Moisture-responsive films of cellulose stearoyl esters showing reversible shape transitions
| Autor: | Andreas Geissler, Markus Gallei, Michaela Standhardt, Christina M. Thiele, Longquan Chen, Kai Zhang, Sascha Mehlhase |
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| Jazyk: | angličtina |
| Rok vydání: | 2015 |
| Předmět: |
Multidisciplinary
Materials science Fabrication Moisture Bilayer Nanoparticle 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Article 0104 chemical sciences chemistry.chemical_compound chemistry Chemical engineering Desorption Molecule Moisture-responsive films cellulose stearoyl esters reversible shape transitions Cellulose Erratum 0210 nano-technology Moisture gradient |
| Zdroj: | Scientific Reports |
| ISSN: | 2045-2322 |
| Popis: | Moisture-responsive materials are gaining greater interest for their potentially wide applications and the readily access to moisture. In this study, we show the fabrication of moisture-responsive, self-standing films using sustainable cellulose as starting material. Cellulose was modified by stearoyl moieties at first, leading to cellulose stearoyl esters (CSEs) with diverse degrees of substitution (DSs). The films of CSE with a low DS of 0.3 (CSE0.3) exhibited moisture-responsive properties, while CSEs with higher DSs of 1.3 or 3 (CSE1.3 and CSE3) not. The CSE0.3 films could reversibly fold and unfold as rhythmical bending motions within a local moisture gradient due to the ab- and desorption of water molecules at the film surface. By spray-coating CSE3 nanoparticles (NPs) onto CSE0.3 films, moisture-responsive films with non-wetting surface were obtained, which can perform quick reversible bending movements and continuous shape transition on water. Furthermore, bilayer films containing one layer of CSE0.3 at one side and one layer of CSE3 at the other side exhibited combined responsiveness to moisture and temperature. By varying the thickness of CSE0.3 films, the minimal bending extent can be adjusted due to altered mechanical resistances, which allows a bending movement preferentially beginning with the thinner side. |
| Databáze: | OpenAIRE |
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