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Cold gas spray (CGS) technology has allowed the development of biofunctional coatings composed of 45S5 and polyetheretherketone (PEEK). The combination of a bioactive glass material embedded in a polymeric matrix makes this composite an interesting material for orthopedic applications since this composite meets the biomechanical and biological requirements of an implant. In the present study, blends of bioactive glass 45S5 and PEEK powder with different granulometry and 45S5/PEEK ratio have been prepared. These mixtures of powders have been deposited onto PEEK substrates by CGS with the goal of incorporating a bioactive additive to the biocompatible polymer, which can improve the bone-implant interaction of PEEK. The deposition efficiency (DE) of the coatings has been evaluated, and from the results obtained, it was possible to conclude that DE is significantly affected by the granulometry and by the 45S5/PEEK ratio of the blends. By scanning electron microscopy (SEM) inspection, it was observed that the use of blends with high 45S5/PEEK ratio lead to the deposition of coatings with high content of 45S5. Finally, the friction behavior of the coatings was analyzed performing ball-on-disk tests and these experiments showed that the presence of glass particles has a beneficial role in the wear resistance.

El tema escogido para el trabajo final de máster desarrollará el papel del revestimiento en la arquitectura de algunos de los proyectos de viviendas plurifamiliares urbanas del arquitecto Lluís Domènech i Montaner. En el proceso simultáneo del desarrollo, el estudio y el entendimiento de la materia a exponer, se identificarán distintos factores para comenzar contextualizando la inspiración – intención, la época y al mismo Arquitecto, Domènech i Montaner, para así ir adentrándose a un contexto especifico de cada caso puntual a desplegar en relación a las obras seleccionadas de uso residencial, para el estudio detallado sobre el papel que ejercen los revestimientos utilizados, en sus fachadas y espacios comunes; sus formas, materiales, técnicas y significados según la intención con la que fueron proyectadas. Por lo anterior y para profundizar de manera general será importante apuntar algunos rasgos claves de la trayectoria profesional de Domènech y especificar en el revestimiento como concepto para afianzar el contenido total de la siguiente investigación. A partir de una selección de obras representativas de la arquitectura residencial urbana, se pretende identificar los revestimientos utilizados. Las formas, los materiales y las técnicas utilizadas e indagar en la finalidad formal de los mismos y el papel que juegan en la definición de estas arquitecturas. Por otra parte, y desde el planteamiento académico, otro objetivo del siguiente trabajo será lograr la adquisición de conocimientos específicos de la arquitectura doméstica de renta de Lluís Domènech i Montaner, poco estudiada de manera sistemática.

Biodegradation of polyesters driven by enzymes is considered as one of the most effective way of degradation of these materials, as a way to control plastics accumulation in the environment. In this study, we present two different strategies to tune the enzymatic degradation of PBS films triggered by a lipase from Pseudomonas cepacia. Firstly, the kinetics of enzymatic degradation of PBS films was regulated by applying multilayer coats of polysaccharide alginate and chitosan (Alg/Chi) films. Secondly, self-degradable PBS films were prepared by embedding lipase-filled alginate particles. For comparison purposes, a detailed enzymatic degradation study of neat PBS films exposed to a lipase from P. cepacia in solution was made to determine the main experimental parameters influencing their degradation in solution. The results showed that an increase in enzyme concentration increased the degradation extent and rate of neat PBS films. At a fixed enzyme concentration, stirring of the solution containing the enzyme and the PBS also increased the biodegradation rate. In the case of the PBS films coated with a different number of Alg/Chi layers by spray-assisted LbL and subjected to enzymatic degradation experiments in solution, the extent of degradation was found to be dependent on the number of protective coating layers. Therefore, the Alg/Chi biobased coating constitutes an effective barrier to the diffusion of the lipase, thus proving its effectiveness in modulating the enzymatic activity as a function of coating thickness. In the case of self-degradable PBS containing lipase-embedded alginate beads (employed to protect the enzyme during high-temperature processing), only limited biodegradation was observed as the amount of encapsulated enzyme employed was too small. Nonetheless, these results are promising, as the enzymatic activity –indicative of the degradation capacity of the enzyme– determined for all these samples was about 2 orders of magnitude lower than that of previous assays., This research was funded by the projects MAT2017-83014-C2-1-P, MAT2017-83014-C2-2-P, PID2020-113045GB-C21 and PID2020-113045GB-C22 funded by MCIN/ AEI /10.13039/501100011033 and by the Basque Government through grant IT1503-22. We would also like to acknowledge the financial support from the BIODEST project; this project has received funding from the European Union’s Horizon 2020 Research and Innovation Programme under the Marie Skłodowska-Curie grant agreement No. 778092. M.I.P. is supported with an FPI contract (PRE2018-086104) to develop a PhD thesis. R.H. is member of the CSIC Interdisciplinary Thematic Platform (PTI+) Interdisciplinary Platform for Sustainable Plastics towards a Circular Economy+ (PTI-SusPlast+). J.M.R. is a FRS-FNRS Senior Research Associate. Authors would also like to thank Dr. Ana Beloqui for helpful discussions on enzymatic activity.

Several inorganic materials such as bioactive glasses, glass–ceramics and calcium phosphates have been shown to be bioactive and resorbable which make them suitable for coating bone implants. This study focuses only on bioactive glasses. These biomaterials are highly biocompatible and can form a strong chemical bond with the tissues. This review comprehensively covers bibliographic reports that have investigated bioactive glass deposition using different thermal spray techniques. The main drawback for the glass coating deposition is the low adherence with the substrate. Some strategies can favour a good bond such as using bond coats, blends, pre-heating the substrate or modifying the glass composition. The characteristics of the feedstock powders are determinant for the properties of the coatings obtained. Porosity and thickness of the coatings can be modulated by using different thermal spray techniques and varying parameters of the process. The degradation rate of some bioactive glasses can achieve kinetics similar to the new bone formation. Taking advantage of its dissolution capacity, glasses can be doped with functional elements. While several biological studies have been performed with bioactive glass materials, there has been relatively little research on the biological response of coated glasses by thermal spray techniques. Research studies have demonstrated the opportunities of this promising material to enhance the bioactivity of the implants.

