Merillas Beatriz, Martín-de León Judith, Villafañe Fernando, Rodríguez-Pérez Miguel Ángel
Cellular Materials Laboratory (CellMat), Condensed Matter Physics Department, Faculty of Science, University of Valladolid, Campus Miguel Delibes, 47011 Valladolid, Spain.
GIR MIOMeT-IU Cinquima-Química Inorgánica, Faculty of Science, University of Valladolid, Campus Miguel Delibes, 47011 Valladolid, Spain.
Nanomaterials (Basel). 2022 Apr 30;12(9):1522. doi: 10.3390/nano12091522.
Highly transparent polyisocyanurate-polyurethane (PUR-PIR) aerogels were synthesized, and their optical properties were studied in detail. After determining the density and structural parameters of the manufactured materials, we analyzed their optical transmittance. It was demonstrated that the catalyst content used to produce the aerogels can be employed to tune the internal structure and optical properties. The results show that the employment of lower catalyst amounts leads to smaller particles forming the aerogel and concomitantly to higher transmittances, which reach values of 85% (650 nm) due to aerogel particles acting as scattering centers. Thus, it was found that the lower this size, the higher the transmittance. The effect of the sample thickness on the transmittance was studied through the Beer-Lambert law. Finally, the scattering mechanisms involved in the light attenuation were systematically evaluated by measuring a wide range of light wavelengths and determining the transition between Rayleigh and Mie scattering when the particles were larger. Therefore, the optical properties of polyurethane aerogels were studied for the first time, opening a wide range of applications in building and energy sectors such as glazing windows.
合成了高透明聚异氰脲酸酯 - 聚氨酯（PUR - PIR）气凝胶，并对其光学性能进行了详细研究。在确定了所制备材料的密度和结构参数后，我们分析了它们的光学透过率。结果表明，用于生产气凝胶的催化剂含量可用于调节其内部结构和光学性能。结果显示，使用较低量的催化剂会导致形成气凝胶的颗粒更小，相应地透过率更高，由于气凝胶颗粒作为散射中心，在650nm处透过率可达85%。因此，发现颗粒尺寸越小，透过率越高。通过比尔 - 朗伯定律研究了样品厚度对透过率的影响。最后，通过测量宽范围的光波长并确定当颗粒较大时瑞利散射和米氏散射之间的转变，系统地评估了光衰减中涉及的散射机制。因此，首次对聚氨酯气凝胶的光学性能进行了研究，为建筑和能源领域（如玻璃窗）开辟了广泛的应用前景。
