Atmospheric Pressure Plasma Chemical Vapor Deposition of Carvacrol Thin Films on Stainless Steel to Reduce the Formation of E. Coli and S. Aureus Biofilms

Minimal Processing Technologies for Production and Preservation of Tailor-Made Foods§

Tailor-made foods, also known as foods with programmable properties, are specialised systems with unique composition prepared by different methods, using the known mechanisms of action of their bioactive ingredients. The development of tailor-made foods involves the evaluation of individual components, including bioactive substances derived from waste products of other productions, such as essential oils. These components are evaluated both individually and in combination within food compositions to achieve specific functionalities. This review focuses on the application of minimal processing technologies for the production and preservation of tailor-made foods. It examines a range of approaches, including traditional and emerging technologies, as well as novel ingredients such as biomolecules from various sources and microorganisms. These approaches are combined according to the principles of hurdle technology to achieve effective synergistic effects that enhance food safety and extend the shelf life of tailor-made foods, while maintaining their functional properties.

Surface Engineering Strategies to Enhance the In Situ Performance of Medical Devices Including Atomic Scale Engineering

Decades of intense scientific research investigations clearly suggest that only a subset of a large number of metals, ceramics, polymers, composites, and nanomaterials are suitable as biomaterials for a growing number of biomedical devices and biomedical uses. However, biomaterials are prone to microbial infection due to Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), Staphylococcus epidermidis (S. epidermidis), hepatitis, tuberculosis, human immunodeficiency virus (HIV), and many more. Hence, a range of surface engineering strategies are devised in order to achieve desired biocompatibility and antimicrobial performance in situ. Surface engineering strategies are a group of techniques that alter or modify the surface properties of the material in order to obtain a product with desired functionalities. There are two categories of surface engineering methods: conventional surface engineering methods (such as coating, bioactive coating, plasma spray coating, hydrothermal, lithography, shot peening, and electrophoretic deposition) and emerging surface engineering methods (laser treatment, robot laser treatment, electrospinning, electrospray, additive manufacturing, and radio frequency magnetron sputtering technique). Atomic-scale engineering, such as chemical vapor deposition, atomic layer etching, plasma immersion ion deposition, and atomic layer deposition, is a subsection of emerging technology that has demonstrated improved control and flexibility at finer length scales than compared to the conventional methods. With the advancements in technologies and the demand for even better control of biomaterial surfaces, research efforts in recent years are aimed at the atomic scale and molecular scale while incorporating functional agents in order to elicit optimal in situ performance. The functional agents include synthetic materials (monolithic ZnO, quaternary ammonium salts, silver nano-clusters, titanium dioxide, and graphene) and natural materials (chitosan, totarol, botanical extracts, and nisin). This review highlights the various strategies of surface engineering of biomaterial including their functional mechanism, applications, and shortcomings. Additionally, this review article emphasizes atomic scale engineering of biomaterials for fabricating antimicrobial biomaterials and explores their challenges.

A Review of Plasma Synthesis Methods for Polymer Films and Nanoparticles under Atmospheric Pressure Conditions

In this paper, we present an overview of recent approaches in the gas/aerosol-through-plasma (GATP) and liquid plasma methods for synthesizing polymer films and nanoparticles (NPs) using an atmospheric-pressure plasma (APP) technique. We hope to aid students and researchers starting out in the polymerization field by compiling the most commonly utilized simple plasma synthesis methods, so that they can readily select a method that best suits their needs. Although APP methods are widely employed for polymer synthesis, and there are many related papers for specific applications, reviews that provide comprehensive coverage of the variations of APP methods for polymer synthesis are rarely reported. We introduce and compile over 50 recent papers on various APP polymerization methods that allow us to discuss the existing challenges and future direction of GATP and solution plasma methods under ambient air conditions for large-area and mass nanoparticle production.

Thin Film Deposition by Atmospheric Pressure Dielectric Barrier Discharges Containing Eugenol: Discharge and Coating Characterizations

Eugenol (4-Allyl-2-methoxyphenol) is the main constituent of clove oil. In addition to being widely used as a condiment, it has been recognized as a powerful bactericide. Owing to that, Eugenol has been used in several applications including odontology and as a conservative for food products. Aiming at the development of natural bactericide coatings, in this work, using an atmospheric pressure plasma in a dielectric barrier discharge (DBD) reactor Eugenol was deposited on stainless steel substrate, with argon as a carrier gas. The discharge power supply was a transformer at 14.4 kV peak-to-peak voltage and 60 Hz frequency. Operating with a gas flow rate at 4 L/min, the active power was around 1.2 W. The maximum plasma electron temperature of the plasma with monomers was about 1.5 eV, estimated by visible emission spectroscopy using a local thermodynamic equilibrium approach. The study also comprehended the analysis of the film structure, aging, and thermal stability using infrared reflectance spectroscopy, and its thicknesses and roughness by profilometry. The thickness of the films was in the range of 1000 to 2400 nm with a roughness of up to 800 nm with good adhesion on the substrate. The FTIR result shows a stable coating with a chemical structure similar to that of the monomer. Aging analysis showed that the film does not degrade, even after exposing the film for 120 days in ambient air and for 1.0 h under a high thermal UV-lamp.