Waterborne polyurethane-urea dispersions (WPUD), which are based on fully biobased amorphous polyester polyol and isophorone diisocyanate (IPDI), have been successfully synthesized obtaining a finishing agent that provides textiles with an enhanced hydrophobicity and water column. Grafting of trans-cyclohexanediol isobutyl POSS (POSS-OH) to the biobased polymer backbone has also been investigated for the first time and its properties compared to a standard chain extender, 1,3-propanediol (PDO). The chemical structure of WPUD has been characterized by Fourier-transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR). The thermal properties have been evaluated by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Mechanical properties have been studied by tensile stress–strain analysis. Moreover, the particle size, particle size distribution (PSD), and stability of developed waterborne dispersions have been assessed by dynamic light scattering (DLS), Z-potential, storage aging tests, and accelerated aging tests by analytical centrifuge (LUM). Subsequently, selected fabrics have been face-coated by the WPUD using the knife coating method and their properties have been assessed by measuring the water contact angle (WCA), oil contact angle (OCA), water column, fabric stiffness, air permeability, and water vapor resistance (breathability). Finally, the surface morphology and elemental composition of uncoated and coated fabrics have been studied by scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS), respectively. All of the synthesized polyurethane-ureas provided the coated substrates with a remarkable hydrophobicity and water column, resulting in a more sustainable alternative to waterproof coatings based on fluoropolymers, such as PTFE. Grafting POSS-OH to the polymeric backbone has led to textile coatings with enhanced hydrophobicity, maintaining thermal, mechanical, and water column properties, giving rise to multifunctional coatings that are highly demanded in protective workwear and technical textiles. Peer Reviewed Objectius de Desenvolupament Sostenible::12 - Producció i Consum Responsables::12.5 - Per a 2030, disminuir de manera substancial la generació de residus mitjançant polítiques de prevenció, reducció, reciclatge i reutilització Objectius de Desenvolupament Sostenible::12 - Producció i Consum Responsables

Wear-resistant coatings development is progressively increasing steeply due to their advantages when applied to mechanical components subjected to abrasive and destructive environments. Titanium nitride (TiN) coating is typically used to enlarge tools and components’ service life and improve their surface quality. On the other hand, AlTiSiN coating intends to be applied to more aggressive environments such as spatial satellites components exposed to solar radiation, extremely high temperatures, and random particles impact. In this work, specimens of Inconel 718 (IN718) were fabricated via laser powder bed fusion (LPBF), and physical vapour deposition (PVD)-deposited with TiN and AlTiSiN as coatings to mechanically and chemically characterise their surface. In this respect, microhardness testing and chemical analysis via glow discharge optical emission spectroscopy (GDOES) were performed. Later, roughness and wear behaviour analyses were carried out to evaluate the mechanical performance of both coatings and their surface and morphological features. The experimental observations allowed the analysis of both studied coatings by comparing them with the substrate processed via LPBF.

The lack of bioactivity of titanium (Ti) is one of the main drawbacks for its application in biomedical implants since it can considerable reduce its osseointegration capacities. One strategy to overcome this limitation is the coating of Ti with hydroxyapatite (HA), which presents similar chemical composition than bone. Nonetheless, most of the strategies currently used generate a non-stable coating and may produce the formation of amorphous phases when high temperatures are used. Herein, we proposed to generate a Ti-HA composite coating on Ti surface to improve the stability of the bioactive coating. The coating was produced by cold gas spraying, which uses relatively low temperatures, and compared to a Ti coating. The coating was thoroughly characterized in terms of morphology, roughness, porosity and phase composition. In addition, the coating was mechanically characterized using a tensile loading machine. Finally, biological response was evaluated after seeding SaOS-2 osteoblasts and measuring cell adhesion, proliferation and differentiation. The novel Ti-HA coating presented high porosity and high adhesion and bond strengths. No change in HA phases was observed after coating formation. Moreover, osteoblast-like cells adhered, proliferated and differentiated on Ti-HA coated surfaces suggesting that the novel coating might be a good candidate for biomedical applications. info:eu-repo/semantics/acceptedVersion

Made available in DSpace on 2019-10-06T17:00:56Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-03-15 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Fundação de Apoio ao Desenvolvimento do Ensino, Ciência e Tecnologia do Estado de Mato Grosso do Sul This work describes the morphology, corrosion resistance, and antibacterial performance of copper coating deposited onto carbon steel by cold gas spray (CGS). Cross-sectional images of the coating showed a dense microstructure, with porosity lower than 1%. XRD analysis revealed no oxides or phases different to pure copper. The results of electrochemical tests demonstrated the efficient barrier properties and the compact microstructure of the coating, which protected the substrate against corrosion in chloride solution for >1000 h. The copper coating was effective as an antimicrobial agent for inhibiting the growth of Staphylococcus aureus, with bacterial growth being completely inhibited after 10 min of direct contact between the bacteria and the coating surface. UNESP - São Paulo State University Institute of Chemistry, Rua Prof. Francisco Degni, 55, P.O. Box 355 Barcelona University CPT, Martí I Franqués 1 Federal University of Mato Grosso do Sul, P.O. Box 549 UNESP - São Paulo State University Institute of Chemistry, Rua Prof. Francisco Degni, 55, P.O. Box 355 CNPq: 153177/2014-4 CNPq: 201325/2014-4 Fundação de Apoio ao Desenvolvimento do Ensino, Ciência e Tecnologia do Estado de Mato Grosso do Sul: 59/300.490/2016

Thermally sprayed 316L stainless steel coatings are commonly used on metallic structures due to their corrosion and wear resistance when compared to carbon steel. Cold Gas Spray (CGS) is a convenient thermal spray process to deposit 316L coatings, producing thick and very dense coatings, with almost no deleterious changes on the feedstock properties to the coating condition. The powder characteristics have influence on the microstructure of the coating, such as porosity and oxide contents, which alter its corrosion and wear behavior. CGS is an efficient technique to reduce the problems associated with material melting commonly found in other conventional thermal spray methods. In this work, different 316L powders, produced by different manufacturers, were deposited by CGS, applying the same equipment and parameters, with the objective to evaluate the relation between the powders’ characteristics and coating properties. Their microstructure, adherence, hardness, as well as the performance on corrosion and wear testing were evaluated. The water atomized powders presented in general better results than gas atomized powders.

For decades, zinc- and aluminum-based coatings have been considered the best material choice for steel corrosion protection since they may act as a protective barrier and show sacrificial behavior. These coatings are often prepared by galvanizing methods. However, their application by thermal spraying techniques (wire arc spraying, WAS and flame spraying, FS) has been proved as a cost-effective solution for the preparation of long-term corrosion-resistant coatings. This review selectively collects the most relevant information about the application and performance of these two techniques on Zn and Al coatings for corrosion protection. The report summarizes separately the Zn and Al data from the effect of the spraying parameters on coating properties on the one hand, and the results shown in long-term studies carried out in relevant and real exposure conditions, on the other. Finally, this review includes a description and comparison of the most recent advances found out with the novel and emerging spray technique, cold gas spray, for the deposition of Zn and Al coatings for corrosion protection purposes. Nevertheless, the use of this technique has not reached the stage of wide industrial application yet and therefore its long-term performance is unknown, which suggests that there is still room for further development.

