The invention relates to the technical field of
polymer nano composite materials, and particularly discloses a preparation method of high-sensitivity anti-freezing composite hydrogel based on multiple synergistic effects and application of the high-sensitivity anti-freezing composite hydrogel in the field of flexible sensing. According to the method, a blending
system of
cellulose nanofibers (CNF) and 3, 4-ethylenedioxythiophene-
polystyrene sulfonate (EDOT: PSS) is innovatively adopted as a conductive reinforcement phase, in-situ
polymerization reaction is induced through a
redox initiation system, and
nanocellulose / PEDOT: PSS composite dispersion liquid is constructed; and further carrying out free radical copolymerization reaction with an
acrylamide (AM)
monomer and a
lithium chloride (LiCl)
antifreeze agent to form the composite hydrogel with an interpenetrating
network structure. Wherein a multi-
hydrogen bond cross-linked network is formed between the CNF and a
polymer matrix through rich hydroxyl groups on the surface of the CNF, so that the
mechanical strength of the hydrogel is macroscopically improved; a PEDOT conductive chain constructs a continuous conductive path in a three-dimensional network, so that the
conductivity of the hydrogel is enhanced; liCl destroys ice
crystal growth
kinetics through hydration, the
freezing point of the
system is reduced to-40 DEG C or below, and meanwhile, the LiCl and a CNF-PAM matrix generate
ion-
dipole interaction to synergistically inhibit the phase separation phenomenon in a low-temperature environment. The hydrogel has excellent mechanical adaptability, wide temperature range stability and rapid
strain response characteristics, and can be widely applied to flexible electronic devices, biomedical sensing and intelligent wearable equipment in extreme environments.