Mechano-Plastic Pyrolysis of Dynamic Covalent Polymer Network toward Hierarchical 3D Ceramics
Ning Zheng1, Jingjing Hou1, Hangbo Zhao2
1State Key Laboratory of Chemical Engineering, College of Chemical and Biological Engineering, Zhejiang University, 38 Zheda Road, Hangzhou, 310027, P. R. China.
Abstract:
Shaping ceramics into complex 3D geometries is desirable yet challenging, particularly those with structural hierarchy spanning different length scales. A mechano-plastic pyrolysis process that overcomes this limitation is reported. In addition to taking advantage of the moldability of organic polymers, the process uniquely incorporates mechano-plasticity via dynamic covalent bond exchange for reconfiguring the shape of a preceramic polymer. The combined steps result in simultaneous shape control at both micro- and macro-scales. Further pyrolysis leads to complex ceramic structures that are otherwise difficult to produce. To enable this process, rational design of the polymer network is required to satisfy an unusual combination of mechano-plasticity and pyrolysis. Overall, the process offers an avenue for efficient fabrication of hierarchical 3D ceramic structures suitable for engineering applications.
Related Concept Videos
Network Covalent Solids
To break or to melt a covalent network solid, covalent bonds must be broken. Because covalent bonds are relatively strong, covalent network solids are typically...
Polymers
Covalent Bonds
Covalent Bonds
When two atoms share electrons to complete their valence shells, they create a covalent bond. An atom's electronegativity—the force with which shared electrons are pulled towards an atom—determines how the electrons are shared. Molecules formed with covalent bonds can be either polar or nonpolar. Atoms with similar electronegativities form nonpolar covalent bonds; the electrons are shared equally. Atoms with different electronegativities share electrons unequally,...
Covalently Linked Protein Regulators
These groups modify specific amino acids in a protein....
Covalent Bonding and Lewis Structures


