Bionic Engineering Strategy for Preparing Flexible Carbon Paper From Waste Polypropylene: Excellent Electromagnetic...

Area of Science:

• Materials Science
• Nanotechnology
• Sustainable Chemistry

Background:

• Flexible paper-based carbon materials are crucial for electromagnetic interference (EMI) shielding applications.
• Developing cost-effective and high-performance EMI shielding materials from recycled resources is a significant challenge.

Purpose of the Study:

• To create an economical and multifunctional polypropylene-based flexible carbon paper (PP-CP) using recycled polypropylene (rPP) and waste pre-oxidized fibers.
• To investigate the structure-property relationships for advanced EMI shielding and other functionalities.

Main Methods:

• Preparation of PP-CP via a liquid phase sulfonation process, utilizing the "heterogeneous swelling" effect of the PP matrix.
• Construction of an interpenetrating network structure from PP-derived carbon and short-cut carbon fibers (SCF).
• Characterization of the material's electrical conductivity, EMI shielding effectiveness (EMI SE), joule heating, hydrophobicity, and breathability.

Main Results:

• A synergistic 3D conductive network was formed by SCF and PP-derived microcracks, achieving high electrical conductivity (7735 S m⁻¹).
• The PP-CP exhibited a maximum EMI shielding effectiveness of 58.8 dB and a specific SE (SSE/t) of 6642 dB·cm²/g in the X-band.
• The material demonstrated excellent joule heating, hydrophobicity, and breathability.

Conclusions:

• The developed PP-CP offers superior multifunctional integration, meeting the demands of next-generation wearable electronic devices.
• This study presents a sustainable approach for utilizing PP and carbon fiber waste, paving the way for resource circularity.