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Office Hours: Wednesday 3:30 - 4:30 p.m. or by appointment • &�Բ�����;•&�Բ�����;&�Բ�����;•&�Բ�����;

Background:

Joseph Maclennan received his B.Sc.(Hons.) in Physics and Electronics from Rhodes University, South Africa, in 1980, and his Ph.D. in Physics from the University of ����ֱ�� in 1988. He then spent five years in the Physical Chemistry Department at the University of Mainz in Germany, the first two as a Humboldt Postdoctoral Fellow. In 1994 he returned to Boulder to rejoin the Liquid Crystal Physics group at the University of ����ֱ��. His research interests center on determining the structure and electro-optic properties of liquid crystal materials, including bent-core and ferroelectric smectics and ferromagnetic colloids, and on understanding the textures and phase transitions of freely-suspended liquid crystal films, including the interactions and ordering behavior of topological defects and islands and the 2D hydrodynamics of liquid droplets.

Selected Publications:

1. "First-principles experimental demonstration of ferroelectricity in a thermotropic nematic liquid crystal: Polar domains and striking electro-optics," X. Chen, E. Korblova, D. Dong, X. Wei, R. Shao, L. Radzihovsky, M. A. Glaser, J. E. Maclennan, D. Bedrov, D. M. Walba, and N. A. Clark, Proceedings of the National Academy of Sciences, 117 (25) 14021−14031 (2020). DOI: 10.1073/pnas.2002290117
2. "Frustration between two- and three-dimensional smectic ordering leads to a biaxial nematic phase,"  D. Chen, D. A. Coleman, C. Zhu, N. Chattham, F. Jenz, X. Cheng, C. Tschierske, M. A. Glaser, J. E. Maclennan, and N. A. Clark, Soft Matter 16 (3), 747−753 (2019). DOI: 10.1039/C9SM01809C
3. "Chiral Incommensurate Helical Phase in a Smectic of Achiral Bent-Core Mesogens," A. A. S. Green, M. R. Tuchband, R. Shao, Y. Shen, R. Visvanathan, A. E. Duncan, A. Lehmann, C. Tschierske, E. D. Carlson, E. Guzman, M. Kolber, D. M. Walba, C. S. Park, M. A. Glaser, J. E. Maclennan, and N. A. Clark, Physical Review Letters 122 (10), 107801 (2019). DOI: 10.1103/PhysRevLett.122.107801
4. "Realization of hydrodynamic experiments on quasi-2D liquid crystal films in microgravity," N. A. Clark, A. Eremin, M. A. Glaser, N. Hall, K. Harth, C. Klopp, J. E. Maclennan, C. S. Park, R. Stannarius, P. Tin, W. N. Thurmes, T. Trittel, Advances in Space Research 60, 737-751 (2017). DOI: 10.1016/j.asr.2017.04.014
5. "Active microrheology of smectic membranes," Z. Qi, K. Ferguson, Y. Sechrest, T. Munsat, C. S. Park, M. A. Glaser, J. E. Maclennan, N. A. Clark, T. Kuriabova, and T. R. Powers, Physical Review E  95 (1), 022702 (2017). DOI: 10.1103/PhysRevE.95.022702
6. "Diastereomeric liquid crystal domains at the mesoscale," D. Chen, M. Tuchband, B. Horanyi, E. Korblova, D. M. Walba, M. A. Glaser, J. E. Maclennan, and N. A. Clark, Nature Communications 6, 7763 (2015). DOI: 10.1038/ncomms8763
7. "Field alignment of bent-core smectic liquid crystals for analog optical phase modulation," Y. Shen, L. Goodhew, R. Shao, M. Moran, E. Korblova, D. Walba, N. A. Clark, J. E. Maclennan, and P. Rudquist, Applied Physics Letters 106 (19), 191101 (2015). DOI: 10.1063/1.4919805
