Schlesinger Maik, Hamad Wadood Y, MacLachlan Mark J
Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, BC V6T 1Z1, Canada.
Soft Matter. 2015 Jun 21;11(23):4686-94. doi: 10.1039/c5sm00745c.
Demand for sustainable functional materials has never been larger. The introduction of functionality into pure cellulose might be one step forward in this field as it is one of the most abundant natural biopolymers. In this paper, we demonstrate a straightforward and scalable way to produce iridescent, mesoporous cellulose membranes with tunable colors and porosity. Concomitant assembly of cellulose nanocrystals (CNCs) and condensation of silica precursors results in CNC-silica composites with chiral nematic structures and tunable optical properties. Removal of the stabilizing silica matrix by alkaline or acid treatment gives access to novel chiral nematic mesoporous cellulose (CNMC) films. Importantly, the optical properties and the mesoporosity can be controlled by either varying the silica-to-CNC ratio, or by varying the substrate used during the evaporation-induced self-assembly process. In order to introduce additional functionality, CNMC has been used to stabilize gold nanoparticles with three different concentrations by wet impregnation. These materials are stable in water and can potentially function in sensors, tissue engineering or functional membranes.
对可持续功能材料的需求从未如此之大。将功能引入纯纤维素可能是该领域向前迈出的一步，因为纤维素是最丰富的天然生物聚合物之一。在本文中，我们展示了一种直接且可扩展的方法来制备具有可调颜色和孔隙率的彩虹色介孔纤维素膜。纤维素纳米晶体（CNC）的伴随组装和二氧化硅前驱体的缩合导致具有手性向列结构和可调光学性质的CNC-二氧化硅复合材料。通过碱处理或酸处理去除稳定的二氧化硅基质可得到新型手性向列介孔纤维素（CNMC）薄膜。重要的是，光学性质和介孔率可以通过改变二氧化硅与CNC的比例，或通过改变蒸发诱导自组装过程中使用的底物来控制。为了引入额外的功能，已通过湿浸渍法使用CNMC来稳定三种不同浓度的金纳米颗粒。这些材料在水中稳定，并且可能在传感器、组织工程或功能膜中发挥作用。
