Robust, Multiresponsive, Superhydrophobic, and Oleophobic Nanocomposites via a Highly Efficient Multifluorination Strategy

Abstract

Artificial superhydrophobic surfaces are garnering constant attention due to their wide applications. However, it is a great challenge for superhydrophobic materials to simultaneously achieve good oil repellency, mechanochemical robustness, adhesion, thermomechanical properties, and multiresponsive ability. Herein, we propose a highly efficient multifluorination strategy to prepare superhydrophobic nanocomposites with the above features, which can be used as monoliths or coatings on various substrates. In this strategy, long-chain perfluorinated epoxy (PFEP) provides outstanding water/oil repellency, tetrafluorophenyl-based epoxy (FEP) possesses good thermodynamic compatibility with PFEP and increases the mechanical performance of the matrix, and carbon nanotubes grafted with perfluorinated segments and flexible spacers (FCNTs) tailor the surface roughness as well as impart multiple functions and ensure good binding interfaces. Notedly, all of the applications of constrained long-chain perfluorinated compounds are achieved via thiol–ene click chemistry, following the ethos of atom economy. The resultant PFEP30/FCNTs40 exhibits superhydrophobicity and oleophobicity, thermal conductivity (1.33 W·m–1·K–1), electronic conductivity (232 S m–1), and electromagnetic interference shielding properties (∼30 dB at 8.2–12.4 GHz, 200 μm). Importantly, after different extreme physical/chemical tests, the PFEP30/FCNTs40 coating still shows outstanding water/oil repellency. In addition, the coating exhibits good photo/electrothermal conversion ability and shows the potential for sensor application. Moreover, the novel strategy provides an efficient guideline for large-scale preparation of robust, multiresponsive, superhydrophobic, and oleophobic materials.

Non-Fluorinated Flexible Superhydrophobic Surface with Excellent Mechanical Durability and Self-Cleaning Performance

“…On the other hand, superhydrophobicity can be achieved on low free energy surfaces . In this term, fluorination treatments are usually used to lower the surface energy adequately. − However, the fluorination treatments have caused some potential threats to the environment and human health. , Therefore, non-fluorinated superhydrophobic surfaces become an urgent need in daily life . Especially, with the development of flexible electronics and wearable devices, − it is crucial and meaningful to construct an environmental-friendly and biocompatible protective layer with excellent water repellency on highly deformable flexible substrates.…”

Polymer Encapsulation Strategy toward 3D Printable, Sustainable, and Reliable Form-Stable Phase Change Materials for Advanced Thermal Energy Storage

“…Ni and Cu foams have the good EMI shielding properties, and the EMI shielding effectiveness (SE) is reinforced after being filled with Si rbw‑250 , because Si rbw‑250 replaces air and further increases the absorption loss (Figure j–k). Ni–Si rbw‑250 (∼58 dB) and Cu–Si rbw‑250 (∼65 dB) exhibit a higher outstanding total EMI SE value in the X-band than the reported PCMs and exceed the standards for commercial EMI shielding materials (20 dB) . In addition, the introduced Ni foams can greatly improve the photo-to-thermal ability .…”

“…As demonstrated in Figure b, the nanoscale-conducting Si-GR/CNT coating can improve the in-plane thermal conductivity, increase the effective energy conversion area, and help heat transfer from the surface to interior. The low surface-energy and micro-/nanoscale rough structures are the keys for constructing superhydrophobic coatings . Si rbw‑250 , as the matrix, do not only provide for the latent heat, but also show the required low surface energy due to their hydrophobic long alkyl and polysiloxane segment (Figure S41).…”

“…Speak specifically, multiple energy conversion helps form-stable PCMs convert solar, electric, magnetic, or even sonic energy from the environment to latent heat; − thermal conductivity plays a crucial role in the thermal charging/discharging process; and EMI shielding exerts positive influence on heat management and human health, when PCMs are applied in electronic packaging and wearable devices. Moreover, superhydrophobic surfaces are also in demand for multiresponsive form-stable PCMs, which offers impressive practicability for self-cleaning, drag reduction, anti-icing, and anti-condensation as well as further improves the long-term solar–thermal conversion efficiency in real world. , However, such multifunctional integration in form-stable PCMs is still technically challenging.…”

“…Moreover, superhydrophobic surfaces are also in demand for multiresponsive form-stable PCMs, 24 which offers impressive practicability for self-cleaning, drag reduction, anti-icing, and anti-condensation as well as further improves the long-term solar−thermal conversion efficiency in real world. 44,45 However, such multifunctional integration in form-stable PCMs is still technically challenging.…”