Herein, the influence of the substrate in the formation of zirconium oxide monolayer, from an aqueous hexafluorozirconic acid solution, by chemical conversion and by electro-assisted deposition, has been approached. The nanoscale dimensions of the ZrO2 film is affected by the substrate nature and roughness. This study evidenced that the mechanism of Zr-EAD is dependent on the potential applied and on the substrate composition, whereas conversion coating is uniquely dependent on the adsorption reaction time. The zirconium oxide based nanofilms were more homogenous in AA2024 substrates if compared to pure Al grade (AA1100). It was justified by the high content of Cu alloying element present in the grain boundaries of the latter. Such intermetallic active sites favor the obtaining of ZrO2 films, as demonstrated by XPS and AFM results. From a mechanistic point of view, the electrochemical reactions take place simultaneously with the conventional chemical conversion process driven by ions diffusion. Such findings will bring new perspectives for the generation of controlled oxide coatings in modified electrodes used, as for example, in the construction of battery cells, in automotive and in aerospace industries, to replace micrometric layers of zinc phosphate by light-weight zirconium oxide nanometric ones. This study is particularly addressed for the reduction of industrial waste by applying green bath solutions without the need of auxiliary compounds and using lightweight ceramic materials.

El nostre article estudia el tractament de la superfície dels interiors de les cases de les famílies benestants de Barcelona entre final del segle XVIIi inici del segle XIX. Ens hem centrat en les estances més valorades i representatives de la casa, que són els salons i, quan ha estat possible, també hem estudiat algunes altres dependències, com ara les estrades (sales de recepció que precedeixen els salons) o les sales amb alcova. A final del segle XVIII, es va manifestar una sensibilitat renovada, per part de la noblesa i de la burgesia que havia assolit una posició destacada en la societat catalana, vers les residències i els seus interiors. En l’escrit, hi mostrem i hi analitzem alguns exemples per tal d’entendre com va ser el tractament de la superfície d’aquests interiors: quins van ser els valors i les expectatives que s’hi van tenir en compte; quin paper van tenir els artistes i els artesans en la seva definició; com van intervenir els arquitectes en la concepció d’aquests espais, si només es van centrar en la composició dels buits i plens o si hi va haver una participació molt més activa. D’altra banda, també apuntem a partir de quines tècniques es van resoldre aquests aspectes i quin va ser el grau de sistematització., This article studies the interiors of houses of the wealthy people of Barcelona in the late 18th and early 19th centuries. We focus on the rooms that were most valued and representative of the house—the drawing rooms—and when possible other rooms such as the estrades (antechambers to the drawing rooms) and rooms with alcoves. In the late 18th century the nobility and the bourgeoisie who had attained an outstanding position in Catalan society showed a renewed sensitivity towards their residences and interiors. We present and analyse some examples of this in order to analyse the treatment of interiors: the values and expectations that are placed in them, the role of artists and craftsmen in defining them, and the intervention of architects in the conception of the spaces. We consider whether the architects only concentrated on the composition of voids and solids or played a more active role. We also discuss the techniques that are used in these interiors and the extent to which they are systematised.

In this study, the self-organized nanoporous tin oxide films were prepared on cold sprayed tin and tin foil through a voltage-controlled anodization method. The optimized cold spray parameters were used to obtain a dense structure. The morphology and crystallinity of the samples were investigated by FE-SEM and XRD, respectively. Firstly, an amorphous oxide film (SnO) with a compact and less regular outer layer and an almost regular and uniform inner layer was grown during anodization. This structure cause formation of close pores at the surface, which reduces the appropriate properties of the porous structure. Herein, a simple way to attain a totally open nanoporous structure is reported. Pulsed ultrasonic anodization ensured to be an effective way to create a mostly uniform open pores structure with few lateral inner cracks. It was found that the porous structure prepared on cold sprayed tin and tin foil are different because of the difference in surface topography and imperfections. The current vs. time curves and the pores formation mechanism of cold sprayed tin and tin foil are discussed. The highest applicable annealing temperature for anodization of cold sprayed tin was 350 °C. Nanoporous structure and adhesion to the substrate were maintained perfectly during the annealing at this temperature. Subsequent annealing at higher temperatures leads to the collapse of the pores structure.

Títol alternatiu emprat a la intranet docent de l'EPSEVG: Disseny de pràctiques de caracterització de recobriments mitjançant corrents induïts Los ensayos que emplean las corrientes inducidas son de tipo no destructivo. Estos ensayos se utilizan para detección de defectos en piezas en capas superficiales y subsuperficiales. También son útiles para distinguir diferentes recubrimientos y poder diferenciar materiales. El objetivo de este trabajo es la diferenciación de recubrimientos por proyección térmica, HVOF (High velocity oxy-fuel) en piezas de base de acero y aluminio, aplicando corrientes inducidas. Para ello, utilizaremos el equipo facilitado por el departamento de Ciencias e ingeniería de Materiales de la EPSEVG, formado por el AeroCheck+ de la marca Ether NDE y el equipo Fischer. Las muestras para trabajar son: de base acero con recubrimiento HVOF de CrC-NiCr y WC-CoCr y de base aluminio con recubrimiento de WC-CoCr y CrC-NiCr. También se estudiarán muestras de base acero con recubrimiento Amperit. Diseñando parámetros aptos para este tipo de piezas, con el equipo AeroCheck+, diferenciaremos los recubrimientos mediante la curva “lift off”. The tests using eddy currents are non-destructive. These tests are used to detect defects in parts in surface and subsurface layers. They are also useful to distinguish different coatings and to be able to differentiate materials. The objective of this study is the differentiation of coatings by thermal projection. HVOF (High velocity oxy-fuel) in steel and aluminium base pieces, applying eddy currents. We will use the equipment provided by the Department of Materials Science and Engineering at EPSEVG, made up of the Ether NDE brand AeroCheck + and the Fischer hardware. The samples to work with are: steel-based with CrC-NiCr and WC-CoCr coating and aluminium-based with WC-CoCr and CrC-NiCr coating. Steel base samples with Amperit coating will also be studied. Designing parameters for this type of piece, with the AeroCheck + equipment, we will differentiate the coatings by means of the “lift off” curve.

