Sepiolite based catalyst supports produced by combined freeze-robocasting technique
Structurally and functionally optimized porous materials can revolutionize many applications that rely on physical and chemical interactions. In general, the design of these materials is based on implementation of functional phases with huge surface area within as small as possible volume. Nevertheless, the real-world applications require to address the issues related to effective mass flow and structural robustness too. Having this in mind, strategies to increase surface area and permeability based on hierarchical porosity distribution and implementation of mass flow oriented porosity hold a great promise. Hierarchical porosity distribution delivers high surface area, whereas mass flow oriented porosity delivers high permeability at low penalty to structural robustness. In this study sepiolite ((Mg4Si6O15(OH)2·6H2O)) based porous scaffolds were shaped using a combination of directional freeze casting and robocasting techniques. Optimization of aqueous suspension rheological parameters in combination with optimized freeze/robocasting conditions permitted to obtain structural support scaffolds with hierarchical porosity distribution, where the main mass flow is guaranteed by robust and highly porous channeled microstructure. Detailed microstructural characterization and function.