Artificial leaves via reproduction of hierarchical structures by a fast molding and curing process

摘要

In this work, we have developed a practical approach for the replication of hierarchical structures on a native leaf surface via a fast two-step molding process combining both the fast curability to prevent shrinkage of cells and the strong resistance to chemical compounds for further applications. The negative replica of the leaf was produced from perfluoropolyether (PFPE) by precise molding followed by a fast curing with UV. A liquid ceramic precursor material (polyvinylsilazane, PVSZ) was used to fabricate the positive leaf structure through the same process as applied for the negative imprint of the surface yielding a highly detailed replica of the native leaf surface structure. Static water contact angle measurements show that the biomimetic surfaces exhibit a wettability similar to the native leaves. A novel approach to replicate the hierarchical surface structures on a leaf surface in a ceramic precursor material derived from polyvinylsilazane (PVSZ) is developed. PFPE negative structures are produced through a fast UV curing to avoid the shrinkage of the cells by loss of water. Subsequently, it is used to fabricate a PVSZ artificial leaf with hierarchical structures by UV- and thermal-curing.