Innovative consolidating products for stone materials: field exposure tests as a valid approach for assessing durability

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A Novel Method for the Combined Photocatalytic Activity Determination and Bandgap Estimation

The ability of a photocatalyst to degrade a target pollutant is a commonly used method to assess its effectiveness for environmental applications, while ultraviolet-visible (UV-vis) spectroscopy and spectroscopic ellipsometry are conventional techniques for the estimation of a semiconductor band gap. In this work, an array of six light-emitting diodes (LEDs), characterized by different emission peaks between 470–370 nm and absorbed power of 3 W, was implemented into an existing standard testing apparatus for the testing of nitrogen oxides degradation in air. The abatement indexes, obtained under different LEDs irradiation, were firstly compared to the ones determined according the standard and, secondly, correlated with the measured LED emission spectrum, in order to estimate the photocatalyst band gap. Results suggest that this expeditious technique can be easily implemented into existing testing apparatus for the estimation of the band gap and for the appraisal of photocatalytic materials under realistic condition

Effect of beta and gamma ray sterilization on the properties of polymeric materials for biomedical applications

The goal of this study is to evaluate the effect of sterilization by gamma and beta radiation on the properties of four different polymeric specimens for biomedical use: a PVC pipe for connection in dialysis and heart surgery devices; a PVC band for enteral and parenteral nutrition bags, a TRIFLEX pipe (internal PE, middle PE/PVC, external PVC) for connection, a PC rigid pipe for the connection of tubes and bags for infusions. The effect of sterilization was studied by means of tensile mechanical characterization, thermo-gravimetric and morphological analysis and FT-IR spectroscopy. UV-VIS spectroscopy was used to evaluate the yellowing index, determined by radiation exposure. For each specimen, a no-sterilized one was tested for comparison

Effect of beta and gamma ray sterilization on the properties of polymeric materials for biomedical applications

The goal of this study is to evaluate the effect of sterilization by beta and gamma radiation on the properties of four different polymeric specimens for biomedical use (Figure 1): a PVC pipe for connection in dialysis and heart surgery devices; a PVC band for enteral and parenteral nutrition bags, a TRIFLEX pipe (internal PE, middle PE/PVC, external PVC) for connection, a PC rigid pipe for the connection of tubes and bags for infusions. The effect of sterilization was studied by means of tensile mechanical characterization, thermo-gravimetric and morphological analysis and FT-IR spectroscopy. UV-VIS spectroscopy was used to evaluate the yellowing index, determined by radiation exposure. For each specimen, a no-sterilized one was tested for comparison

Electrically Conductive DSP Cement Composites

Electromagnetic shielding and propagation in concrete structures are getting more and more interest in radiation hazard problems and wireless communications. The protection of sensitive environment is nowadays carried out by appropriate shielding room made of metallic walls. Even if effective they are heavy structures not adequate for the installation over existing building walls. The using of concrete composites filled by conductive elements represents a valid alternative to metallic shielded room since they can be adopted to directly build up the building walls and/or to easily plaster existing wall

Short-term chemical and physical changes in Invisalign appliances

To investigate the short-term optical, chemical and morphological changes in Invisalign appliances

Highly Stable Self-Cleaning Paints Based on Waste-Valorized PNC-Doped TiO₂ Nanoparticles

Adding photocatalytically active TiO2 nanoparticles (NPs) to polymeric paints is a feasible route toward self-cleaning coatings. While paint modification by TiO2-NPs may improve photoactivity, it may also cause polymer degradation and release of toxic volatile organic compounds. To counterbalance adverse effects, a synthesis method for nonmetal (P, N, and C)-doped TiO2-NPs is introduced, based purely on waste valorization. PNC-doped TiO2-NP characterization by vibrational and photoelectron spectroscopy, electron microscopy, diffraction, and thermal analysis suggests that TiO2-NPs were modified with phosphate (PO), imine species (RN-R), and carbon, which also hindered the anatase/rutile phase transformation, even upon 700 °C calcination. When added to water-based paints, PNC-doped TiO2-NPs achieved 96% removal of surface-adsorbed pollutants under natural sunlight or UV, paralleled by stability of the paint formulation, as confirmed by micro-Fourier transform infrared (FTIR) surface analysis. The origin of the photoinduced self-cleaning properties was rationalized by three-dimensional (3D) and synchronous photoluminescence spectroscopy, indicating that the dopants led to 7.3 times stronger inhibition of photoinduced e–/h+ recombination when compared to a benchmark P25 photocatalyst