Abstract：
Fibrillated cellulose-based nanocomposites can improve energy efficiency of building envelopes, especially windows, but efficiently engineering them with a flexible ability of lighting and thermal management remains highly challenging. Herein, a scalable interfacial engineering strategy is developed to fabricate haze-tunable thermal barrier films tailored with phosphorylated cellulose nanofibrils (PCNFs). Clear films with an extremely low haze of 1.6% (glass-scale) are obtained by heat-assisted surface void packing without hydrophobization of nanocellulose. PCNF gel cakes serve here as templates for surface roughening, thereby resulting in a high haze (73.8%), and the roughened films can block heat transfer by increasing solar reflection in addition to a reduced thermal conduction. Additionally, obtained films can tune distribution of light from visible to near-infrared spectral range, enabling uniform colored lighting and inhibiting localized heating. Furthermore, an integrated simulation of lighting and cooling energy consumption in the case of office buildings shows that the film can reduce the total energy use by 19.2-38.1% under reduced lighting levels. Such a scalable and versatile engineering strategy provides an opportunity to endow nanocellulose-reinforced materials with tunable optical and thermal functionalities, moving their practical applications in green buildings forward.
摘要：
纤维素基纳米复合材料可以提高建筑围护结构的能源效率，尤其是窗户,但有效的工程他们与照明和热管理的灵活能力仍然极具挑战性。在这里，开发了一种可扩展的界面工程策略，以制造用磷酸化纤维素纳米原纤维（PCNFs）定制的雾度可调的热障膜。通过热辅助表面空隙填充获得具有1.6%(玻璃尺度)的极低雾度的透明膜,而没有纳米纤维素的疏水化。PCNF凝胶蛋糕在这里用作表面粗糙化的模板，从而导致高雾度(73.8%)，并且粗糙化的膜可以通过除了降低的热传导之外增加太阳反射来阻挡热传递。此外,获得的薄膜可以调整从可见光到近红外光谱范围的光的分布，使均匀的颜色照明和抑制局部加热。此外，在办公建筑的情况下，对照明和冷却能耗的综合模拟表明，该膜可以在减少照明水平下将总能耗减少19.2-38.1%。这种可扩展和通用的工程策略提供了一个机会，赋予纳米纤维素增强材料可调的光学和热功能，推动其在绿色建筑中的实际应用。
