Sun, 06 Jul 2008 05:43:11 BST CiteULike: weeks's watchlist http://www.citeulike.org/user/weeks/watchlist CiteULike.org en-gb Copyright © 2004-2008 citeulike.org http://www.citeulike.org/user/kedmond/article/2090365 <i>Nat Phys, Vol. 2, No. 3. (March 2006), pp. 200-206.</i><br /><br />Some liquids do not crystallize below the melting point, but instead enter into a supercooled state and on cooling eventually become a glass at the glass-transition temperature. During this process, the liquid dynamics not only drastically slow down, but also become progressively more heterogeneous. The relationship between the kinetic slowing down and growing dynamic heterogeneity is a key problem of the liquid–glass transition. Here, we study this problem by using a liquid model, with a crystalline ground state, for which we can systematically control frustration against crystallization. We found that slow regions having a high degree of crystalline order emerge below the melting point, and their characteristic size and lifetime increase steeply on cooling. These crystalline regions lead to dynamic heterogeneity, suggesting a connection to the complex free-energy landscape and the resulting slow dynamics. These findings point towards an intrinsic link between the glass transition and crystallization. Frustration on the way to crystallization in glass Hiroshi Shintani Hajime Tanaka doi:10.1038/nphys235 Nat Phys, Vol. 2, No. 3. (March 2006), pp. 200-206. 2007-12-11T15:41:59-00:00 2006 Nat Phys 2 3 200 206 crystals dyn-het glass granular jamming structure http://www.citeulike.org/user/kedmond/article/2845957 <i>Nat Mater, Vol. 6, No. 3. (March 2007), pp. 202-205.</i><br /><br />Three-dimensional photonic crystals, or periodic materials, that do not allow the propagation of photons in all directions with a wavelength in the visible region have not been experimentally fabricated, despite there being several potential structures and the interesting applications and physics that this would lead to1. We show using computer simulations that two structures that would enable a bandgap in the visible region, diamond and pyrochlore, can be self-assembled in one crystal structure from a binary colloidal dispersion. In our approach, these two structures are obtained as the large (Mg) and small (Cu) sphere components of the colloidal analogue of the MgCu2 Laves phase2, whose growth can be selected and directed using appropriate wall patterning. The method requires that the particles consist of different materials, so that one of them can be removed selectively after drying (for example, by burning or dissolution). Photonic calculations show that gaps appear at relatively low frequencies indicating that they are robust and open for modest contrast, enabling fabrication from more materials. Self-assembly route for photonic crystals with a bandgap in the visible region Antti-Pekka Hynninen Job Thijssen Esther Vermolen Marjolein Dijkstra Alfons van Blaaderen doi:10.1038/nmat1841 Nat Mater, Vol. 6, No. 3. (March 2007), pp. 202-205. 2008-05-29T22:05:04-00:00 2007 Nat Mater 6 3 202 205 colloidal crystals self-assembly simulation structure http://www.citeulike.org/user/kedmond/article/2090467 <i>Nat Phys, Vol. 2, No. 4. (April 2006), pp. 268-274.</i><br /><br />The cooperative rearrangement of groups of many molecules has long been thought to underlie the dramatic slowing of liquid dynamics on cooling towards the glassy state. For instance, there exists experimental evidence for cooperatively rearranging regions (CRRs) on the nanometre length scale near the glass transition. The random first-order transition (RFOT) theory of glasses predicts that, near the glass-transition temperature, these regions are compact, but computer simulations and experiments on colloids suggest CRRs are string-like. Here, we present a microscopic theory within the framework of RFOT, which unites the two situations. We show that the shapes of CRRs in glassy liquids should change from being compact at low temperatures to fractal or ‘stringy’ as the dynamical crossover temperature from activated to collisional transport is approached from below. This theory predicts a correlation of the ratio of the dynamical crossover temperature to the laboratory glass-transition temperature, and the heat-capacity discontinuity at the glass transition. The predicted correlation quantitatively agrees with experimental results for 21 materials. The shapes of cooperatively rearranging regions in glass-forming liquids Jacob Stevenson Jorg Schmalian Peter Wolynes doi:10.1038/nphys261 Nat Phys, Vol. 2, No. 4. (April 2006), pp. 268-274. 2007-12-11T15:53:07-00:00 2006 Nat Phys 2 4 268 274 clusters colloidal dyn-het molecular simulation theory http://www.citeulike.org/user/kedmond/article/2761617 <i>Physical Review Letters, Vol. 100, No. 15. (2008)</i><br /><br />Collective behavior of driven granular matter is often strikingly analogous to that of thermal systems. Here we use a vibrated quasi-two-dimensional granular matter as a model system and investigate the mechanism of the liquid-glass transition. We demonstrate by direct observation the existence of long-lived medium-range crystalline order, which is found to be closely related to both dynamic heterogeneity and slow dynamics. Our findings are remarkably similar to recent numerical results on model thermal liquids and thus open an intriguing possibility of understanding the dynamic arrest in both thermal and athermal systems in a unified manner. Direct Observation of Medium-Range Crystalline Order in Granular Liquids Near the Glass Transition Keiji Watanabe Hajime Tanaka doi:10.1103/PhysRevLett.100.158002 Physical Review Letters, Vol. 100, No. 15. (2008) 2008-05-06T14:51:16-00:00 2008 Physical Review Letters 100 15 APS dyn-het glass granular structure http://www.citeulike.org/user/kedmond/article/2782024 <i>Microfluidics and Nanofluidics, Vol. 4, No. 1. (21 January 2008), pp. 129-144.</i><br /><br />Abstract  Optofluidic technology is believed to provide a breakthrough for the currently underlying problems in microfluidics and photonics/optics by complementary integration of fluidics and photonics. The key aspect of the optofluidics technology is based on the use of fluidics for tuning the optical properties and addressing various functional materials inside of microfluidic channels which have build-in photonic structures. Through the optofluidic integrations, fluidics enhances the controllability and tunability of optical systems. In particular, colloidal dispersion gives novel properties such as photonic band-gaps and enhanced Raman spectrum that conventional optofluidic devices cannot exhibit. In this paper, the state of the art of the colloidal dispersions is reviewed especially for optofluidic applications. From isolated singlet colloidal particles to colloidal clusters, their self-organized assemblies lead to optical manipulation of the photonic/optical properties and responses. Finally, we will discuss the prospects of the integrated optofluidics technology based on colloidal systems. Optofluidics technology based on colloids and their assemblies Seung-Kon Lee Shin-Hyun Kim Ji-Hwan Kang Sung-Gyu Park Won-Jong Jung Se-Hoon Kim Gi-Ra Yi Seung-Man Yang doi:10.1007/s10404-007-0218-8 Microfluidics and Nanofluidics, Vol. 4, No. 1. (21 January 2008), pp. 129-144. 