TY - JOUR
T1 - Sequential Dual Alignments Introduce Synergistic Effect on Hexagonal Boron Nitride Platelets for Superior Thermal Performance
AU - Chen, Yunxia
AU - Gao, Zhiming
AU - Hoo, Simon A.
AU - Tipnis, Varun
AU - Wang, Renjing
AU - Mitevski, Ivan
AU - Hitchcock, Dale
AU - Simmons, Kevin L.
AU - Sun, Ya Ping
AU - Sarntinoranont, Malisa
AU - Huang, Yong
N1 - Publisher Copyright:
© 2024 Wiley-VCH GmbH.
PY - 2024/6/20
Y1 - 2024/6/20
N2 - Planarly aligning 2D platelets is challenging due to their additional orientational freedom compared to 1D materials. This study reports a sequential dual-alignment approach, employing an extrusion-printing-induced shear force and rotating-magnetic-field-induced force couple for platelet planarly alignment in a yield-stress support bath. It is hypothesized that the partial alignment induced by a directional shear force facilitates subsequent axial rotation of the platelets for planar alignment under an external force couple, resulting in a synergistic alignment effect. This sequential dual-alignment approach achieves better planar alignment of 2D modified hexagonal boron nitride (mhBN). Specifically, the thermal conductivity of the 40 wt% mhBN/epoxy composite is significantly higher (692%) than that of unaligned composites, surpassing the cumulative effect of individual methods (only 133%) with a 5 times more synergistic effect. For 30, 40, and 50 wt% mhBN composites, the thermal conductivity values (5.9, 9.5, and 13.8 W m−1 K−1) show considerable improvement compared to the previously reported highest values (5.3, 6.6, and 8.6 W m−1 K−1). Additionally, a 3D mhBN/epoxy heat sink is printed and evaluated to demonstrate the feasibility of device fabrication. The approach enables the planar alignment of electrically or thermally conducting 2D fillers during 3D fabrication.
AB - Planarly aligning 2D platelets is challenging due to their additional orientational freedom compared to 1D materials. This study reports a sequential dual-alignment approach, employing an extrusion-printing-induced shear force and rotating-magnetic-field-induced force couple for platelet planarly alignment in a yield-stress support bath. It is hypothesized that the partial alignment induced by a directional shear force facilitates subsequent axial rotation of the platelets for planar alignment under an external force couple, resulting in a synergistic alignment effect. This sequential dual-alignment approach achieves better planar alignment of 2D modified hexagonal boron nitride (mhBN). Specifically, the thermal conductivity of the 40 wt% mhBN/epoxy composite is significantly higher (692%) than that of unaligned composites, surpassing the cumulative effect of individual methods (only 133%) with a 5 times more synergistic effect. For 30, 40, and 50 wt% mhBN composites, the thermal conductivity values (5.9, 9.5, and 13.8 W m−1 K−1) show considerable improvement compared to the previously reported highest values (5.3, 6.6, and 8.6 W m−1 K−1). Additionally, a 3D mhBN/epoxy heat sink is printed and evaluated to demonstrate the feasibility of device fabrication. The approach enables the planar alignment of electrically or thermally conducting 2D fillers during 3D fabrication.
KW - 3D embedded printing
KW - dual alignments
KW - hexagonal boron nitride
KW - synergistic effect
KW - yield-stress support bath
UR - http://www.scopus.com/inward/record.url?scp=85188150605&partnerID=8YFLogxK
U2 - 10.1002/adma.202314097
DO - 10.1002/adma.202314097
M3 - Article
AN - SCOPUS:85188150605
SN - 0935-9648
VL - 36
JO - Advanced Materials
JF - Advanced Materials
IS - 25
M1 - 2314097
ER -