Phytic acid modified soy protein isolate/chitosan film: A multi-functional and degradable bio-based composite material for fire alarm sensor

Currently, interest in the development of a new sustainable sensors that does not cause pollution and exhibits rapid response for fire is increasing. Herein, a highly sensitive, flame-retardant, degradable film sensor (SCGP films) is developed by using a green and non-toxic scheme, which is comprising soybean protein isolate, chitosan, graphene, iron ions (Fe 3+ ), and phytic acid. The films exhibited reversible temperature response/recovery times (i.e., 2.6 s / 4.3 s) in wide range of 68.1–194.3 °C. The SCGP films showed a fast response time (3 s) to fire, and a continuous alarm during the long-term combustion (145 s). Moreover, the films can keep the structure intact after immersion in water for 30 days or under ultrasonic treatment. Therefore, the SCGP films can be assembled into a multifunctional sensor system which provides an eco-friendly scheme for multi-functional film sensor that can be applied in the fields of fire safety.