Copper sulfide anchored MXene improving photo-responsive self-healing polyurethane with enhanced mechanical and antibacterial properties

Diseases caused by bacterial infection are becoming a major threat to human health. Therefore, developing efficient antibacterial materials is of great significance in improving medical care and protecting people's health. In this work, an accordion-like structural Ti3C2@CuS was synthesized by copper sulfide (CuS) nanospheres anchored firmly on the surface of Ti3C2Tx via the hydrothermal method. The multilayer Ti3C2@CuS becomes few-layered nanosheets after ultrasonic treatment, which have an enjoyable dispersion in the polyurethane (PU) matrix. PU and the released Cu2+ from Ti3C2@CuS are firmly linked by a coordination bond, which improves the mechanical properties and thermal stability of Ti3C2@CuS-PU and reduces the heavy metal ion pollution by blocking the Cu2+ released by forming coordination bonds. Moreover, Ti3C2@CuS-PU exhibits an excellent self-healing performance after 30 tensile cycles. Additionally, Ti3C2Tx and CuS could improve the separation efficiency of the electron-hole pairs of CuS to produce more reactive oxygen species (ROS) to kill bacteria. Ti3C2@CuS-PU maintains a highly long-term sterilization ability of more than 90 % in 30 days because of the synergistic effect of the sustained release of copper ions, the elevated ROS production ability, and the excellent dispersion of Ti3C2@CuS in PU. This work demonstrates a simple and promising route for designing multifunctional antibacterial self-healing materials.