eprintid: 7340 rev_number: 5 userid: 6 dir: disk0/00/00/73/40 datestamp: 2011-11-10 19:39:16 lastmod: 2016-11-15 13:41:07 status_changed: 2011-11-10 19:39:16 type: thesis_degree metadata_visibility: show contact_email: fay4@pitt.edu item_issues_count: 0 eprint_status: archive creators_name: Yan, Fangyong creators_email: fay4@pitt.edu creators_id: FAY4 title: SELF-ASSEMBLY OF LIQUID CRYSTALS AND CHIRAL SUPERSTRUCTURES: FROM COARSE-GRAINED TO FULLY ATOMISTIC MODELS ispublished: unpub divisions: sch_as_chemistry full_text_status: public keywords: atomistic simulation; bent-core molecule; chiral tuning; design principle; liquid crystal mixtures abstract: Computer simulations have been used to study the self-assembly of liquid crystals and/or chiral superstructures in both coarse-grained and fully atomistic models. In chapters 4-6, coarse-grained models of rigid achiral bent-core and linear molecules were found to self-assemble to chiral superstructures and liquid crystalline phases. Chiral superstructures were calculated to be minima of the potential energy surface using energy minimization and Monte Carlo parallel tempering simulations. Chiral dopants were found to induce the system to adopt a consistent chiral twist direction, the first molecular scale computer simulation of this effect. Superstructural chirality can be tuned into rigid linear particles by the appropriate spacing of Lennard-Jones (LJ) particles. These results point to design rules that can be manipulated for the experimental synthesis of chiral structures from achiral particles.In chapters 7-8, the largest liquid crystal atomistic simulations to date, to our knowledge,have been performed for both a series of single component liquid crystals and liquid crystalmixtures. It was also demonstrated for the first time, to our knowledge, the formation of smectic phases from an isotropic liquid state at the all atom level. These simulations are in good agreement with experiments,[1, 2] and show that atomistic simulations are capable of capturing macroscopic phase behavior changes induced by a small variation in the structure of single component liquid crystal molecules, or by concentration change in the liquid crystal mixtures. This opens up the possibility of theoretically designing and screening liquid crystals with desired properties. date: 2011-07-01 date_type: completed institution: University of Pittsburgh refereed: TRUE etdcommittee_type: committee_chair etdcommittee_type: committee_member etdcommittee_type: committee_member etdcommittee_type: committee_member etdcommittee_name: Jordan, Kenneth D etdcommittee_name: Johnson, J. Karl etdcommittee_name: Rosi, Nathaniel etdcommittee_name: Coalson, Rob etdcommittee_email: jordan@pitt.edu etdcommittee_email: karlj@pitt.edu etdcommittee_email: nrosi@pitt.edu etdcommittee_email: COALSON@pitt.edu etdcommittee_id: JORDAN etdcommittee_id: KARLJ etdcommittee_id: NROSI etdcommittee_id: COALSON etd_defense_date: 2011-04-18 etd_approval_date: 2011-07-01 etd_submission_date: 2011-04-19 etd_access_restriction: 5_year etd_patent_pending: FALSE assigned_doi: doi:10.5195/pitt.etd.2011.7340 thesis_type: dissertation degree: PhD committee: Kenneth D. Jordan (jordan@pitt.edu) - Committee Chair committee: J. Karl Johnson (karlj@pitt.edu) - Committee Member committee: Nathaniel Rosi (nrosi@pitt.edu) - Committee Member committee: Rob Coalson (COALSON@pitt.edu) - Committee Member etdurn: etd-04192011-221750 other_id: http://etd.library.pitt.edu/ETD/available/etd-04192011-221750/ other_id: etd-04192011-221750 citation: Yan, Fangyong (2011) SELF-ASSEMBLY OF LIQUID CRYSTALS AND CHIRAL SUPERSTRUCTURES: FROM COARSE-GRAINED TO FULLY ATOMISTIC MODELS. Doctoral Dissertation, University of Pittsburgh. (Unpublished) document_url: http://d-scholarship-dev.library.pitt.edu/7340/1/Fangyong-Thesis-corrected.pdf