Fri, 04 Jul 2008 23:47:01 BST CiteULike: Tag monodisperse http://www.citeulike.org/tag/monodisperse CiteULike.org en-gb Copyright © 2004-2008 citeulike.org http://www.citeulike.org/user/rodney/article/1537225 <i>Advanced Materials, Vol. 12, No. 10. (2000), pp. 693-713.</i><br /><br />This article presents an overview of current research activities that center on monodispersed colloidal spheres whose diameter falls anywhere in the range of 10 nm to 1 &mgr;m. It is organized into three parts: The first part briefly discusses several useful methods that have been developed for producing monodispersed colloidal spheres with tightly controlled sizes and well-defined properties (both surface and bulk). The second part surveys some techniques that have been demonstrated for organizing these colloidal spheres into two- and three-dimensionally ordered lattices. The third part highlights a number of unique applications of these crystalline assemblies, such as their uses as photonic bandgap (PBG) crystals; as removable templates to fabricate macroporous materials with highly ordered and three-dimensionally interconnected porous structures; as physical masks in lithographic patterning; and as diffractive elements to fabricate new types of optical sensors. Finally, we conclude with some personal perspectives on the directions towards which future research in this area might be directed. Monodispersed Colloidal Spheres: Old Materials with New Applications Y Xia B Gates Y Yin Y Lu doi:10.1002/(SICI)1521-4095(200005)12:10<693::AID-ADMA693>3.0.CO;2-J Advanced Materials, Vol. 12, No. 10. (2000), pp. 693-713. 2007-08-06T03:01:11-00:00 2000 Advanced Materials 12 10 693 713 colloidal monodisperse monolayer spheres http://www.citeulike.org/user/rodney/article/1427736 <i>Langmuir, Vol. 22, No. 4. (14 February 2006), pp. 1822-1827.</i><br /><br />Abstract: We report on the preparation of monodisperse, fluorescent hematite-silica core-shell ellipsoids, with adjustable shapes ranging from spindles to nearly spheres, that are suitable for optical rotational diffusion studies. Hematite cores are grafted with poly(vinylpyrrolidone) which ensures colloidal stability during the silica coating provided by the base-catalyzed hydrolysis and polymerization of tetraethoxysilane. Using tetramethylammonium hydroxide as base instead of the volatile ammonia facilitates continuous seeded growth of silica to colloids with a desired aspect ratio. A convenient feature of the hematite-silica particles is the rapid dissolution of the iron oxide core by acid, producing hollow silica ellipsoids that can be optically matched to near transparency. The control of shape and size of the silica ellipsoids, their optical properties, and the fairly high yield in comparison to other preparation methods for nonspherical model colloids make the ellipsoids very suitable for quantitative studies. As a case in point, we have measured the rotational diffusion coefficient of fluorescent ellipsoids with rotational fluorescence recovery after photobleaching. Dye-labeled ellipsoids can be imaged with confocal microscopy. Fluorescent Monodisperse Silica Ellipsoids for Optical Rotational Diffusion Studies S Sacanna L Rossi BWM Kuipers AP Philipse doi:10.1021/la052484o Langmuir, Vol. 22, No. 4. (14 February 2006), pp. 1822-1827. 2007-07-01T22:35:33-00:00 2006 Langmuir 22 4 1822 1827 aspherical diffusion ellipsoidal fluorescence monodisperse optical rotational silica http://www.citeulike.org/user/rodney/article/1567866 <i>pp. 182-184.</i><br /><br />We have prepared monodisperse suspensions of nematic liquid crystal droplets in water. The droplets are stabilized by polyvinyl alcohol, a polymer that induces planar anchoring of the liquid crystal molecules at the surface of the droplets. The resultant particles exhibit strong optical anisotropy while having a spherical shape. As a consequence, the light scattering from the particles contains a strong depolarized component. We report a simple application of this feature by performing dynamic light scattering experiments to measure the rotational diffusion of colloidal spheres in a dilute suspension. Rotational Diffusion of Monodisperse Liquid Crystal Droplets P Hsu P Poulin DA Weitz pp. 182-184. 