Textural features are widespread in many soils, provide pedogenetic evidence, and are fundamental in soil classification systems. The presence of these features and their conservation over time require certain processes and soil forming factors. This study investigates the genesis of textural pedofeatures, especially clay coatings, and the stressful conditions that can eventually lead to their disappearance. To achieve this goal, four profiles with clay-enriched horizons have been studied (macro- and micromorphology, physical, chemical and mineralogical properties and classification) along a transect in the siliceous Iberian Chain (NE-Spain). The profiles, which have unmistakable illuvial accumulations in various horizons (Bhs, Bt, Btk), are classified (ST/WRB) as: a Spodosol/Podzol in the headslope, two Alfisol/Luvisols in the backslope and an Alfisol/Calcisol in the footslope. For the latter soil, the apparently strong difference in their classification to the first hierarchical level is due to the weight that the WRB places on the presence of an argic recarbonated horizon on a calcic horizon. Clay illuviation was identified in all the soils, with coatings and infillings of microlaminated clay. These clayey pedofeatures are mostly mechanically fragmented or deformed, which is micromorphologically evidenced by an undulating, wavy extinction that does not run completely parallel to the surfaces they cover. Different destructive processes are identified along the soil transect; so, cryoturbation is the dominant process in the Podzol located at the highest elevation (Moncayo Massif). Instead, the clay coatings in the Btk horizon of the footslope (Calcisol) are covered and deformed by the growth of secondary calcite. The textural pedofeatures in this soil, which is very clayey, can also undergo argilloturbation processes, like in the backslope soils (Luvisols). In conclusion, several ongoing stress processes, that sometimes require different environmental conditions (polygenetic), affect most textural pedofeatures and lead to their progressive alteration and disappearance. Different projects of the Research Results Transfer Office of the University of Zaragoza (Ref. 2017/0535, ref. 2018/0416; ref. UZ2020-TEC-01) provided financial support for this research.

This work analyzes the differences found in hard metal coatings produced by two high velocity thermal spray techniques, namely high velocity oxy-fuel (HVOF) and high velocity air-fuel (HVAF). Additionally, the effect of the metallic matrix and ceramic composition and the original carbide grain size on coating properties is compared to the most studied standard reference material sprayed by HVOF, WC-Co. For this evaluation, the physical properties of the coatings, including feedstock characteristics, porosity, thickness, roughness, hardness, and phase composition were investigated. Several characterization methods were used for this purpose: optical microscopy (OM), scanning electronic microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDS), and X-ray Diffraction (XRD), among others. The final performance (abrasive wear and corrosion resistance) shown by the coatings obtained by these two methodologies was also analyzed. Thus, the abrasive wear resistance was analyzed by the rubber-wheel test, while the corrosion resistance was characterized with electrochemical methods. The characterization results obtained clearly showed that the coatings exhibit different microstructures according to feedstock powder characteristics (carbide grain size and/or composition) and the thermal spray process used for its deposition. Thus, the incorporation of WB to the cermet composition led to a high hardness coating, and the complementary hardness and toughness of the WC-Co coatings justify its better abrasion resistance. The presence of Ni on the metal matrix increases the free corrosion potential of the coating to more noble region. However, the WC-Co coatings show a lower corrosion rate and hence a higher protective performance than the rest of the coatings.

Una pila de combustible d’òxid sòlid (SOFC) treballa a temperatures molt elevades, per sobre dels 700ºC , això provoca que l’interconnector metàl·lic de la pila es vegi sotmès a condicions extremes sota les que acaba donant lloc a l’oxidació d’un dels seus elements, el crom. La volatilització i posterior difusió del crom oxidat dins del sistema suposa un gran problema per al funcionament de la pila i el seu rendiment decreix de manera notable. L’objectiu de l’estudi és aconseguir un recobriment de Ni-Mo-P sobre una mostra d’un interconnector metàl·lic per estudiar la seva possible aplicació dins d’una pila SOFC per tal de protegir-la de la difusió del crom oxidat. Per aconseguir-ho s’utilitzen dues tècniques de recobriment combinades, primer es realitza un recobriment electrolític de níquel i posteriorment un recobriment electroless de Ni-Mo-P. Mitjançant aquesta tècnica es busca obtenir una capa contínua, homogènia i uniforme de Ni-Mo-P adherida lo millor possible a la superfície i que aporti valors elevats de resistència a la oxidació, una bona resistència mecànica i una bona conductivitat elèctrica. Aquest assaig es duu a terme sota diferents condicions per analitzar la velocitat del recobriment en funció del voltatge i del temps aplicats. Una vegada fet l’assaig es realitza un estudi superficial mitjançant un microscopi electrònic de rastreig (SEM) on s’examinen els diferents tipus de materials de la superfície del metall per comprovar que efectivament s’ha realitzat el recobriment desitjat. Malauradament s’observa que no s’ha aconseguit la deposició esperada seguint el procediment plantejat degut a la complexitat de l’experiment. Es proposen possibles alternatives d’assaig trobades a la bibliografia. Una pila de combustible de óxido sólido (SOFC) trabaja a temperaturas muy elevadas, por encima de los 700ºC, esto provoca que el interconector metálico de la pila se vea sometido a condiciones extremas bajo las que acaba dando lugar a la oxidación de uno de sus elementos, el cromo. La volatilización y posterior difusión del cromo oxidado dentro del sistema supone un gran problema para el funcionamiento de la pila y su rendimiento decae de manera notable. El objetivo de este estudio es conseguir un recubrimiento de Ni-Mo-P sobre una muestra de un interconector metálico para estudiar su posible aplicación dentro de una pila SOFC para protegerla de la difusión del cromo oxidado. Para conseguirlo se usan dos técnicas de recubrimiento combinadas, primero se realiza un recubrimiento electrolítico de níquel y posteriormente un recubrimiento electroless de Ni-Mo-P. Mediante esta técnica se busca obtener una capa continua, homogénea y uniforme de Ni-Mo-P adherida lo mejor posible a la superficie y que aporte valores elevados de resistencia a la oxidación, una buena resistencia mecánica y una buena conductividad eléctrica. Este ensayo se lleva a cabo a distintas condiciones para analizar la velocidad del recubrimiento en función del voltaje y del tiempo aplicados. Una vez hecho el ensayo se realiza un estudio superficial mediante un microscopio electrónico de barrido (SEM) donde se examinan los distintos tipos de materiales de la superficie del metal para comprobar que efectivamente se ha realizado el recubrimiento deseado. Desafortunadamente se observa que no se ha conseguido la deposición esperada siguiendo el procedimiento planteado debido a la complejidad del experimento. Se proponen posibles alternativas de ensayo encontradas en la bibliografía. A Solid Oxide Fuel Cell (SOFC) Works at very high temperatures, above 700ºC, this causes the metal interconector of the cell to be subjected to extreme conditions under which it ends up leading to the oxidation of one of its elements, chromium. The volatilization and subsequent diffusion of oxidized chromium within the system poses a major problem for the operation of the cell and its performance decrease markedly. The aim of the study is to obtain a Ni-Mo-P coating on a sample of a metal interconnector to study its possible application inside a SOFC in order to protect the fuel cell from the diffusion of oxidized chromium. To achieve this, two combined coating techniques are used, first an electrolytic nickel coating and then an electroless Ni-Mo-P coating. These techniques seek to achieve a contiuous and uniform layer of Ni-Mo-P adhered as best as possible to the Surface and that provides high values of oxidation resistance, good mechanical strength and good electrical conductivity. This test is carried out under different conditions in order to analyse the speed of the coating depending on the voltage and the time applied. Once the test has been performed, a superficial study is made by Scanning Electron Microscopy (SEM) where the different types of materials on the metal surface are examined to verify that the desired coating has indeed been made. Unfortunately, it is observed that the expected deposition has not been achieved following the proposed procedure due to the complexity of the experiment. Possible alternatives found in the literature are proposed for this study.

