Printable carbon nanotube superplastics for thermal management.

While plastics are integral to modern life, their limitations in mechanical, thermal, and electrical properties hinder their use in advanced applications, particularly thermal management. We have developed a scalable in-situ nanotube-polymer fusion and hot-working process for mass-producing carbon nanotube superplastics (CNTSPs) designed to overcome these limitations. By integrating up to 59 wt% CNTs and inducing spontaneous fusion with polymer molecules while retaining the original long CNT length, we achieve enhanced CNT alignment and packing density. This unique structure yields CNTSPs with exceptional thermal performance: a high thermal conductivity (143 ± 5.8 W m-1 K-1) and a highly directional heat transfer, evidenced by a thermal conductivity anisotropy ratio of ∼123, which is crucial for efficient electronic device cooling when the heat sink is located at opposite ends of the device. Additionally, these CNTSPs exhibit high mechanical strength (663 ± 18 MPa) and electrical conductivity (8.6 × 104 S m-1). We demonstrate the ability to shape CNTSPs into various objects by three-dimensional printing and hot pressing. This progression provides a scalable approach for mass production of superplastics combining the core advantages of CNTs with the processability of conventional plastics.