Lightweight self-cleaning trans-polyisoprene/multiwalled carbon nanotubes open-cell composite material: Its electromagnetic shielding performance

Abstract

In this work, the open-cell material has been prepared by phase separation-sol-gel method, where trans-polyisoprene (TPI) is used as the raw material. Dichloromethane (DCM) has been used as a good solvent for TPI, and anhydrous ethanol as a poor solvent to achieve the phase separation. The formation of pores has been tuned and studied by adjusting the quantity of anhydrous ethanol. It has been determined that the best ratio of raw materials, good solvents and poor solvents is 1:12:1.5. On this basis, the preparation process has been improved, and an open cell superhydrophobic composite material with good electromagnetic interference shielding effectiveness (EMI SE) and self-cleaning functions has been prepared. Multiwalled carbon nanotubes (MWCNTs) filler can form an effective 3D conductive network, and the material can be regarded as a disorderly accumulation of countless petal-like TPI flake particles with 1–10 µm size, forming interconnected and scattered cells through free overlap. The structure can make the composite material rough and form a multi-scale rough surface. The prepared TPI/MWCNTs open-cell composites (TMOCs) material has a low density of 0.27 g/cm3 and a water contact angle (CA) of 153.5° (in line with super-hydrophobic characteristics) and the EMI SE can be up to 26 dB at a thickness of 5 mm and the corresponding specific EMI SE has been achieved as high as 95.6 dB/(g/cm3), which is far exceeding that of many carbon-based composite materials with similar density. This simple and inexpensive preparation process with excellent self-cleaning property and EMI SE of the materials can promote the practical application of such materials.

Keywords

• coatings
• electromagnetic interference shielding
• superhydrophobic