Surface functionalization of 3D printed structures: Aesthetic and antibiofouling properties

Abstract

Additive manufacturing (AM) is a hot topic nowadays, having a first order in importance in research trends, improving existent technologies and carrying them further. AM can be applied to ceramics, which have importance in current technologies. Their capability to maintain functional properties for long time periods, combined with the easiness to process and the abundance of raw materials, make them a fundamental part of mankind development. Within ceramics, stoneware has a wide range of uses but in some conditions, it can be affected by biofouling. Ti(O)N and Ag-Ti(O)N coatings over 3D printed stoneware, were presented as multifunctional solution, linking aesthetical and antimicrobial properties. Films were developed by reactive direct current (DC) magnetron sputtering and characterized physical, chemical and morphologically, as well as regarding their colour variation. Moreover roughness, wettability, antibacterial and antibiofouling were also evaluated. The results revealed that the Ag doped coatings (with or without oxygen addition) had an enhanced multifunctionality compared to control samples (without Ag). Ag nanoparticles addition created a surface with potential antibacterial and antibiofouling activities, in order to resist outdoors and aqueous environments, making these films able to be applied in architectural pieces as sculptures or other decorative parts, maintaining their properties with good aesthetical properties. implants, soft tissue replacements, drug deliveries, among others [2]; aerospace industry, in reduced volume parts and replacements parts for aircraft with advanced materials as aluminium alloys, titanium alloys, nickel super-alloys and special steels; automotive industry, in the development of some structural and engine parts; and tooling industry, like moulds with complex refrigeration systems enabling better performances and higher life time, [3]. Additive manufacturing, namely with metals and polymers, is no longer the future, it is the unavoidable present, but the additive manufacture of ceramic materials is still far from the desired maturity. Abundance, easy manipulation, low cost, heat resistance and long life time span are the main characteristics of ceramics [4] and across human history, new technologies have enlarged its uses. Chemically, ceramics can be considered as compounds formed between metallic and non-metallic elements with predominant ionic bonding but having a

Antimicrobial TiN-Ag Coatings in Leather Insole for Diabetic Foot

“…The XRD pattern of TiN coating indicates that the most intense peaks are located at 36.8 • and 42.9 • , which are very close to the TiN (111) and TiN (200) peaks. Previous studies in TiN-Ag coatings deposited by magnetron sputtering reported this behavior [19,24].…”

Cu oxidation mechanism on Cu-Zr(O)N coatings: Role on functional properties

“…To control the O/N ratio and consequently tune the colour pallet, a duty cycle controller was used with 45 s period in a square wave for O 2 addition on the reactive atmosphere. The duty cycle used in this study was the same as that used in previous studies by the authors [15] and which has been explained in previous these studies [23][24][25][26][27]. The O 2 duty cycle set-ups were 20, 40, 80 (exclusively for Zr(O)N system) and 100% (only in Cu added films), which correspond to the flow values and times shown in table 1.…”

“…By adding carbon, the colour shifted towards black tones. In fact, in a previous study [15], the authors of this investigation reported the same colour shifting in Ti(O)N coatings and also ZrN x O y coatings [16]. They revealed four distinct zones in Zr(O)N system: Zone I and II, where coatings were based on ZrN and performed a wide colour pallet from pale yellow or golden tones to dark blue; Oxynitrides (zone III) and oxides (zone IV), which presented a semitransparent optical behaviour.…”

“…The antibacterial activity of the films was tested using Staphylococcus epidermidis ATCC 12228 (obtained from American Type Cell Collection). Zone of inhibition (ZoI) or halo tests adapted from Kirby-Bauer method [30], were performed to evaluate the antibacterial activity of samples according to our previous study [15]. All experiments were repeated in triplicate and at least in three independent assays.…”

“…interesting tones for different markets. Some authors have reported that the oxygen inclusion in oxynitrides with a transitional metal turned the base colour into 'bluish' tones with low luminosity [15,38,58]. Also, the presence of Cu in the coating structure promotes faster oxygen incorporation due the decrease on the Zr content.…”