Presenter: Dr. Jeffrey J. Schwartz (University of California, Los, Angeles）
Topic: What’s on The Outside Counts Too: Surface-Dipole Modulated Assembly
Time: 10:00 AM, Feb. 22th (Wednesday)
Location: Conference Room B, BLDG909-1F
Abstract
Detailed understanding and control of theintermolecular forces that govern molecular assembly are necessary to engineerstructure and function at the nanoscale. Liquid crystal (LC) assembly isexceptionally sensitive to surface properties, capable of transducing nanoscaleintermolecular interactions into a macroscopic optical readout. Self-assembledmonolayers (SAMs) modify surface interactions and are known to influence LCalignment. Here, we exploit the different dipole magnitudes and orientations ofcarboranethiol and -dithiol positional isomers to deconvolve the influence ofSAM-LC dipolar coupling from variations in molecular geometry, tilt, and order.Director orientations and anchoring energies are measured for LC cells employingvarious carboranethiol and -dithiol isomer alignment layers. The normalcomponent of the molecular dipole in the SAM, toward or away from theunderlying substrate, was found to determine the in-plane LC directororientation relative to the anisotropy axis of the surface. By using LCalignment as a probe of interaction strength, we elucidate the role of dipolarcoupling of molecular monolayers to their environment in determining molecularorientations. We apply this understanding to advance the engineering ofmolecular interactions at the nanoscale.
Biography:
EDUCATION
Doctor ofPhilosophy(Ph.D.), Physics
University ofCalifornia, Los Angeles 2009-2016
Advisor: Paul S. Weiss
Master ofScience(M.S.), Physics 2009-2010
University ofCalifornia, Los Angeles
Bachelor ofScience(B.S.), Physics
The University ofTexas at Dallas 2005-2009
Minor: Mathematics
PUBLICATIONS
◦Surface Dipole Control ofLiquidCrystal Alignment. Jeffrey J. Schwartz, Alexandra M.Mendoza, NatchaWattanatorn, Yuxi Zhao, Vinh Nguyen, Alexander M. Spokoyny, Chad A.Mirkin, Toma′sˇ Basˇe, and Paul S. Weiss, J. Am. Chem. Soc. 138, 5957 (2016).
◦Defect-Tolerant Aligned Dipoleswithin Two-Dimensional Plastic Lattices. John C. Thomas, Jeffrey J. Schwartz,J. Nathan Hohman, Shelley A. Claridge, Harsharn S. Auluck, Andrew C. Serino,Alexander M. Spokoyny, Giang Tran, Kevin F. Kelly, Chad A. Mirkin, JeromeGilles,
◦Differentiating Amino AcidResidues and Side Chain Orientations in Peptides Using Scanning TunnelingMicroscopy. Shelley A. Claridge, John C. Thomas, Miles A. Silverman, JeffreyJ.Schwartz, Yanlian Yang, Chen Wang, and Paul S. Weiss, J. Am. Chem. Soc. 135,18528
◦Molecular Flux Dependence ofChemical Patterning by Microcontact Printing. Jeffrey J.Schwartz, J. Nathan Hohman, Elizabeth I. Morin, and Paul S.Weiss, ACS Appl. Mater.
◦Electrons, Photons, and Force:Quantitative Single-Molecule Measurements from Physics to Biology. Shelley A.Claridge, Jeffrey J. Schwartz, and Paul S. Weiss, ACS Nano5, 693
◦ Field Emission Properties ofZnO,ZnS and GaN Nanostructures. Y. Mo, J. J. Schwartz, M. H. Lynch, P. A. Ecton, A.Neogi, J. M. Perez, Y. Fujita, H. W. Seo, Q. Y. Chen, L. W.Tu, and N. J. Ho, inNanoscale Photonics and Optoelectronics, edited by Z. M. Wang and A.
Contact:Prof. Lifeng Chi