"100% Electromagnetic Wave Absorption"... Next-Generation Material 'Maxine' Rapidly Approaching Practical Use

Domestic Research Teams Including KAIST Succeed in 'Vertically Standing' by Applying Electric Field
Centimeter-Scale Large-Area Production Possible, Advantageous for Automated Processes

[Asia Economy Reporter Kim Bong-su] Domestic researchers have developed a technology that could accelerate the commercialization of the next-generation new material "MXene," known for its ability to absorb and shield electromagnetic waves, thereby maximizing the material for high-capacity batteries and stealth capabilities.

The Korea Advanced Institute of Science and Technology (KAIST) announced on the 11th that Professor Dongki Yoon's chemistry team, together with Dr. Seonjun Kim from the Korea Institute of Science and Technology (KIST), Professor Jongmin Koo from Sungkyunkwan University, and Professor Yoonchan Kang from Korea University, succeeded for the first time in the world in vertically standing and aligning the next-generation new material MXene, which can shield and absorb electromagnetic waves, in a single direction.

People say it is impossible to stand a single sheet or multiple sheets of paper vertically on a flat floor because they are thin and flexible. The joint research team of Dongki Yoon and Seonjun Kim developed a technology that can vertically and linearly align MXene nanosheets, which are thinner and more flexible than one ten-thousandth the thickness of ordinary paper.

MXene is a two-dimensional material composed of the transition metal titanium and the organic material carbon. Similar to graphene, which has excellent electrical properties, MXene is highly conductive and lightweight. Additionally, it dissolves well in various solvents, making it easy to process. However, due to its paper-like properties, research has predominantly focused on horizontal alignment. In this study, the team focused on the phenomenon where MXene nanosheets dispersed in the eco-friendly solvent water align linearly along an applied alternating electric field. Since the surface of MXene carries a strong negative charge, the sheets arrange vertically rather than horizontally in a thin cell about 100 micrometers thick to maximize their distance from each other. Moreover, the vertical alignment of MXene nanosheets dispersed in water can be reversibly controlled depending on the presence or absence of the electric field.

When MXene is instantaneously frozen under an applied electric field and dried using freeze-drying that utilizes sublimation, electron microscopy directly confirms that the MXene nanosheets stand vertically on the substrate with edges as thin as nanometers (one hundred-thousandth the thickness of a hair). Previous studies required mixing other additives to achieve vertical alignment, which limited the utilization of MXene’s inherent properties and restricted the desired vertical arrangement to very narrow micrometer-scale areas. The electric field method used in this study allows large-area production on the centimeter scale with pure MXene and is advantageous for automated processes.

Furthermore, the orientation of vertically aligned MXene can be freely controlled according to the direction of the electric field. By designing various electrodes, the research team demonstrated for the first time that windmill shapes and even letters can be created. Currently, standing MXene vertically is attracting significant attention because it induces rapid ion movement, enabling the production of capacitors with high capacitance. Through this research, by utilizing advantages such as reversible control, large-area production, and directional control, it is expected that not only high-capacity capacitors but also the widely known excellent electromagnetic wave shielding properties of MXene can be reversibly adjusted as needed. Additionally, vertically aligned MXene could be applied in more diverse fields such as optics, sensors, and electronic packaging.

Professor Yoon explained, "If two-dimensional materials are considered as thin lenses for sunglasses that can block electromagnetic waves, previous research involved MXene sheets aligned horizontally, showing performance similar to ordinary sunglasses. Through this research, by standing the lenses vertically, it is possible to absorb or shield electromagnetic waves in that direction, overcoming previous limitations and maximizing the advantages of two-dimensional materials." He added, "This research can be seen as developing an efficient and universally applicable innovative platform that realizes the vertical alignment of two-dimensional materials, which was previously considered impossible."

This research was published in the international academic journal Nature Communications and was recognized for its excellence by being featured in the journal’s Editors’ Highlights.

This content was produced with the assistance of AI translation services.