Influence of polar groups on the wetting properties of vertically aligned multiwalled carbon nanotube surfaces

Autor(es)

Ramos, S. C. ^{[1, 2]} ; Lobo, A. O. ^[3] ; de Vasconcelos, G. ^[4] ; Antunes, E. F. ^{[5, 1]} ; Trava-Airoldi, V. J. ^[1] ; Corat, E. J. ^[1]

Afiliação do(s) autor(es)

^[1] Inst Nacl Pesquisas Espaciais, Lab Assoc Sensores & Mat, BR-12227010 Sao Jose Dos Campos, SP - Brazil

^[2] Univ Estado Bahia, UNEB, Dept Ciencias, BR-46400000 Caetite, BA - Brazil

^[3] Univ Vale Paraiba, UniVaP, Inst Pesquisa & Desenvolvimento, IP&D, Lab Nanatecnol Biomed, BR-12244000 Sao Jose Dos Campos, SP - Brazil

^[4] Inst Estudos Avancados, IEAv, BR-12228001 Sao Jose Dos Campos, SP - Brazil

^[5] ITA, BR-12228900 Sao Jose Dos Campos, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: THEORETICAL CHEMISTRY ACCOUNTS; v. 130, n. 4-6, p. 1061-1069, DEC 2011.
• Citações Web of Science: 10

Resumo

In this work, we have studied superhydrophilic and superhydrophobic transitions on the vertically aligned multiwalled carbon nanotube (VACNT) surfaces. As-grown, the VACNT surfaces were superhydrophobic. Pure oxygen plasma etching modified the VACNT surfaces to generate superhydrophilic behavior. Irradiating the superhydrophilic VACNT surfaces with a CO(2) laser (up to 50 kW cm(-2)) restored the superhydrophobicity to a level that depended on the laser intensity. Contact angle and surface energy measurements by the sessile drop method were used to examine the VACNT surface wetting. X-ray photoelectron spectroscopy (XPS) showed heavy grafting of the oxygen groups onto the VACNT surfaces after oxygen plasma etching and their gradual removal, which also depended on the CO(2) laser intensity. These results show the great influence of polar groups on the wetting behavior, with a strong correlation between the polar part of the surface energy and the oxygen content on the VACNT surfaces. In addition, the CO(2) laser treatment created an interesting cage-like structure that may be responsible for the permanent superhydrophobic behavior observed on these samples. (AU)

• Processo FAPESP: 07/00013-4 - Novos materiais, estudos e aplicações inovadoras em diamante-CVD, diamond-like-carbon (DLC) e carbono nanoestruturado obtidos por deposição química a partir da fase vapor
• Beneficiário: Evaldo Jose Corat
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 06/03525-3 - Sintese de nanotubos de carbono para aplicacoes tribologicas e estruturais.
• Beneficiário: Erica Freire Antunes
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 08/11642-5 - Desenvolvimento de estruturas à base de nanotubos de carbono, polímeros biorreabsorvíveis e fibra de carbono para estudos envolvendo células regenerativas e células-tronco hematopoiéticas
• Beneficiário: Anderson de Oliveira Lobo
• Modalidade de apoio: Bolsas no Brasil - Doutorado