Polydimethylsiloxane Composite Sponge Decorated with Graphene/Carbon Nanotube via Polydopamine for Multifunctional Applications

Recently, polydimethylsiloxane (PDMS)-based porous materials have been regarded as ideal candidates in various applications. We created a PDMS composite sponge decorated with reduced graphene oxide (rGO)/carbon nanotube (CNT) fillers via polydopamine (PDA). Specifically, a manufactured PDMS sponge was prepared by a sacrificial template approach and then PDA was decorated on a network of PDMS sponges by dopamine self-polymerization. PDA tightly and firmly attached to the PDMS sponge skeleton, which makes the superhydrophobic PDMS sponge hydrophilic providing adsorption sites for rGO and CNT fillers; thus, the compatibility between fillers and the PDMS matrix was improved. The developed rGO-CNT/PDA@PDMS composite sponge exhibited excellent sensing characteristics, photothermal effect, and superwettability simultaneously. The rGO-CNT/PDA@PDMS-based sensor has a wide strain range (0–60%), high sensitivity (GF = 2.13), and stability (500 loading/unloading cycles). Additionally, rGO-CNT/PDA@PDMS exhibits excellent oil–water separation performance and high-efficiency absorption of oils. Simultaneously, the rGO-CNT/PDA@PDMS sponge was also proved to possess good photothermal conversion performance. Therefore, the environmentally friendly and multifunctional rGO-CNT/PDA@PDMS composite sponge exhibits superior potential for application in flexible intelligent wearable devices, oily wastewater, and seawater desalination.