Isolated Mesoporous Microstructures Prepared by Stress Localization-Induced Crack Manipulation.
Cracks observed in brittle materials are mostly regarded as defects or failures. However, they can be a valuable tool when implemented in a controlled way. Here, we introduce a strategy to control the crack propagation of mesoporous micropatterns (prisms and pyramids), which leads to the isolation of well-defined microstructures. Mesoporous micropatterns were fabricated by the soft imprinting technique with wet TiO2nanoparticle (NP) pastes, followed by sintering to remove organic components. Since the volume of the paste significantly shrinks during the sintering step, stress is localized at the edge of micropatterns, in good agreement with finite element method simulations, creating well-defined cracks and their propagation. It was demonstrated that the degree of stress localization is determined by the thickness of residual layers, NP size, and heating rate. After controlled crack propagation and delamination of microparticles from the substrates, mesoporous microwires and microparticles were successfully produced and functionalized from the isolated mesoporous prisms and pyramids. The method proposed in this study for controlled crack manipulation and delamination opens a door for straightforward and economical fabrication of well-defined mesoporous microparticles.
The National Creative Research Initiative Center for Intelligent Hybrids, The World Class University Program for Chemical Convergence for Energy and Environment, School of Chemical and Biological Engineering, Seoul National University , Seoul 08826, Republic of Korea.
Sanghyuk
S
Wooh
The National Creative Research Initiative Center for Intelligent Hybrids, The World Class University Program for Chemical Convergence for Energy and Environment, School of Chemical and Biological Engineering, Seoul National University , Seoul 08826, Republic of Korea.
Soojin
S
Lee
The National Creative Research Initiative Center for Intelligent Hybrids, The World Class University Program for Chemical Convergence for Energy and Environment, School of Chemical and Biological Engineering, Seoul National University , Seoul 08826, Republic of Korea.
Yunchan
Y
Lee
School of Chemical and Biological Engineering, Seoul National University , Seoul 08826, Republic of Korea.
Ji Ho
JH
Ryu
School of Chemical and Biological Engineering, Seoul National University , Seoul 08826, Republic of Korea.
Won Bo
WB
Lee
Department of Chemical and Biomolecular Engineering, Seoul National University of Science & Technology , Seoul 01811, Republic of Korea.
Hyunsik
H
Yoon
The National Creative Research Initiative Center for Intelligent Hybrids, The World Class University Program for Chemical Convergence for Energy and Environment, School of Chemical and Biological Engineering, Seoul National University , Seoul 08826, Republic of Korea.
Kookheon
K
Char
crack manipulation; delamination; mesoporous prism(s); mesoporous pyramid(s); soft lithography; stress localization