Additive manufacturing is gaining importance thanks to its multiple advantages. Stereolithography (SLA) shows the highest accuracy and the lowest anisotropy, which has facilitated the emergence of new applications as dentistry or tissue engineering. However, the availability of commercial photopolymers is still limited, and there is an increasing interest in developing resins with properties adapted for these new applications. The addition of graphenebased nanomaterials (GBN) may provide interesting advantages, such as improved mechanical properties and bioactivity. However, there is a lack of knowledge regarding the effect of GBNs on the polymerization reaction. A photopolymerizable acrylic resin has been used, and the effect of the addition of 0.1wt% of graphene (G); graphene oxide (GO) and graphite nanoplatelets (GoxNP) on printability and polymerization have been investigated. It was observed that the effect depended on GBN type, functionalization and structure (e.g., number of layers, size, and morphology) due to differences in the extent of dispersion and light absorbance. The obtained results showed that GO and GoxNP did not significantly affect the printability and quality of the final structure, whilst the application of G exhibited a negative effect in terms of printability due to a reduction in the polymerization degree. GO and GoxNP-loaded resins showed a great potential to be used for manufacturing structures by SLA.

Bone possesses an inherent capacity to fix itself. However, when a defect larger than a critical size appears, external solutions must be applied. Traditionally, an autograft has been the most used solution in these situations. However, it presents some issues such as donor-site morbidity. In this context, porous biodegradable scaffolds have emerged as an interesting solution. They act as external support for cell growth and degrade when the defect is repaired. For an adequate performance, these scaffolds must meet specific requirements: biocompatibility, interconnected porosity, mechanical properties and biodegradability. To obtain the required porosity, many methods have conventionally been used (e.g., electrospinning, freeze-drying and salt-leaching). However, from the development of additive manufacturing methods a promising solution for this application has been proposed since such methods allow the complete customisation and control of scaffold geometry and porosity. Furthermore, carbon-based nanomaterials present the potential to impart osteoconductivity and antimicrobial properties and reinforce the matrix from a mechanical perspective. These properties make them ideal for use as nanomaterials to improve the properties and performance of scaffolds for bone tissue engineering. This work explores the potential research opportunities and challenges of 3D printed biodegradable composite-based scaffolds containing carbon-based nanomaterials for bone tissue engineering applications.

Silane-based coatings with nanoparticles have been widely used in applications related to surface protection. Between them, the improvement of corrosion resistance by increasing the hydrophobicity is one of the main research goals. However, most coatings present problems of low wear resistance and poor aesthetic appearance. Therefore, the overall goal of this research is to manufacture hydrophobic sol-gel coatings based on silanes which comply with good tribological and aesthetical properties. In the present study, stainless steel plates were coated with a silane-based solution containing zirconia nanoparticles by dip coating. Water–ethanol solutions with silanes (methyltrimethoxysilane (MTS) and tetrathoxysilane (TEOS)) and different percentages of ZrO₂ nanoparticles were prepared. Gloss, color, contact angle, surface energy, wear resistance, and thickness of coating were analyzed to elucidate the effect of zirconium oxide on the performance of the coatings. Results demonstrate that the ZrO₂–silane coatings on stainless steel offer a balanced combination of properties: low wettability, high wear resistance, and similar color and brightness compared to pristine stainless steel.

Generally, polymeric materials present an issue related to their low surface energy: low painting ability. The main aim of this work is to improve the adhesion between polymeric surfaces (polydimethylsiloxane (PDMS), and acrylonitrile-butadiene-styrene (ABS)) and paints (epoxy (EP), and polyurethane (PU)-based). In order to increase adhesion, hydrophilic modification of surfaces by atmospheric pressure plasma torch treatment (APPT) was proposed. Furthermore, it can permit dissimilar joints, i.e., ABS with a metal joined by a silicone (based PDMS), to be painted. The surface modifications were characterized by measurements of surface energy and roughness. In addition, the effectiveness of the pre-treatment on improving paint adhesion was confirmed by scratch, cross-cut, and adhesion tests. Results showed the possibility of coating both ABS and PDMS with a PU-based paint when treated with plasma. As a novel result, polymer and metal panels joined by silicone were able to be painted with the PU paint.