Mon, 07 Jul 2008 03:37:05 BST CiteULike: dchen's Zhou http://www.citeulike.org/user/dchen/author/Zhou CiteULike.org en-gb Copyright © 2004-2008 citeulike.org http://www.citeulike.org/user/dchen/article/2910642 <i>Soft Matter, 2008, 4, 1151 - 1157, DOI: 10.1039/b714376a</i><br /><br />Stimuli-responsive polymer gels have received considerable attention due to their singular mechanical properties, which make them materials of choice for niche applications. Polymer gels comprising either physical or chemical cross-links can undergo controlled and reversible shape changes in response to an applied field. The stimulus or external field applied may include thermal, electrical, magnetic, pH, UV/visible light, ionic or metallic interactions or combinations thereof. The shape change can manifest itself in two-dimensional actuation, bending motion, or three-dimensional actuation, volume change. This reversible contraction and expansion of polymer gels as well as their mechanical properties are similar to that of biological muscles. This review will describe and critique some of the recent advances in the field of stimuli-responsive polymer gels including the design of new classes of polymeric gels, controlled actuation in response to external stimuli, and ability to tailor material properties for different applications. Stimuli-responsive polymer gels Suk-Kyun Ahn Rajeswari Kasi Seong-Cheol Kim Nitin Sharma Yuxiang Zhou Soft Matter, 2008, 4, 1151 - 1157, DOI: 10.1039/b714376a 2008-06-20T14:55:03-00:00 Soft Matter, 2008, 4, 1151 - 1157, DOI: 10.1039/b714376a 2008 gel polymer review http://www.citeulike.org/user/dchen/article/2767689 <i>Physical Review Letters, Vol. 100, No. 8. (2008)</i><br /><br />Modified water models with scaled charges are used to investigate solvent polarity effects on DNA structure. Several intensive molecular dynamics simulations of the DNA EcoRI dodecamer d(CGCGAATTCGCG) in different model solvents are performed. When the polarity of the solvent molecule decreases, from overpolarized to less polarized, DNA experiences the conformational transitions of constrainedB form(A-B)mixA form. We demonstrate that one important cause of these structure changes is the competition between hydration and direct cation coupling to the free oxygen atoms in the phosphate groups on DNA backbones. Solvent-Induced DNA Conformational Transition B Gu FS Zhang ZP Wang HY Zhou doi:10.1103/PhysRevLett.100.088104 Physical Review Letters, Vol. 100, No. 8. (2008) 2008-05-07T23:28:21-00:00 2008 Physical Review Letters 100 8 APS 2008 biology people http://www.citeulike.org/user/dchen/article/2722869 <i>Physics of Fluids, Vol. 6, No. 1. (1994), pp. 80-94.</i><br /><br />View this record in Web of Science Pressure-driven flow of suspensions of liquid drops Hua Zhou C Pozrikidis Physics of Fluids, Vol. 6, No. 1. (1994), pp. 80-94. 2008-04-27T00:15:54-00:00 1994 Physics of Fluids 6 1 80 94 AIP emulsion flow qualifer http://www.citeulike.org/user/dchen/article/2186364 <i>Science, Vol. 312, No. 5780. (16 June 2006), pp. 1631-1633.</i><br /><br />We present systematic and detailed measurements of interparticle contact forces inside three-dimensional piles of frictionless liquid droplets. We measured long-range chainlike correlations of the directions and magnitudes of large forces, thereby establishing the presence of force chains in three dimensions. Our correlation definition provides a chain persistence length of 10 mean droplet diameters, decreasing as load is applied to the pile. We also measured the angles between contacts and showed that the chainlike arrangement arises from the balance of forces. Moreover, we found that piles whose height was comparable to the chain persistence length exhibited substantially greater strain hardening than did tall piles, which we attributed to the force chains. Together, the results establish a connection between the microscopic force network and the elastic response of meso- or macroscopic granular piles. The conclusions drawn here should be relevant in jammed systems generally, including concentrated emulsions and piles of sand or other heavy particles. 10.1126/science.1125151 Measurement of Forces Inside a Three-Dimensional Pile of Frictionless Droplets J Zhou S Long Q Wang AD Dinsmore doi:10.1126/science.1125151 Science, Vol. 312, No. 5780. (16 June 2006), pp. 1631-1633. 2008-01-01T22:04:40-00:00 2006 Science 312 5780 1631 1633 dinsmore emulsion force qualifier