Two-Dimensional Polyaniline Crystal (2DPANI) – Metallic Conductivity
By Mufaddal Shakir
1 min read
Two-Dimensional Polyaniline Crystal (2DPANI) – Metallic Conductivity
Researchers at TU Dresden and the Max Planck Institute created a 2D polyaniline crystal that conducts electricity like a metal even between its layers. This breakthrough opens doors for lightweight, metal-free organic electronics and efficient electrodes for energy and sensor applications.
Due to their exceptional electrical conductivity, conducting polymers like polyaniline, polythiophene, and polypyrrole have become popular substitutes for conventional metals and semiconductors because they are inexpensive, lightweight, and flexible. Even with great advancements, these materials mostly transmit electrons down their chains of polymers. But because the molecules don't bond strongly and the electronic interactions are weak, conductivity between the polymer strands or layers is still restricted.
Synthesis of 2D polyaniline crystal
In cooperation with international partners, a research team from TU Dresden and the Max Planck Institute of Microstructure Physics Halle has created and characterized a multilayered two-dimensional polyaniline crystal (2DPANI). "This material exhibits exceptional conductivity, not only within its layers but also vertically across the layers. This is what we call metallic out-of-plane charge transport, or 3D conduction. This is a fundamental breakthrough in polymer research," explains Thomas Heine, Chair of Theoretical Chemistry at TU Dresden.
Findings of the research
The research team synthesized the new polymer and carried out direct current transport studies. In comparison to traditional linear conducting polymers, the results demonstrated an anisotropic conductivity of 16 S/cm in-plane and 7 S/cm out-of-plane, which was around three orders of magnitude greater. Additionally, low-temperature experiments confirmed the material's remarkable metallic out-of-plane electric transport capabilities by demonstrating that out-of-plane conductivity increases as temperature falls, a behavior typical of metals. Further measurements revealed a DC conductivity of around 200 S/cm.
This discovery makes it possible for organic and polymeric materials devoid of metals to exhibit three-dimensional metallic conductivity. This creates fascinating new opportunities for sensor technologies, electronics, and electromagnetic shielding applications.