2008-05-09T23:49:42-00:00 2008 Microfluidics and Nanofluidics 4 1 129 144 colloidal fluid self-assembly http://www.citeulike.org/user/kedmond/article/2781999 <i>Opt. Express, Vol. 15, No. 21. (17 October 2007), pp. 14129-14145.</i><br /><br />We introduce the concept of metafluids—liquid metamaterials based on clusters of metallic nanoparticles which we will term Artificial Plasmonic Molecules (APMs). APMs comprising four nanoparticles in a tetrahedral arrangement have isotropic electric and magnetic responses and are analyzed using the plasmon hybridization (PH) method, an electrostatic eigenvalue equation, and vectorial finite element frequency domain (FEFD) electromagnetic simulations. With the aid of group theory, we identify the resonances that provide the strongest electric and magnetic response and study them as a function of separation between spherical nanoparticles. It is demonstrated that a colloidal solution of plasmonic tetrahedral nanoclusters can act as an optical medium with very large, small, or even negative effective permittivity, ε eff , and substantial effective magnetic susceptibility, Χ eff = μ eff −1, in the visible or near infrared bands. We suggest paths for increasing the magnetic response, decreasing the damping, and developing a metafluid with simultaneously negative ε eff and μ eff . Plasmonic nanoclusters: a path towards negative-index metafluids Yaroslav Urzhumov Gennady Shvets Jonathan Fan Federico Capasso Daniel Brandl Peter Nordlander Opt. Express, Vol. 15, No. 21. (17 October 2007), pp. 14129-14145. 2008-05-09T23:39:20-00:00 2007 Opt. Express 15 21 14129 14145 OSA clusters colloidal structure http://www.citeulike.org/user/kedmond/article/2735404 <i>Nature materials, Vol. 6, No. 12. (December 2007), pp. 966-971.</i><br /><br />Recent large-scale computer simulations suggest that it may be possible to create a new class of soft solids, called 'bijels', by stabilizing and arresting the bicontinuous interface in a binary liquid demixing via spinodal decomposition using particles that are neutrally wetted by both liquids. The interfacial layer of particles is expected to be semi-permeable; hence, if realized, these new materials would have many potential applications, for example, as micro-reaction media. However, the creation of bijels in the laboratory faces serious obstacles. In general, fast quench rates are necessary to bypass nucleation, so that only samples with limited thickness can be produced, which destroys the three-dimensionality of the putative bicontinuous network. Moreover, even a small degree of unequal wettability of the particles by the two liquids can lead to ill-characterized, 'lumpy' interfacial layers and therefore irreproducible material properties. Here, we report a reproducible protocol for creating three-dimensional samples of bijel in which the interfaces are stabilized by essentially a single layer of particles. We demonstrate how to tune the mean interfacial separation in these bijels, and show that mechanically, they indeed behave as soft solids. These characteristics and their tunability will be of great value for microfluidic applications. Bicontinuous emulsions stabilized solely by colloidal particles. EM Herzig KA White AB Schofield WC Poon PS Clegg doi:10.1038/nmat2055 Nature materials, Vol. 6, No. 12. (December 2007), pp. 966-971. 2008-04-29T20:39:54-00:00 2007 Nature materials 1476-1122 6 12 966 971 colloidal material self-assembly http://www.citeulike.org/user/kedmond/article/2735360 <i>Nat Mater, Vol. 6, No. 12. (December 2007), pp. 921-922.</i> Colloids: A useful boundary Anthony Dinsmore doi:10.1038/nmat2062 Nat Mater, Vol. 6, No. 12. (December 2007), pp. 921-922. 2008-04-29T20:15:42-00:00 2007 Nat Mater 6 12 921 922 Nature Publishing Group colloidal self-assembly structure http://www.citeulike.org/user/kedmond/article/2759089 <i>Physical Review Letters, Vol. 95, No. 24. (2005)</i><br /><br />The phase diagram of a polydisperse hard-sphere system is examined by numerical minimization of a discretized form of the Ramakrishnan-Yussouff free-energy functional. Crystalline and glassy local minima of the free energy are located and the phase diagram in the density-polydispersity plane is mapped out by comparing the free energies of different local minima. The crystalline phase disappears and the glass becomes the equilibrium phase beyond a "terminal" value of the polydispersity. A crystal-to-glass transition is also observed as the density is increased at high polydispersity. The phase diagram obtained in our study is qualitatively similar to that of hard spheres in a quenched random potential. Equilibrium Glassy Phase in a Polydisperse Hard-Sphere System Pinaki Chaudhuri Smarajit Karmakar Chandan Dasgupta HR Krishnamurthy AK Sood doi:10.1103/PhysRevLett.95.248301 Physical Review Letters, Vol. 95, No. 24. (2005) 2008-05-05T20:00:41-00:00 2005 Physical Review Letters 95 24 APS colloidal glass polydisperse http://www.citeulike.org/user/kedmond/article/2759016 <i>Nature, Vol. 413, No. 6857. (18 October 2001), pp. 711-713.</i> Suppression of crystal nucleation in polydisperse colloids due to increase of the surface free energy Stefan Auer Daan Frenkel doi:10.1038/35099513 Nature, Vol. 413, No. 6857. (18 October 2001), pp. 711-713. 2008-05-05T19:04:46-00:00 2001 Nature 413 6857 711 713 colloidal crystals polydisperse http://www.citeulike.org/user/kedmond/article/1116822 <i>PNAS, Vol. 104, No. 8. (20 February 2007), pp. 2585-2590.</i><br /><br />Oil-water mixtures are ubiquitous in nature and are particularly important in biology and industry. Usually additives are used to prevent the liquid droplets from coalescing. Here, we show that stabilization can also be obtained from electrostatics, because of the well known remarkable properties of water. Preferential ion uptake leads to a tunable droplet charge and surprisingly stable, additive-free, water-in-oil emulsions that can crystallize. For particle-stabilized ("Pickering") emulsions we find that even extremely hydrophobic, nonwetting particles can be strongly bound to (like-charged) oil-water interfaces because of image charge effects. These basic insights are important for emulsion production, encapsulation, and (self-)assembly, as we demonstrate by fabricating a diversity of structures in bulk, on surfaces, and in confined geometries. 