Life Cycle Assessment of Flexible Electromagnetic Shields

Nowadays, fiber based flexible electromagnetic shields have widespread applications in ensuring Electromagnetic Compatibility (EMC). Shielding is a solution of EMC, and the main methods to estimate shielding effectiveness are represented by the circuit method and the impedance method. Magnetron sputtering of metallic layers represents a novel technique to impart electric conductive properties to fabrics. Coating of fabrics represents a second main option to manufacture textile shields beside the insertion of conductive yarns in the fabric structure. Life Cycle Assessment (LCA) is often used to assess a comparatively modern with a classical manufacturing process in order to prove its eco-friendly character. This chapter comparatively assesses flexible EM shields manufactured of fabrics with inserted conductive yarns with and without magnetron plasma coating. The copper plasma coating of cotton fabrics with inserted silver yarns increases shielding effectiveness (EMSE) by 8–10 dB. In order to keep for the LCA study the same functional unit of 50 dB at 100 MHz for one sqm of fabric, the fabric structure is modeled with a reduced distance between the inserted conductive yarns. Results of the LCA study show a substantial impact on the environment for the plasma coated fabric upon using a laboratory scale deposition set-up

Plasma deposition of antibacterial nano-coatings on polymeric materials

Non-woven textile materials with antimicrobial properties are of high demands for applications ranging from medical dressing to everyday cleaning products. A plasma assisted route to engineer antimicrobial nano-composite coatings is proposed. Nano-particles of Ag, Cu and ZnO are tested as antimicrobial agents with average nano-particle size of 20-50 nm. Nanoparticles are incorporated in between two layers of an organosilicon film. The effect of the barrier coating on nano-particles release is determined by XPS. Antibacterial efficiency of the samples against P. aeruginosa ATCC 9027 and S. aureus M u50 bacteria shows that all treated samples exhibit higher antibacterial efficiency against S. aureus. The antibacterial efficiency of AgNPs and CuNPs is above 90% which is practically interesting for medical application while ZnONPs shows lower antibacterial efficiency.This work is supported by the M.Era-Net project IWT 140812 “PlasmaTex”.info:eu-repo/semantics/publishedVersio

Atmospheric pressure plasma deposition of organosilicon thin films by direct current and radio-frequency plasma jets

Thin film deposition with atmospheric pressure plasmas is highly interesting for industrial demands and scientific interests in the field of biomaterials. However, the engineering of high-quality films by high-pressure plasmas with precise control over morphology and surface chemistry still poses a challenge. The two types of atmospheric-pressure plasma depositions of organosilicon films by the direct and indirect injection of hexamethyldisiloxane (HMDSO) precursor into a plasma region were chosen and compared in terms of the films chemical composition and morphology to address this. Although different methods of plasma excitation were used, the deposition of inorganic films with above 98% of SiO2 content was achieved for both cases. The chemical structure of the films was insignificantly dependent on the substrate type. The deposition in the afterglow of the DC discharge resulted in a soft film with high roughness, whereas RF plasma deposition led to a smoother film. In the case of the RF plasma deposition on polymeric materials resulted in films with delamination and cracks formation. Lastly, despite some material limitations, both deposition methods demonstrated significant potential for SiOx thin-films preparation for a variety of bio-related substrates, including glass, ceramics, metals, and polymers.This research was funded by EU H2020 M.Era-Net “PlasmaTex” project. Funding of the Romanian team was insured by the Romanian Ministry of Research and Innovation under the contract 31/2016/UEFISCDI. This work was funded by the Portuguese Foundation for Science and Technology FCT/MCTES (PIDDAC) and co-financed by European funds (FEDER) through the PT2020 program, research project M-ERA-NET/0006/2014. Slovenian team research was funded through the Ministry of Education, Science and Sport and Slovenian Research Agency (ARRS)

Effect of dispersion solvent on the deposition of PVP-Silver nanoparticles onto DBD plasma-treated polyamide 6,6 fabric and Its antimicrobial efficiency

