兼具荧光可视化的含银钙钛矿抗菌涂层研究OA

Objective The growth of bacteria in public environments poses potential risks to human health and facility safety.Bacterial adhesion to material surfaces represents a primary route of transmission.Therefore,protecting material surfaces against bacterial contamination remains a significant challenge.The antimicrobial functionalization of coatings provides an effective strategy for addressing these issues.Compared to traditional meth-ods,such as surface cleaning or the direct addition of antimicrobial agents,this approach provides long-lasting and uniform antimicrobial effects on surfaces while ensuring safety and ease of use.In this study,a silver-containing Cs2Ag0.6Na0.4InCl6:Bi3+fluorescent material is prepared and combined with an epoxy-polyester powder coating to form a multifunctional composite coating.Its structural morphology,luminescent proper-ties,antibacterial performance,and the effects of water immersion and UV irradiation on these properties are investigated.This multifunctional composite coating exhibits highly efficient antimicrobial capabilities and good luminescent properties.It also demonstrates superior stability un-der water immersion and UV irradiation,providing a new strategy for developing safe and highly effective antimicrobial materials. Methods Cs2Ag0.6Na0.4InCl6:Bi3+fluorescent perovskite powders were synthesized using a mechanochemical method,incorporated into an epoxy-polyester powder coating matrix,and fabricated into multifunctional composite coatings using powder coating technology.This method stabilized silver ions within the perovskite lattice and achieved sustained release.This approach not only prolonged the duration of the antibacterial effect but also reduced environmental risks.Bacterial cell walls,proteins,and DNA were disrupted by released Ag+ions,directly inhibiting bacterial growth.Simultaneously,under illumination,the perovskite absorbed photons and generated photo-induced electrons and holes,which produced reactive oxygen species(ROS)that acted synergistically with silver ions to enhance antibacterial efficiency.The crystal structure of the composite coating was characterized using X-ray diffraction(XRD).Surface morphology and elemental distribution were analyzed using scanning electron microscopy(SEM)and energy-dispersive X-ray spectroscopy(EDS).Optical properties were investigated using photoluminescence(PL),photo-luminescence excitation(PLE),and ultraviolet-visible(UV-vis)spectroscopy.Antibacterial performance against Escherichia coli was evaluated by measuring CFU after a specified exposure time.Durability tests,including water immersion and UV aging,were also conducted to assess coat-ing stability. Results and Discussions XRD analysis confirmed that the Cs2Ag0.6Na0.4InCl6:Bi3+powder retained a crystal structure consistent with that of stan-dard Cs2NaInCl6 even after it was embedded in the polymer matrix.Characteristic diffraction peaks remained detectable even when the phosphor content in the coating was as low as 10%,which indicated good crystallinity and phase stability.Scanning electron microscopy(SEM)images showed that the fluorescent particles were approximately 2 µm in size,with no obvious cracks or pores observed between the particles,while the overall surface remained smooth,which indicated good coating uniformity.EDS results indicated a uniform elemental distribution,with no sig-nificant segregation observed.Optical measurements indicated that all experimental samples were excited by 365 nm UV light and exhibited an emission peak at 630 nm.Both luminescence intensity and UV-visible absorption increased with the proportion of phosphor.Because of the local energy levels introduced by the added Ag+and Bi3+ions,the composite coating exhibited a new absorption peak at 380‒450 nm.This behavior not only preserved the main band absorption of the perovskite but also introduced additional excited states,which further enhanced the material's photoluminescence efficiency.Observations under a metallographic microscope at 20×and 50×magnification revealed a uniform fluorescence distribution across the coating under UV irradiation.After 30 days of water immersion and 5 days of UV aging,respectively,the composite coat-ing showed no blistering,cracking,or peeling on its surface,and the PL intensity remained at approximately 80%,which indicated that the coat-ing exhibited good weather resistance and stability.Antibacterial testing showed that,compared to the control group of pure epoxy-polyester coat-ings,the fluorescent composite coating exhibited a significantly reduced colony-forming unit(CFU)count.Calculations indicated that the antibac-terial rate against Escherichia coli reached 99.53%,which demonstrated that the composite coating effectively inhibited the growth of Escherichia coli. Conclusions The results indicate that the phosphors in the coating exhibit good crystallinity and uniform distribution,while the coating demon-strates stable photoluminescence under UV irradiation and during water immersion.In addition,the silver-doped coating effectively inhibits Esch-erichia coli,demonstrating excellent antimicrobial efficacy.This method provides a balance among material safety,ease of use,and versatility,providing a viable approach for developing functional antimicrobial coatings.Currently,the antibacterial performance of commercially available coatings can typically be evaluated only through instrumental testing,making it difficult for ordinary consumers to assess their effectiveness.The fluorescent antibacterial composite coating investigated in this study combines fluorescence properties with antibacterial performance,providing the potential for the visual evaluation of antibacterial activity based on fluorescence intensity:higher fluorescence intensity corresponds to stron-ger antibacterial effects,whereas a decrease in fluorescence intensity over time can indicate reduced antibacterial performance,providing a refer-ence for assessing the service life of the coating.This approach offers a potential strategy for developing intuitive and visual methods for evaluat-ing antibacterial capability in the future.