Neuron-Inspired Self-Healing Composites via Dynamic Construction of Polypyrrole-Decorated Carbon Nanotubes for Smart Physiochemical Sensing

Mimicking
human skin’s functions to develop intelligent
materials have inspired extensive exploration in the design and synthesis
of a novel device. However, how to simulate neuron function and integrate
highly sensitive, positive perceptions and self-healing into one single
material remains a challenge. Here, we prepared a recycled polyurethane
(PU) with high tensile strength values (11.37 ± 0.03 MPa), high
maximum elongation (1130 ± 11.59%), and high self-healing property
(100% for 6 h at 25 °C) and a smart PU composite of polypyrrole-decorated
carbon nanotubes with higher sensitivity. The smart composite can
not only actively identify physical change such as strain, moisture,
and temperature but also proactively detect various chemical environment
changes such as acid, alkali, oxidant, and reductant (T: 25–90 °C, ΔR/R0 values were 0.1–1.6; strain: 10–150%,
ΔR/R0 values were
2.5–27; 0.01–0.1 mol L–1 oxidant solutions,
ΔR/R0 values were
0.66–0.75; 0.01–0.1 mol L–1 reductant
solutions, ΔR/R0 values were 0.51–0.65; 0.1–0.5 mol L–1 acid solutions, ΔR/R0 values were 0.54–0.58; and 0.1–0.5 mol L–1 alkali solutions, ΔR/R0 values were 0.42–0.46). More importantly,
the signal values of the smart composite can quickly return to the
initial values after eliminating physical and chemical stimuli. The
abovementioned features of the smart composite, the high physicochemical
response, and significant restorability make it potentially possible
to apply it in intelligent chemical manufacturing.