Supplementary Material: https://www.mdpi.com/2079-4991/10/4/607/s1Polyvinylpyrrolidone-coated silver nanoparticles (PVP-AgNPs) dispersed in ethanol, water and water/alginate were used to functionalize untreated and dielectric barrier discharge (DBD) plasma-treated polyamide 6,6 fabric (PA66). The PVP-AgNPs dispersions were deposited onto PA66 by spray and exhaustion methods. The exhaustion method showed a higher amount of deposited AgNPs. Water and water-alginate dispersions presented similar results. Ethanol amphiphilic character showed more affinity to AgNPs and PA66 fabric, allowing better uniform surface distribution of nanoparticles. Antimicrobial effect in E. coli showed good results in all the samples obtained by exhaustion method but using spray method only the DBD plasma treated samples displayed antimicrobial activity (log reduction of 5). Despite the better distribution achieved using ethanol as a solvent, water dispersion samples with DBD plasma treatment displayed better antimicrobial activity against S. aureus bacteria in both exhaustion (log reduction of 1.9) and spray (methods log reduction of 1.6) due to the different oxidation states of PA66 surface interacting with PVP-AgNPs, as demonstrated by X-Ray Photoelectron Spectroscopy (XPS) analysis. Spray method using the water-suspended PVP-AgNPs onto DBD plasma-treated samples is much faster, less agglomerating and uses 10 times less PVP-AgNPs dispersion than the exhaustion method to obtain an antimicrobial effect in both S. aureus and E. coli.This research was funded by FEDER funds through the Operational Competitiveness Program – COMPETE and by National Funds through Fundação para a Ciênciae Tecnologia (FCT) under the project POCI01-0145-FEDER-007136 and UID/CTM/00264/2019. A. Zille also acknowledges financial support of the FCT project PTDC/CTM-TEX/28295/2017 financed by FCT, FEDER and POCI.Isabel Ribeiro (SFRH/BD/137668/2018) acknowledges FCT, Portugal, for its doctoral grant financial support. A. Zille also acknowledges financial support of the FCT project PTDC/CTM-TEX/28295/2017 financed by FCT, FEDER and POCI

Controlled antibacterial activity of polyester fabric by immobilization of silver nanoparticles in thin films

FCT Research contract (IF/00071/2015), the project PTDC/CTM-TEX/28295/2017 financed by FCT, FEDER and POCI of Portugal 2020, the project UID/CTM/00264/2019 of 2C2T under the COMPETE and FCT/MCTES (PIDDAC) co-financed by FEDER through the PT2020 program. Ana Isabel Ribeiro acknowledges FCT the PhD scholarship SFRH/BD/137668/201

Effect of PEDOT:PSS with secondary dopants and DBD plasma treatment on the conductive properties of polyester fabrics

[Excerpt] Introduction Smart textiles have the capability to interact with the surrounding environment and react in different ways, namely in electrical conduction. The conductive properties of these materials are useful in medical, healthcare, and protective clothing.This research was funded by FEDER funds through the Operational Competitiveness Program– COMPETE, under the projects POCI-01-0247-FEDER-068924, and by National Funds through Fundação para a Ciência e Tecnologia (FCT), under the project UID/CTM/00264/2020. Ana Isabel Ribeiro and Cátia Alves acknowledge FCT, MCTES, FSE, and UE PhD grant SFRH/BD/145269/2019 and 2022.10454.BD

Shellac Thin Films Obtained by Matrix-Assisted Pulsed Laser Evaporation (MAPLE)

We report on the fabrication of shellac thin films on silicon substrates by matrix-assisted pulsed laser evaporation (MAPLE) using methanol as matrix. Very adherent, dense, and smooth films were obtained by MAPLE with optimized deposition parameters, such as laser wavelength and laser fluence. Films with a root mean square (RMS) roughness of 11 nm measured on 40 × 40 µm2 were obtained for a 2000-nm-thick shellac film deposited with 0.6 J/cm2 fluence at a laser wavelength of 266 nm. The MAPLE films were tested in simulated gastric fluid in order to assess their capabilities as an enteric coating. The chemical, morphological, and optical properties of shellac samples were investigated by Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and atomic force microscopy (AFM)

