Eco-Friendly
Flame-Retardant Phase-Change Composite
Films Based on Polyphosphazene/Phosphorene Hybrid Foam and Paraffin
Wax for Light/Heat-Dual-Actuated Shape Memory
posted on 2024-02-02, 17:05authored byYang Zhou, Wei Liu, Shuangkun Zhang, Huan Liu, Zhanpeng Wu, Xiaodong Wang
Multiactuated
shape memory materials are a class of promising intelligent
materials that have received great interest in the fields of self-healing,
anticounterfeiting, biomedical, soft robotic, and smart thermal management
applications. To obtain a light/heat-dual-actuated shape memory material
for thermal management applications in fire safety, we have designed
a type of halogen-free flame-retardant phase-change composite film
based on polyaryloxyphosphazene (PDAP)/phosphorene (PR) hybrid foam
as a support material and paraffin wax (PW) as a phase-change material
(PCM). PDAP was synthesized as a flexible foam matrix through the
ring-opening polymerization of hexachlorocyclotriphosphazene, followed
by a substitution reaction of aryloxy groups. The porosity of the
PDAP foam is improved by introducing PR nanosheets, facilitating a
high latent heat capacity of the PDAP–PR/PW composite films
for thermal management applications. The PDAP–PR/PW composite
films can implement rapid shape recovery within 65 s in the heating
process, which is much shorter than that of the corresponding film
without PR nanosheets (185 s). Furthermore, the PDAP–PR/PW
composite films also exhibit light-actuated shape memory behavior
thanks to their good solar-to-thermal energy absorption and conversion
contributed by PR nanosheets as a highly effective photothermal material.
More importantly, the presence of PR nanosheets imparts an excellent
flame-retardant property to the PDAP–PR/PW composite films.
The PDAP–PR/PW composite film can be self-extinguished within
2 s after the flame. Through an innovative integration of flexible
polyphosphazene foam, PR nanosheets, and solid–liquid PCM to
obtain a sensitive actuating response to light and heat, this study
offers a new approach for developing multiactuated and eco-friendly
flame-retardant shape memory materials to meet the requirement of
applications with a requirement of fire safety in soft actuators,
thermal therapy, control devices, and so on.