= Special Seminar 1 =
■ 제 목 : Soft Condensed Matter Physics
■ 연 사 : Professor. David J Pine (Department of Physics, New York University)
■ 일 시 : 2012. 9. 3(Mon) 16:00~18:00
■ 장 소 : 응용공학동(W1-1) 신소재공학과 2427호
We study complex fluids, including Brownian and non-Brownian particle suspensions, emulsions, polymers (including DNA), and mixtures of the above. Much of our research focuses on self-assembly, both to understand how nature employs it to form complex and useful structures, and to develop methods to manipulate and exploit it to make new materials. We are also interested in the dynamics of complex fluids. This includes Brownian motion, rheology (the study of viscosity and elasticity in complex fluids), and hydrodynamics. Our approach is mostly experimental. It is also highly interdisciplinary. We synthesize exotic multifunctional colloids, employing the ever-expanding methods of colloid chemistry. We use optical methods, including light scattering, optical microscopy, and particle tracking, to probe the structure and dynamics of complex fluids. We use a variety of commercial and home-made rheometers to probe the viscoelastic and nonlinear rheological properties of complex fluids. The links above and on the right provide information about various research projects in our lab as well as some definitions of terms that may be unfamiliar to those new to soft condensed matter physics.
= Special Seminar 2 =
■ 제 목 : From Ultradense Arrays of Nanodots to Nanolines : A Route to Addressable Media
■ 연 사 : Professor. Thomas P. Russell (Department of Polymer Science & Engineering, University of Massachusetts)
■ 일 시 : 2012. 9. 7(Fri) 13:30~15:00
■ 장 소 : 응용공학동(W1-1) 영상강의실 Multimedia Hall
As the size scale of features continue to shrink in devices, the use of self-assembly, i.e. a “bottom up” approach, for device fabrication becomes increasingly important. Yet, simple self-assembly alone will not be sufficient to meet the increasing demands place on the registry of structures, particularly nanostructured materials. Several criteria are key in the rapid advancement and technology transfer for self-assembling systems. Specifically, the assembly processes must be compatible with current “top down” approaches, where standard photolithographic processes are used for device fabrication. Secondly, simple routes must be available to induce long-range order, in either two or three dimensions, in a rapid, robust and reliable manner. Thirdly, the in-plane orientation and, therefore, ordering of the structures, must be susceptible to a biasing by an external, macroscopic means in at least one, if not two directions, so that individual elements can be accessed in a reliable manner. Block copolymers, specifically block copolymers having a cylindrical microdomain morphology, are one such material that satisfy many, if not all, of the criteria that will be necessary for device fabrication. A simple, versatile approach to the directed self-assembly of block copolymers into a macroscopic array of unidirectionally aligned cylindrical microdomains on reconstructed faceted single crystal surfaces or on flexible, inexpensive polymeric replicas was discovered. High fidelity pattern transfer to a master mold is shown. The exceptional alignment arises from entropic penalties of chain packing in the facets coupled with the bending modulus of the cylindrical microdomains. The atomic crystalline ordering of the substrate is transferred, over multiple length scales, to the block copolymer microdomains, opening avenues to large-scale roll-to-roll-type and nanoimprint processing of perfectly patterned surfaces and as templates and scaffolds for nanowire arrays.