Cellulose nanocrystals are renewable plant-based colloidal particles capable of forming photonic films by solvent-evaporation-driven self-assembly. So far, the cellulose nanocrystal self-assembly process has been studied only at a small scale, neglecting the limitations and challenges posed by the continuous deposition processes that are required to exploit this sustainable material in an industrial context. Here, we addressed these limitations by using roll-to-roll deposition to produce large-area photonic films, which required optimization of the formulation of the cellulose nanocrystal suspension and the deposition and drying conditions. Furthermore, we showed how metre-long structurally coloured films can be processed into effect pigments and glitters that are dispersible, even in water-based formulations. These promising effect pigments are an industrially relevant cellulose-based alternative to current products that are either micro-polluting (for example, non-biodegradable microplastic glitters) or based on carcinogenic, unsustainable or unethically sourced compounds (for example, titania or mica).

纤维素纳米晶体是可再生的植物基胶体颗粒，能够通过溶剂蒸发驱动的自组装形成光子薄膜。到目前为止，纤维素纳米晶体自组装过程仅进行了小规模的研究，忽略了在工业环境中利用这种可持续材料所需的连续沉积过程所带来的限制和挑战。在这里，我们通过使用卷对卷沉积来生产大面积光子薄膜来解决这些限制，这需要优化纤维素纳米晶体悬浮液的配方以及沉积和干燥条件。此外，我们还展示了如何将一米长的结构彩色薄膜加工成可分散的效果颜料和闪光粉，甚至在水基配方中也是如此。这些有前途的效果颜料是工业相关的基于纤维素的替代品，可替代当前产品，这些产品要么是微污染的（例如，不可生物降解的微塑料闪光），要么是基于致癌、不可持续或不道德来源的化合物（例如，二氧化钛或云母）。