Vertically aligned carbon nanotubes (VACNT) surfaces coated with polyethylene for enhanced dew harvesting

Author(s)

Pinheiro, Romario Araujo ^[1] ; Rosa, Filipe Menezes ^{[1, 2]} ; Volu, Rene Martins ^{[1, 3]} ; de Vasconcelos, Getulio ^[3] ; Trava-Airoldi, Vladimir Jesus ^{[1, 2]} ; Corat, Evaldo Jose ^{[1, 2]}

Affiliation

^[1] Inst Nacl Pesquisas Espaciais LABAS INPE, Lab Associado Sensores & Mat, Sao Jose Dos Campos, SP - Brazil

^[2] de Vasconcelos, Getulio, Inst Estudos Avancados, Dept Ciencia \& Tecnol Aerosp IEAv DCTA, Sao Jose Dos Campos, SP, Brazil.Pinheiro, Romario Araujo, Inst Nacl Pesquisas Espaciais LABAS INPE, Lab Associado Sensores & Mat, Sao Jose Dos Campos, SP - Brazil

^[3] Inst Estudos Avancados, Dept Ciencia & Tecnol Aerosp IEAv DCTA, Sao Jose Dos Campos, SP - Brazil

• Document type: Journal article
• Source: DIAMOND AND RELATED MATERIALS; v. 107, AUG 2020.
• Web of Science Citations: 0

Abstract

In this work we prepared vertically aligned carbon nanotubes (VACNT) based super-hydrophobic surfaces with enhanced dew condensation. Coating these VACNT with a nanometric polyethylene (PE) layer preserved morphology, but normalized surface energy increasing its super-hydrophobicity. Samples of as grown VACNT with the PE coating (VACNT-PE samples) and VACNT samples treated by CO2 laser and with PE coating (VACNT/laser-PE samples) show a much higher condensation for low surface temperatures (T-s < 288 K). M this low temperature, it changes from a low adhesion Cassie Baxter wetting state to a more adhesive one. Despite this larger adhesion, water collection enlarges instead of decreasing. Hierarchical condensation is the most likely effect contributing for this further increase. The cage-like morphology left by laser tracks on VACNT/laser-PE sustain larger droplets that removes all water underneath and neighbor regions while moving. In these conditions the volume collection is over 30 times larger than at dew point, with a high volumetric efficiency. (AU)

• FAPESP's process: 12/15857-1 - Scientific studies and innovation application on CVD diamond, DLC and carbon nanostructures obtained by chemical vapor deposition technique
• Grantee: Vladimir Jesus Trava-Airoldi
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 16/07912-3 - Development of a microfluidic System of nanocomposite diamond/carbon nanotubes for atmosphere water harvesting.
• Grantee: Romário Araújo Pinheiro
• Support Opportunities: Scholarships in Brazil - Doctorate