Onishi Kazuki, Tokudome Yasuaki, Kariya Kohei, Kurokawa Takuma, Murata Hidenobu, Nakahira Atsushi
Department of Materials Science, Osaka Metropolitan University, 1-1, Gakuencho, Naka-ku, Sakai, Osaka 599-8531, Japan.
Department of Materials Science, Osaka Prefecture University, 1-1, Gakuencho, Naka-ku, Sakai, Osaka 599-8531, Japan.
ACS Appl Mater Interfaces. 2024 Apr 3;16(13):16903-16911. doi: 10.1021/acsami.4c02345. Epub 2024 Mar 19.
Free-standing films without the need for any support materials attract attention because of their excellent flexibility in use and ability to be transferred to various substrates. However, free-standing films containing large amounts of inorganic crystalline particles are hard to achieve due to their low strength. In this study, we found the possibility of preparing a free-standing composite film of CuS/polyvinylpyrrolidone (PVP) at a large loading of CuS (>50%) from a concentrated colloidal dispersion of CuS nanoparticles modified with PVP. Despite the large amount of inorganic crystals contained in the free-standing film, the film was strong enough to be handled without any support materials. As a proof-of-concept application of the free-standing film, a solar water evaporation experiment was performed. The CuS/PVP free-standing film exhibited photothermal conversion under light illumination to generate heat and accelerate water evaporation, achieving an evaporation rate of 4.35 kg·m h and an evaporation efficiency of 96.3% at a power density of 3 suns. In addition, thanks to the free-standing feature, one side of the CuS/PVP film could be hydrophobized with polydimethylsiloxane to form a Janus thin film, allowing for floating on the water surface. As a result, effective water evaporation was achieved because of the selective evaporation of water from the air/water interface.
无需任何支撑材料的自支撑薄膜因其在使用中具有出色的柔韧性以及能够转移到各种基材上而备受关注。然而，由于强度较低，制备含有大量无机晶体颗粒的自支撑薄膜很难实现。在本研究中，我们发现从用聚乙烯吡咯烷酮（PVP）改性的硫化铜纳米颗粒的浓胶体分散体中，以高负载量的硫化铜（>50%）制备硫化铜/聚乙烯吡咯烷酮（PVP）自支撑复合薄膜的可能性。尽管自支撑薄膜中含有大量无机晶体，但该薄膜强度足以在无需任何支撑材料的情况下进行处理。作为自支撑薄膜的概念验证应用，进行了太阳能水蒸发实验。硫化铜/PVP自支撑薄膜在光照下表现出光热转换，产生热量并加速水蒸发，在3个太阳的功率密度下实现了4.35 kg·m²·h的蒸发速率和96.3%的蒸发效率。此外，由于具有自支撑特性，硫化铜/PVP薄膜的一侧可用聚二甲基硅氧烷进行疏水化处理，形成一种Janus薄膜，使其能够漂浮在水面上。结果，由于从空气/水界面选择性蒸发水，实现了有效的水蒸发。
