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Item Anatase film on orotracheal tubes to mitigate Staphylococcus aureus(American Scientific Publishers) Manfroi, Lucas Augusto; Silva, Michely Glenda Pereira da; Vieira, Angela Aparecida; Macário, Paulo Fabrício; Silva, Newton Soares da; Marques, Francisco Chagas; Vieira, LuciaBacterial contamination in hospital environments is a significant concern for patient admissions. Aiming to reduce contamination, titanium dioxide film (TiO2) in the anatase phase has been prepared on the surface of polyvinyl chloride (PVC) tubes. The PVC tube material was used to study the film’s effectiveness in inhibit- ing bacterial growth and cell viability. The morphology and composition of deposited films were investigated using a Scanning Electron Microscope (SEM) and Energy Dispersive Spectroscopy (EDS) map. In addition, Fourier-Transform Infrared Spectroscopy (FTIR) and XRD diffractogram were used to analyze film composition and phase, respectively. The adhesion of TiO2 film on PVC substrate was determined using ScotchTM tape-test according to ASTM: D3359-09, 2010, and the film surface morphology was analyzed by the MEV-FEG tech- nique and EDS map. The bacterial viability was performed with Staphylococcus aureus, and cell viability was performed using L929 strain mouse fibroblasts. The results of TiO2 in the anatase phase deposited by ALD on the PVC surface demonstrate good adherence and the film’s effectiveness in inhibiting bacterial growth and cell viability.Item Evaluation of Mechanical, Spectroscopic, and Morphological Properties of DLC Coatings with TiO2 Integration via PECVD and ALD on 316L Stainless Steel for Applications in UV Radiation-Prone and Saline Environments(2024-08-08) Vieira, Lúcia; Oliveira, Virgínia Klausner de; Oliveira Filho, Irapuan Rodrigues de; Aguzzoli, Cesar; Fukumasu, Newton Kiyoshi; Macário, Paulo Fabrício; São José dos CamposThis study presents an innovative dual-layer coating approach integrating titanium dioxide (TiO2) onto diamond-like carbon (DLC)-coated 316L stainless steel. The combination of PECVD-deposited DLC and ALD-deposited TiO2 aims to preserve the inherent tribological properties of DLC while mitigating UV-induced degradation. By leveraging the ability of TiO2 to absorb, reflect, and scatter UV light, this dual-layer strategy significantly enhances the durability of DLC coatings in radiation-prone environments. The effects of accelerated aging through UV exposure on DLC and DLC/TiO2 films were evaluated using an Accelerated Weathering Tester. The Salt Spray test, and Ferroxyl test were employed to verify corrosion resistance, and film’s permeability. Comprehensive analyses were conducted to assess the structural and mechanical properties before and after UV exposure, including Raman spectroscopy, profilometry, SEM, EDS, nanoindentation, and tribometry. The results demonstrate that the TiO2 layer effectively mitigates UV-induced damage, preserving the DLC film’s integrity and tribological performance even after 408 h of UV aging. Specifically, the DLC/TiO2 coatings maintained lower roughness, higher hardness, and better adhesion than DLC-only coatings under identical conditions. Additionally, the films' behavior in marine atmospheric conditions showed that the DLC and DLC/TiO2-coated films exhibited significantly enhanced corrosion resistance compared to the bare 316L stainless steel, maintaining the integrity of the coating even under prolonged exposure to adverse environments. This research significantly advances protective coating technology by enhancing the durability and performance of DLC films, particularly in aerospace and other demanding industries where exposure to UV radiation is a critical concern.Item Sputtering of micro-carbon-silver film (μC-Ag) for endotracheal tubes to mitigate respiratory infections(IOP science) Silva, Michely Glenda Pereira da; Manfroi, Lucas Augusto; Lobo, Larissa Zamboni; Vieira, Angela Aparecida; Macário, Paulo Fabrício; Fukumasu, Newton Kiyoshi; Silva, Newton Soares da; Tschiptschin, André Paulo; Marques, Francisco das Chagas; Vieira, LuciaPolyurethane (PU) substrates are biocompatible materials widely used to manufacture endotracheal tubes. However, in common with other biomedical materials, they are liable to the formation of microbial films. The occurrence of pneumonia in intubated patients treated at intensive care units often takes the form of ventilator-associated pneumonia (VAP). The issue relates to the translocation of pathogenic microorganisms that colonize the oropharyngeal mucosa, dental plaque, stomach, and sinuses. New