10.1073/pnas.0610589104 Electrostatics at the oil-water interface, stability, and order in emulsions and colloids Mirjam Leunissen Alfons van Blaaderen Andrew Hollingsworth Matthew Sullivan Paul Chaikin doi:10.1073/pnas.0610589104 PNAS, Vol. 104, No. 8. (20 February 2007), pp. 2585-2590. 2007-02-21T19:34:58-00:00 2007 PNAS 104 8 2585 2590 colloidal monodisperse salt self-assembly structure http://www.citeulike.org/user/kedmond/article/2735204 <i>Journal of Colloid and Interface Science, Vol. 245, No. 2. (15 January 2002), pp. 292-300.</i><br /><br />We report a single step procedure to prepare monodisperse colloidal poly(methyl)methacrylate (PMMA) particles where fluorescent dyes are incorporated into the polymer network. The particles are sterically stabilized against flocculation by poly(12-hydroxystearic acid). The fluorescent dyes are RITC (rhodamine isothiocyanate)-aminostyrene (RAS) and 4-methylaminoethylmethacrylate-7-nitrobenzo-2-oxa-1,3-diazol (NBD-MAEM), which are prepared from (commercially available) RITC and 4-chloro-7-nitrobenzo-2-oxa-1,3-diazol (NBD-Cl), respectively, as starting materials. The particles can be grown larger with nonfluorescent PMMA. Examples of the usefulness of these model particles in colloid science are given. Preparation of Monodisperse, Fluorescent PMMA-Latex Colloids by Dispersion Polymerization Gilles Bosma Chellapah Pathmamanoharan Els de Hoog Willem Kegel Alfons van Blaaderen Henk Lekkerkerker doi:10.1006/jcis.2001.7986 Journal of Colloid and Interface Science, Vol. 245, No. 2. (15 January 2002), pp. 292-300. 2008-04-29T18:44:51-00:00 2002 Journal of Colloid and Interface Science 245 2 292 300 colloidal fluorescence monodisperse synthesis http://www.citeulike.org/user/kedmond/article/2709774 <i>Physical Review E (Statistical, Nonlinear, and Soft Matter Physics), Vol. 76, No. 5. (2007)</i><br /><br />We find that a liquid jet can bounce off a bath of the same liquid if the bath is moving horizontally with respect to the jet. Previous observations of jets rebounding off a bath (e.g., the Kaye effect) have been reported only for non-Newtonian fluids, while we observe bouncing jets in a variety of Newtonian fluids, including mineral oil poured by hand. A thin layer of air separates the bouncing jet from the bath, and the relative motion replenishes the film of air. Jets with one or two bounces are stable for a range of viscosity, jet flow rate and velocity, and bath velocity. The bouncing phenomenon exhibits hysteresis and multiple steady states. Bouncing jet: A Newtonian liquid rebounding off a free surface Matthew Thrasher Sunghwan Jung Yee Pang Chih Chuu Harry Swinney doi:10.1103/PhysRevE.76.056319 Physical Review E (Statistical, Nonlinear, and Soft Matter Physics), Vol. 76, No. 5. (2007) 2008-04-23T18:50:25-00:00 2007 Physical Review E (Statistical, Nonlinear, and Soft Matter Physics) 76 5 APS fluid journal-club http://www.citeulike.org/user/kedmond/article/2184079 <i>Nat Phys, Vol. 3, No. 4. (April 2007), pp. 260-264.</i> Measurement of growing dynamical length scales and prediction of the jamming transition in a granular material Aaron Keys Adam Abate Sharon Glotzer Douglas Durian doi:10.1038/nphys572 Nat Phys, Vol. 3, No. 4. (April 2007), pp. 260-264. 2007-12-31T22:01:32-00:00 2007 Nat Phys 3 4 260 264 dyn-het granular jamming monodisperse http://www.citeulike.org/user/kedmond/article/2678397 <i>The Journal of Chemical Physics, Vol. 124, No. 21. (2006)</i><br /><br />View This Record in Scopus Nature of the breakdown in the Stokes-Einstein relationship in a hard sphere fluid Sanat Kumar Grzegorz Szamel Jack Douglas The Journal of Chemical Physics, Vol. 124, No. 21. (2006) 2008-04-16T15:47:53-00:00 2006 The Journal of Chemical Physics 124 21 AIP diffusion dyn-het rotation simulation http://www.citeulike.org/user/kedmond/article/2651302 <i>Physical Review Letters, Vol. 96, No. 1. (2006)</i><br /><br />Particle concentration is a dominant control parameter for colloids and other soft matter systems. We demonstrate a simple technique, "dielectrophoretic equilibrium," implemented as an "electric bottle," a planar capacitor in a larger volume. The uniform E field in the capacitor traps particles in this force-free region at a higher density than in the zero field regions outside. We show how the technique measures the equation of state and we initiate and grow colloidal crystals. "Dielectrophoretic equilibria" enable the study of a complete concentration-dependent phase diagram from a single microscopic sample, obviating the previous need for preparing a large number of samples. An Electric Bottle for Colloids MT Sullivan K Zhao AD Hollingsworth RH Austin WB Russel PM Chaikin doi:10.1103/PhysRevLett.96.015703 Physical Review Letters, Vol. 96, No. 1. (2006) 2008-04-11T01:03:28-00:00 2006 Physical Review Letters 96 1 APS colloidal structure http://www.citeulike.org/user/kedmond/article/2650355 <i>Langmuir, Vol. 21, No. 24. (22 November 2005), pp. 11510-11517.</i><br /><br />Abstract: We describe the synthesis and characterization of stable suspensions of monodisperse fluorescently labeled silica dumbbell particles. Pure dispersions of silica dumbbells with center-to-center lengths from 174 nm to 2.3 m were produced with a variety of aspect ratios. Individual particles in concentrated dispersions of these particles could be imaged with confocal microscopy. These particles can be used as a colloidal model system for addressing fundamental questions about crystal and glass formation of low-aspect-ratio anisotropic particles. They also have potential in photonic applications and electro-optical devices. Synthesis of Colloidal Silica Dumbbells PM Johnson CM Vankats A Vanblaaderen doi:10.1021/la0518750 Langmuir, Vol. 21, No. 24. (22 November 2005), pp. 11510-11517. 