Temperature-induced resistance transition behaviors of melamine sponge composites wrapped with different graphene oxide derivatives

Temperature-responsive resistance transition behaviors of the melamine sponges wrapped with different graphene oxide derivatives (i.e. nanoribbon, wide-ribbon and sheet) were investigated. Melamine sponge composites coated by three types of GO derivatives were prepared by a simple dip-coating approach. All these composites show good mechanical flexibility and reliability (almost unchanged compressive stress at 70 % strain after 100 cycles), high hydrophobicity (water contact angle >120 degrees), excellent flame resistance (self-extinguishing) and structural stability even after burning, which was used to construct the resistance-based fire alarm/warning sensor. Notably, the different resistance response behaviors of such sensors are strongly dependent on the GO size and network formed on the MF skeleton surface. Typically, at a fixed high temperature of similar to 350 degrees C, the three fire alarm sensors show different response time (to trigger the alarm light) of 6.3, 8.4 and 11.1 s for nanoribbon, wide-ribbon and sheet at the same concentration, respectively. The structural observation and chemical analysis demonstrated that the discrepancy of temperature-responsive resistance transition behaviors of various GO derivatives was strongly determined by their different thermal reduction degrees during the high-temperature or flame treating process. This work offers a design and development for construction of smart fire alarm device for potential fire prevention and safety applications. (C) 2021 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.