Dual physically crosslinked healable polyacrylamide/cellulose nanofibers nanocomposite hydrogels with excellent mechanical properties.

•Small amount of cellulose nanofibers (CNF) effectively reinforced polyacrylamide (PAM) based nanocomposite hydrogels.•Posttreatment of PAM/CNF composite hydrogels with FeCl3 solution generated further improvement of mechanical properties.•Hydrogen bonding and ionic coordination serve as dual physical crosslinks in obtained nanocomposite hydrogels.•The hydrogels show healing ability and excellent mechanical properties that are adjustable via altering CNF dosages and/or Fe3+ concentrations.