CNT/Copolymer Hybrid Interphase Dramatically Enhances Thermal Conductivity and Mechanical Strength in Carbon Fiber Composites

July 12, 2026

Thermo-X International

Overview

A new study demonstrates a significant simultaneous improvement in thermal conductivity and mechanical strength of carbon fiber (CF)/epoxy composites by coating CF with a CNT/copolymer hybrid interphase. The resulting CF@(CNT/P)/epoxy composites showed a 32.4% increase in interlaminar shear strength and a 46.2% increase in flexural strength, alongside improved in-plane and out-of-plane thermal conductivities. Furthermore, an electromagnetic shielding effectiveness of 38.6 dB was achieved, paving the way for broad applications in high-power electronic information systems.

In Depth

Key Findings

A novel approach has been developed that revolutionize the performance of carbon fiber (CF)/epoxy composites. By coating carbon fibers with a carbon nanotube (CNT)/copolymer hybrid interphase, researchers have demonstrated a significant simultaneous enhancement in both the thermal conductivity and mechanical strength of the composite material. This innovative CF@(CNT/P)/epoxy composite not only achieved a 32.4% increase in interlaminar shear strength (ILSS) and a 46.2% increase in flexural strength but also exhibited excellent electromagnetic shielding effectiveness.

Technical / Measurement Details

The research team first created a specific hybrid layer of CNTs and a copolymer on the surface of carbon fibers. This interphase layer is crucial not only for improving adhesion between the CF and the epoxy matrix but also for effectively transferring the superior thermal and electrical properties of CNTs throughout the composite material. Specifically, this CNT/copolymer hybrid layer enhances the composite’s performance in the following aspects:

Improved Mechanical Strength: A 32.4% increase in interlaminar shear strength improves resistance against delamination, while a 46.2% increase in flexural strength significantly enhances the material’s rigidity and fracture toughness.
Enhanced Thermal Conductivity: Leveraging the high thermal conductivity of CNTs, both in-plane and out-of-plane thermal conductivities of the composite are improved. This is critical for heat dissipation and thermal management in high-power electronic devices.
Electromagnetic Shielding Effectiveness: A high electromagnetic shielding effectiveness of 38.6 dB was demonstrated, which is highly effective for blocking external electromagnetic interference and preventing malfunctions in internal electronic equipment.

These properties indicate that the CNT/copolymer interphase acts not merely as an adhesive but as a “smart layer” that enhances the overall functionality of the composite material.

Background & Context

Industries such as aerospace, automotive, and electronics constantly demand lightweight, high-strength, and multifunctional composite materials. Particularly, thermal management and electromagnetic compatibility (EMC) are critical challenges influencing the reliability and performance of electronic information systems, which are increasingly dense and high-power. While traditional carbon fiber reinforced plastics (CFRPs) excel in lightweight and high strength, they have limitations in thermal conductivity and electromagnetic shielding performance. CNTs, with their high aspect ratio and excellent electrical and thermal properties, have been investigated as promising nanomaterials to address these issues. However, uniform dispersion within the composite and good interfacial bonding with the matrix have been major barriers to commercialization. The development of this CNT/copolymer hybrid interphase offers an innovative solution to overcome these challenges.

Strategic Significance & Outlook

This CF@(CNT/P)/epoxy composite technology is expected to find broad applications in fields requiring advanced thermal management and electromagnetic shielding, such as high-power electronic information systems, advanced aerospace structures, and lightweight components for next-generation EVs. The ability to simultaneously enhance thermal conductivity, mechanical strength, and electromagnetic shielding effectiveness enables multifunctionality previously difficult to achieve with conventional materials. Future efforts will focus on validating the scalability of the material manufacturing process, assessing long-term durability, and conducting tests for integration into specific products. If commercialized, this technology could establish new standards for the design and manufacturing of high-performance composite materials, contributing to the advancement of various cutting-edge industries.

Source: https://www.researchgate.net/publication/408489097_Simultaneously_improving_thermal_conductivities_and_mechanical_strength_of_carbon_fibersepoxy_composites_via_CNTcopolymer_hybrid_interphase

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