Fabrication and characterization of porous mullite ceramics derived from fluoride assisted Metakaolin Al OH 3 annealing for filtration applications

In this work, polycrystalline mullite whiskers are synthesized by fluoride assisted method from metakaolin and several aluminum containing compounds such as amp; 947; Al OH 3, AlF3 3H2O, and amp; 945; Al2O3 corundum . The mullite formation and crystallization are assessed both in ex situ and in situ synchrotron X ray diffraction experiments under synthesis conditions. Polycrystalline mullite starts to form from metakaolin, Al OH 3, and AlF3 3H2O reactants at 680 C, whereas mullite does not form even at 1000 C when corundum is used. Porous mullite ceracmics are fabricated at sintering temperatures between 1000 and 1700 C and tested for water permeance. Scanning Electron Microscopy SEM and synchrotron X ray tomography amp; 956;CT reveal that ceramics are comprised of pore channels with an interlocked network of mullite whiskers. With competitive porosity up to 63 , compressive strength up to 20 MPa , and pure water flux up to 579 L m2 h at 1 bar , fabricated mullite ceramics are promising candidates for water filtration and purificatio

Extrusion based additive manufacturing of fungal based composite materials using the tinder fungus Fomes fomentarius

Background Recent efforts in fungal biotechnology aim to develop new concepts and technologies that convert renewable plant biomass into innovative biomaterials. Hereby, plant substrates become metabolized by filamentous fungi to transform them into new fungal based materials. Current research is thus focused on both understanding and optimizing the biology and genetics underlying filamentous fungal growth and on the development of new technologies to produce customized fungal based materials. Results This manuscript reports the production of stable pastes, composed of Fomes fomentarius mycelium, alginate and water with 71 wt. mycelium in the solid content, for additive manufacturing of fungal based composite materials. After printing complex shapes, such as hollow stars with up to 39 mm in height, a combination of freeze drying and calcium crosslinking processes allowed the printed shapes to remain stable even in the presence of water. The printed objects show low bulk densities of 0.12 amp; 8201; amp; 8201;0.01 g cm3 with interconnected macropores. Conclusions This work reports for the first time the application of mycelium obtained from the tinder fungus F. fomentarius for an extrusion based additive manufacturing approach to fabricate customized light weight 3D objects. The process holds great promise for developing light weight, stable, and porous fungal based materials that could replace expanded polystyrene produced from fossil resource