protective materials can provide a more effective therapeutic approach to mitigating bacterial films. This work concerns microcrystalline carbon film containing dispersed silver nanoparticles (μC-Ag) deposited on PU substrates using a physical vapor deposition sputtering process. For the first time, carbon paper was used to produce a carbon target with holes exposing a silver disk positioned under the carbon paper, forming a single target for use in the sputtering system. The silver nanoparticles were well distributed in the carbon film. The adherence characteristics of the μC-Ag film were evaluated using a tape test technique, and electron dispersive x-ray mapping was performed to analyze the residual particles after the tape test. The microbicidal effect of the thin film was also investigated using species S. aureus, a pathogenic microorganism responsible for most infections of the lower respiratory tract involving VAP and ventilator-associated tracheobronchitis (VAT). The results demonstrated that μC-Ag films on PU substrates are promising materials for mitigating pathogenic microorganisms on endotracheal tubes.Item Enhancing UV Radiation Resilience of DLC-Coated Stainless Steel with TiO2: A Dual-Layer Approach(MDPI) Macário, Paulo Fabrício; Silveira, Carolina Hahn da; Vieira, Angela Aparecida Moraes; Marcondes, André Ricardo; Marques, Francisco das Chagas; Fechine, Guilhermino José Macêdo; Vieira, LuciaThis study presents an innovative dual-layer coating approach integrating titanium dioxide (TiO2) onto diamond-like carbon (DLC)-coated 316L stainless steel. The combination of PECVD- deposited DLC and ALD-deposited TiO2 aims to preserve the inherent tribological properties of DLC while mitigating UV-induced degradation. By leveraging the ability of TiO2 to absorb, reflect, and scatter UV light, this dual-layer strategy significantly enhances the durability of DLC coatings in radiation-prone environments. The effects of accelerated aging through UV exposure on DLC and DLC/TiO2 films were evaluated using an Accelerated Weathering Tester. Comprehensive analyses were conducted to assess the structural and mechanical properties before and after UV exposure, including Raman spectroscopy, profilometry, SEM, EDS, nanoindentation, and tribometry. The results demonstrate that the TiO2 layer effectively mitigates UV-induced damage, preserving the DLC film’s integrity and tribological performance even after 408 h of UV aging. Specifically, the DLC/TiO2 coatings maintained lower roughness, higher hardness, and better adhesion than DLC- only coatings under identical conditions. This research significantly advances protective coating technology by enhancing the durability and performance of DLC films, particularly in aerospace and other demanding industries where exposure to UV radiation is a critical concern.Item Tribocorrosion Susceptibility and Cell Viability Study of 316L Stainless Steel and Ti6Al4V Titanium Alloy with and without DLC Coatings(MDPI) Sene, Ana Claudia; Silva, Michely Glenda Pereira da; Macário, Paulo Fabrício; Vieira, Angela Aparecida; Leite, Priscila Maria Sarmeiro Correa Marciano; Silva, Newton Soares da; Marques, Francisco Das Chagas; Vieira, LúciaStainless steel (SS316L) and titanium alloy (Ti6Al4V) exhibit suitable properties for biomed- ical applications; however, the tribocorrosion of these materials, which is associated with metallosis, is still a significant concern. This work investigates the effectiveness of DLC smoothing coatings applied to the metals to reduce tribocorrosion and improve cell viability. The study was motivated by many reports of metallosis caused by metal debris in the soft tissues of the body. DLC coatings were produced using the plasma-enhanced chemical vapor deposition (PECVD) technique. The cytotoxicity, genotoxicity, and cell viability of metallic samples with and without DLC coatings were analyzed, considering the chemical composition of the coating and metallic components. The results show that the DLC coatings presented suitable interaction properties and no cytotoxicity or genotoxicity when exposed to the cellular environment, compared with the control group (p < 0.0001). They also demonstrated cell viability, low friction representing a reduction of 80%, and hardness 23–26 GPa, making them ideal for use on fixed implants. It is necessary to control the thickness and roughness of the coating to avoid pinholes and increase the corrosion protection of implants. These DLC coatings with low friction coefficients could facilitate the fixation of implantable pins and screws, including Kirschner wires.