8. "Mutual Diffusion of Inclusions in Freely Suspended Smectic Liquid Crystal Films," Z. Qi, Z. H. Nguyen, C. S. Park, M. A. Glaser, J. E. Maclennan, N. A. Clark, T. Kuriabova, and T. R. Powers, Physical Review Letters 113 (12), 128304 (2014). DOI: 10.1103/PhysRevLett.113.128304
9. "Chiral heliconical ground state of nanoscale pitch in a nematic liquid crystal of achiral molecular dimers," D. Chen, J. H. Porada, J. B. Hooper, A. Klittnick, Y. Shen, M. R. Tuchband, E. Korblova, D. Bedrov, D. M. Walba, M. A. Glaser, J. E. Maclennan, and N. A. Clark, PNAS 110 (40), 15931–15936 (2013). DOI:10.1073/pnas.1314654110
10. "Nanoconfinement of guest materials by helical nanofilament networks of bent-core mesogens,” D. Chen, C. Zhu, H. Wang, J. E. Maclennan, M. A. Glaser, E. Korblova, D. M. Walba, J. A. Rego, E. A. Soto-Bustamante, and N. A. Clark, Soft Matter  9, 462–471 (2013).  DOI: 10.1039/c2sm25997d
11. "Athermal photofluidization of glasses," G. J. Fang, J. E. Maclennan, Y. Yi, M. A. Glaser, M. Farrow, E. Korblova, D. M. Walba, T. E. Furtak, and N. A. Clark, Nature Communications 4, 1521 (2013).  DOI: 10.1038/ncomms2483
12. "Spontaneous Fluid Ferroelectric Order in a Bent-Core Liquid Crystal of  Orthorhombic Smectic Layers," R. A. Reddy, C. Zhu, R. Shao, E. Korblova, T. Gong,  Y. Shen, E. Garcia, M. A. Glaser, J. E. Maclennan, D. M. Walba, and  N. A. Clark, Science 332, 72–77 (2011). DOI: 10.1126/science.1197248
13. "Chiral Isotropic Liquids from Achiral Molecules," L. E. Hough, M. Spannuth, M. Nakata, D. A. Coleman, C. D. Jones, G. Dantlgraber, C. Tschierske, J. Watanabe, E. Körblova, D. M. Walba, J. E. Maclennan, M. A. Glaser, N. A. Clark, Science 25, 452–456 (2009).
14. "Organization of liquid crystals on submicron scale topographic patterns with fourfold symmetry prepared by thiolene photopolymerization-based nanoimprint lithography," Y. W. Yi, V. Khire, C. N. Bowman, J. E. Maclennan, and N. A. Clark, Journal of Applied Physics 103, 093518 (2008).
15. "Direct Measurement of Interaction Forces between Islands on Freely Suspended Smectic C Films using Multiple Optical Tweezers," A. Pattanaporkratana, C. S. Park, J. E. Maclennan, and N. A. Clark, Ferroelectrics 344, 71 (2006).
16. "Electric Field Induced Chirality Flipping in Smectic Liquid Crystals," M. Nakata, R.-F. Shao, J. E. Maclennan, W. Weissflog, and N. A. Clark, Physical Review Letters 96, 067802 (2006).
17. "Polarization-Modulated Smectic Liquid Crystal Phases," D. A. Coleman, J. Fernsler, N.Chattham, M. Nakata, Y. Takanishi, E. Korblova, D. R.Link, R.-F.Shao, W.G. Jang, J. E. Maclennan, O. Mondain-Monval, C. Boyer, W. Weissflog, G. Pelzl, L.-C. Chien, J. Zasadzinski, J. Watanabe, D. M. Walba, H. Takezoe, and N. A. Clark, Science 301, 1204-1211 (2003).
18. "Control of Molecular Orientation in Electrostatically Stabilized Ferroelectric Liquid Crystals," D. Coleman, D. Mueller, N. A. Clark, J. E. Maclennan, R.-F. Shao, S. Bardon, and D. M. Walba, Physical Review Letters 91, 175505 (2003).