Eskilson Olof, Zattarin Elisa, Silander Jennifer, Hallberg Tomas, Åkerlind Christina, Selegård Robert, Järrendahl Kenneth, Aili Daniel
Laboratory of Molecular Materials, Division of Biophysics and Bioengineering, Department of Physics, Chemistry, and Biology, Linköping University, 581 83 Linköping, Sweden.
Department of Electromagnetic Signatures, FOI-Swedish Defence Research Agency, 583 30 Linköping, Sweden.
ACS Appl Mater Interfaces. 2024 Oct 2;16(39):52894-52901. doi: 10.1021/acsami.4c10244. Epub 2024 Sep 22.
Broadband light-absorbing materials are of large interest for numerous applications ranging from solar harvesting and photocatalysis to low reflection coatings. Fabrication of these materials is often complex and typically utilizes coating techniques optimized for flat and hard materials. Here, we show a self-assembly based strategy for generating robust but mechanically flexible broadband light-absorbing soft materials that can conform to curved surfaces and surface irregularities. The materials were fabricated by adsorbing large quantities of gold nanoparticles (AuNPs) on the nanofibrils of hydrated bacterial cellulose (BC) membranes by tailoring the interaction potential between the cellulose nanofibrils and the AuNPs. The highly efficient self-assembly process resulted in very dense multilayers of AuNPs on the nanofibrils, causing extensive broadening of the localized surface plasmon resonance band and a striking black appearance of the BC membranes. The nanocomposite materials showed an absorptance >96% in both the visible and the near-infrared wavelength range. The AuNP-functionalized BC membranes demonstrated excellent conformability to curved and structured surfaces and could adopt the shape of highly irregular surface structures without any obvious changes in their optical properties. The proposed self-assembly based strategy enables the fabrication of soft and conformable broadband light-absorbing nanocomposites with unique optical and mechanical properties using sustainable cellulose-based materials.
宽带吸光材料在众多应用中具有极大的吸引力，这些应用涵盖从太阳能收集、光催化到低反射涂层等领域。这些材料的制备通常很复杂，且通常采用针对平坦和硬质材料优化的涂层技术。在此，我们展示了一种基于自组装的策略，用于制备坚固但具有机械柔韧性的宽带吸光软材料，这种材料能够贴合曲面和表面不规则之处。通过调整纤维素纳米纤维与金纳米颗粒（AuNPs）之间的相互作用势，将大量金纳米颗粒吸附在水合细菌纤维素（BC）膜的纳米纤维上，从而制备出这些材料。高效的自组装过程导致纳米纤维上形成非常致密的金纳米颗粒多层结构，使局域表面等离子体共振带大幅展宽，并使BC膜呈现出显著的黑色外观。这些纳米复合材料在可见光和近红外波长范围内的吸收率均大于96%。金纳米颗粒功能化的BC膜对曲面和结构化表面表现出优异的贴合性，能够呈现高度不规则表面结构的形状，而其光学性质没有任何明显变化。所提出的基于自组装的策略能够利用可持续的纤维素基材料制备出具有独特光学和机械性能的柔软且贴合的宽带吸光纳米复合材料。
