title: Highly Flexible and Self-Healable Thermal Interface Material Based on Boron Nitride Nanosheets and a Dual Cross-Linked Hydrogel.
abstract: The booming growth of flexible and stretchable electronic devices with increasing power and multifunctionalities calls for novel highly efficient thermal interface materials (TIMs) with versatile functions, such as high deformability and self-healing ability, whereas traditional metallic-based or grease-based ones could hardly provide. Herein, we report a highly flexible and self-healable dual-cross-linked hydrogel-based nanocomposite filled with hexagonal boron nitride (h-BN) nanosheets fabricated by in situ polymerization of acrylic acid (AA). The thermal conductivity of the composites can be tuned by adjusting both fraction of BNNSs and water content. Although a solid, the highly flexible characteristic of the developed TIMs enables a perfect ability to replicate the texture of a rough surface, which may greatly enhance thermal transfer between adjacent surfaces. By increasing the water content to soften the material, it can be recycled and reused for different kinds of rough surface. In addition, benefiting from the dual-cross-linked structure, the composites are capable of recovering both mechanical strength and thermal conductivity even from severe structural breakdowns, for example, three consecutive cutting and healing cycles. This study may pave the way to fabrication of multifunctional highly flexible TIMs, which may promote the development of heat dissipation materials.
authors.affiliation: Department of Physics and Materials Science, City University of Hong Kong , 83 Tat Chee Avenue, Hong Kong SAR, China.
authors.forename: Hongbo
authors.identifier: http://orcid.org/0000-0001-6436-8312
authors.initials: H
authors.lastname: Jiang
authors.affiliation: Department of Physics and Materials Science, City University of Hong Kong , 83 Tat Chee Avenue, Hong Kong SAR, China.
authors.forename: Zifeng
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Department of Physics and Materials Science, City University of Hong Kong , 83 Tat Chee Avenue, Hong Kong SAR, China.
authors.forename: Huiyuan
authors.initials: H
authors.lastname: Geng
authors.affiliation: Department of Physics and Materials Science, City University of Hong Kong , 83 Tat Chee Avenue, Hong Kong SAR, China.
authors.forename: Xiufeng
authors.initials: X
authors.lastname: Song
authors.affiliation: Department of Physics and Materials Science, City University of Hong Kong , 83 Tat Chee Avenue, Hong Kong SAR, China.
authors.forename: Haibo
authors.identifier: http://orcid.org/0000-0002-0281-3617
authors.initials: H
authors.lastname: Zeng
authors.affiliation: Department of Physics and Materials Science, City University of Hong Kong , 83 Tat Chee Avenue, Hong Kong SAR, China.
authors.forename: Chunyi
authors.identifier: http://orcid.org/0000-0001-6766-5953
authors.initials: C
authors.lastname: Zhi
keywords: boron nitride nanosheets; hydrogel; self-healing; thermal conductivity; thermal interface materials