Bioinspired green biopolymers for fine dust filter applicationsTuesday (20.03.2018) 17:40 - 18:00 Part of:
Natural biopolymer fibers like silk are sophisticated hierarchically structured materials, combining a set of interesting features, e.g. extraordinary mechanical properties, biocompatibility, and biodegradability. In this study we focussed on spider and lacewing silk, and utilized a well-established biotechnological approach to produce the recombinant protein mimics eADF4(C16) (engineered Araneus diadematus fibroin 4 dragline silk) and ChryC1 (Chrysoperla carnea lacewing silk 1) [1,2]. These green biopolymers as well as poly(lactic acid), and poly(ethylene oxide) polymers were electro-spun as nonwoven meshes in the sub-micrometer range onto filter templates layers to evaluate relevant filter parameters such as particle deposition, air permeability, and pressure drop. The silk fiber meshes displayed a higher fine dust filter efficiency at moderate pressure drop differences compared to that made of PLA and PEO. Filters equipped with silk meshes with fiber diameters <250 nm showed improved filter qualities in comparison to that of commercially available air filter devices (with melt blown fibers in the >20 μm regime). In particular, sub-micrometer particles (0.2–1 μm) were filtered more efficiently by the silk-based filters due to interception and impaction effects yielding a low pressure drop . Moreover, filters comprising silk proteins displayed a much lower demand on fine-dust-layer material (40–210 mg m−2) in comparison to that of conventional filters (50 g m−2). Thus, the high-performance silk biopolymer filters can be employed in vacuum cleaner bags with an improved air permeability and lowered pressure drop.