7 documents found, page 1 of 1
Protective coatings for complex organic flexible materials I: characterization ...
Tiss, Belgacem; Martínez-Martínez, D.; Mansilla, C.; Gomes, J. R.; Abreu, C. S.; Pereira, N.; Cunha, L.The escalating imperative to combat the climate change has generated sustainability trends, leading to a rising demands for eco-friendly products. Cork and rubber are versatile materials based or derived from natural sources with various industrial uses and applications. This work represents the first part of a comprehensive investigation focusing on cork, with rubber being the subject of a subsequent paper. Co...
Advanced UV shielding for cork: a comparative study of ZnO and TiO2 films throu...
Tiss, Belgacem; Martínez-Martínez, D.; Mansilla, C.; Cunha, L.This study evaluates the potential of ZnO and TiO2 films produced by magnetron sputtering to protect cork from the ageing effects induced by the solar radiation, particularly its UV component. This approach was validated first by exposure of cork under coated glass, and then extended to coated cork. The variation of color coordinates (L*, a*, b*) after exposure to a sun simulator lamp demonstrated that ZnO film...
Long term degradation kinetics and UV shielding efficiency of TiO2 and ZnO coat...
Tiss, Belgacem; Martínez-Martínez, D.; Mansilla, C.; Baron, E. Le; Disdier, A.; Cunha, L.This work investigates the application of transparent oxide coatings to enhance the UV resistance of rubber and cork, and it explores their degradation kinetics under accelerated UV exposure. Thus, TiO2 and ZnO of varying thicknesses were deposited using magnetron sputtering on both substrates. TiO2 films were amorphous with dense morphology (thickness: 72 ± 3 nm to 130 ± 3 nm), while ZnO films were polycrystal...
Growth of Al:ZnO nano-flowers by pulsed laser ablation deposition
Tiss, B.; Martínez-Martínez, D.; Silva, B.; Bouguila, N.; El Mir, L.; Almeida, B.; Moura, C.; Cunha, L.Aluminium-doped (3%) zinc oxide thin films (AZO) were prepared, using pulsed laser deposition, with varying deposition times. The target was fabricated from compacted aluminium-doped zinc oxide nano-powder produced by sol–gel. The films had a growth consisting of nanostructures in the form of columns with sharp ends which, for certain deposition times, resemble nano-flowers or nano-leaves. The small spheroid-li...
Hardness, adhesion, and wear behavior of magnetron cosputtered Ti:Zr-O-N thin f...
Cristea, D.; Scărlătescu, A. I.; Bulai, G.; Martínez-Martínez, D.; Oliveira, C. I. da Silva; Yan, G.; Cunha, L.Reactive magnetron sputtering was used to deposit Ti:Zr-O-N thin films, by using a single Zr target, with Ti ribbons placed on the erosion track of the Zr sputtering target. Zr-O-N thin films have been also deposited in the same chamber to be used as reference films. The number of Ti ribbons, the applied sputtering current, and the reactive gas flow were the variable parameters. The films were analyzed in terms...
Protective films on complex substrates of thermoplastic and cellular elastomers...
Martínez-Martínez, D.; Tiss, Belgacem; Glanzmann, L.N.; Wolthuizen, D.J.; Cunha, L.; Mansilla, C.; De Hosson, J.Th.M.Deposition of thin films is an appropriate methodology to enhance the performance of a material by modification of its surface, while keeping the properties of the bulk largely unaffected. However, a practical implementation becomes less straightforward when dealing with sensitive or complex substrates, for instance, those which cannot be subjected to harsh treatments, such as cleaning and etching, or extreme d...
Functional behaviour of TiO2films doped with noble metals
Rodrigues, M. S.; Borges, J.; Gabor, C.; Munteanu, D.; Apreutesei, M.; Steyer, P.; Lopes, C.; Pedrosa, P.; Alves, E.; Barradas, N. P.; Cunha, L.To evaluate the effects of different concentrations of noble metal in a TiO2 matrix, different films of both Ag:TiO2 and Au:TiO2 systems were prepared. Mechanical and tribological characterization was carried out to evaluate the coatings response as a function of the noble metals composition and (micro)structure of the films. The overall set of results indicates that the amorphous films reveal better results th...