Wed, 09 Jul 2008 13:28:16 BST CiteULike: dchens Bailey http://www.citeulike.org/user/dchen/author/Bailey CiteULike.org en-gb Copyright © 2004-2008 citeulike.org http://www.citeulike.org/user/dchen/article/2883601 <i>Physical Review E (Statistical, Nonlinear, and Soft Matter Physics), Vol. 75, No. 3. (2007)</i><br /><br />Recently it was found that fluid smectic phases of bent core liquid crystals formed freestanding fibers of extremely high slenderness ratios. Studies of these fibers showed that their structure was composed of concentric cylindrical smectic layers. For this configuration to be stable there must be an energy term that desires bending of the smectic layers. We show that an energy term that deals with the divergence of the dipolar direction can encourage layer bending if the layer chirality value is allowed to vary. The energy term associated with holding the layer chirality is closely related to layer compressions and electrical self-interactions. For our model, we assumed a simple smectic-C geometry with constant molecular tilt and cone angle defined by the director with respect to the layer normal, but allowed a constant variation of the polar direction about the director. Applying this simplified model to a free energy which accounts for director distortions, divergence of the polar direction, biaxial layer strain, surface tension, and electrical self-interactions, we were able to show consistency between the stable fiber radius and other properties predicted in our model to results from experimental studies. Structure and stability of bent core liquid crystal fibers C Bailey Jr A Jákli doi:10.1103/PhysRevE.75.031701 Physical Review E (Statistical, Nonlinear, and Soft Matter Physics), Vol. 75, No. 3. (2007) 2008-06-11T19:04:44-00:00 2007 Physical Review E (Statistical, Nonlinear, and Soft Matter Physics) 75 3 APS 2007 liquidcrystal pre shear structure theory http://www.citeulike.org/user/dchen/article/2711055 <i>Physical Review Letters, Vol. 93, No. 10. (2004), 108302.</i> Limits to Gelation in Colloidal Aggregation S Manley L Cipelletti V Trappe AE Bailey RJ Christianson U Gasser V Prasad PN Segre MP Doherty S Sankaran AL Jankovsky B Shiley J Bowen J Eggers C Kurta T Lorik DA Weitz doi:10.1103/PhysRevLett.93.108302 Physical Review Letters, Vol. 93, No. 10. (2004), 108302. 2008-04-23T23:55:21-00:00 2004 Physical Review Letters 93 10 108302 American Physical Society clusters colloids gel weitz http://www.citeulike.org/user/dchen/article/2710243 <i>Physical Review Letters, Vol. 95, No. 4. (2005)</i><br /><br />Colloidal silica gels are shown to stiffen with time, as demonstrated by both dynamic light scattering and bulk rheological measurements. Their elastic moduli increase as a power law with time, independent of particle volume fraction; however, static light scattering indicates that there are no large-scale structural changes. We propose that increases in local elasticity arising from bonding between neighboring colloidal particles can account for the strengthening of the network, while preserving network structure. Time-Dependent Strength of Colloidal Gels S Manley Benny Davidovitch Neil Davies L Cipelletti AE Bailey RJ Christianson U Gasser V Prasad PN Segre MP Doherty S Sankaran AL Jankovsky B Shiley J Bowen J Eggers C Kurta T Lorik DA Weitz doi:10.1103/PhysRevLett.95.048302 Physical Review Letters, Vol. 95, No. 4. (2005) 2008-04-23T21:08:32-00:00 2005 Physical Review Letters 95 4 APS colloids gel weitz