Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University , 1800 Lihu Road, Wuxi 214122, China.
ACS Appl Mater Interfaces. 2017 Oct 18;9(41):36281-36289. doi: 10.1021/acsami.7b08763. Epub 2017 Oct 9.
Ultraviolet (UV) light is known to be harmful to human health and cause organic materials to undergo photodegradation. In this Research Article, bioinspired dopamine-melanin solid nanoparticles (Dpa-s NPs) and hollow nanoparticles (Dpa-h NPs) as UV-absorbers were introduced to enhance the UV-shielding performance of polymer. First, Dpa-s NPs were synthesized through autoxidation of dopamine in alkaline aqueous solution. Dpa-h NPs were prepared by the spontaneous oxidative polymerization of dopamine solution onto polystyrene (PS) nanospheres template, followed by removal of the template. Poly(vinyl alcohol) (PVA)/Dpa nanocomposite films were subsequently fabricated by a simple casting solvent. UV irradiation protocols were set up, allowing selective study of the extra-shielding effects of Dpa-s versus Dpa-h NPs. In contrast to PVA/Dpa-s films, PVA/Dpa-h films exhibit stronger UV-shielding capabilities and can almost block the complete UV region (200-400 nm). The excellent UV-shielding performance of the PVA/Dpa-h films mainly arises from multiple absorption because of the hollow structure and large specific area of Dpa-h NPs. Moreover, the wall thickness of Dpa-h NPs can be simply controlled from 28 to 8 nm, depending on the ratio between PS and dopamine. The resulting films with Dpa-h NPs (wall thickness = ∼8 nm) maintained relatively high transparency to visible light because of the thinner wall thickness. The results indicate that the prepared Dpa-h NPs can be used as a novel UV absorber for next-generation transparent UV-shielding materials.
已知紫外线(UV)对人体健康有害,并会导致有机材料发生光降解。在这篇研究文章中,我们引入了仿生多巴胺-黑色素固体质点(Dpa-s NPs)和空心纳米粒子(Dpa-h NPs)作为紫外线吸收剂,以提高聚合物的紫外线屏蔽性能。首先,通过多巴胺在碱性水溶液中的自氧化合成了 Dpa-s NPs。通过多巴胺溶液在聚苯乙烯(PS)纳米球模板上的自发聚合,随后去除模板,制备了 Dpa-h NPs。然后通过简单的浇铸溶剂制备了聚乙烯醇(PVA)/Dpa 纳米复合材料薄膜。建立了紫外线辐照方案,允许选择性研究 Dpa-s 与 Dpa-h NPs 的额外屏蔽效应。与 PVA/Dpa-s 薄膜相比,PVA/Dpa-h 薄膜表现出更强的紫外线屏蔽能力,几乎可以阻挡整个紫外线区域(200-400nm)。PVA/Dpa-h 薄膜具有优异的紫外线屏蔽性能,主要源于由于空心结构和大的比表面积,Dpa-h NPs 的多次吸收。此外,Dpa-h NPs 的壁厚可以根据 PS 和多巴胺的比例从 28nm 简单地控制到 8nm。由于壁厚较薄,具有 Dpa-h NPs(壁厚约为 8nm)的薄膜仍保持相对较高的可见光透明度。结果表明,所制备的 Dpa-h NPs 可用作下一代透明紫外线屏蔽材料的新型紫外线吸收剂。