2007-08-16T01:47:34-00:00 182 184 brownian crystal diffusion droplets liquid monodisperse rotational http://www.citeulike.org/user/rbgrubbs/article/2320669 <i>J. Am. Chem. Soc., Vol. 130, No. 5. (6 February 2008), pp. 1718-1726.</i><br /><br />Abstract: The synthesis of molecularly defined -caprolactone oligomers and polymers up to the 64-mer, via an exponential growth strategy, is described. By careful selection of orthogonal protecting groups, t-butyldimethylsilyl (TBDMS) ether for the hydroxyl group and benzyl (Bn) ester for the carboxylic acid group, a highly efficient synthetic strategy was developed with yields for both deprotection steps being essentially quantitative and for the coupling reactions using 1,3-dicyclohexylcarbodiimide (DCC), yields of 80-95% were obtained even at high molecular weights. This allows monodisperse dimers, tetramers, octamers, 16-mers, 32-mers and 64-mers to be prepared in gram quantities and fully characterized using mass spectroscopy, size exclusion chromatography (SEC), and IR and NMR spectroscopy. Thermal and physical properties were measured using thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), atomic force microscopy (AFM), and small-angle X-ray scattering (SAXS). These results conclusively show a distinct structure/property relationship with a close correlation between the number of repeat units and physical properties. In addition, a number of marked differences were observed on comparison with the parent poly(caprolactone) polymer. Molecularly Defined Caprolactone Oligomers and Polymers: Synthesis and Characterization K Takizawa C Tang CJ Hawker doi:10.1021/ja077149w J. Am. Chem. Soc., Vol. 130, No. 5. (6 February 2008), pp. 1718-1726. 2008-02-01T21:22:15-00:00 2008 J. Am. Chem. Soc. 130 5 1718 1726 monodisperse http://www.citeulike.org/user/kedmond/article/1389134 <i>Langmuir, Vol. 22, No. 1. (3 January 2006), pp. 57-62.</i><br /><br />Abstract: We describe a six-step method for making colloidal clusters of 2, 3, or 4 silica particles with a radius of 1.2 m. This method, originally described by Manoharan et al. (Manoharan, V. N.; Elsesser, M. T.; Pine, D. J. Science 2003, 301, 483), is based on the encapsulation of silica spheres in emulsion droplets. The originality of our work lies in the preparation of monodisperse emulsions, which allows us to obtain some high yields of small aggregates over a wide range of conditions. Using optical microscopy and disk centrifugation, we show that the relative fractions of 2, 3, and 4 particle aggregates are controlled by the emulsification conditions, particularly the concentration of silica in the dispersed phase. Our best yields are obtained using low to moderate shear rates, a highly viscous continuous phase, and intermediate amounts of silica. The sedimentation of the colloidal solution into a gradient of concentration leads to aqueous suspensions of identical clusters. Since the overall process can easily be scaled up, large quantities of identical clusters may be prepared, which should allow the thermodynamic properties of these new colloidal objects to be measured for the first time. These nonspherical particles could serve as building blocks for more complex assemblies, such as colloidal crystals which could find applications as photonic materials. Preparation of Doublet, Triangular, and Tetrahedral Colloidal Clusters by Controlled Emulsification D Zerrouki B Rotenberg S Abramson J Baudry C Goubault F Leal-Calderon DJ Pine J Bibette doi:10.1021/la051765t Langmuir, Vol. 22, No. 1. (3 January 2006), pp. 57-62. 2007-06-14T03:52:26-00:00 2006 Langmuir 22 1 57 62 colloidal emulsions monodisperse qualifier self-assembly 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/1300574 <i>Langmuir, Vol. 22, No. 17. (15 August 2006), pp. 7128-7131.</i><br /><br />Abstract: The simple strategy of coating a closely packed colloid monolayer with a nanometer-thick metal film to connect colloidal spheres and then gently sonicating produces a series of colloid metastructures, including rods and planar sheets. These structures can be fluorescently labeled, which can serve as a probe to monitor their dynamics in complex environments. The metal coating modulates fluorescence emission as these structures rotate in suspension. By analyzing the time sequence of fluorescence images using single-particle tracking techniques, here we measure the rotational dynamics of a rodlike tetramer, quantifying rotation along the long axis. Rotation in Suspension of a Rod-Shaped Colloid L Hong SM Anthony S Granick doi:10.1021/la061169e Langmuir, Vol. 22, No. 17. (15 August 2006), pp. 7128-7131. 