JOSEPH MACLENNAN

Professor Attendant Rank, Physics Department, University of Colorado

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 Colorado 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 Colorado. His research interests center on determining the structure and electro-optic properties of ferroelectric liquid crystals, including bent-core and de Vries type materials, and on understanding the textures and phase transitions of freely-suspended liquid crystal films, including the ordering behavior of islands and liquid droplets. Self-assembled monolayers and topographically patterned surfaces are being studied as novel liquid crystal alignment surfaces. He has developed extensive computer code for modeling the optical response of liquid crystals in applied fields and the reorientation dynamics of azo-SAMs.

Selected Publications

  • "Chirality-Preserving Growth of Helical Filaments in the B4 Phase of Bent-Core Liquid Crystals,"
    D. Chen, J. E. Maclennan, R. Shao, D. K. Yoon, H. Wang, E. Korblova, D. M. Walba, M. A. Glaser, and N. A. Clark, Journal of the American Chemical Society 133, 12656–12663 (2011).
  • "Photodegradation of Azobenzene-Based Self-assembled Monolayers Characterized by In-Plane Birefringence," G. Fang, Y. Shi, J. E. Maclennan, D. M. Walba, and N. A. Clark, Langmuir 27, 10407–10411 (2011).
  • "Effective conductivity due to continuous polarization reorientation in fluid ferroelectrics," Y. Shen,
    T. Gong, R. Shao, E. Korblova, J. E. Maclennan, D. M. Walba, and N. A. Clark, Physical Review E 84, 020701(R) (2011).
  • "Cooperative Liquid-Crystal Alignment Patterns Generated by Overlaid Topography," Y. Yi, J. E. Maclennan, and N. A. Clark, Physical Review E 83, 051708 (2011).
  • "Interface Structure of the Dark Conglomerate Phase," D. Chen, Y. Shen, C. Zhu, L. E. Hough, N. Gimeno, M. A. Glaser, J. E. Maclennan,
    M. Blanca Ros, and N. A. Clark, Soft Matter 7, 1879–1883 (2011).
  • "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).
  • "Crossover between 2D and 3D fluid dynamics in the diffusion of islands in ultrathin freely suspended smectic films," Z. H. Nguyen,
    M. Atkinson, C. S. Park, J. E. Maclennan, M. A. Glaser, and N. A. Clark, Physical Review Letters 105, 268304 (2010).
  • "Photo-Reversible Liquid Crystal Alignment using Azobenzene-Based Self-Assembled Monolayers: Comparison of the Bare Monolayer and Liquid Crystal Reorientation Dynamics," G. Fang, Y. Shi, J. E. Maclennan, N. A. Clark, M. J. Farrow, and D. M. Walba, Langmuir 26, 17482–17488 (2010).
  • "Pre-transitional orientational ordering of a calamitic liquid crystal by helical nanofilaments of a bent-core mesogen, " D. Chen, C. Zhu,
    R. Shoemaker, E. Korblova, D. Walba, M. Glaser, J. Maclennan, and N. Clark, Langmuir 26, 15541–15545 (2010).
  • "High Contrast Polarimeter for Precision Measurement of the In-Plane Birefringence of Molecular Monolayers," G. Fang, J. Maclennan, and
    N. Clark, Langmuir 26, 11686–11689 (2010).
  • "Triclinic Fluid Order," N. Chattham, E. Korblova, R. Shao, D. M. Walba, J. E. Maclennan, and N. A. Clark, Physical Review Letters 104, 067801 (2010).
  • "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).
  • "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).
  • "Electric-Field-Driven Deracemization," A. Kane, R.-F. Shao, J. E. Maclennan, L. Wang, D. M. Walba, and N. A. Clark, ChemPhysChem 8 , 170 – 174 (2007).
  • "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); also in www.e-lc.org .
  • "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).
  • "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).
  • "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).
  • "Spontaneous Formation of Horizontal Chevrons in Smectic-C* Liquid Crystals," G. Strangi, D. A. Coleman, J. E. Maclennan, M. Copic, and
    N. A. Clark, Applied Physics Letters 78 , 1532 (2001).
  • "A Ferroelectric Liquid Crystal Conglomerate Composed of Racemic Molecules," D. M. Walba, E. Körblova, R. Shao, J. E. Maclennan,
    D. R. Link, M. A. Glaser, and N. A. Clark, Science 288 , 2181 (2000).
  • "Spontaneous Formation of Polar Chiral Layers from Achiral Molecules in a Novel Antiferroelectric Liquid Crystal Phase," D. R. Link, G. Natale, R. Shao, J. E. Maclennan, N. A. Clark, E. Korblova, and D. M. Walba, Science 278, 1924-1927 (1997).
  • "Simultaneous Observation of Electric Field Coupling to Longitudinal and Transverse Ferroelectricity in a Chiral Liquid Crystal," D. R. Link,
    J. E. Maclennan, and N. A. Clark, Physical Review Letters 77, 2237-2240 (1996).
  • "Textures in Hexatic Films of Non-Chiral Liquid Crystals: Symmetry Breaking and Modulated Phases," J. E. Maclennan, U. Sohling, N. A. Clark, and M. Seul, Physical Review E49, 3207-3224 (1994).
  • "Freely suspended liquid crystal film transfer: A new method of creating thin smectic films on solid substrates," J. Maclennan, G. Decher, and U. Sohling, Applied Physics Letters 59, 917-919 (1991).
  • "Visible polarized light transmission spectroscopy of the electro-optic switching behaviour of surface stabilized ferroelectric liquid crystal cells," Z. Zhuang, N. A. Clark, and J. E. Maclennan, Liquid Crystals 10, L409-417 (1991).
  • "Thermal fluctuation effects in ferroelectric liquid crystal polarization reversal: Light scattering from a transient domain wall foam,"
    J. E. Maclennan and N. A. Clark, Physical Review A44, 2543-2557 (1991).

Parting Shot: the Big Picture
 
 
email: Joseph.Maclennan@Colorado.EDU