2008-04-10T19:12:15-00:00 2005 Langmuir 21 24 11510 11517 clusters colloidal self-assembly synthesis http://www.citeulike.org/user/kedmond/article/2630631 <i>Physical Review Letters, Vol. 100, No. 10. (2008)</i><br /><br />Density profiles are the most common measure of inhomogeneous structure in confined fluids, but their connection to transport coefficients is poorly understood. We explore via simulation how tuning particle-wall interactions to flatten or enhance the particle layering of a model confined fluid impacts its self-diffusivity, viscosity, and entropy. Interestingly, interactions that eliminate particle layering significantly reduce confined fluid mobility, whereas those that enhance layering can have the opposite effect. Excess entropy helps to understand and predict these trends. Tuning Density Profiles and Mobility of Inhomogeneous Fluids Gaurav Goel William Krekelberg Jeffrey Errington Thomas Truskett doi:10.1103/PhysRevLett.100.106001 Physical Review Letters, Vol. 100, No. 10. (2008) 2008-04-04T21:36:07-00:00 2008 Physical Review Letters 100 10 APS confinement simulation structure http://www.citeulike.org/user/cgguido/article/2483988 <i>Physical Review Letters, Vol. 78, No. 24. (16 June 1997), 4581.</i><br /><br />Using molecular dynamics simulations we study the out of equilibrium dynamic correlations in a model glass-forming liquid. The system is quenched from a high temperature to a temperature below its glass transition temperature and the decay of the two-time intermediate scattering function C ( t w ; t + t w ) is monitored for several values of the waiting time t w after the quench. We find that C ( t w ; t + t w ) shows a strong dependence on the waiting time; i.e.; aging; depends on the temperature before the quench; and; similar to the case of spin glasses; can be scaled onto a master curve. Aging Effects in a Lennard-Jones Glass Walter Kob Jean-Louis Barrat doi:10.1103/PhysRevLett.78.4581 Physical Review Letters, Vol. 78, No. 24. (16 June 1997), 4581. 2008-03-07T13:10:46-00:00 1997 Physical Review Letters 78 24 4581 American Physical Society no-tag http://www.citeulike.org/user/kedmond/article/2449291 <i>Langmuir, Vol. 24, No. 3. (5 February 2008), pp. 621-625.</i><br /><br />Abstract: Orientation-dependent interactions can drive unusual self-assembly of colloidal particles. This study, based on combined epifluorescence microscopy and Monte Carlo simulations, shows that amphiphilic colloidal spheres, hydrophobic on one hemisphere and charged on the other, assemble in water into extended structures not formed by spheres of uniform surface chemical makeup. Small, compact clusters each comprised of less than 10 of these Janus spheres link up, as increasing salt concentration enhances electrostatic screening, into wormlike strings. Clusters of Amphiphilic Colloidal Spheres L Hong A Cacciuto E Luijten S Granick doi:10.1021/la7030818 Langmuir, Vol. 24, No. 3. (5 February 2008), pp. 621-625. 2008-02-29T20:20:35-00:00 2008 Langmuir 24 3 621 625 clusters colloidal self-assembly http://www.citeulike.org/user/kedmond/article/2416039 <i>J. Am. Chem. Soc., Vol. 130, No. 4. (30 January 2008), pp. 1335-1340.</i><br /><br />Abstract: We report a technique for continuous production of microparticles of variable size with new forms of anisotropy including alternating bond angles, configurable patchiness, and uniform roughness. The sequence and shape of the anisotropic particles are configured by exploiting a combination of confinement effects and microfluidics to pack precursor colloids with different properties into a narrow, terminal channel. The width and length of the channel relative to the particle size fully specify the configuration of the anisotropic particle that will be produced. The precursor spheres packed in the production zone are then permanently bonded into particles by thermal fusing. The flow in the production zone is reversed to release the particles for collection and use. Particles produced have linear chain structure with precisely configured, repeatable bond angles. With software programmable microfluidics, sequence and shape anisotropy are combined to yield synthesized homogeneous (type "A"), surfactantlike (type "A-B") or triblock (type "A-B-A") internal sequences in a single device. By controlling the dimensions of the microfluidic production zone, triangular prisms and particles with controlled roughness and patchiness are produced. The fabrication method is performed with precursors spheres with diameter as small as 3.0 m. Programmable Fluidic Production of Microparticles with Configurable Anisotropy KE Sung SA Vanapalli D Mukhija HA Mckay J Mireckimillunchick MA Burns MJ Solomon doi:10.1021/ja0762700 J. Am. Chem. Soc., Vol. 130, No. 4. (30 January 2008), pp. 1335-1340. 2008-02-22T22:30:39-00:00 2008 J. Am. Chem. Soc. 130 4 1335 1340 clusters colloidal self-assembly synthesis http://www.citeulike.org/user/cgguido/article/2392081 <i>Colloid & Polymer Science, Vol. 274, No. 11. (1 November 1996), pp. 1072-1080.</i><br /><br />We present procedures for preparing sterically stabilized polymer particles whose refractive index can be controlled over a range of a few percent. Particle sphericity and size distribution are such that suspensions crystallize at high concentrations. This at least ensures that Brownian motion dominates over particle settling and that the polydispersity is no more than about 10%. Of particular interest are new particles comprising poly(methylmethacrylate-co-trifluoroethylacrylate) that can be optically matched in single solvent, namely cis-decalin. Refractive index variation in nonaqueous sterically stabilized copolymer particles SM Underwood W Megen doi:10.1007/BF00658372 Colloid & Polymer Science, Vol. 274, No. 11. (1 November 1996), pp. 1072-1080. 2008-02-18T03:25:04-00:00 1996 Colloid & Polymer Science 274 11 1072 1080 no-tag http://www.citeulike.org/user/cgguido/article/2391372 <i>Science, Vol. 281, No. 5375. (17 July 1998), pp. 389-392.</i><br /><br />10.1126/science.281.5375.389 Reversible Hydrogels from Self-Assembling Artificial Proteins Wendy Petka James Harden Kevin Mcgrath Denis Wirtz David Tirrell doi:10.1126/science.281.5375.389 Science, Vol. 281, No. 5375. (17 July 1998), pp. 389-392. 2008-02-17T20:17:14-00:00 1998 Science 281 5375 389 392 no-tag http://www.citeulike.org/user/cgguido/article/2391346 <i>Journal of Molecular Biology, Vol. 328, No. 1. (18 April 2003), pp. 193-204.