The targeted storage of substances and the demand-driven release is of interest for many applications. A bio-based and fully biodegradable storage material could replace non-regenerative materials, which are currently in use. One material that can accomplish these requirements are so-called hemp shives, the wood-like pulp of the useful hemp stem, which accrues after the hemp fiber has been removed by machine. Due to their composition and highly porous microstructure, the shives can absorb multiple of their own weight in water. This property makes them an excellent reversible absorber and transport material for water and for the constituents of aqueous solutions.
Objectives and project plan
The aim of HanAkku is to load the hemp shives with chemical substances specifically for the respective application, and to release the absorbed substances again in a controlled manner during use. The use of hemp, one of the oldest crops in Europe, which can be cultivated without fungicides, herbicides and insecticides, is to be expanded to include new technical applications.
Technological leaps are worked out for HanAkku materials through the following possible uses:
• Water transport/energy storage: HanAkkuHP (HP = hydrophilic)
• Loading and use as fertilizer: HanAkkuIO (IO = loading with ultimately ionic materials)
• Loading with active ingredients (plant breeding): HanAkkuOP (OP = loading with hydrophobic (oleophilic molecules)
The functionalization of the hemp shives for tailor-made loading is achieved through modification with cheap bio-based raw materials. Hemp shives are not food and unlike other porous materials, are not produced by an energy-intensive or complex method using synthetic chemical processes. As an tailor-made alternative to bio-based fertilizers or synthetic fertilizers that contain accumulating and environmentally harmful chemical compounds such as binders made of styrene-butadiene or isocyanate-based coatings in the case of (long-term) fertilizers, HanAkku materials do not need any such synthetic solutions. The possibility of using them to develop materials for crop protection that are 100 percent bio-based/bio-compatible and biodegradable would mean a new generation of ecological functional materials for agriculture.