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Direct ink writing of hierarchical porous alumina‐stabilized emulsions: Rheology and printability
Author(s) -
Chan Shareen S. L.,
Sesso Mitchell L.,
Franks George V.
Publication year - 2020
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/jace.17305
Subject(s) - materials science , porosity , rheology , composite material , extrusion , scanning electron microscope , emulsion , ceramic , particle size , modulus , chemical engineering , engineering
Abstract Bio‐inspired multi‐scaled (hierarchical) porous structures have remarkable strength and stiffness‐to‐density properties. Direct ink writing (DIW) or robocasting, an additive manufacturing (or also commonly known as 3D printing) material extrusion technique is able to create near‐net‐shaped complex geometries. A new approach of combining DIW, colloidal particle‐stabilized emulsion paste inks and partial densification to create tailored architectures of hierarchical porosity on three scales has been demonstrated. The printed and sintered ceramic lattice structures possess relatively high overall porosity of 78.7% (on average), comprising mainly (64.7%) open porosity. The effects of formulation (surfactant and oil concentrations, solids particle size, and mixing speed) on rheology and pore size and morphology have been investigated. The rheological properties (storage modulus, yield stress, and recovery of storage modulus) of the emulsions have been found to delineate the samples with good shape retention from those that slump. Additionally, the internal features of the sintered structures have been analyzed via X‐ray tomography and scanning electron microscope. The role of emulsion stability on printability and the internal structure of the prints has been investigated.