</i><br /><br />Activation of glutamate decarboxylase (GAD) by calcium-bound calmodulin (CaM) is required for normal plant growth through regulation of [gamma]-aminobutyrate and glutamate metabolism. The interaction of CaM with the C-terminal domain of GAD is believed to induce dimerization of the enzyme, an event implicated for Ca2+-dependent enzyme activation. Here, we present the solution structure of CaM in complex with a dimer of peptides derived from the C-terminus of Petunia hybrida GAD. The 23 kDa ternary complex is pseudo-symmetrical with each domain of CaM bound to one of the two antiparallel GAD peptides, which form an X-shape with an interhelical angle of 60[degree sign]. To accommodate the dimeric helical GAD target, the two domains of CaM adopt an orientation markedly different from that seen in other CaM-target complexes. Although the dimeric GAD domain is much larger than previously studied CaM-binding peptides, the two CaM domains appear closer together and make a number of interdomain contacts not observed in earlier complexes. The present structure of a single CaM molecule interacting with two target peptides provides new evidence for the conformational flexibility of CaM as well as a structural basis for the ability of CaM to activate two enzyme molecules simultaneously. Structural Basis for Simultaneous Binding of Two Carboxy-terminal Peptides of Plant Glutamate Decarboxylase to Calmodulin Kyoko Yap Tao Yuan Tapas Mal Hans Vogel Mitsuhiko Ikura doi:10.1016/S0022-2836(03)00271-7 Journal of Molecular Biology, Vol. 328, No. 1. (18 April 2003), pp. 193-204. 2008-02-17T20:04:06-00:00 2003 Journal of Molecular Biology 328 1 193 204 no-tag http://www.citeulike.org/user/cgguido/article/2391339 <i>J. Biol. Chem., Vol. 272, No. 37. (12 September 1997), pp. 23050-23056.</i><br /><br />There exist two types of nitric-oxide synthase (NOS); constitutive isozymes that are activated by binding calmodulin in response to elevated Ca2+ and an inducible isozyme that binds calmodulin regardless of Ca2+. To study the structural basis of the difference in Ca2+ sensitivity, we have designed synthetic peptides of minimal lengths derived from the calmodulin-binding domain of endothelial NOS (eNOS) and that of macrophage NOS (iNOS). A peptide, KRREIPLKVLVKAVLFACMLMRK, derived from human iNOS sequence, retained the ability to bind to calmodulin both in the presence and absence of Ca2+, while a peptide derived from human eNOS sequence, RKKTFKEVANAVKISASLMG, bound to calmodulin only in the presence of Ca2+. Circular dichroism and two-dimensional 1H nuclear magnetic resonance studies suggested that both peptides assume nascent [alpha]-helical structures in aqueous solution. When mixed with calmodulin, both peptides showed circular dichroism spectra characteristic for [alpha]-helix. In contrast to other target proteins, the addition of iNOS peptide to calmodulin did not affect the Ca2+ binding of calmodulin appreciably. The peptide derived from the calmodulin-binding domain of iNOS, therefore, binds in [alpha]-helical structures both to Ca2+-calmodulin and apo-calmodulin, which is unique among various target proteins of calmodulin. 10.1074/jbc.272.37.23050 Circular Dichroism and 1H NMR Studies on the Structures of Peptides Derived from the Calmodulin-binding Domains of Inducible and Endothelial Nitric-oxide Synthase in Solution and in Complex with Calmodulin. NASCENT alpha -HELICAL STRUCTURES ARE STABILIZED BY CALMODULIN BOTH IN THE PRESENCE AND ABSENCE OF Ca2+ Mamoru Matsubara Nobuhiro Hayashi Koiti Titani Hisaaki Taniguchi doi:10.1074/jbc.272.37.23050 J. Biol. Chem., Vol. 272, No. 37. (12 September 1997), pp. 23050-23056. 2008-02-17T20:00:59-00:00 1997 J. Biol. Chem. 272 37 23050 23056 no-tag http://www.citeulike.org/user/cgguido/article/2389300 <i>J. Phys. Chem. B, Vol. 111, No. 27. (12 July 2007), pp. 7796-7801.</i><br /><br />Abstract: Microgel particles with a soft repulsive interaction potential are investigated with particle tracking methods to study the phase behavior of soft-sphere systems. The use of poly(N-isopropylacrylamide) particles allows the effective volume fraction of a sample to be tuned via thermal modulation without altering the particle number density. This allows for investigation of the phase behavior of an assembly as a function of its initial packing density. In particular, we have elucidated the influence of soft colloid "overpacking" on the freezing effective volume fraction (eff,f). These studies thereby illustrate the interplay between energetics/packing forces occurring at the colloidal and polymer chain length scales. Phase Behavior in Highly Concentrated Assemblies of Microgels with Soft Repulsive Interaction Potentials Ashley St. John V Breedveld LA Lyon doi:10.1021/jp071630r J. Phys. Chem. B, Vol. 111, No. 27. (12 July 2007), pp. 7796-7801. 2008-02-16T23:27:44-00:00 2007 J. Phys. Chem. B 111 27 7796 7801 nipa http://www.citeulike.org/user/cgguido/article/2066011 <i>The Journal of Chemical Physics, Vol. 124, No. 12. (2006)</i><br /><br />  Gel to glass transition in simulation of a valence-limited colloidal system E Zaccarelli Saika Voivod SV Buldyrev AJ Moreno P Tartaglia F Sciortino The Journal of Chemical Physics, Vol. 124, No. 12. (2006) 2007-12-06T09:30:33-00:00 2006 The Journal of Chemical Physics 124 12 AIP no-tag http://www.citeulike.org/user/kedmond/article/2052388 <i>Langmuir, Vol. 19, No. 15. (22 July 2003), pp. 5963-5966.</i><br /><br />Abstract: Monodisperse cross-linked composite PMMA latex particles have been developed. The chemical cross-linking of the PMMA facilitates the preparation of particles consisting of a fluorescent core and a large nonfluorescent shell. These core-shell spheres can be dispersed in a density and refractive index matching mixture. This results in an ideal colloidal hard sphere model system that can be used to study many fundamental problems such as freezing, melting, and the glass transistion using quantitative confocal scanning laser microscopy. Furthermore, precize control over the size and the properties of the core and the shell(s) facilitates other applications of this model system. Monodisperse Core-Shell Poly(methyl methacrylate) Latex Colloids RPA Dullens EM Claesson D Derks A Vanblaaderen WK Kegel doi:10.1021/la034636q Langmuir, Vol. 19, No. 15. (22 July 2003), pp. 5963-5966. 2007-12-03T20:34:22-00:00 2003 Langmuir 19 15 5963 5966 colloidal monodisperse synthesis http://www.citeulike.org/user/kedmond/article/2052375 <i>Langmuir, Vol. 20, No. 3. (3 February 2004), pp. 658-664.</i><br /><br />Abstract: We report a single step preparation of monodisperse fluorescent poly(methyl)methacrylate (PMMA) lattices cross-linked with ethylene glycol dimethacrylate with radii in the range 150-1000 nm using dispersion polymerization. The particles are applied as fluorescent cores in core-shell PMMA particles for confocal microscopy (Dullens et al. Langmuir 2003, 19, 5963). Contrary to un-cross-linked particles, these cross-linked colloids are stable in good solvents for PMMA as well. Therefore we studied the properties of the cross-linked PMMA particles in the good solvents tetrahydrofuran (THF), chloroform, and toluene using light scattering and confocal scanning laser microscopy. We show that the particles swell instantaneously and that their volume can increase up to more than seven times their volume in poor solvents. Further, it is very likely that the particles are charged in THF. Preparation and Properties of Cross-Linked Fluorescent Poly(methyl methacrylate) Latex Colloids RPA Dullens EM Claesson WK Kegel doi:10.1021/la035729a Langmuir, Vol. 20, No. 3. (3 February 2004), pp. 658-664. 