Title
Coupled chiral structure in graphene-based film for ultrahigh thermal conductivity both in-plane and through-plane directions
Author
Xin Meng, Hui Pan, Chengling Zhu, Zhixin Chen, Tao Lu, Da Xu, Yao Li, Shenmin Zhu
Year
2018
Journal
ACS Applied Materials & Interfaces
Abstract
The development of high performance thermal management materials to dissipate excessive heat both in-plane and through–plane is of special interest, to maintain efficient operation and prolong the life of electronic devices. Herein, we designed and constructed a graphene-based composite film which contains chiral liquid crystals (cellulose nanocrystals, CNCs) inside graphene oxide (GO). The composite film was prepared by annealing and compacting of self-assembled GO-CNC which contains chiral smectic liquid crystal structures. The helical arranged nanorods of carbonized CNC acts as in-plane connections which bridge neighboring graphene sheets. More interestingly, the chiral structures also act as through plane connections which bridge the upper and lower graphene layers. As a result, the graphene-based composite film shows extraordinary thermal conductivity, both in-plane (1820.4 W·m-1·K-1) and through-plane (4.596 W·m-1·K-1) directions. As a thermal management material, the heat dissipation and transportation behaviors of the composite film were investigated using a self-heating system and the results showed that the real-time temperature of the heater covered with the film was 44.5 C lower than a naked heater. The prepared film shows a much higher efficiency of heat transportation than that of the common-used thermal conductive Cu foil. Additionally, this graphene-based composite film exhibits the excellent mechanical strength of 31.6 MPa, and the electrical conductivity of 667.4 S·cm-1. The strategy reported here may open a new avenue to the development of high performance thermal management films.
Full Article
Instrument
J-815
Keywords
Circular dichroism, Nanostructures, Materials