Affiliation:
1. Technische Universität Berlin Faculty III Process Sciences Institute of Materials Science and Technologies Fachgebiet Werkstofftechnik/Chair of Materials Science & Engineering Straße des 17. Juni 135 10623 Berlin Germany
2. Technische Universität Berlin Faculty III Process Sciences Institute of Materials Science and Technologies Fachgebiet Keramische Werkstoffe/Chair of Advanced Ceramic Materials Straße des 17. Juni 135 10623 Berlin Germany
3. Technische Universität Berlin Faculty III Process Sciences Institute of Materials Science and Technologies Fachgebiet Polymerwerkstoffe und ‐technologien/Chair of Polymer Materials and Technologies Ernst‐Reuter‐Platz 1 10587 Berlin Germany
4. Berliner Hochschule für Technik Fachbereich II Mathematics‐Physics‐Chemistry Luxemburger Str. 10 13353 Berlin Germany
Abstract
AbstractBioinspired, graded structures with hierarchical porosity, combining high surface area with low density, are attractive for a wide range of applications. Local adaptation of properties makes it possible to fine‐tune their strength and degradation kinetics over time. Production of such structures is, however, still scientifically and technically challenging. A versatile approach for fabricating hierarchical, porous structures from water‐glass (WG), exploiting its inherent foaming ability in conjunction with robocasting, for applications such as, bone‐replacement scaffolds, is presented. The unique processing route that is proposed uses a purely inorganic, mouldable sodium silicate hydrogel based on WG as ink for robocasting, which makes it cost‐effective and highly environmentally friendly. The WG‐based hydrogels can be used in a pure state, and also as carrier systems, e.g., for tricalcium phosphate. Following heat treatment at a relatively low temperature of 450 °C, the robocast parts develop hierarchical porosities. Multi‐microscale porosity is created due to foaming during heating, in addition to the macroscale porosity designed during robocasting. The suggested process opens up a powerful alternative to fabrication routes presently available for hierarchically porous structures.
Subject
Electrochemistry,Condensed Matter Physics,Biomaterials,Electronic, Optical and Magnetic Materials