One Step e-Beam Radiation Cross-Linking of Quaternary Hydrogels Dressings Based on Chitosan-Poly(Vinyl-Pyrrolidone)-Poly(Ethylene Glycol)-Poly(Acrylic Acid)

We report on the successful preparation of wet dressings hydrogels based on Chitosan-Poly(N-Vinyl-Pyrrolidone)-Poly(ethylene glycol)-Poly(acrylic acid) and Poly(ethylene oxide) by e-beam cross-linking in weakly acidic media, to be used for rapid healing and pain release of infected skin wounds. The structure and compositions of hydrogels investigated according to sol-gel and swelling studies, network parameters, as well as FTIR and XPS analyses showed the efficient interaction of the hydrogel components upon irradiation, maintaining the bonding environment while the cross-linking degree increasing with the irradiation dose and the formation of a structure with the mesh size in the range 11–67 nm. Hydrogels with gel fraction above 85% and the best swelling properties in different pH solutions were obtained for hydrogels produced with 15 kGy. The hydrogels are stable in the simulated physiological condition of an infected wound and show appropriate moisture retention capability and the water vapor transmission rate up to 272.67 g m−2 day−1, to ensure fast healing. The hydrogels proved to have a significant loading capacity of ibuprofen (IBU), being able to incorporate a therapeutic dose for the treatment of severe pains. Simultaneously, IBU was released up to 25% in the first 2h, having a release maximum after 8 h

Plasma Processing with Fluorine Chemistry for Modification of Surfaces Wettability

Using plasma in conjunction with fluorinated compounds is widely encountered in material processing. We discuss several plasma techniques for surface fluorination: deposition of fluorocarbon thin films either by magnetron sputtering of polytetrafluoroethylene targets, or by plasma-assisted chemical vapor deposition using tetrafluoroethane as a precursor, and modification of carbon nanowalls by plasma treatment in a sulphur hexafluoride environment. We showed that conformal fluorinated thin films can be obtained and, according to the initial surface properties, superhydrophobic surfaces can be achieved

Chemistry-Induced Effects on Cell Behavior upon Plasma Treatment of pNIPAAM

In the field of bioengineering, depending on the required application, the attachment of various biological entities to the biomaterial is either favored or needs to be prevented. Therefore, different surfaces modification strategies were developed in combination with the characteristics of the materials. The present contribution reports on the use of the specific surface property of a thermoresponsive polymer poly(N-isopropylacrylamide) pNIPAAM obtained by spin coating in combination with plasma treatment for tuning cell behavior on treated polymeric surfaces. Topographical information for the plasma-treated pNIPAAM coatings obtained by Atomic Force Microscopy (AFM) measurements evidenced a more compact surface for Ar treatment due to combined etching and redeposition, while for oxygen, a clear increase of pores diameter is noticed. The chemical surface composition as determined by X-ray Photoelectron Spectroscopy showed the specific modifications induced by plasma treatment, namely strong oxidation for oxygen plasma treatment illustrated by eight times increase of O-C=O contribution and respectively an increase of C-N/O=C-N bonds in the case of ammonia plasma treatment. Structural information provided by FTIR spectroscopy reveals a significant increase of the carboxylic group upon argon and mostly oxygen plasma treatment and the increase in width and intensity of the amide-related groups for the ammonia plasma treatment. The biological investigations evidenced that L929 fibroblast cells viability is increased by 25% upon plasma treatment, while the cell attachment is up to 2.8 times higher for the oxygen plasma-treated surface compared to the initial spin-coated pNIPAAM. Moreover, the cell detachment process proved to be up to 2–3 times faster for the oxygen and argon plasma-treated surfaces and up to 1.5 times faster for the ammonia-treated surface. These results show the versatility of plasma treatment for inducing beneficial chemical modifications of pNIPAAM surfaces that allows the tuning of cellular response for improving the attachment-detachment process in view of tissue engineering