Pinho Ana C, Morais Paula V, Pereira Manuel F, Piedade Ana P
Department of Mechanical Engineering, CEMMPRE, University of Coimbra, 3030-788 Coimbra, Portugal.
Department of Life Sciences, CEMMPRE, University of Coimbra, 3000-456 Coimbra, Portugal.
Polymers (Basel). 2025 Jan 11;17(2):171. doi: 10.3390/polym17020171.
The idea supporting the investigation of the current manuscript was to develop customized filters for air conditioners with different pore percentages and geometry with the additional advantage of presenting antibacterial performance. This property was expected due to the reinforcement of Cu nanoparticles in the polymeric matrix of poly(lactic acid) (PLA) and polyurethane (TPU). The filaments were characterized by their chemical composition, thermal and mechanical properties, and antibacterial behavior before and after processing by fused filament fabrication. An X-ray photoelectron spectroscopy showed that the nanocomposite filaments presented Cu particles at their surface in different valence states, including Cu, Cu, and Cu. After processing, the metallic particles are almost absent from the surface, a result confirmed by micro-computer tomography (μ-CT) characterization. Antibacterial tests were made using solid-state diffusion tests to mimic the dry environment in air conditioner filters. The tests with the nanocomposite filaments showed that bacteria proliferation was hindered. However, no antibacterial performance could be observed after processing due to the absence of the metallic element on the surface. Nevertheless, antimicrobial performance was observed when evaluated in liquid tests. Therefore, the obtained results provide valuable indications for developing new nanocomposites that must maintain their antimicrobial activity after being processed and tested in the dry conditions of solid-state diffusion.
支持当前手稿研究的想法是开发具有不同孔隙率和几何形状的定制空调过滤器，并具有抗菌性能这一额外优势。由于在聚乳酸（PLA）和聚氨酯（TPU）的聚合物基体中增强了铜纳米颗粒，预期会有这种性能。通过熔丝制造对长丝进行加工前后，对其化学成分、热性能和机械性能以及抗菌行为进行了表征。X射线光电子能谱表明，纳米复合长丝在其表面呈现出不同价态的铜颗粒，包括Cu、Cu和Cu。加工后，表面几乎没有金属颗粒，这一结果通过微计算机断层扫描（μ-CT）表征得到证实。使用固态扩散试验进行抗菌测试，以模拟空调过滤器中的干燥环境。对纳米复合长丝的测试表明，细菌增殖受到阻碍。然而，由于表面没有金属元素，加工后未观察到抗菌性能。尽管如此，在液体测试中评估时观察到了抗菌性能。因此，所获得的结果为开发新的纳米复合材料提供了有价值的指示，这些纳米复合材料在固态扩散的干燥条件下进行加工和测试后必须保持其抗菌活性。
