The photothermal stability of CNFs/ZnAl-LDHs composited films: Influence of the crystal morphology of ZnAl-LDHs

The existence of hydroxyl and carboxyl groups makes the photothermal stability of cellulose nanofibers (CNFs) poor and thus limits its scale application. This problem could be solved by doping layered double hydroxides (LDHs) nanopowders with opposite charge on the surface of CNFs . This work mainly focused on investigation of the influence of the crystal morphology of the inorganic ultraviolet shielding agent (i.e. ZnAl-LDHs) on the thermal stability of CNFs/ZnAl-LDHs composited films. The results showed that the morphology of LDHs was positively correlated with the photothermal stability of CNFs-based films. Specially, the ZnAl-LDHs with uniform crystal morphology could be prepared by controlling the molar ratio of Zn/Al at 3:1 and thus enhance the photothermal stability of CNFs-based films without any serious light transmittance deteriorating after doping. This work provided a practical and effective way for preparation of photothermal-stable CNFs-based transparent films for industrial application in the fields of photonics and electronics.