Plasma sprayed bioactive glass coatings were studied using crushed 45S5 bioactive glass powder. It is widely accepted that plasma sprayed coating microstructure is highly affected by the characteristics of the powder and the parameters set on the spraying process. Once the coating deposition was optimized, two strategies were carried out to analyse their effect on the coating adhesion: cooling with carbon dioxide while spraying and a post heat treatment to the as-sprayed coatings. Scanning electron microscopy and X-ray diffraction were used for analyse the obtained coatings. Additionally, coating adhesion to the substrate and degradation of the coatings in Tris buffer solution were evaluated for the different samples studied. Coatings have been tested in vitro to evaluate their response by immersion in simulated body fluid, Hank's Balanced Salt Solution. The results show an increase in the adhesion strength for the heat treated samples due to the stress relaxation achieved above glass transition temperature. Moreover, in the bioactivity test an apatite layer at the coatings surface was produced for all the strategies studied.

Due to the continuous evolution of the industry, there has been an increasing demand for cutting tools that have properties such as significant hardness, resistance to corrosion, and wear. This has motivated the research, development and implementation of coatings that present a combination of good mechanical and tribological properties, which increase the performance of these tools. For this reason, throughout this work, the effect that monolayer (CrAlSiN) and multilayer (CrAlN) coatings have on micromechanical properties has been analyzed and compared. In addition, the effect of working with different bilayer thicknesses, and the effect of different types of substrates (Inconel, 1.2344 steel and WC-Co) have been analyzed. Scratch adhesion, monotonic spherical indentation, and microhardness tests were performed. The damages obtained after performing each test were evaluated through light microscopy, confocal microscopy and SEM. It was verified that when using multilayer coatings, an improvement in the micromechanical properties is obtained. And in turn, these properties improve with their bilayer thickness. In this way, an increase in hardness was obtained that was from 19% to 76% compared to the monolayer coating. In turn, an improvement in adhesion was obtained, as well as the contact pressure necessary for the appearance of plastic deformation. On the other hand, it was demotivated that among the three substrates analyzed, WC-Co is the one that presents a better combination of the analyzed properties. In this way, by having a monolayer coating on said substrate, even higher results are obtained, than when multilayer coatings are used on the steel. Lately, thanks to the tribological and mechanical properties of diamond coatings such as carbon (DLC), their use in industry has increased. That is why, the knowledge of the factors that control their properties and, therefore, the final performance of the coated components in practical tribological applications, becomes increasingly important. In this work, from the DLC samples analyzed, using the Ramana spectroscopy technique, two different structures were identified. Thus, one is known as amorphous carbon and the other is known as amorphous tetrahedral carbon. The latter is expected to present a better combination of mechanical properties.

Titanium dental implants are widely used for the replacement of damaged teeth. However, bacterial infections at the interface between soft tissues and the implant can impair the functionality of the device and lead to failure. In this work, the preparation of an antifouling coating of polyethylene glycol (PEG) on titanium by pulsed electrodeposition was investigated in order to reduce Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) adhesion while maintaining human fibroblast adhesion. Different pulsed conditions were prepared and characterized by contact angle, Focused Ion Beam (FIB), Fourier Transformed Infrared Spectroscopy in the Attenuated Total Reflectance mode (ATR-FTIR), and X-ray photoelectron spectroscopy (XPS). XPS tested fibronectin adsorption. S. aureus, E. coli and human fibroblast adhesion was tested in vitro in both mono and co-culture settings. Physicochemical characterization proved useful for confirming the presence of PEG and evaluating the efficiency of the coating methods. Fibronectin adsorption decreased for all of the conditions, but an adsorption of 20% when compared to titanium was maintained, which supported fibroblast adhesion on the surfaces. In contrast, S. aureus and E. coli attachment on coated surfaces decreased up to 90% vs. control titanium. Co-culture studies with the two bacterial strains and human fibroblasts showed the efficacy of the coatings to allow for eukaryotic cell adhesion, even in the presence of pre-adhered bacteria.

Reinforced Inconel625 coatings have been successfully deposited by means of cold gas spray (CGS). Alumina has been simultaneously sprayed achieving a homogeneous distribution along the deposit with good cohesion between particles. The aim of this study was to investigate whether ceramic reinforcement could improve the mechanical and tribological properties of Inconel625 cold-sprayed coatings, while keeping the oxidation and corrosion resistance capacity. Furthermore, alumina particles were found to improve the spraying feasibility, by avoiding WC nozzle clogging during the process. A proper optimization of the spraying conditions was carried out in order to obtain the lowest possible porosity and best embedment of the alumina. Then, the mechanical and tribological properties as well as corrosion and oxidation behavior were characterized. Alumina acts as a reinforcement, improving the effects of abrasive and sliding wear. Regarding the oxidation and corrosion behavior, the coatings exhibit reasonably good oxidation resistance at temperatures up to 900 &deg, C. The electrochemical corrosion performance in NaCl solution showed potentially lower noble corrosion values and corrosion current densities than bulk Inconel.

Possibilities of the development of new anti-erosion coatings for wind turbine blade surface protection on the basis of nanoengineered polymers are explored. Coatings with graphene and hybrid nanoreinforcements are tested for their anti-erosion performance, using the single point impact fatigue testing (SPIFT) methodology. It is demonstrated that graphene and hybrid (graphene/silica) reinforced polymer coatings can provide better erosion protection with lifetimes up to 13 times longer than non-reinforced polyurethanes. Thermal effects and energy dissipation during the repeated soft impacts on the blade surface are discussed.

