Lanfranchi Andrea, Megahd Heba, Lova Paola, Comoretto Davide
Dipartimento di Chimica e Chimica Industriale, Università degli Studi di Genova, Via Dodecaneso 31, 16146, Genoa, Italy.
ACS Appl Mater Interfaces. 2022 Mar 30;14(12):14550-14560. doi: 10.1021/acsami.1c25037. Epub 2022 Mar 19.
Preventing solar heating is nowadays of paramount interest in energy savings and health preservation. For instance, in building thermalization solar heating consumes an excess of energy leading to harmful CO emissions, while in food and beverage packaging it may lead to variation of organoleptic properties or even health issues. The phenomenon is attributed to the large presence of moieties with highly absorbing vibrational overtones and combination bands in the near-infrared spectral region that induces heating in water, moisture, and in polymers used in packaging. Thus, reducing and controlling the light absorbed by these materials with effective low-cost passive systems can play a major role in energy saving and health preservation. In this work, different polymer dielectric mirrors are reported, made of poly(-vinylcarbazole) and either cellulose acetate or poly(acrylic acid), and able to selectively reflect near-infrared radiation while maintaining high transparency in the visible range. To this end, simple, tandem, and superperiodic mirrors are used to shield radiation impinging on samples of water and paraffin, demonstrating shielding efficiencies up to 52% with respect to unshielded references, promising a new paradigm to solve thermal management issues.
如今，防止太阳加热在节能和健康保护方面具有至关重要的意义。例如，在建筑热化过程中，太阳加热消耗过多能量，导致有害的一氧化碳排放，而在食品和饮料包装中，它可能导致感官特性变化甚至健康问题。这种现象归因于在近红外光谱区域大量存在具有高吸收泛音和组合带的基团，这些基团会在水、水分以及包装中使用的聚合物中引发加热。因此，用有效的低成本被动系统减少和控制这些材料吸收的光，在节能和健康保护方面可以发挥重要作用。在这项工作中，报道了不同的聚合物介质镜，它们由聚（乙烯基咔唑）与醋酸纤维素或聚丙烯酸制成，能够选择性地反射近红外辐射，同时在可见光范围内保持高透明度。为此，使用简单镜、串联镜和超周期镜来屏蔽照射到水和石蜡样品上的辐射，相对于未屏蔽的参考样品，屏蔽效率高达52%，有望为解决热管理问题提供一种新的范例。
