Novel CNFs-based organic UV-adsorber intercalated ZnAl-LDHs composited films with superior photothermal stability and mechanical properties

Abstract

The improvement of the photothermal stability and mechanical properties for cellulose nanofibers (CNFs) is a highly desirable yet challenging research topic due to its wide applications. Featuring the 2D-organized structure and various characteristics, layered double hydroxides (LDHs) shows tremendous potential in improving the photothermal stability and mechanical properties of CNFs matrix. Herein, a series of ZnAl-LDHs nanosheets intercalated with different organic molecules were synthesized and subsequently doped into CNFs matrix for preparing CNFs/LDHs composited films. It was showed that doping UV-adsorber intercalated ZnAl-LDHs into the CNFs matrix can significantly enhance UV-shielding ability of CNFs/LDHs composited films due to the synergistic effect between organic anions and the interaction between organic anions and metal cations in LDHs laminates. And the CNFs/HUL (HUL = HALS/UV-P-LDHs) composited film exhibited outstanding UV-shielding ability (UV-shielding rate > 60%) among the considered films, which is comparable to that of the reported materials. Compared with the pristine CNFs film, compositing with HUL rendered the increasing of tensile strength from 80 to 110 MPa. The superior photothermal stability and mechanical properties of CNFs/HUL composited film highlight its great application potential in the fields of coating and packaging.