[CATALÀ] Com a acabat decoratiu en negre i protecció contra la corrosió de l’acer, des de fa segles, el pavonat en calent ha sigut el mètode més utilitzat a la industria, sobretot a la industria armamentista. El pavonat en calent, bàsicament és un bany químic amb el qual es genera una capa d’òxid de ferro (magnetita) sobre l’acer base, que dona aquest color típic de les armes. Els productes i reactius per al bany, actualment venen definits per els fabricants, i els paràmetres del procés, que són la concentració, la temperatura i el temps del bany, també venen recomanats per obtenir uns resultats acceptables. Aquest projecte té com a objectiu caracteritzar el procés de pavonat en calent, de manera òptima, per obtenir els millors resultats en quant a propietats decoratives, tribològiques i mecàniques aportades per la capa de magnetita. La part experimental s’ha dut a terme mitjançant la recreació del procés industrial a escala de laboratori, amb productes i reactius actuals a la industria, i per la via de múltiples intents amb variacions dels paràmetres del procés. La part analítica es composa de diferents estudis metal·logràfics a les mostres pavonades amb els diferents paràmetres, assajos de Pin on Disk i microdureses. L’anàlisi i discussió dels resultats obtinguts porten a unes conclusions que donen els paràmetres òptims per obtenir peces pavonades de bona qualitat, amb un procés estable. [ANGLÈS] As a decorative black finish and protection against corrosion of steel, for centuries, hot blackening has been the most used method in industry, especially in the weapons industry. Hot blackening is basically a chemical bath by which a layer of iron oxide (magnetite) is generated on the base steel, which gives this typical and bright black of the weapons. Bath products and reagents are currently defined by manufacturers, and the parameters of the process, which are the concentration, temperature and timing of the bath, are also recommended by the suppliers for obtaining acceptable results. This project aims to characterize the hot blackening process, in an optimum way, to obtain the best results in terms of decorative, tribological and mechanical properties contributed by the magnetite layer. The experimental part has been carried out by recreating the industrial process on the laboratory environment, with current products and reagents in the industry, and through multiple attempts with variations of the process parameters. The analytical part consists of different metallographic studies about this attempts samples of blackened material with different parameters, tests of Pin on Disk and microhardness. The analysis and discussion of the results obtained, leads to some conclusions that give the optimum parameters to obtain good quality on the blackened pieces, with a stable process.

The impact of porous WC-12wt%Co and WC-17wt%Co particles onto homologous, smooth surfaces is simulated through a coupled Eulerian-Lagrangian, three-dimensional finite element model, in order to study the build-up mechanisms of cold sprayed WC-Co coatings. Deformation of hardmetal particles upon impact involves compaction and spreading of a rim, whose bottom face experiences heating, close to or even above the melting point of the matrix, and develops large equivalent plastic strain. The rim therefore adheres strongly to the underlying hardmetal. SEM observations of cold sprayed WC-Co particles deposited onto a smooth hardmetal surface show metallurgic bonding of the heated matrix and mechanical fixation as WC grains from the particle indent and penetrate into the underlying material. Little deformation and heating are instead seen in the middle of the contact surface, where adhesion is limited. Deformation of the particle requires the criterion for ductile failure of the hardmetal to be exceeded. This means the deformed rim is also extensively failed and ejects fragments as it spreads. Increasing the momentum of the particle enhances the spreading of the rim and promotes its bonding to the underlying surface, but also causes ejection of larger fragments, as well as the elastic storage of a greater amount of rebound energy, which can result in eventual rebounding of the entire particle or its poorly bonded central portion. It is therefore inferred that the deposition efficiency of cold sprayed hardmetals cannot increase linearly with impact velocity, and it is further impaired with stiff, dense particles and/or with very hard materials (e.g. WC-12Co as compared to WC-17Co).