2007-05-16T17:25:39-00:00 2006 Langmuir 22 17 7128 7131 colloidal fluorescence microscopy monodisperse moon rotation self-assembly http://www.citeulike.org/user/kedmond/article/1337781 <i>Colloid & Polymer Science, Vol. 282, No. 1. (1 December 2003), pp. 7-13.</i><br /><br />We discuss a dispersion polymerization procedure for preparing monodisperse and micron-sized poly(methyl methacrylate) (PMMA) particles in hexanes with methacryloxypropyl-terminated polydimethylsiloxane stabilizers. We investigate the effects of the stabilizer molecular weight, stabilizer concentration, and monomer concentration on the particle size and polydispersity. We find that a minimum molecular weight of 10 000 g/mol is necessary to synthesize colloidally stable PMMA dispersions. The particle polydispersity is minimal (=5%) for stabilizer to monomer weight ratios of 0.02 to 0.1, while PMMA particles prepared under conditions outside this range are polydisperse. The particle diameter can be varied from 0.4 to 1.5 µm by appropriate choices of stabilizer and monomer concentrations. Stable PMMA suspensions can be prepared at up to 26.3% solids. The dispersions are stable in most liquid aliphatics, and are monodisperse enough to form ordered domains at high concentration. This single-stage synthesis, requiring only commercially available materials, may be of interest to those seeking a simple way to prepare highly monodisperse non-aqueous dispersions in the micron size range. Preparation of monodisperse PMMA microspheres in nonpolar solvents by dispersion polymerization with a macromonomeric stabilizer Sascham Klein Vinothann Manoharan Davidj Pine Fredf Lange doi:10.1007/s00396-003-0915-0 Colloid & Polymer Science, Vol. 282, No. 1. (1 December 2003), pp. 7-13. 2007-05-27T21:14:34-00:00 2003 Colloid & Polymer Science 282 1 7 13 clusters colloidal monodisperse qualifier synthesis http://www.citeulike.org/user/kedmond/article/1201447 <i>Langmuir, Vol. 16, No. 2. (25 January 2000), pp. 347-351.</i><br /><br />Abstract: We describe an experimental technique for the production of highly monodisperse emulsions (with minimum achievable polydispersities <3%). The phase to be dispersed is introduced into a coflowing, surfactant-laden continuous phase via a tapered capillary. Drops detach from the capillary when the streamwise forces exceed the force due to interfacial tension. Drop size is a function of the capillary tip diameter, the velocity of the continuous phase, the extrusion rate, and the viscosities and interfacial tension of the two phases. Emulsions composed of a variety of fluids and with drop sizes ranging from 2 to 200 m have been produced using this technique. Monodisperse Emulsion Generation via Drop Break Off in a Coflowing Stream PB Umbanhowar V Prasad DA Weitz doi:10.1021/la990101e Langmuir, Vol. 16, No. 2. (25 January 2000), pp. 347-351. 2007-04-01T04:16:17-00:00 2000 Langmuir 16 2 347 351 emulsions fluid monodisperse http://www.citeulike.org/user/kedmond/article/1854349 <i>Journal of Colloid and Interface Science, Vol. 256, No. 2. (15 December 2002), pp. 325-330.</i><br /><br />We describe a single-stage synthesis of fluorescent hard-sphere polymer colloids. Monodisperse sterically stabilized poly(methyl methacrylate) spheres were prepared by a dispersion copolymerization of methyl methacrylate and methacrylic acid in the presence of a nonpolymerizable dye. The PMMA colloids are intensely fluorescent and when dispersed in hydrocarbons interact as classical hard spheres. At high concentrations they rapidly nucleate highly ordered three-dimensional colloidal crystals. Four different fluorophores were investigated to minimize the degree of fluorescence photobleaching at [lambda]=488 nm. The dye, 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate (DiIC18), was observed to photobleach at a significantly slower rate than existing materials (Bosma et al., J. Colloid Interface Sci.245, 292 (2002); Jardine and Bartlett, Colloid Surf. A, in press). We show the usefulness of the resulting DiIC18 particles for confocal investigations of colloidal phenomena. Fluorescent Hard-Sphere Polymer Colloids for Confocal Microscopy Andrew Campbell Paul Bartlett doi:10.1006/jcis.2002.8669 Journal of Colloid and Interface Science, Vol. 256, No. 2. (15 December 2002), pp. 325-330. 