2007-12-03T20:31:49-00:00 2004 Langmuir 20 3 658 664 colloidal monodisperse synthesis http://www.citeulike.org/user/kedmond/article/2019405 <i>Soft Matter, Vol. 2 (2006), pp. 805-810.</i><br /><br />In this article we highlight our recent work on the development of crosslinked core–shell polymethyl-methacrylate colloids and their application as colloidal model hard spheres for quantitative confocal microscopy. Moreover, we demonstrate that synthesizing colloids (cooking) does not only lead to the final core–shell particles, but also to intermediate-product-particles, which are interesting in their own right and offer additional possibilities for various physical experiments (looking). In particular, we focus on the application of crosslinked latex particles as microgel particles, non-spherically shaped particles as model particles for shape-induced geometrical frustration and the final core–shell particles for the direct measurement of thermodynamic properties using quantitative real-space confocal microscopy. Colloidal hard spheres: cooking and looking Roel Dullens doi:10.1039/b607017e Soft Matter, Vol. 2 (2006), pp. 805-810. 2007-11-29T21:25:27-00:00 2006 Soft Matter 2 805 810 colloidal fluorescence synthesis http://www.citeulike.org/user/kedmond/article/2007848 <i>Solid State Communications, Vol. 139, No. 11-12. (September 2006), pp. 557-561.</i><br /><br />I discuss how colloidal particles organize when they are confined by emulsion droplets. In these systems, the interplay between surface tension and interparticle repulsion drives the formation of complex, non-crystalline 3D arrangements. These can be classified into three groups: colloidosomes, or Pickering emulsions, structures that form when particles are bound to the interface of a spherical droplet; colloidal clusters, small polyhedral configurations of colloids formed by capillary forces generated in an evaporating emulsion droplet; and supraparticles, ball-shaped crystallites formed in the interior of emulsion droplets. I discuss the preparation, properties, and structure of each of these systems, using relevant results from geometry to describe how the particles organize. Colloidal spheres confined by liquid droplets: Geometry, physics, and physical chemistry Vinothan Manoharan doi:10.1016/j.ssc.2006.04.038 Solid State Communications, Vol. 139, No. 11-12. (September 2006), pp. 557-561. 2007-11-28T22:06:18-00:00 2006 Solid State Communications 139 11-12 557 561 clusters colloidal droplets self-assembly http://www.citeulike.org/user/kedmond/article/2007672 <i>Nat Mater, Vol. 6, No. 7. (2007), pp. 557-562.</i> Anisotropy of building blocks and their assembly into complex structures Sharon Glotzer Michael Solomon doi:10.1038/nmat1949 Nat Mater, Vol. 6, No. 7. (2007), pp. 557-562. 2007-11-28T21:37:26-00:00 2007 Nat Mater 6 7 557 562 colloidal material self-assembly structure synthesis http://www.citeulike.org/user/kedmond/article/1947615 <i>Science, Vol. 318, No. 5852. (9 November 2007), pp. 924-925.</i><br /><br />10.1126/science.1148009 CHEMISTRY: Enhancing Colloids Through the Surface Erik Nelson Paul Braun doi:10.1126/science.1148009 Science, Vol. 318, No. 5852. (9 November 2007), pp. 924-925. 2007-11-21T01:27:41-00:00 2007 Science 318 5852 924 925 biophysics colloidal self-assembly structure synthesis http://www.citeulike.org/user/cgguido/article/1911661 <i>Methods, Vol. 19, No. 3. (November 1999), pp. 373-385.</i><br /><br />Deconvolution is a computational method used to reduce out-of-focus fluorescence in three-dimensional (3D) microscope images. It can be applied in principle to any type of microscope image but has most often been used to improve images from conventional fluorescence microscopes. Compared to other forms of 3D light microscopy, like confocal microscopy, the advantage of deconvolution microscopy is that it can be accomplished at very low light levels, thus enabling multiple focal-plane imaging of light-sensitive living specimens over long time periods. Here we discuss the principles of deconvolution microscopy, describe different computational approaches for deconvolution, and discuss interpretation of deconvolved images with a particular emphasis on what artifacts may arise. Three-Dimensional Imaging by Deconvolution Microscopy James Mcnally Tatiana Karpova John Cooper Jose Conchello doi:10.1006/meth.1999.0873 Methods, Vol. 19, No. 3. (November 1999), pp. 373-385. 2007-11-14T01:18:01-00:00 1999 Methods 19 3 373 385 deconvolution microscopy http://www.citeulike.org/user/cgguido/article/1911645 <i>Science, Vol. 248, No. 4951. (6 April 1990), pp. 73-76.</i><br /><br />Molecular excitation by the simultaneous absorption of two photons provides intrinsic three-dimensional resolution in laser scanning fluorescence microscopy. The excitation of fluorophores having single-photon absorption in the ultraviolet with a stream of strongly focused subpicosecond pulses of red laser light has made possible fluorescence images of living cells and other microscopic objects. The fluorescence emission increased quadratically with the excitation intensity so that fluorescence and photo-bleaching were confined to the vicinity of the focal plane as expected for cooperative two-photon excitation. This technique also provides unprecedented capabilities for three-dimensional, spatially resolved photochemistry, particularly photolytic release of caged effector molecules. 10.1126/science.2321027 Two-photon laser scanning fluorescence microscopy W Denk JH Strickler WW Webb doi:10.1126/science.2321027 Science, Vol. 248, No. 4951. (6 April 1990), pp. 73-76. 2007-11-14T01:10:42-00:00 1990 Science 248 4951 73 76 microscopy two-photon http://www.citeulike.org/user/cgguido/article/1900631 <i>The Journal of Chemical Physics, Vol. 111, No. 12. (1999), pp. 5441-5454.</i><br /><br />Molecular dynamics simulations are used to explore the spatial fluctuations associated with structural relaxation and particle transport in a supercooled binary mixture in two dimensions. The study includes (i) the characterization of heterogeneities in the local particle dynamics in terms of their length scale and lifetime, (ii) the relationship between local kinetics and local structure/composition, and (iii) preliminary identification of the principal collective motions involved in the long-time relaxation of the supercooled liquid. Relaxation dynamics and their spatial distribution in a two-dimensional glass-forming mixture DN Perera P Harrowell The Journal of Chemical Physics, Vol. 111, No. 12. (1999), pp. 5441-5454. 