[eng] The main objective of this research work was to produce environmentally friendly cermets coatings, Ni and Co free matrix, alternative to conventional WC- Co, by thermal spray processes. WC-Co cermets has always been one of the most on demand coatings in anti-wear and anti-corrosion applications in industry but environmental problems caused by heavy metals matrix (Co and Ni) force the redesign of many conventional processes. These elements are not harmful in their fundamental state, but processing generate changes in oxidation states that make them carcinogenic and mutagenic. For this reason, this research has focused on either replacing the existing processes or use raw materials that are less harmful. Therefore depositing the green carbides cermets onto the different substrates by conventional or novel (CGS) techniques are the main motivation points of this thesis. No one has previously successfully deposited such material by CGS or HVOF method with the same properties as the conventional WC-Co which was also one of the main motivation points. In this work we could produce Ti-TiC coatings with different percentage of Carbide phase by CGS, TiC-based with FeCrAlTi metal matrix by HVOF method, SiC-based cermets with Ti and TiCr metal matrixes by both CGS and HVOF technique and WC-based cermet with Ti metal matrix by CGS, HVOF and APS techniques. For this reason the main objectives of this Thesis entitled “Deposition of green carbide cermets coatings by thermal spray techniques”. GLOBAL TREND FOR TIC SYSTEM: For all three Ti-TiC powders by increasing the SOD from 20 to 40, hardness has been increased which can be related to the decreasing the porosity of produced coatings by increasing the carbide phase which can be observed at SEM micrographs. The Higher adhesion strength of coating related to Ti-65%TiC can be explained by higher amount of hard carbide phase. When powder impact the substrate, powder with higher amount of hard phase deforms the substrate more and immerge the substrate deeper and as a result stronger mechanical bonding between the coating and substrate will be happened. From the wear rate comparison of obtained coatings regarding different Ti-TiC cermets can be resulted that Ti-65%TiC showed better wear resistance properties because of higher hardness and lower porosity. The optimal coating for Ti-TiC system was obtained at medium pressure and medium-high temperature related to Ti- 65%TiC and by increasing the temperature, there was an erosion and the coating was brittle and fully cracked. At high pressure and high temperature there was no deposition at all. Obtained coating related to TiC-FeCrAlTi by HVOF showed relatively good microstructural and mechanical properties. GLOBAL TREND FOR SIC SYSTEM: For this system there was no significant difference between microstructural properties of obtained coatings related to both powders by CGS method, both coatings had a hardness of about 500 HV. Though in order to improve the microstructural properties of coating related to Ti-SiC especially the hardness, coating went through the thermal treatment (annealing at 750°C). The microstructure of the coating was significantly changed because the interfaces between the deposited powder particles tended to disappear and a stronger metallurgical bond was formed [61–63]. HVOF coating of Ti-SiC presented higher hardness value than CGS mainly because of decomposition of Ti-SiC powder during the process and therefore hardening effect of SiO2 phase. Besides a higher hardness, HVOF coating was more brittle (less fracture toughness value) than CGS coating due to the lower content in elemental ductile Ti matrix and the presence of fragile and hard SiO2 phase formed during the HVOF spraying process. The lower value of fracture toughness in HVOF coating can be also attributed to the fact that during CGS the powder is not subjected to phase changes and no draining of the ductile free metallic matrix in the microstructure happens. The Ti present in the coating is kept and acts as a ductile element hence improving the fracture toughness of the CGS coating. Wear rate comparison of formed coatings related to Ti-SiC by CGS and HVOF using Propylene was shown in previous chapter, significantly lower wear rate of cold sprayed coating of Ti- SiC than HVOF can be explained by higher fracture toughness value of obtained coatings by CGS despite of higher hardness value of obtained coating by HVOF. Wear rate comparison of formed coating related to TiCr-SiC by HVOF and using H2 and Ti-SiC by HVOF and using Propylene showed that coating related to TiCr- SiC had better wear resistance than Ti-SiC because of less formed porosity in coating especially on top of the coating which was in contact with rubber wheel also from the results of fracture toughness of coatings can be explained that coating from TiCr-SiC had more fracture toughness value than the one from Ti- SiC by HVOF. GLOBAL TREND FOR WC SYSTEM: Ti-WC (400HV) was deposited onto the carbon steel substrate by HVOF and a coating with hardness of almost 900 HV was obtained. The produced coating by using Propylene had higher hardness than the one produced by using H2 though the thickness of coating for both coatings was not thick enough. This powder was sprayed onto the carbon steel substrate with a bond coat layer of Titanium by CGS in order to increase the adhesion between the powder particles and the substrate surface and after obtaining the coating the sample went through the post thermal treatment (HT Temperature: 650°C, HT isotherm: 60 mins, Ramp: 5 (°C/min), Atmosphere: Vacuum) in order to increase the hardness of the coating. After HT, hardness of coating reached a value of 1200 HV from 750 which was considerable. The higher hardness of HVOF Ti-WC than CGS can be explained because of decarburization of WC particles during HVOF, as the particles are exposed to hot and usually Oxygen rich environment. As a result, W2C and depending on the processing conditions even W is formed as well as volatile CO and CO2. From Ti-WC (650HV) and (1500 HV) powders the coatings were produced by APS technique though they were so porous. CONCLUSIONS: From this study following findings can be resulted: 1. Green cermets coatings with different metallic matrix (Ti, FeCrAlTi) and different carbides (TiC, SiC, WC) have been produced successfully by different thermal spray techniques and can be used as alternative to WC- Co or Cr3C2-NiCr for anti-wear applications. Because of the high density of WC-Co and Cr3C2-NiCr coatings in applications where command reduction in weight is needed and its high relative cost as compared to TiC based hard metals and hazardous nature of Cobalt and Nickel matrix, green cermet coatings can be good alternatives in the bench market. 2. In CGS method has been observed a trend which by increasing the temperature to the max and increasing the pressure, visible cracks in deposited particles, weak bonding in central area of splats-substrate interface, less penetration and less plastic deformation have been observed. This trend can be explained by impact velocity of the particles which has been increased by increasing the spraying temperature and pressure till the critical value (the optimal condition) and afterward the excessive particle velocities has been resulted erosion and avoiding a proper deposition process. Spraying pressure and temperature both had the direct relation with the impact velocity of particles though increasing the pressure affected the impact velocity of particles more than the temperature. This phenomena has led to a decrease in hardness value and fracture toughness of produced coatings. The optimal parameters have been set at intermediate temperatures and pressures. 3. In HVOF there was no significant difference between mechanical properties of the coatings by using hydrogen and propylene as fuel gases. Though for each system, produced coatings by using Propylene as fuel gas had slightly higher hardness value and lower wear rate which was considered as the optimum coating by HVOF for each system. 4. In general HVOF has produced coatings with presence of continues oxide phases network and lower content in elemental ductile metal matrix which as a result higher hardness and lower fracture toughness has been achieved. In contrast CGS has produced coatings with absence of fragile oxide phases which has led to the higher fracture toughness but lower hardness value. In CGS the hard carbide phase was not melted and was not distributed in metallic matrix homogenously and that is why it has lower value of hardness against HVOF coatings. The optimum coating of this study which can be considered as the alternative to WC-Co or Cr3C2-NiCr for anti-wear applications was Ti-WC by CGS after a post heat treatment. This coating reached the significantly enhanced microstructural properties due to the release of residual stress during the thermal treatment and hardness value of 1200 HV with significantly low wear rate., [spa] En primer lugar, el objetivo principal de este trabajo de investigación fue producir recubrimientos cermets de respetuosos del medio ambiente, matriz libre de Ni y Co, alternativa a WC-Co convencional, por la proyecciones térmicas. WC-Co cermets siempre ha sido uno de los recubrimientos más demandados en aplicaciones anti desgaste y anticorrosión en la industria, pero los problemas ambientales de la matriz de metales (Co y Ni) se han debido a cambios en los procesos convencionales. Estos elementos no son dañinos en su estado fundamental, pero el procesamiento genera cambios en los estados de oxidación que los hacen cancerígenos. Por eso, esta tesis se ha centrado en reemplazar los procesos existentes o utilizar materias primas que son menos nocivas. Por lo tanto, depositar los nuevos cermets en los diferentes sustratos por proyecciones térmicas convencionales o novedosas (CGS) son los principales puntos de motivación de esta tesis. Nadie ha depositado previamente con éxito dicho material por el método CGS o HVOF con las mismas propiedades que el WC-Co convencional, que también fue uno de los principales puntos de motivación. En este trabajo podríamos producir recubrimientos de Ti-TiC con diferentes porcentajes de fase de Carburo por CGS, TiC con aleación metálica de FeCrAlTi por método HVOF, SiC con matrices metálicas de Ti y TiCr por ambas técnicas CGS y HVOF y WC cermet con matriz de metal Ti por técnicas CGS, HVOF y APS. Por eso, los objetivos principales de esta Tesis se titulan "Deposición de respetuoso con el medio ambiente recubrimientos de los cermets por el proyecciones térmicas".

Cold gas spray technology has been used to build up coatings of Fe-base metallic glass onto different metallic substrates. In this work, the effect of the substrate properties on the viscoplastic response of metallic glass particles during their impact has been studied. Thick coatings with high deposition efficiencies have been built-up in conditions of homogeneous flow on substrates such as Mild Steel AISI 1040, Stainless Steel 316L, Inconel 625, Aluminum 7075-T6, and Copper (99.9%). Properties of the substrate have been identified to play an important role in the viscoplastic response of the metallic glass particles at impact. Depending on the process gas conditions, the impact morphologies show not only inhomogeneous deformation but also homogeneous plastic flow despite the high strain rates, 10 8 to 10(9) s(-1), involved in the technique. Interestingly, homogenous deformation of metallic glass particles is promoted depending on the hardness and the thermal diffusivity of the substrate and it is not exclusively a function of the kinetic energy and the temperature of the particle at impact. Coating formation is discussed in terms of fundamentals of dynamics of undercooled liquids, viscoplastic flow mechanisms of metallic glasses, and substrate properties. The findings presented in this work have been used to build up a detailed scheme of the deposition mechanism of metallic glass coatings by the cold gas spraying technology.

Atmospheric plasma spraying is used here to obtain titanium sub-oxide coatings on the following electrode substrates: a 316 stainless steel sheet, an aluminium alloy 2024 sheet, a carbon–polymer composite and nickel foam. It is necessary to increase the roughness of the substrate to aid the adhesion of the coating to the smooth electrodes; this is especially critical for the fragile carbon–polymer composite. High-energy conditions increase the strain caused by the mismatch between coefficients of thermal expansion when coating the thin steel and aluminium sheets, and degraded the carbon–polymer composite and nickel foam. Therefore, it is necessary to adjust the spraying parameters to lower-energy conditions in order to achieve well-bonded and homogeneous coatings on all four substrates and avoid the presence of cracks in their cross-section area. The suitability of the coated materials as battery electrodes was studied.

