DET - Departamento de Engenharia Têxtil
URI Permanente desta comunidadehttps://repositorio.ufrn.br/handle/1/134
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Navegando DET - Departamento de Engenharia Têxtil por Autor "Alves Júnior, Clodomiro"
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Artigo Effects of gas composition during plasma modification of polyester fabrics(ELSEVIER, 2006) Costa, Thércio Henrique de Carvalho; Feitor, Michelle Cequeira; Alves Júnior, Clodomiro; Freire, P. B.; Bezerra, Clovis de MedeirosIn order to increase the hydrophilicities and to improve dyeability, poly(ethylene terephathalate) (polyester) fabrics were treated in low pressure and temperature plasma. Different plasma atmosphere were used in this work, leaving the gas type (oxygen, nitrogen, methane and hydrogen) as plasma variables, other parameters like pressure, exposure time, voltage and current were not variables in the process. After plasma treatment, the properties of the fabric, including surface morphology and chemical alteration, were investigated. The polyester fabrics treated with different plasma gases exhibited different morphological changes. The capillary method was applied to evaluate the improvement in water uptake of polyester fabrics, which indicated a good wettability to all atmospheres used in this work, except for a mixture containing methane, hydrogen and nitrogenArtigo Novel antibacterial silver coating on PET fabric assisted with hollow-cathode glow discharge(Wiley, 2020-07-30) Nascimento, Rubens Maribondo do; Naeem, Muhammad; Felipe, M. B. M. C.; Medeiros, Silvia Regina Batistuzzo de; Costa, Thércio Henrique de Carvalho; Libório, Maxwell Santana; Alves Júnior, Clodomiro; Nascimento, Igor Oliveira; Sousa, R. R. M.; Feitor, Michelle CequeiraThe silver-coated fabrics are of much importance because of their outstanding antibacterial features and are useable in several medical and hygienic applications. The silver deposition on fabrics by conventional techniques is not feasible because of their high processing cost, long processing duration, complex equipment, and multiple steps processing (nanoparticle synthesis and subsequent deposition on fabrics). In this novel study, the antibacterial silver coating is deposited by using a hollow cathode discharge (HCD) capable of generating high-density plasma, and thus it exhibits high-efficiency processing. The silver is deposited on woven and non-woven PET fabrics for various treatment times (10-60 minutes), and their antibacterial performance against E. coli and S. aureus bacterial is tested. The XRD results verified the deposition of silver with (111) preferred orientation, while SEM analysis depicted the uniform/ homogeneous deposition of silver particles. The interfacial free energy of adhesion depicts that after the silver deposition on both fabrics, the surface is actively unfavorable for bacterial adhesion. The antibacterial test revealed that the silver-coated woven and non-woven PET fabrics exhibit exceptional antibacterial activity against E. coli and S. aureus bacteria. As the HCD technique is relatively cost-effective, no need for specific sputtering targets, eco-friendly, and require single-step processing for silver deposition. Thus the results are expected to be of remarkable importance to prepare silver-coated antibacterial fabrics useable in hospitals and other appropriate applicationsArtigo Surface modification of polyester fabric by non-thermal plasma treatment(IOP Publishing Ltd, 2012) Silva, Ruthilene Catarina Lima da; Alves Júnior, Clodomiro; Nascimento, José Heriberto Oliveira do; Neves, J. R. O.; Teixeira, V.In the present study it was carried out a surface modification of polyester fabric by plasma treatment with aim of providing hidrophilicity to fabric. In the process it were used three different gaseous atmosphere with mixtures of argon, nitrogen and/or oxygen [(1) Ar + N2 (4:2), (2) Ar + N2 +O2 (4:2:2) and N2 + O2 (2:0.6)] and maintained others parameters such as pressure, current and time of treatment fixed at 1.35 mBar, 0.08 A and 30 minutes, respectively. The plasma treatment was monitored by optical emission spectroscopy (OES) to identify the species presents in the plasma reactor. Chemical changes in the fabric surface after plasma treatments were determined by Fourier Transform Infrared (FTIR) and X-ray photoelectron spectroscopy (XPS). Wicking properties were used to evaluate hydrophilicity of the fabric. Wicking measurement showed that the hydrophilicity of polyester fabric was remarkably improved after treatment and was explained by XPS analysis indicating higher presence of functional groups containing nitrogen and oxygenArtigo Thin tin and tio2 film deposition in glass samples by cathodic cage(Materials Research, 2015-04) Feitor, Michelle Cequeira; Sousa, Rômulo Ribeiro Magalhães de; Araújo, Francisco Odolberto de; Costa, Thercio Henrique de Carvalho; Nascimento, Igor Oliveira; Santos, Francisco Eroni Paes; Alves Júnior, ClodomiroThin nitride and titanium dioxide films were produced using an innovative technique called cathodic cage depositon. Uniformity, three-dimensionality and high rate deposition are some of the advantages of this technique. In this study we discuss the influences of temperature, treatment time and gaseous atmosphere on the characteristics of the deposited films. The TiN (titanium nitride) and TiO2 (titanium dioxide) films were produced using a high deposition rate of 2,5 μm/h at a work temperature and pressure of 400°C and 150 Pa respectively. EDS technique was used to identify the chemical composition of the thin film deposited, whilst Raman spectroscopy indicated the phases present confirmed by DRX analysis. The thickness of the deposited films was studied using electron microscopy scanning. The results based on the deposition parameters confirm the great efficiency and versatility of this technique, which allows a uniform three-dimensional film deposition on any material without the appearance of stress. Compared to other techniques, cathodic cage deposition enables deposition at lower temperaturesArtigo Tratamento em plasma de tecido 100% Aramida para análise de molhabilidade(2008-01-19) Costa, Thércio Henrique de Carvalho; Feitor, Michelle Cequeira; Alves Júnior, Clodomiro; Freire, P. B.; Bezerra, Clovis de Medeiros; Furtado, Duciane Oliveira de FreitasUm tecido de fibras de Aramida (Kevlar) foi tratado em plasma de O2, Ar, e N2, a fim de estudar os efeitos sobre a hidrofilicidade deste material. Foram usadas as técnicas de arraste vertical e MEV (microscopia eletrônica de varredura) para analisar as amostras. As amostras tratadas em plasma de O2 e N2 apresentaram uma melhoria substancial na hidrofilidade, a qual foi atribuída à formação de rugosidade na superfície das fibras.