Self-healing, reusable and conductive cellulose nanocrystals-containing adhesives

Abstract

Adhesives have wide applications in many fields such as wood products, biomedical engineering and electronics. Despite the much progress achieved, it remains a challenge to fabricate self-healing, reusable and conductive adhesives. Herein, a new type of adhesives with self-healing, reusability and conductivity have been fabricated via physical mixing of cellulose nanocrystals (CNC), gallic acid (GA), and poly(N-vinylpyrrolidone) (PVP). Different characteristics of the prepared adhesives, including the self-healing, conductivity, reusability and high adhesion, have been investigated. The CNC/GA/PVP adhesives show excellent conductivity by lighting up a LED lamp. The adhesive sample with 10.2 wt% CNC possesses high lap shear strength of 4.91 MPa for glass, 4.39 MPa for wood, and 3.94 MPa for aluminum substrates. Based on the dynamic hydrogen bonding, the adhesives have excellent reusability without significant reduction in the lap shear strength. These self-healing, reusable and conductive adhesives have great potential as conductive adhesive materials in many applications.