higher fluid uptake than comparable PVA-propolis systems, as shown by the swelling tests and by the propolis delivery tests. Samples with 15% propolis content or more inhibited S. aureus colonies with 80% reduction, and are therefore highly absorbent and compliant antimicrobial gels for wound healing.

The introduction at CERN of new extremely energetic particle accelerators, such as the high-luminosity large hadron collider (HL-LHC) or the proposed future circular collider (FCC), will increase the energy stored in the circulating particle beams by almost a factor of two (from 360 to 680 MJ) and of more than 20 (up to 8500 MJ), respectively. In this scenario, it is paramount to assess the dynamic thermomechanical response of materials presently used, or being developed for future use, in beam intercepting devices (such as collimators, targets, dumps, absorbers, spoilers, windows, etc.) exposed to potentially destructive events caused by the impact of energetic particle beams. For this reason, a new HiRadMat experiment, named "MultiMat", was carried out in October 2017, with the goal of assessing the behaviour of samples exposed to high-intensity, high-energy proton pulses, made of a broad range of materials relevant for collimators and beam intercepting devices, thinfilm coatings and advanced equipment. This paper describes the experiment and its main results, collected online thanks to an extensive acquisition system and after the irradiation by non-destructive examination, as well as the numerical simulations performed to benchmark experimental data and extend materials constitutive models. Keywords Dynamic material behaviour • Thermomechanical stresses • Carbon-based and copper composites • Molybdenum and tungsten alloys • Particle beam impacts • Quasi-instantaneous heat deposition * M.

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