Zhao Yineng, Hu Fei, Tenhaeff Wyatt E
Materials Science Program, University of Rochester, Rochester, New York 14627, United States.
Department of Chemical Engineering, University of Rochester, Rochester, New York 14627, United States.
Macromolecules. 2025 Jan 29;58(3):1265-1278. doi: 10.1021/acs.macromol.4c02242. eCollection 2025 Feb 11.
Fluoropolymers possess among the lowest indexes of refraction for dense, continuous materials, but their crystallinity typically leads to light scattering and haze. In this work, we studied poly(1,1,2,2-perfluorodecyl acrylate) (pPFDA) as a low-index fluoropolymer and successfully suppressed its crystallization while preserving its desirable low index of refraction (1.36 at 633 nm wavelength) and hydrophobicity (water contact angle of 122°). This was achieved through copolymerization between the hydrophobic 1,1,2,2-perfluorodecyl acrylate (PFDA) and -vinylpyrrolidone (NVP) using initiated chemical vapor deposition (iCVD). The resulting copolymer p(PFDA--VP) film was smooth (roughness <2 nm), highly transparent, thermally robust, and mechanically flexible. This contrasted with pPFDA homopolymer films, which were rough (roughness >30 nm), hazy, and disintegrated at 70 °C due to melting. Moreover, the copolymerization resulted in a 16-fold improvement in the deposition kinetics. To demonstrate its excellent performance in practical applications, the low-index copolymer was paired with a high-index poly(divinylbenzene) (pDVB) ( = 1.59) to build a six-layer interference coating. A six-layer fully polymeric interference coating with precise, independent control of each individual layer's thickness was prepared for the first time by iCVD. Optimized for broadband antireflection, it reduced the surface reflectance to 1% over the entire visible spectrum, while withstanding large mechanical strain.
对于致密的连续材料而言，含氟聚合物的折射率是最低的，但它们的结晶度通常会导致光散射和雾度。在这项工作中，我们研究了聚（1,1,2,2-全氟癸基丙烯酸酯）（pPFDA）作为一种低折射率含氟聚合物，并成功抑制了其结晶，同时保留了其理想的低折射率（633nm波长下为1.36）和疏水性（水接触角为122°）。这是通过使用引发化学气相沉积（iCVD）使疏水性的1,1,2,2-全氟癸基丙烯酸酯（PFDA）与N-乙烯基吡咯烷酮（NVP）共聚来实现的。所得的共聚物p（PFDA-NVP）薄膜光滑（粗糙度<2nm）、高度透明、热稳定性好且机械柔韧性佳。这与pPFDA均聚物薄膜形成了对比，后者粗糙（粗糙度>30nm）、有雾度，并且在70°C时由于熔化而分解。此外，共聚使沉积动力学提高了16倍。为了证明其在实际应用中的优异性能，将低折射率共聚物与高折射率的聚（二乙烯基苯）（pDVB）（n = 1.59）配对，以构建六层干涉涂层。首次通过iCVD制备了一种六层全聚合物干涉涂层，能够精确独立地控制每一层的厚度。该涂层针对宽带抗反射进行了优化，在整个可见光谱范围内将表面反射率降低到1%，同时能够承受较大的机械应变。
