Discovery of New Two-Dimensional Materials and Their Use in Current and Future Technologies

Yury GOGOTSI

Gogotsi@drexel.edu / http://nano.materials.drexel.edu

Chi Won AHN

cwahn@nnfc.re.kr

We live in the materials word. Materials defined the progress of humanity, as people moved from Stone Age to Bronze Age and then to Iron Age. Receiving access to new materials enabled new tools and technologies. We entered the Silicon Age more that half-a-century ago and, as a result, electronic and computer technologies greatly accelerated the technical progress, changing our life. What is next? Probably the Nanomaterials Age. The era of assembly of new materials, structures and devices from nanoscale building blocks providing any imaginable, but impossible in conventional materials, combinations of properties and functions. Assembly from nanoparticles will allow integration of electronics, energy harvesting and storage into all items surrounding us, creating self-powered internet of things and wearable internet. 2D materials, like graphene, dozens of which are available nowadays and thousands more expected in the near future, provide very attractive building blocks, because, unlike 1D (nanotubes and nanowires) or 0D (nanoparticles and quantum dots) materials, they can easily assemble and self-assemble into dense structures, just like bricks in the wall.

There are currently many insulating and semiconducting 2D materials available, which can be used as single sheets in devices, or as building blocks. 2D transition metal carbides and nitrides (MXenes) have been expanding rapidly since their discovery at Drexel University in 2011. They added metallically conductive 2D building blocks to the available materials list. Approximately 30 different MXenes have been synthesized, and the structure and properties of numerous other MXenes have been predicted using DFT calculations. Moreover, the availability of solid solutions on M (transition metal) and X (carbon or nitrogen) sites, control of surface terminations, and the discovery of ordered double-M MXenes offer the potential for synthesis of dozens of new materials. This presentation will describe the discovery of MXenes, their synthesis by selective etching of layered ceramic precursors as well as delamination into single-layer 2D sheets and assembly into films and 3D structures. Their properties and applications in energy storage, optoelectronics, plasmonics, electromagnetic interference shielding, antennas, electrocatalysis, medicine, sensors, water purification/desalination and other fields will be discussed. Many applications of MXenes have become possible as a result of collaboration between the US and Korean scientists and the focus of the presentation will be on those applications.

Acknowledgement: This work was supported by KNRF via the FIRST Nano Co-op Center.

What Can We Do with Laser in Head and Neck Disease

Phil-Sang Chung MD, PhD

Department of Otorhinolaryngology-Head and Neck Surgery,
Beckman Laser Institute Korea
Dankook University, Cheonan, Korea

pschung@dankook.ac.kr

The biophotonics using laser or light emitting diode (LED) is now widely used in medical area. Especially in Head and neck area, many optical tools are available for diagnosis and treatment, even in tissue regeneration. Nowadays, laser cordectomy is treatment choice in early glottic carcinoma. And also laser can be used in many head and neck surgery. Photodynamic therapy and diagnosis (PDT and PDD) is very useful for early diagnosis and noninvasive treatment for mucosal disease including oral cavity, pharynx and larynx.

With the improvement of tissue optics and optical diagnosis, we can use light in early diagnosis of cancer in surface as well as in deep space. Narrow band imaging (NBI) can offer a better detection for superficial cancer compared to white light. For tissue perfusion we can use laser speckle imaging (LSI) or near infrared light (NIR) with Indocyanine Green, with these the flap failure and ischemic damage can be easily detected during or after surgery. For superficial lesion, multiphoton microscopy (MPM), can offer optical diagnosis which can substitute tissue biopsy in some cases. Also optical coherence tomography can give us many functional and structural information for diagnosis and treatment.

Light can enhance the differentiation of stem cell and also neovascularization in tissue, which enhance angiogenesis to improved survival of vascular compromised tissue after surgery or radiation therapy..

Key words : Laser, biophotonics