Enhancement of Dielectric Permittivity of Ti3C2Tx MXene/Polymer Composites by Controlling Flake Size and Surface Termination
AuthorsTu, Shao Bo
Hedhili, Mohamed N.
Alshareef, Husam N.
KAUST DepartmentFunctional Nanomaterials and Devices Research Group
Material Science and Engineering Program
Physical Science and Engineering (PSE) Division
Embargo End Date2020-07-15
Permanent link to this recordhttp://hdl.handle.net/10754/656181
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AbstractWe report a strong effect of the MXene flake size and surface termination on the dielectric permittivity of MXene polymer composites. Specifically, poly(vinylidene fluoride-trifluoro-ethylene-chlorofluoroehylene) or P(VDF-TrFE-CFE) polymer embedded with large (ca. 4.5 μm) Ti3C2Tx flakes achieves a dielectric permittivity as high as 105 near the percolation limit of 15.3 wt % MXene loading. In comparison, the dielectric permittivity of MXene/P(VDF-TrFE-CFE) using small (ca. 1.5 μm) Ti3C2Tx flakes (S-MXene) achieves a dielectric permittivity of 104 near the percolation limit of 16.8 wt %. Meanwhile, increasing the concentration of surface functional groups on the MXene surface (−O, −F, and −OH) by extending the etching time gives a dielectric constant of 2204 near the percolation limit of 15.7 wt %. The ratio of permittivity to the loss factor of our large flake composite is superior to that of the small flake composite, and to all previously reported carbon-based fillers in P(VDF-TrFE-CFE). We show that the dielectric permittivity enhancement is strongly related to the charge accumulation at the surfaces between the two dimensional (2D) MXene flakes and the polymer matrix under an external applied electric field.
SponsorsResearch reported in this publication is supported by King Abdullah University of Science and Technology (KAUST). The TEM analysis was individually completed by J.Z. The authors would like to thank Chenhui Zhang and Dr. Fei Xue for their helpful discussion, and the Advanced Nanofabrication, Imaging, and Characterization Laboratory at KAUST for their excellent assistance.
PublisherAmerican Chemical Society (ACS)