ORS7-1554
Hierarchical Engineering of SWCNT/Conjugated Polymer Composites for Flexible EMI Shielding: Doping, Crosslinking, and Impedance Modulation
Topic
S7. Innovations in Polymeric Composites: From Design and Processing to Industrial Applications
When and Where
Sep 29, 2026
16:15 - 16:30
Room 107
Session Chairs
Jin MIYAWAKI
Presenter(s)
Minseon Kim (Konkuk University)
Co-Author(s)
Abstract
Flexible electromagnetic interference (EMI) shielding materials increasingly require a combination of high electrical conductivity, mechanical durability, and effective wave attenuation. Here, we report hierarchical engineering of single-walled carbon nanotube (SWCNT)/conjugated polymer (CP) composites through molecular doping, covalent crosslinking, and impedance modulation. CP wrapping enabled uniform SWCNT networks and robust free-standing films with a Young’s modulus above 13 GPa and tensile strength above 96 MPa. Comparison of F4TCNQ and AuCl₃ showed that dopant-dependent charge generation governed conductivity, dielectric loss, and shielding behavior. The optimized 50 wt% SWCNT composite exhibited an electrical conductivity above 5000 S·cm⁻¹, EMI shielding effectiveness (SE) above 75 dB in the X-band, and stable performance after 300,000 folding cycles at a 3 mm bending radius.
Sequential azide-based crosslinking followed by AuCl₃ doping reinforced SWCNT/CP hybrid-fiber junctions, improved load transfer, and reduced junction resistance, increasing Young’s modulus and tensile strength by 37.6% and 40.8%, respectively. The crosslinked composite maintained shielding performance after 50,000 folding cycles under severe bending with a radius of 1 mm.
To achieve absorption-dominant shielding, a magnetic carbonyl iron particle/polyurethane layer was combined with an AuCl₃-doped SWCNT/PBTTT layer. The magnetic layer modulated the input impedance, reducing reflectance and increasing absorptance while retaining the high SE of the SWCNT layer. The bilayer coating suppressed radiated emissions from an electric-vehicle on-board charger, with performance comparable to aluminum housing.
Overall, this work establishes a hierarchical design framework that integrates charge transport control, network reinforcement, and impedance modulation to achieve highly conductive, mechanically robust, and absorption-dominant flexible EMI shielding materials.
Sequential azide-based crosslinking followed by AuCl₃ doping reinforced SWCNT/CP hybrid-fiber junctions, improved load transfer, and reduced junction resistance, increasing Young’s modulus and tensile strength by 37.6% and 40.8%, respectively. The crosslinked composite maintained shielding performance after 50,000 folding cycles under severe bending with a radius of 1 mm.
To achieve absorption-dominant shielding, a magnetic carbonyl iron particle/polyurethane layer was combined with an AuCl₃-doped SWCNT/PBTTT layer. The magnetic layer modulated the input impedance, reducing reflectance and increasing absorptance while retaining the high SE of the SWCNT layer. The bilayer coating suppressed radiated emissions from an electric-vehicle on-board charger, with performance comparable to aluminum housing.
Overall, this work establishes a hierarchical design framework that integrates charge transport control, network reinforcement, and impedance modulation to achieve highly conductive, mechanically robust, and absorption-dominant flexible EMI shielding materials.