This study develops a rapid method to confer superhydrophobicity on 316L stainless steel surfaces with an amphiphilic reagent such as dodecanoic acid. The highest contact angle (approaching 173°) was obtained after forming hierarchical structures with a non-aqueous electrolyte by an electrolytic process. Our goal was to induce superhydrophobicity directly on 316L stainless steel substrates and to establish which molecules cause the effect. The superhydrophobic behaviour is analysed by contact angle measurements, scanning electron microscopy (SEM), IR spectroscopy and atomic force microscopy (AFM). The growth mechanism is analysed using FE-SEM, TOF-SIMS and XPS in order to determine the molecules involved in the reaction and the growth. The TOF-SIMS analysis revealed that the Ni 2 + ions react with lauric acid to create an ester on the stainless steel surface.

The cold spray coating properties and performances are largely affected by feedstock characteristics and the employed processing parameters. Starting from experimental results obtained from the bibliographic data, the relationships between starting particles, processing conditions, and coating properties obtained by cold gas spray were analyzed. The relationships among these properties and particle velocity were described for various material systems. The effect on particle flattening, hardness, and porosity were largely described. Finally, the influence of the different parameters on the process output and on the coating properties was analytically defined through the employment of the multi-objective simulation tool modeFRONTIER. The analysis of data from the bibliography is a new trend that can also be applied to cold spray in order to analyze the effect of powder The cold spray coating properties and performances are largely affected by feedstock characteristics and the employed processing parameters. Starting from experimental results obtained from the bibliographic data, the relationships between starting particles, processing conditions, and coating properties obtained by cold gas spray were analyzed. The relationships among these properties and particle velocity were described for various material systems. The effect on particle flattening, hardness, and porosity were largely described. Finally, the influence of the different parameters on the process output and on the coating properties was analytically defined through the employment of the multi-objective simulation tool modeFRONTIER. The analysis of data from the bibliography is a new trend that can also be applied to cold spray in order to analyze the effect of powder properties and spraying parameters on the cold spray (CS) process. and spraying parameters on the cold spray (CS) process.

A highly rough titanium coating obtained by Cold Gas Spray (CGS) has been characterized by means of high-resolution 3D microtomography (micro-CT) with the aim to evaluate its open and close porosity for possible use in orthopaedic implants to promote osseointegration. Micro-CT allowed a qualitative and quantitative description of the main features, morphology of the pores and surface roughness of the coating. Several numerical values were obtained to describe size, form and distribution of the closed/inner and open/outer pores. Additionally, surface roughness and open porosity were image-analyzed to find the effective surface for osseointegration.

A large amount of packaging has been used and discarded daily, and most of them are discarded in the nature and require many years to decompose. The use of synthetic polymers, due to its advantages and processability, is widely diffused industrially on the development of packaging, however raw materials from renewable sources are an attractive alternative for this purpose. Polymers from renewable sources in the production of packaging results in a product capable of degrading in a shorter period of time when compared to traditional ones, therefore influencing for a greater sustainability in the world. Several chemical compounds exhibit antimicrobial behavior and they can be found in plant extracts or in essential oils. Therefore, in order to confer antimicrobial properties on edible films and coatings, it is possible to add in its composition plant extracts and / or essential oils from various plant species. Thus, this chapter is aimed to describe packaging from renewable sources with antimicrobial properties, antimicrobial agents capable to be added in theses packaging, the incorporation form of those agents and the application of an antimicrobial packaging in food science field The research leading to these results has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 712949 (TECNIOspring PLUS) and from the Agency for Business Competitiveness of the Government of Catalonia

A challenge currently facing the orthopedics sector consists in the durability problems posed by joint prosthesis based on metal-on-metal contacts. While the diamond-like carbon (DLC)-based coating solves the shortcomings of wear and friction found in the uncoated metal parts, they are generally subject to adhesion failures that may prove to be catastrophic. Our coatings were deposited with a specific multilayered composition that changes from highly metallic at the metal interface, up to a DLC at the sliding contact region. These coatings show very good wear performance results when tested in a highly humid air atmosphere as well as when they are tested in water immersion or in bovine serum. The friction coefficients of our DLC-against-DLC tribological pair are found to be always less than 0.1, while wear rates are extremely low, under 2.5¿×¿10-8¿mm3/N¿m, and it produces highly polished surfaces. The compressive stresses of our coatings are always lower than 2.5¿GPa, and when combined with good interface adhesion to the CoCrMo metal substrates, make the coatings highly resistant to delamination even after prolonged test runs. Raman analyses do not reveal any detectable changes even after very long test runs, indicating that no tribochemical reactions occur on the DLC coating.

The medium and high temperature tribological behavior of different iron aluminide thermal spray coatings was investigated. Several powders synthesized through different routes (ball milling, self-decomposition, and self-propagating high-temperature sintering (SHS)) were evaluated. High heterogeneity of conventional High Velocity Oxygen Fuel (HVOF) coatings plays a vital role in their sliding performance, but as long as their integrity is preserved under high temperature oxidizing conditions, the wear rates are found to be acceptable, as it occurs in the case of ball milled Fe-40Al (at.%) powder. The friction phenomenon and wear mechanisms were analyzed in detail through the wear track morphology, contact surface, and friction coefficients. The occurrence of brittle phases in the sprayed coatings, which are also present when tested at high temperatures, appeared to be crucial in accelerating the coating failure.

Three different surface treatments on a Ti6Al4V alloy have been in vitro tested for possible application in cementless joint prosthesis. All of them involve the novelty of using the Cold Spray technology for their deposition: (i) an as-sprayed highly rough titanium and, followed by the deposition of a thin hydroxyapatite layer with (ii) microcrystalline or (iii) nanocrystalline structure. Primary human osteoblasts were extracted from knee and seeded onto the three different surfaces. Cell viability was tested by MTS and LIVE/DEAD assays, cell differentiation by alkaline phosphatase (ALP) quantification and cell morphology by Phalloidin staining. All tests were carried out at 1, 7 and 14 days of cell culture. Different cell morphologies between titanium and hydroxyapatite surfaces were exhibited. At 1 day of cell culture, cells on the titanium coating were spread and flattened, expanding the filopodia actin filaments in all directions, while cells on the hydroxyapatite coatings showed round like-shape morphology due to slower attachment. Higher cell viability was detected at all times of cell culture on titanium coating due to a better attachment at 1 day. However, from 7 days of cell culture, cells on hydroxyapatite showed good attachment onto surfaces and highly increased their proliferation, mostly on nanocrystalline, achieving similar cell viability levels than titanium coatings. ALP levels were significantly higher in titanium, in part, because of greatest cell number. Overall, the best cell functional results were obtained on titanium coatings whereas microcrystalline hydroxyapatite presented the worst cellular parameters. However, results indicate that nanocrystalline hydroxyapatite coatings may achieve promising results for the faster cell proliferation once cells are attached on the surface.