Robust superhydrophobic polyurea@cellulose nanocrystal coating

Abstract

More and more attention has been paid to the fabrication of superhydrophobic polymeric coatings recently, which have enormous potential in the field of waterproofing and self-cleaning applications. In this work, polyurea (PU) particles were firstly prepared through the condensation polymerization between isophorone isocyanate (IPDI) and water. By the combination of cellulose nanocrystals (CNC), polyurea@cellulose nanocrystal (PU@CNC) particles were successfully fabricated. After modification with 1H,1H,2H,2H-perfluorodecyltrichlorosilane (PFDTS), superhydrophobic PU@CNC particles were obtained. Then, after adding fluorocarbon lacquer, a superhydrophobic PU@CNC coated surface was fabricated with the assistance of a spraying method. The as-prepared PU@CNC coating exhibited best liquid repellency when the mass ratio of IPDI and CNC was approximately 1/10. Furthermore, favorable mechanical durability was confirmed by the abrasion test. The results showed that the water contact angles on the PU@CNC coated surface remained above 152° and sliding angles were less than 5° even after 200 abrasion cycles. All these results indicate that the coating is suitable for widespread practical applications.