Cleaning Strategies of Synthesized Bioactive Coatings by PEO on Ti-6Al-4V Alloys of Organic Contaminations

Abstract

The effect of various cleaning methods on coating morphology and their effectiveness in removing organic contaminants has been studied in this research. Bioactive coatings containing titanium oxides and hydroxyapatite (HAP) were obtained through plasma electrolytic oxidation in aqueous electrolytes and molten salts. The cleaning procedure for the coated surface was performed using autoclave (A), ultraviolet light (UV), radio frequency (RF), air plasma (P), and UV-ozone cleaner (O). The samples were characterized using scanning electron microscopy (SEM) with an EDS detector, X-ray photoelectron spectroscopy (XPS), X-ray phase analysis (XRD), and contact angle (CA) measurements. The conducted studies revealed that the samples obtained from molten salt exhibited a finer crystalline structure morphology (275 nm) compared to those obtained from aqueous electrolytes (350 nm). After applying surface cleaning methods, the carbon content decreased from 5.21 at.% to 0.11 at.% (XPS), which directly corresponds to a reduction in organic contaminations and a decrease in the contact angle as follows: A > UV > P > O. This holds true for both coatings obtained in molten salt (25.3° > 19.5° > 10.5° > 7.5°) and coatings obtained in aqueous electrolytes (35.2° > 28.3° > 26.1° > 16.6°). The most effective and moderate cleaning method is ozone treatment.

An Innovative Design to Enhance Osteoinductive Efficacy and Biomechanical Behavior of a Titanium Dental Implant

“…Bioactive coatings, achieved via diverse surface modification techniques such as plasma electrolytic oxidation in aqueous electrolytes and molten salts, have been extensively explored [9]. Furthermore, recent advances in dental implant technology have harnessed bioactive molecules, especially growth factors, to enhance osteoconduction and osteoinduction, thereby facilitating better integration with the surrounding bone [10][11][12].…”

Effect of Anodic Oxidation Pulse Voltage on Antibacterial Properties and Biocompatibility of Ti-Ag Alloy

“…Hu et al [34] utilized ultrasonic-MAO technology to create a coating Coatings 2024, 14, 405 3 of 23 on the Ti-3Cu alloy, exhibiting robust long-term antibacterial properties and promoting early cell adhesion. Schwartz et al [35] prepared TiO 2 and HAp bioactive coatings by plasma electrolytic oxidation in aqueous electrolytes and molten salts, and cleaned the coatings with autoclave (A), ultraviolet light (UV), radio frequency (RF), air plasma (P), and UV-ozone cleaner (O), providing an effective and mild surface modification treatment method for cleaning and disinfecting organic pollutants on the surface of bioactive coatings. Through the research of Liu et al [10], a multifunctional TiO 2 /Cu 2 O coating was prepared on the Ti-5Cu alloy by the AO process.…”

Antireflection Property and Corrosion Resistance of Black Ceramic Superhydrophobic Coatings on Aluminum Alloy

“…Compared with other surface treatment methods, MAO possesses the advantages of simple operation, controllable coating, and environmentally friendly, [ 22 ] which is one of the most useful methods to solve the corrosion problem of Al alloys. Schwartz et al [ 23 ] used PEO method to produce bioactive coatings on the surface of the Ti–6Al–4 V alloy using aqueous electrolytes and molten salt, the coatings consisted of rutile, anatase, and hydroxyapatite (HAP) crystals. However, micro‐pores and micro‐cracks due to discharge can be inevitably generated during the preparation of PEO coating, which provides an opportunity for corrosive ions to enter the coating surface, causing severe reduction of the coating corrosion resistance in applications.…”