Jeonbuk National University Innovates Advanced Composites for Electronics

In a significant advancement, researchers from Jeonbuk National University in South Korea have pioneered new fabrication methods and predictive models for segregated conductive polymer composites (S-CPCs), aiming to enhance the performance of modern wearable and portable electronic devices. With the increasing integration of high-performance components and wireless technologies in these devices, mitigating challenges such as electromagnetic interference (EMI) and heat accumulation has become crucial. The findings have been published in Advanced Composites and Hybrid Materials, and highlight the potential of these materials in revolutionizing electronic device reliability.

The demand for materials that can effectively manage electrical interference and heat dissipation is on the rise, as overheating can severely impact device functionality and lifespan. S-CPCs represent a promising solution, utilizing a unique three-dimensional structure, where conductive fillers are strategically concentrated along polymer boundaries. This design allows these composites to maintain significant electrical and thermal conductivity even with minimal filler use.

However, practical applications of S-CPCs have faced limitations due to challenges in fabrication and existing theoretical models that fail to fully account for their unique internal structures. Recognizing this gap, Professor Seong Yun Kim, along with his research team from the Department of Organic Materials and Fiber Engineering, devised an innovative fabrication strategy to address the problem of micro-void formation during production.

The research team blended polypropylene (PP) — which has a melting point of 150 °C — with a lower-melting PP terpolymer (130 °C) to alleviate the development of micro-voids. By carefully balancing the quantities of these polymers, the team established an effective processing strategy that minimizes void formation while enhancing the electrical and thermal properties of the composites. In their experiments, two types of S-CPCs were developed: one incorporating graphitic nanoplatelets (GNPs) and the other using hexagonal boron nitride (h-BN). GNPs are known for their excellent conductivity, while h-BN is highly regarded for its insulation properties alongside good thermal conductivity.

Utilizing micro-computed tomography (μ-CT), the internal structures of the composites were examined, leading to the identification of important factors influencing performance, such as excluded volume — regions inaccessible to fillers — and the presence of micro-voids. The optimal formulation achieved demonstrated a remarkable increase in the amount of filler incorporated, with G-SCs achieving a filler enhancement of 4.93% and B-SCs hitting 12.15%. Consequently, G-SCs exhibited pervasive improvements with electrical conductivity soaring by 124.07% and thermal conductivity rising by 68.11%. Meanwhile, B-SCs displayed a noteworthy 53.54% improvement in thermal conductivity.

An essential contribution of this research is the new segregated percolation models developed by the team, merging excluded volume and micro-void effects with existing percolation theory. These new models accurately predict the conductivity of the composites, aligning closely with experimental findings and providing a robust framework for future material design.

Professor Kim concluded, “The materials we have developed can serve as immediate solutions for next-generation EMI shielding and thermal management, while our modeling approaches will foster the design of customized advanced materials across various industries.” This comprehensive strategy encapsulates both structural optimization and theoretical innovation, signaling a new era for conductive polymer composites tailored for future advancements in electronic and energy systems.

For further reference, readers can consult the original paper titled Advanced percolation models incorporating excluded volume effects in segregated composites via nano-interconnection and micro-void structure optimization in Advanced Composites and Hybrid Materials.

Conclusion

In summary, the ongoing research at Jeonbuk National University not only enhances the physics of material design but also paves the way for innovative engineering solutions that can effectively address the challenges faced by modern electronic devices. By merging theoretical insights with practical fabrication techniques, the implications of this work could resonate across multiple sectors, marking a progressive leap toward enhanced materials efficiency and performance in technology today.