3D Printable and Sub‐Micrometer Porous Polymeric Monoliths with Shape Reconfiguration Ability by Miniemulsion Templating

Abstract

Porous monoliths prepared by high internal phase emulsion (HIPE)templating have received various attentions in the fields of catalysis, separation, and tissue engineering. However, the application of the monoliths from HIPE is limited by their poor mechanical performance and the difficulty of fabricating hierarchically porous structures. Additive manufacturing is an emerging technique that achieves high design freedom by depositing materials layer-by-layer. This work designs medium internal phase emulsion (MIPE) ink with the concept of miniemulsion to prepare 3D printable porous polymeric monoliths with sub-micrometer pores. High shear energy is used to reduce the droplet size of the internal phase and jam the emulsion ink. The jammed MIPE ink shows prominent shear-thinning behavior and appropriate elastic modulus for direct ink writing (DIW). After printing, the external phase composed of stearyl acrylate and hexanediol diacrylate can be cured by photopolymerization to produce poly(MIPE) with interconnected pores in the size of several hundred nanometers. The printed poly(MIPE) demonstrates high mechanical strength and can be reprogrammed into complex geometries difficult for the common DIW processes. The proposed technique provides a new route to fabricate hierarchically porous monoliths with a drastic change of pore dimension, high mechanical strength, and tunable shape reconfiguration.

Thermally Induced Gelation of Cellulose Nanocrystals in Deep Eutectic Solvents for 3D Printable and Self-Healable Ionogels

“…The ink should also have a high storage modulus and yield stress during printing, so the printed materials can be stacked successfully and even span unsupported areas. Several strategies, such as F127-based micelles, jamming, and colloidal suspension, have been investigated to achieve the unique rheological properties required for DIW. Interestingly, the physically percolated networks of colloidal gels can further add new functionality and mechanical reinforcement to printed objects …”

Direct Ink Writing of Pickering Emulsions Generates Ultralight Conducting Polymer Foams with Hierarchical Structure and Multifunctionality

“…[27][28][29] The precise control over the macroscopic architecture inherent in the 3D printing techniques can be integrated with tailored bottom-up approaches to elaborating bioinspired porous structures across multiple length scales. [30] Among 3D printing techniques, direct ink writing (DIW) based on the extrusion of shear-thinning inks can lead to complex structures composed of various materials.. [27,[31][32][33] DIW of Pickering emulsions [34][35][36][37][38] or particle-stabilized foams [35,[39][40][41][42][43] has been deemed as a viable approach to developing lightweight 3D printed items with hierarchical pores and remarkable mechanical efficiency. The inks featured by sufficiently high storage moduli and yield stresses are required to fulfill the rheological demand.…”