A general strategy for vertically aligned heterostructures: Liquid metal-dominated thermal conduction enabled by talc nanosheet encapsulation

One-step chlorosulfuric acid-H 2 O 2 intercalation for talc exfoliation & hydroxylation. • A strategy of “surface modification − solution-phase self-assembly − oriented compression”. • LTC exhibits an out-of-plane thermal conductivity of 14.356 W·m −1 ·K −1 . • Expands the application of low-cost talc in TIMs. The miniaturization and high integration of microelectronic devices demand thermal interface materials (TIMs) with both high thermal conductivity and electrical insulation. Although abundant and low-cost, talc exhibits intrinsically low thermal conductivity (∼2.5  W·m −1 ·K −1 ), limiting its thermal management applications. Here we propose a tailored design strategy: using exfoliated talc nanosheets (TNS) as a 2D encapsulating scaffold for liquid metal (LM) to construct vertically oriented LM-dominated thermal pathways. Hydroxylated TNS were first prepared via a one-step chlorosulfonic acid/H 2 O 2 method. Thiomalic acid was used as a bifunctional molecular bridge to uniformly anchor LM droplets onto TNS. Subsequent pressure-induced alignment preferentially orients TNS along the vertical direction, resulting in preferentially vertically aligned liquid metal networks. Despite talc’s low intrinsic conductivity, the resulting LM/TNS@CR (LTC) composite achieves an out-of-plane thermal conductivity of 14.356 ± 0.147  W·m −1 ·K −1 while maintaining excellent electrical insulation. This work not only utilizes low‑cost talc for the fabrication of thermal management materials, but also establishes a viable design framework: using vertically oriented liquid metal networks as the primary heat‑transport channels and employing exfoliable layered mineral hosts as encapsulating scaffolds, thereby achieving high thermal conductivity, electrical safety, and leakage suppression. Exfoliation of Talc and Construction of a 2D Material Heterostructure with High Through‑Plane Thermal Conductivity. Download: Download high-res image (177KB) Download: Download full-size image