Electrophoretically‐Deposited Metal‐Decorated CNT Nanoforests with High Thermal/Electric Conductivity and Wettability Tunable from Hydrophilic to Superhydrophobic

Abstract

A single-step, room-temperature, and scalable electrophoretic deposition process is reported to form nanocomposites on any electrically conductive surface with metal nanoparticle decorated carbon nanotubes (CNTs). The contact angles (CAs) can be easily tuned from ≈60° to 168° by varying the deposition voltage, while hydrophobicity and superhydrophobicity surprisingly arise from the hydrophilic CNTs being deposited. The relatively high voltage tends to vertically align CNTs during deposition, leading to architectural micro/nanoscale roughness on the surface. The combination of the multiscale roughness along with the low surface energy of hydrocarbon functional groups on the CNT surface has enabled facile wettability control, including the Petal and Lotus effects. Further, the relatively vertical orientation of the CNTs, without any coating, allows for current and heat transfer along their axis with superior conductivity. Similar behavior in terms of CA control is seen for all three divalent metal ions in the deposition solution (i.e., Cu 2+ , Ni 2+ , and Zn 2+ ) that are used to charge the CNTs while eventually getting co-deposited. This implies that this method could possibly be extended to other metals by selecting appropriate charging salt. A patterning technique is also demonstrated for facile fabrication of superhydrophobic CNT-metal islands surrounded by hydrophilic CNT coating.

Engineering Carbon Nanotube Forest Superstructure for Robust Thermal Desalination Membranes

“…After seeding catalyst precursors (i.e., PVP and FeCl 3 ) on the pristine SFM, a distinct peak at 1603 cm −1 , corresponding to CO,14d and relatively small peaks at 1491 and 1296 cm −1 , assigned to the stretching vibration of C−N originating from PVP, were observed in the FTIR spectrum of the PVP/FeCl 3 @SFM membrane (red line in Figure c, left panel). Upon surface functionalization with both the VCNTF and HCNTF, signal intensities of the unsaturated carbon stretching vibration (C‐) at 3402 cm −1 and aromatic carbon frame stretching vibration (C−C) at 1456 cm −1 increased dramatically (green lines in Figure c, left panel), thereby confirming the successful grafting of the CNT‐based materials.…”

Fabrication of Hydrophobic Lignin-Based Films through Tandem Chemical Modification and Plasma Treatment

“…39 For instance, carbon nanotube forests (CNTFs) with nanoscale roughness exhibited superhydrophobic surfaces, which can be utilized in biosensors 40 and electrochemical applications. 41 In another study, oxygen plasma etching on hydrophobic surfaces showed nanoscale roughness with strong hydrophobicity after the stabilization due to the hydrophobic recovery effect with time. 38 Plasma etching has been applied to prepare superhydrophobic paper, creating a hierarchical topography, although nanoforest structures were not observed.…”

Enhanced Strength and Modulus in Low Graphene‐Carbon Fiber Epoxy Composites Achieved by Optimizing the Electrodeposition Parameters and Solution Concentration

“…Interestingly, the R‐0.1 wt.% graphene‐deposited fabric showed higher contact angle values compared to the 0.1 wt.% specimen. The increased hydrophobicity compared to PCFs, likely due to the micro‐roughness created by the edge deposition of G‐COOH [29]. The hydrophilic nature of Mg(OH) 2 /MgO was confirmed through XPS on the carbon fiber, and the hydrophilic nature of carboxylated graphene should, in principle, enhance the overall hydrophilicity due to their polar and hydroxyl‐rich nature.…”