Publications by authors named "William Chiappim"

Article Synopsis
  • This study introduces an inexpensive plasma device that employs a 3D-printed design using a parallel-plate dielectric barrier discharge with a metallic mesh electrode.
  • The device operates on atmospheric air without requiring additional gas supply and significantly modifies the surface composition of polyethylene, reducing carbon levels and increasing oxygen after treatment.
  • It effectively reduces microbial load by over 99% within 1 to 10 minutes while maintaining Vero cell viability between 91% and 96%, indicating its potential for material surface modifications and infection control applications.
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In the presented study, a novel approach for thermal atomic layer deposition (ALD) of AlO thin films using plasma-activated water (PAW) as a co-reactant, replacing traditionally employed deionized (DI) water, is introduced. Utilizing ex situ PAW achieves up to a 16.4% increase in the growth per cycle (GPC) of AlO films, consistent with results from plasma-enhanced atomic layer deposition (PEALD).

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and are primary contaminants of barley, capable of producing several mycotoxins, mainly type B trichothecenes and zearalenone. Cold plasma decontamination has been gaining prominence, seeking to control the fungal and mycotoxin contamination of food and feed and to improve product quality. To reach this objective, the present study was divided into two parts.

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A conical-shaped atmospheric pressure plasma jet (CS-APPJ) was developed to overcome a standard limitation of APPJs, which is their small treatment area. The CS-APPJs increase the treatment area but use the same gas flow. In the present work, polypropylene samples were treated by CS-APPJ and characterized by scanning electron microscope (SEM), the contact angle, Fourier-transformed infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS).

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In this study, different plasma-activated liquids were evaluated for their antimicrobial effects against , as well as for their cytotoxicity on mammalian cells. The PALs were prepared from distilled (DIS), deionized (DI), filtered (FIL), and tap (TAP) water. Additionally, 0.

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The growing need for increasingly miniaturized devices has placed high importance and demands on nanofabrication technologies with high-quality, low temperatures, and low-cost techniques. In the past few years, the development and recent advances in atomic layer deposition (ALD) processes boosted interest in their use in advanced electronic and nano/microelectromechanical systems (NEMS/MEMS) device manufacturing. In this context, non-thermal plasma (NTP) technology has been highlighted because it allowed the ALD technique to expand its process window and the fabrication of several nanomaterials at reduced temperatures, allowing thermosensitive substrates to be covered with good formability and uniformity.

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The activation of water by non-thermal plasma creates a liquid with active constituents referred to as plasma-activated water (PAW). Due to its active constituents, PAW may play an important role in different fields, such as agriculture, the food industry and healthcare. Plasma liquid technology has received attention in recent years due to its versatility and good potential, mainly focused on different health care purposes.

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The wearable sensors have attracted a growing interest in different markets, including health, fitness, gaming, and entertainment, due to their outstanding characteristics of convenience, simplicity, accuracy, speed, and competitive price. The development of different types of wearable sensors was only possible due to advances in smart nanostructured materials with properties to detect changes in temperature, touch, pressure, movement, and humidity. Among the various sensing nanomaterials used in wearable sensors, the piezoresistive type has been extensively investigated and their potential have been demonstrated for different applications.

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Article Synopsis
  • The study focuses on the properties of Al-doped TiO thin films, known as TiO/AlO nanolaminates, created using plasma-enhanced atomic layer deposition (PEALD) on silicon and glass substrates.
  • It highlights the differences in chemical phases, noting that crystalline films have excess oxygen, while amorphous films do not, along with a diagram illustrating this oxygen distribution.
  • The research shows how changing the film's structure from crystalline to amorphous affects surface hardness and optical properties, which is significant for enhancing performance in various technologies like biosensors and solar cells.
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This work proposes the use of a dielectric barrier discharge (DBD) reactor operating at atmospheric pressure (AP) using air and sub-atmospheric pressure (SAP) using air or argon to treat polyamide 6.6 (PA6.6) fabrics.

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Article Synopsis
  • * The study indicates that silver's oxidation state affects the resultant nanoparticles, with +1 producing AgS and +2 yielding more metallic silver; also, lighting conditions during synthesis impact nanoparticle size and shape.
  • * Shorter synthesis times with light lead to smaller (∼6 nm) spherical nanoparticles, while longer times or darkness result in larger particles; photoluminescence data suggest increased radiative recombination in nanoparticles produced under optimized conditions.
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In this paper, we report the plasma-enhanced atomic layer deposition (PEALD) of TiO and TiO/AlO nanolaminate films on p-Si(100) to fabricate metal-oxide-semiconductor (MOS) capacitors. In the PEALD process, we used titanium tetraisopropoxide (TTIP) as a titanium precursor, trimethyl aluminum (TMA) as an aluminum precursor and O plasma as an oxidant, keeping the process temperature at 250 °C. The effects of PEALD process parameters, such as RF power, substrate exposure mode (direct or remote plasma exposure) and AlO partial-monolayer insertion (generating a nanolaminate structure) on the physical and chemical properties of the TiO films were investigated by Rutherford backscattering spectroscopy (RBS), Raman spectroscopy, grazing incidence X-ray diffraction (GIXRD), and field emission scanning electron microscopy (FESEM) techniques.

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Silica wet gels with the same silica content were prepared by the sonohydrolysis of tetraethoxysilane (TEOS) with additions of dimethylformamide (DMF). DMF plays a role in the overall hydrolysis/gelification/aging step of the sol-gel process, providing more consolidated wet gels with larger syneresis degrees and densities. The structure of the as-obtained wet gels can be interpreted as being built up of mass-fractal domains with fractal dimension D = 2.

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