Preparation of CNF/PDMS Superhydrophobic Coatings with Good Abrasion Resistance Using a One-Step Spray Method.

Jingda Huang,Mengmeng Li,Qian Li,Siqun Wang,Qiang Wu,Peihao Cai

doi:10.3390/ma13235380

Abstract

Complex preparation methods and weak mechanical properties of superhydrophobic coatings hinder their applicability. To address these problems, cellulose nanofibers (CNFs) were used as structural materials to augment the roughness properties, while polydimethylsiloxane (PDMS) was used as the adhesive. Based on the results of previous studies, superhydrophobic coatings with good mechanical properties can be prepared by spraying the mixture onto a substrate surface; herein, the mixture comprised modified CNFs and PDMS. The resulting coating possessed excellent superhydrophobicity, which allowed a maximum water contact angle (WCA) of 158°. Furthermore, it exhibited great knife-scratch-resistance properties and good abrasion performance, which was evaluated by abrading with 800-grit sandpaper for 19 cycles (abrasion length of 380 cm) under a 100 g load. Based on the simple operation and abrasion resistance, the coating shows great potential for practical application.

Highlights

Superhydrophobic bionic technology is developing rapidly because of the excellent properties that facilitate its utilization in waterproofing, anti-fouling, drag-reducing, and self-cleaning applications [1].Superhydrophobic coatings exhibit a water contact angle (WCA) of greater than 150◦ and a slide angle (SA)of less than 10◦ [2,3]; there are two basic conditions to satisfy, namely, reasonable roughness and low surface free energy [4]
cellulose nanofibers (CNFs) after modification was aggregated due to mutual entanglement of CNF during modification, which is proven in the following Surface Morphologies section
A feasible way to prepare the CNF/PDMS superhydrophobic coatings was achieved by spraying the CNF/PDMS mixture onto the substrate surfaces, with the hydrophobic PDMS serving as the adhesive

Summary

Introduction

Superhydrophobic bionic technology is developing rapidly because of the excellent properties that facilitate its utilization in waterproofing, anti-fouling, drag-reducing, and self-cleaning applications [1].Superhydrophobic coatings exhibit a water contact angle (WCA) of greater than 150◦ and a slide angle (SA)of less than 10◦ [2,3]; there are two basic conditions to satisfy, namely, reasonable roughness and low surface free energy [4]. TiO2 and ZnO nanoparticles have been commonly used to build superhydrophobic coatings. A superhydrophobic fabric was obtained using TiO2 particles that were grown in situ on textile fabric by a hot-pot reaction to increase the surface roughness; subsequently, these were modified to exhibit low energies using silane [17]. Siddaramanna et al first modified ZnO particles to exhibit hydrophobic properties and directly attached these particles to an aluminum alloy surface to prepare a superhydrophobic coating [18].

Methods

Results

Conclusion