Work

Cross-scale asymmetric coupling enables mechanically robust titanium alloys with surface charge transfer mediated photothermal-photodynamic synergy

Year: 2026

Type: article

Abstract: Integrating mechanical strengthening with biological functionality remains a major challenge for titanium-based wearable and protective technologies under complex service conditions. Herein, a mechanism-driven strategy coupling gradient microstructure engineering with asymmetric conjugated molecular design to achieve synergistic mechanical and photothermal performance is reported. Functionally graded Ti-6Al-4.13V-0.31Zr-0.08B components were fabricated via wire arc additive manufacturing (WAAM) by introducing ZrB 2 and V powders, leading to TiB reinforcement, α-lamella refinement, suppressed prior-β grain growth, and a 12.5% hardness increase (382.3 HV). An asymmetric molecule (BO-2F-Br) was rationally designed to enhance intramolecular charge transfer (ICT), strengthen spin-orbit coupling (SOC), and promote intersystem crossing, thereby increasing photothermal conversion and reactive oxygen species (ROS) generation. Notably, BO-2F-Br shows strong adhesion on the titanium surface. Furthermore, the BO-2F-Br-coated gradient titanium alloy exhibited a photothermal conversion efficiency of 51%, higher than the uncoated (30%) and BO-Br-Br-coated samples (45%). Under light irradiation, antibacterial rates reached 95.6% against Escherichia coli and 93.9% against Staphylococcus aureus . This study provides a pathway toward multifunctional titanium systems with enhanced mechanical and antibacterial performance.

Source: Chemical Engineering Journal

DOI: 10.1016/j.cej.2026.181810