Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747AG, Groningen, The Netherlands.
Department of Polymer Engineering and Color Technology, Amirkabir University of Technology, P.O. Box 1587-4413, Tehran, Iran.
Nat Commun. 2023 Feb 7;14(1):664. doi: 10.1038/s41467-023-36303-8.
Polydopamine is a biomimetic self-adherent polymer, which can be easily deposited on a wide variety of materials. Despite the rapidly increasing interest in polydopamine-based coatings, the polymerization mechanism and the key intermediate species formed during the deposition process are still controversial. Herein, we report a systematic investigation of polydopamine formation on halloysite nanotubes; the negative charge and high surface area of halloysite nanotubes favour the capture of intermediates that are involved in polydopamine formation and decelerate the kinetics of the process, to unravel the various polymerization steps. Data from X-ray photoelectron and solid-state nuclear magnetic resonance spectroscopies demonstrate that in the initial stage of polydopamine deposition, oxidative coupling reaction of the dopaminechrome molecules is the main reaction pathway that leads to formation of polycatecholamine oligomers as an intermediate and the post cyclization of the linear oligomers occurs subsequently. Furthermore, TRIS molecules are incorporated into the initially formed oligomers.
聚多巴胺是一种仿生自粘聚合物，可以很容易地沉积在各种各样的材料上。尽管人们对基于聚多巴胺的涂层越来越感兴趣，但聚合机制和沉积过程中形成的关键中间物种仍存在争议。在此，我们报道了对凹凸棒石纳米管上聚多巴胺形成的系统研究；凹凸棒石纳米管的负电荷和高表面积有利于捕获参与聚多巴胺形成的中间产物，并减缓该过程的动力学，以揭示各种聚合步骤。X 射线光电子能谱和固态核磁共振波谱的数据表明，在聚多巴胺沉积的初始阶段，多巴胺醌分子的氧化偶联反应是主要的反应途径，导致聚邻苯二酚胺低聚物的形成，作为中间产物，随后发生线性低聚物的环化。此外，TRIS 分子被掺入到最初形成的低聚物中。
