Fabrication of Graphite/Hydroxyethyl Cellulose (HEC)/Silicone Gel Composites with Aligned Structure for Electromagnetic Interference Shielding and Thermal Management

Abstract

Nowadays, materials with both excellent thermal management properties and electromagnetic interference (EMI) shielding properties have more and more practical application scenarios and are gaining widespread attention. Herein, the composite with both excellent EMI shielding properties and high thermal management properties was successfully prepared by mixing graphite flakes with hydroxyethyl cellulose solution using a convenient and effective freeze-casting method, freeze-drying and then the liquid silicone gel was casted into the aligned Graphite/hydroxyethyl cellulose (HEC) skeleton with vacuum assisted permeation method. The composites with a loading of 18.2 vol% graphite have a high thermal conductivity of 2.66 W m <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> k <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> in the vertical direction In addition, its EMI shielding effectiveness (SE) is up to 48 dB in the horizontal direction and 25 dB in the vertical direction in the frequency band range of 8.2-12.4 GHz. Such composite is a promising and potential material for thermal management and electromagnetic shielding due to its excellent properties.