2007-11-12T01:53:38-00:00 1999 The Journal of Chemical Physics 111 12 5441 5454 AIP no-tag http://www.citeulike.org/user/cgguido/article/1900586 <i>The Journal of Chemical Physics, Vol. 89, No. 10. (1988), pp. 6461-6469.</i> Relaxation and flow mechanisms in “fragile” glass-forming liquids Frank Stillinger The Journal of Chemical Physics, Vol. 89, No. 10. (1988), pp. 6461-6469. 2007-11-12T01:38:26-00:00 1988 The Journal of Chemical Physics 89 10 6461 6469 AIP bibtex-import flow glass liquids relaxation shear supercooled transformations viscosity http://www.citeulike.org/user/cgguido/article/1875698 <i>Physical Review E, Vol. 51, No. 5. (May 1995), 4626.</i><br /><br />We report the results of a large scale computer simulation of a binary supercooled Lennard-Jones liquid. We find that at low temperatures the curves for the mean squared displacement of a tagged particle for different temperatures fall onto a master curve when they are plotted versus rescaled time tD ( T ); where D ( T ) is the diffusion constant. The time range for which these curves follow the master curve is identified with the α-relaxation regime of mode-coupling theory (MCT). This master curve is fitted well by a functional form suggested by MCT. In accordance with idealized MCT; D ( T ) shows a power-law behavior at low temperatures. The critical temperature of this power law is the same for both types of particles; and also the critical exponents are very similar. However; contrary to a prediction of MCT; these exponents are not equal to the ones determined previously for the divergence of the relaxation times of the intermediate scattering function [Phys. Rev. Lett. 73 ; 1376 (1994)]. At low temperatures; the van Hove correlation function (self as well as distinct part) shows almost no sign of relaxation in a time interval that extends over about three decades in time. This time interval can be interpreted as the β-relaxation regime of MCT. From the investigation of these correlation functions; we conclude the hopping processes are not important on the time scale of the β relaxation for this system and for the temperature range investigated. We test whether the factorization property predicted by MCT holds and find that this is indeed the case for all correlation functions investigated. The distance dependences of the critical amplitudes are in qualitative agreement with the ones predicted by MCT for some other mixtures. The non-Gaussian parameter for the self part of the van Hove correlation function for different temperatures follows a master curve when plotted against time t . Testing mode-coupling theory for a supercooled binary Lennard-Jones mixture I: The van Hove correlation function Walter Kob Hans Andersen doi:10.1103/PhysRevE.51.4626 Physical Review E, Vol. 51, No. 5. (May 1995), 4626. 2007-11-07T00:31:38-00:00 1995 Physical Review E 51 5 4626 American Physical Society no-tag http://www.citeulike.org/user/cgguido/article/1900525 <i>Reports of the Institute of Fluid Science, Vol. 19 (2007), pp. 51-56.</i> Aging of tetrahedral structure in a Lennard-Jones glass GC Cianci ER Weeks Reports of the Institute of Fluid Science, Vol. 19 (2007), pp. 51-56. 2007-11-12T01:13:18-00:00 2007 Reports of the Institute of Fluid Science 19 51 56 The Institute of Fluid Science no-tag http://www.citeulike.org/user/cgguido/article/1900353 <i>Physical Review E, Vol. 66, No. 3. (2002), pp. 030101-030105.</i><br /><br />We present a calculation of a fourth-order; time-dependent density correlation function that measures higher-order spatiotemporal correlations of the density of a liquid. From molecular dynamics simulations of a glass-forming Lennard-Jones liquid; we find that the characteristic length scale of this function has a maximum as a function of time which increases steadily beyond the characteristic length of the static pair correlation function g ( r ) in the temperature range approaching the mode coupling temperature from above. This length scale provides a measure of the spatially heterogeneous nature of the dynamics of the liquid in the alpha-relaxation regime. Growing correlation length on cooling below the onset of caging in a simulated glass-forming liquid N Lačević FW Starr TB Schrøder VN Novikov SC Glotzer doi:10.1103/PhysRevE.66.030101 Physical Review E, Vol. 66, No. 3. (2002), pp. 030101-030105. 2007-11-12T00:33:00-00:00 2002 Physical Review E 66 3 030101 030105 American Physical Society caging correlations lennard-jones simulation http://www.citeulike.org/user/cgguido/article/1875705 <i>Physical Review E, Vol. 60, No. 3. (1999), pp. 3107-3119.</i><br /><br />Using extensive molecular dynamics simulations of an equilibrium; glass-forming Lennard-Jones mixture; we characterize in detail the local atomic motions. We show that spatial correlations exist among particles undergoing extremely large (“mobile”) or extremely small (“immobile”) displacements over a suitably chosen time interval. The immobile particles form the cores of relatively compact clusters; while the mobile particles move cooperatively and form quasi-one-dimensional; stringlike clusters. The strength and length scale of the correlations between mobile particles are found to grow strongly with decreasing temperature; and the mean cluster size appears to diverge near the mode-coupling critical temperature. We show that these correlations in the particle displacements are related to equilibrium fluctuations in the local potential energy and local composition. Spatial correlations of mobility and immobility in a glass-forming Lennard-Jones liquid Claudio Donati Sharon Glotzer Peter Poole Walter Kob Steven Plimpton doi:10.1103/PhysRevE.60.3107 Physical Review E, Vol. 60, No. 3. (1999), pp. 3107-3119. 2007-11-07T00:33:19-00:00 1999 Physical Review E 60 3 3107 3119 American Physical Society correlations glass lennard-jones simulation http://www.citeulike.org/user/cgguido/article/1900317 <i>Pramana, Vol. 64, No. 6. (2005), pp. 1109-1120.</i> Aging, rejuvenation and memory phenomena in spin glasses V Dupuis F Bert JP Bouchaud J Hammann F Ladieu D Parker E Vincent Pramana, Vol. 64, No. 6. (2005), pp. 1109-1120. 2007-11-12T00:21:01-00:00 2005 Pramana 64 6 1109 1120 bibtex-import http://www.citeulike.org/user/cgguido/article/1900292 <i>Physics World, Vol. 12 (1999), pp. 54-54.</i> Glass Physics: Still not transparent K Binder J Bashnagel W Kob Physics World, Vol. 12 (1999), pp. 54-54. 