Raining-inspired method for construction of porous film material
Xiaomin Wang,
Heyi Pan,
Lin Lian,
Xiangjun Gong,
Yang Wang,
Chaoqun Zhang
Affiliations
Xiaomin Wang
Key Laboratory for Biobased Materials and Energy of Ministry of Education, College of Materials and Energy, South China Agricultural University, 483 Wushan Road, Guangzhou, 510642, PR China; Maoming Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Maoming, 525000, PR China
Heyi Pan
Key Laboratory for Biobased Materials and Energy of Ministry of Education, College of Materials and Energy, South China Agricultural University, 483 Wushan Road, Guangzhou, 510642, PR China; Maoming Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Maoming, 525000, PR China
Lin Lian
Faculty of Materials Science and Engineering, South China University of Technology, Guangzhou, 510640, PR China
Xiangjun Gong
Faculty of Materials Science and Engineering, South China University of Technology, Guangzhou, 510640, PR China
Yang Wang
Key Laboratory for Biobased Materials and Energy of Ministry of Education, College of Materials and Energy, South China Agricultural University, 483 Wushan Road, Guangzhou, 510642, PR China; Maoming Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Maoming, 525000, PR China; Corresponding authors.
Chaoqun Zhang
Key Laboratory for Biobased Materials and Energy of Ministry of Education, College of Materials and Energy, South China Agricultural University, 483 Wushan Road, Guangzhou, 510642, PR China; Maoming Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Maoming, 525000, PR China; Corresponding authors.
The low-temperature environment caused by solvent evaporation leads to the condensation of water vapor into water droplets that remain on the surface of the film to form breath figure patterns. The conventional approach to regulate the pore morphology in the breath figure process is to optimize the ambient temperature, humidity, and solution concentration. However, realizing a wide adjustable window of pore size and uniform distribution of the pore are still challenges. Here, inspired by the rainfall phenomenon, we proposed a simple and efficient method called the “raining boxing method” (RBM) for preparing porous films based on exogenously given water droplets as templates. The RBM broadened the adjustable window of pore size (0.6–225 µm in this work) and solved the inherent problem of radial reduction of pore size from the film center to the edge caused by the significant difference in low-temperature duration at different locations accompanying the solvent evaporation process. Furthermore, this method could realize multi-types porous films, including surface porous films, spongy porous films, and honeycomb porous films, and could be universally applied in the casting process of various polymer solutions.