Tratamento de polímeros com jato de plasma em pressão atmosférica
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Data
2013-06-28
Autores
Ricci Castro, Alonso Hernan [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
O tratamento com plasma não térmico é um dos métodos mais limpos e baratos para modi car as propriedades super ciais dos polímeros. Os polímeros tratados têm importantes aplicações na indústria e na medicina. Ele permite introduzir ou modi car grupos quí- micos na superfície polimérica sem alterar o seu volume. Neste trabalho foi desenvolvido um jato de plasma a pressão atmosférica, que foi utilizado no tratamento de superfícies de polietileno e policarbonato. O jato operou com argônio e hélio a pressão atmosférica. O estudo foi centrado em caracterizar o jato de plasma e os efeitos dele sobre a superfície dos polímeros. Neste contexto, primeiro foi estudado o jato de plasma, no qual pode se observar como a pluma do plasma variou com a tensão e o uxo do gás. Análise por espectroscopia óptica de emissão (OES) mostrou as espécias ativas geradas no plasma, e aquelas geradas pela interação do plasma com o ar. Medidas elétricas mostra que a carga transferida e a potência associada ao jato de plasma, variam com a separação do bocal do jato de plasma com a plataforma porta amostras, a potência média varia de forma direta com a tensão aplicada. Posteriormente foram estudados os efeitos na superfície dos polímeros tratados com jato de plasma. Estes efeitos foram relacionados com o tempo de tratamento. Foram utilizadas microscopia de força atômica (AFM), análise por fotoel étrons de raios X (XPS), espectroscopia infravermelha com transformada de Fourier (FTIR) e medida de ângulo de contato para investigar as superfícies dos polímeros antes e após tratamento por plasma. A análise com AFM mostrou que os polímeros apresentaram diferentes topogra as da superfícies, antes e após tratamento. As amostras tratadas mostraram uma diminuição na medida do ângulo de contato, no caso de polietileno as medidas variaram de 91...
Non-thermal plasma treatment is one of the cleanest methods to modify super cial properties of polymers, that have important applications in industry and medicine. Nonthermal plasma allows to introduce and or modify chemical groups on the polymeric surface without altering its bulk properties. In this work a plasma jet at atmospheric pressure was developed and utilized in surface treatment of polyethylene and polycarbonate. The plasma jet operated at atmospheric pressure with Argon and Helium. The study focused on plasma jet characterization and its e ect on polymer surfaces. Within this context, rst was investigation how the plasma plume varied with the applied tension and the gas ow. The optical emission spectroscopy identi ed the active species generated within the plasma and those generated by interaction between plasma and air. Electric measurements shows that the transferred charge and the power associated of the plasma jet vary with the space between the nozzle of plasma jet and the sample platform. The mean jet power scales with associated the applied tension. Afterwards, the e ects on polymer surface induced by plasma jet were studied. These e ects were directly related to the treatment time. Treated polymers were analysed by atomic force microscopy (AFM), X-ray photo-electron spectroscopy (XPS), Fourier transform infra-red spectroscopy (FTIR) and through water contact angle measurements. Analysis with AFM showed that polymers present di erent surface topographies before and after the treatment. Treated samples exhibit reduction of their water contact angle; on the polyethylene case, tha WCA change from 91 degrees to 36 degrees. For polycarbonate it decreased from 71 degrees to 20 degrees after the plasma treatment. The analyses with XPS and FTIR of treated samples showed that plasma... (Complete abstract click electronic access below)
Non-thermal plasma treatment is one of the cleanest methods to modify super cial properties of polymers, that have important applications in industry and medicine. Nonthermal plasma allows to introduce and or modify chemical groups on the polymeric surface without altering its bulk properties. In this work a plasma jet at atmospheric pressure was developed and utilized in surface treatment of polyethylene and polycarbonate. The plasma jet operated at atmospheric pressure with Argon and Helium. The study focused on plasma jet characterization and its e ect on polymer surfaces. Within this context, rst was investigation how the plasma plume varied with the applied tension and the gas ow. The optical emission spectroscopy identi ed the active species generated within the plasma and those generated by interaction between plasma and air. Electric measurements shows that the transferred charge and the power associated of the plasma jet vary with the space between the nozzle of plasma jet and the sample platform. The mean jet power scales with associated the applied tension. Afterwards, the e ects on polymer surface induced by plasma jet were studied. These e ects were directly related to the treatment time. Treated polymers were analysed by atomic force microscopy (AFM), X-ray photo-electron spectroscopy (XPS), Fourier transform infra-red spectroscopy (FTIR) and through water contact angle measurements. Analysis with AFM showed that polymers present di erent surface topographies before and after the treatment. Treated samples exhibit reduction of their water contact angle; on the polyethylene case, tha WCA change from 91 degrees to 36 degrees. For polycarbonate it decreased from 71 degrees to 20 degrees after the plasma treatment. The analyses with XPS and FTIR of treated samples showed that plasma... (Complete abstract click electronic access below)
Descrição
Palavras-chave
Jato de plasma, Polimeros, Aspereza de superfície, Análise espectral, Microscopia, Plasma jets
Como citar
RICCI CASTRO, Alonso Hernan. Tratamento de polímeros com jato de plasma em pressão atmosférica. 2013. [86] f. Dissertação (mestrado) – Universidade Estadual Paulista Júlio de Mesquita Filho, Faculdade de Engenharia de Guaratinguetá, 2013.