2007-11-12T00:10:33-00:00 1999 Physics World 12 54 54 no-tag http://www.citeulike.org/user/cgguido/article/1900279 <i>Journal of Colloid and Interface Science, Vol. 109, No. 1. (January 1986), pp. 161-171.</i><br /><br />We present an experimental study of phase transitions induced in polystyrene latices by hydroxyethylcellulose and interpret the results by applying perturbation theory from statistical mechanics to an interaction potential derived from the volume exclusion mechanism of Akasura and Oosawa. The predictions agree semiquantitatively with the measured colloidal phase densities and the critical polymer concentration above which flocculation occurs for a wide range of ionic strengths. The theory also predicts the type of phase transition, i.e., fluid-solid or fluid-fluid, observed by Sperry. The agreement between experiment and theory demonstrates the predictive capability of the perturbation theory for weakly aggregating colloidal suspensions. An experimental and theoretical study of phase transitions in the polystyrene latex and hydroxyethylcellulose system AP Gast WB Russel CK Hall doi:10.1016/0021-9797(86)90291-2 Journal of Colloid and Interface Science, Vol. 109, No. 1. (January 1986), pp. 161-171. 2007-11-12T00:04:37-00:00 1986 Journal of Colloid and Interface Science 109 1 161 171 no-tag http://www.citeulike.org/user/cgguido/article/1900263 <i>Journal of Colloid and Interface Science, Vol. 55, No. 3. (June 1976), pp. 487-498.</i><br /><br />Flocculation of a monodisperse polystyrene latex by the addition of sodium polyacrylate (SPA) is studied by bulk observation and in situ observation of the particles by an optical microscope. The results of the bulk observation, namely, the apparent feature of flocculation produced by various amount of SPA added, are in accordance with knowledge now widely known, except that in the presence of certain amounts of SPA the subsided sediment and the wall of the vessel are tinted with iridescence. But the results of the microscopic observation are rather striking; (1) the particles in each floc are arranged in highly regular hexagonal arrays, (2) the flocs (preferably called crystallites) grow and finally attain an equilibrium state with the environment, (3) nucleation, segregation and so forth are observed. These processes are reversible; namely, by shaking the vessel, the flocs are decomposed into a dispersion of single particles and upon quiet standing form again. The behavior of the particles closely resembles what we picture about the growth of real crystals (of atoms or molecules) from vapor. Ordered structure in weakly flocculated monodisperse latex Akira Kose Sei Hachisu doi:10.1016/0021-9797(76)90059-X Journal of Colloid and Interface Science, Vol. 55, No. 3. (June 1976), pp. 487-498. 2007-11-11T23:56:13-00:00 1976 Journal of Colloid and Interface Science 55 3 487 498 no-tag http://www.citeulike.org/user/cgguido/article/1900254 <i>The Journal of Chemical Physics, Vol. 49, No. 8. (1968), pp. 3609-3617.</i> Melting Transition and Communal Entropy for Hard Spheres William Hoover Francis Ree The Journal of Chemical Physics, Vol. 49, No. 8. (1968), pp. 3609-3617. 2007-11-11T23:51:46-00:00 1968 The Journal of Chemical Physics 49 8 3609 3617 AIP bibtex-import http://www.citeulike.org/user/cgguido/article/1900163 <i>(01 April 2002)</i><br /><br />Defects and geometrical patterns embedded in orderly arrays of atoms and molecules explain important everyday phenomena such as why soap is slippery, why steel is strong, and how a liquid crystal display device works. An understanding of how to pin vortex defects in superconductors is essential for applications such as magnetic levitation and improved magnetic resonance imaging devised for medical diagnosis. This book discusses the crucial role played by defects and geometry in disrupting order in solids, superconductors, superfluids, liquid crystals and polymers. Defects & Geometry in Condensed Matter Physics David Nelson (01 April 2002) 2007-11-11T23:09:56-00:00 2002 Cambridge University Press glass review structure tetrahedra http://www.citeulike.org/user/cgguido/article/1900142 <i>Nuclear Physics B, Vol. 240, No. 1. (20 August 1984), pp. 113-139.</i><br /><br />Order in supercooled liquids and metallic glasses is related to a regular icosahedral "crystal" consisting of 120 particles inscribed on the surface of a sphere in four dimensions. Hyperspherical harmonics and the discrete symmetry group of this four-dimensional platonic solid can be used to construct an order parameter for glasses in three-dimensional flat space. A uniformly frustrated Landau expansion in this order parameter suggests a ground state with a regular array of wedge disclination lines. Homotopy theory is used to classify all topologically stable defects. A generalization of Bloch's theorem for electronic states in flat space solids allows explicit diagonalization of tight binding models defined on the curved-space icosahedral crystal. Symmetry, Landau theory and polytope models of glass David Nelson Michael Widom doi:10.1016/0550-3213(84)90281-5 Nuclear Physics B, Vol. 240, No. 1. (20 August 1984), pp. 113-139. 2007-11-11T23:02:01-00:00 1984 Nuclear Physics B 240 1 113 139 glass structure theory http://www.citeulike.org/user/cgguido/article/1900118 <i>Science, Vol. 270, No. 5239. (1995), pp. 1177-1179.</i> Real-Space Structure of Colloidal Hard-Sphere Glasses A van Blaaderen P Wiltzius Science, Vol. 270, No. 5239. (1995), pp. 1177-1179. 2007-11-11T22:50:11-00:00 1995 Science 270 5239 1177 1179 bibtex-import http://www.citeulike.org/user/cgguido/article/1900024 <i>Physical Review Letters, Vol. 84, No. 10. (6 March 2000), 2275.</i><br /><br />We use multispeckle dynamic light scattering to measure the dynamic structure factor; f ( q ;τ); of gels formed by aggregation of colloids. Although the gel is an elastic solid; f ( q ;τ) nearly completely decays on long time scales; with an unusual form; f ( q ;τ)∼exp-(τ / τ f ) μ ; with μ≈1.5 and with τ f ∝ q -1 . A model for restructuring of the gel with aging correctly accounts for this behavior. Aging leads to a dramatic increase in τ f ; however; all data can be scaled on a single master curve; with τ f asymptotically growing linearly with age. This behavior is strikingly similar to that predicted for aging in disordered glassy systems; offering convincing proof of the universality of these concepts. Universal Aging Features in the Restructuring of Fractal Colloidal Gels Luca Cipelletti S Manley RC Ball DA Weitz doi:10.1103/PhysRevLett.84.2275 Physical Review Letters, Vol. 84, No. 10. (6 March 2000), 2275. 2007-11-11T22:14:46-00:00 2000 Physical Review Letters 84 10 2275 American Physical Society gel light-scattering