Improving flame retardancy and self-cleaning performance of cotton fabric via a coating of in-situ growing layered double hydroxides (LDHs) on polydopamine

In order to improve flame retardancy and soiling resistance of cotton fabric, a safe coating was fabricated on its surface. At first dopamine was polymerized on the cotton surface to be polydopamine (PDA), and then layered double hydroxides (LDHs) grew in situ on the platform of PDA by the coordination of catechol groups and metal ions. Cone calorimetry test results showed the coating reduced heat and smoke release during burning. Most important, more than 94% smoke was suppressed by the PDA-LDHs coating. Little cotton left after combustion but more than 10.2% of char was remained for the treated fabric by PDA-LDHs. On the other hand further covered by polydimethylsiloxane (PDMS), the treated cotton exhibited enhanced resistance to soiling and became more durable. For more than 96% oil/water separation efficiency, the treated cotton fabric can be expected to be an ideal filtration material.