Pathogenic bacteria adhesion and formation of biofilm on the implant are the most common reasons for healthcare-associated device failure. Cationic amphiphilic polymer brushes containing covalently linked quaternary ammonium salts (QASs) are considered to be the most promising bactericidal materials, but these surfaces still suffer from incomplete bactericidal ability and serious microorganism accumulation. With this in mind, a novel kind of hierarchical surface integrating both geminized cationic amphiphilic antibacterial upper layer and zwitterionic antifouling sublayer has been developed in this study. Measurements of X-ray photoelectron spectroscopy, spectroscopic ellipsometry, atomic force microscopy, water contact angle, and surface ζpotential were performed to investigate the surface functionalization process. The thicknesses and grafting densities of the pAGC 8 upper blocks have been optimized to avert the mutual interference among different components. The optimal hierarchical surface exhibits an ultrahigh antibacterial activity and a potent self-cleaning functionality against both Staphylococcus aureus and Escherichia coli bacteria, as well as a certain protein repellence ability. Such a novel hierarchical architecture provides innovative guidance for the construction of super-antibacterial and self-cleaning brushes in many biomedical applications.
Persistent luminescence (PersL) materials containing deep traps have attracted great attention in the field of optical information storage. However, the lack of nanomaterials with satisfactory light storage ability has become one of the main obstacles to the practical applications. In this work, NaMgF3:Tb3+@NaMgF3:Tb3+ nanoparticles are reported which exhibit excellent light storage ability into deep traps upon X‐ray irradiation and controllable photon emissions under thermal stimulation. A surface passivation strategy by constructing a core–shell structure is adopted, which is proved valid to greatly enhance the PersL efficiency. To understand the possible mechanism on the light storage and thermally stimulated PersL in the NaMgF3:Tb3+@NaMgF3 nanoparticles, an energy level diagram is built and the electronic transition processes are clarified. According to the proposed mechanism, the Tb3+ ions possibly serve as both emitting centers and trap centers in the NaMgF3 host during the X‐ray irradiation. Due to the excellent dispersibility and stability in water, luminescent inks containing the nanoparticles are successfully prepared and the applications to inkjet printing optical information storage and information decryption are demonstrated. The developed NaMgF3:Tb3+@NaMgF3 PersL nanoparticles may inspire further research on lanthanide‐activated fluoride PersL nanoparticles and provide new opportunities to the next‐generation information storage and biomedical technologies.
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