korean english


Home > 게시판 > 세미나

아래와 같이 콜로퀴움을 개최하오니 많이 참석해 주시기 바랍니다.

4시 20분부터 제1과학관 31214 e+강의실에서 간단한 다과를 제공합니다.

아 래

Title: 연성물질 기반 위상학적 결함구조의 상전이와 응용

Speaker: 윤   동   기  교수님 (KAIST)

Date & Time: Nov. 8. (Wed.) 2017, 4:30 PM

Place: Natural Science 1,  Room No. 31214

Abstract: Topological defect structure is one of the most interesting topic in physics and material sciences. Especially, the topological defect transition was highlighted by Nobel prize in physics last year. But this topic is hard to understand and realize in the practical condition because the size and time-scale are huge in cosmos or so tiny in skyrmion system. So, we proposed to use liquid crystal (LC) materials to directly show this interesting topic, phase transition of topological defect [1].

In details, LCs are materials in widespread use as the basis of display technologies, have drawn much recent attention for their defects that draw together such concepts as topology, self-assembly, and micro-patterned materials. However, relatively little is known about the fate of the defects during a phase transition from one LC phase to another. Here, we examine defects in the in-situ thermal phase transition from nematic to smectic A in hybrid-aligned LC droplets on water substrates using experimental, theoretical and numerical analyses. The hybrid-aligned nematic droplet spontaneously generates boojum defects. During cooling, toric focal conic domains arise through a sequence of morphological transformations involving nematic stripes and locally aligned focal conic domains. This simple experiment reveals a surprisingly complex pathway by which very different types of defects may be related across the nematic-smectic A phase transition, and presents new possibilities for controlled deformation and patterning of LCs, which are useful in the patterning applications such as hydrophobic surface, illumination, and sensors [2-5].



[1] Min-Jun Gim, et al, “Morphogenesis of liquid crystal topological defects during the nematic-smectic A phase transition” Nature Communications, 8, 15453 (20170

[2] Dae Seok Kim, et al, “Controlling Gaussian and mean curvatures at microscale by sublimation and condensation of smectic liquid crystals” Nature Communications, 7, 10236 (2016)

[3] Dae Seok Kim, et al, “Fabrication of Periodic Nanoparticle Clusters Using Soft Lithographic Template”, J. Mater. Chem. C, 3, 4598 (2015)

[4] Dae Seok Kim, et al, "Fast Fabrication of Sub-200-nm Nanogrooves using Liquid Crystal Material" ACS Applied Materials & Interfaces 8, 11851 (2016)

[5] Dae Seok Kim, et al, “Arrangement and SERS Applications of Nanoparticle Clusters Using Liquid Crystals” ACS Applied Materials & Interfaces, 9, 7787 (2017)


번호 제목 날짜 조회 수
공지 <12/8(Thu.) 11:00am>노벨상 소개 강연 - 2016년 노벨 물리학상: 위상 응집 물리의 탄생 2016.11.28 1020543
681 2019학년도 2학기 콜로퀴움 일정 2019.07.17 420261
680 <12/3> Magnetic couplings, optical spectra, and spin-orbit exciton in 5d Mott insulator Sr2IrO4 2012.11.26 309943
679 2017학년도 1학기 콜로퀴움 일정 2017.01.05 254019
678 2020학년도 1학기 콜로퀴움 일정 2020.01.31 250949
677 <8/30(Wed.)10:30>​Technology convergence and applications of Large-Area Electronics, e-Textiles, bio-sensors and bio-electronics 2017.08.29 207823
676 <3/14>Adaptive Optics for the Human Eye and Ophthalmic Applications 2008.03.12 204325
675 <Mar.3(Wed.)>Scaling laws in Natural Language Processing 2021.02.25 198154
674 <10/25> Wave properties of dipole-exchange spin waves in confined magnetic thin films 2006.10.25 185550
673 <5/16(토)> 세미나 개최 안내 2015.05.18 185214
672 <5/16> 물리학자가 바라 본 단백질: 왜, 어떻게 연구하는가? 2012.05.10 184410
671 <12/21> Special Seminar by Professor Ilya Vekhter 2010.11.30 179816
670 BK 석학초청 특별세미나 - Frustration and dimensional reduction in multi-orbital systems 2011.10.28 178314
669 <6/11> Advanced Physiological Optics and Its Ophthalmic Applications 2014.05.28 172364
668 <6/17> Oscillating Fuzzy Sphere and M5/anti M5 configurations in ABJM model 2009.06.16 162589
667 <May. 25(Wed.) 4:30 PM> Functional Materials @ Nanoscale: Electronics, Energy and ‘Green’Healthcare Applications 2016.05.23 161617
666 <4/2> Radio Detection of Ultra High Energy Cosmic Rays and Neutrinos in Antarctica 2014.03.26 152963
665 <Nov. 18(Wed.) 4:30 PM> Single-molecule chemistry and spectroscopy on ultrathin insulating films 2015.11.11 152272
664 <6/2> The black hole search at the LHC: critical comment 2011.06.01 152206
663 2020학년도 2학기 콜로퀴움 일정 2020.07.16 150192