2007-11-02T04:24:17-00:00 2002 Journal of Colloid and Interface Science 256 2 325 330 colloidal monodisperse synthesis http://www.citeulike.org/user/kedmond/article/1210848 <i>Science, Vol. 298, No. 5595. (1 November 2002), pp. 1006-1009.</i><br /><br />We present an approach to fabricate solid capsules with precise control of size, permeability, mechanical strength, and compatibility. The capsules are fabricated by the self-assembly of colloidal particles onto the interface of emulsion droplets. After the particles are locked together to form elastic shells, the emulsion droplets are transferred to a fresh continuous-phase fluid that is the same as that inside the droplets. The resultant structures, which we call "colloidosomes," are hollow, elastic shells whose permeability and elasticity can be precisely controlled. The generality and robustness of these structures and their potential for cellular immunoisolation are demonstrated by the use of a variety of solvents, particles, and contents. Colloidosomes: Selectively Permeable Capsules Composed of Colloidal Particles AD Dinsmore Ming Hsu MG Nikolaides Manuel Marquez AR Bausch DA Weitz doi:10.1126/science.1074868 Science, Vol. 298, No. 5595. (1 November 2002), pp. 1006-1009. 2007-04-05T12:51:02-00:00 2002 Science 298 5595 1006 1009 colloidal droplets emulsions microscopy monodisperse self-assembly http://www.citeulike.org/user/kedmond/article/1410022 <i>Langmuir, Vol. 21, No. 12. (7 June 2005), pp. 5298-5306.</i><br /><br />Abstract: The development of model materials and image processing methods to directly visualize and quantify colloidal rod assembly by means of confocal laser scanning microscopy (CLSM) is reported. Monodisperse fluorescent colloidal rods are prepared by the uniaxial extensional deformation of sterically stabilized microspheres at elevated temperatures. The particles are stably dispersed in refractive index matching mixed organic solvents for CLSM. An image processing algorithm is developed to detect rod backbones and extract particle centroids and orientation angles from the CLSM image volumes. By means of these methods we quantify the distribution of rod orientation angles in self-assembled structures of rods formed by sedimentation. We find the observations to be consistent with aspect-ratio-dependent jamming and orientational order/disorder transition in the rod sediments. Direct Visualization of Colloidal Rod Assembly by Confocal Microscopy A Mohraz MJ Solomon doi:10.1021/la046908a Langmuir, Vol. 21, No. 12. (7 June 2005), pp. 5298-5306. 2007-06-25T02:35:18-00:00 2005 Langmuir 21 12 5298 5306 colloidal microscopy monodisperse qualifier rotation synthesis http://www.citeulike.org/user/kedmond/article/1825032 <i>Proceedings of the National Academy of Sciences, Vol. 104, No. 29. (17 July 2007), pp. 11901-11904.</i><br /><br />Polymeric micro- and nanoparticles play a central role in varied applications such as drug delivery, medical imaging, and advanced materials, as well as in fundamental studies in fields such as microfluidics and nanotechnology. Functional behavior of polymeric particles in these fields is strongly influenced by their shape. However, the availability of precisely shaped polymeric particles has been a major bottleneck in understanding and capitalizing on the role of shape in particle function. Here we report a method that directly addresses this need. Our method uses routine laboratory chemicals and equipment to make particles with >20 distinct shapes and characteristic features ranging in size from 60 nm to 30 microm. This method offers independent control over important particle properties such as size and shape, which is crucial to the development of nonspherical particles both as tools and products for a variety of fields. 10.1073/pnas.0705326104 From the Cover: Making polymeric micro- and nanoparticles of complex shapes Julie Champion Yogesh Katare Samir Mitragotri doi:10.1073/pnas.0705326104 Proceedings of the National Academy of Sciences, Vol. 104, No. 29. (17 July 2007), pp. 11901-11904. 2007-10-26T13:15:53-00:00 2007 Proceedings of the National Academy of Sciences 104 29 11901 11904 colloidal journal-club monodisperse synthesis http://www.citeulike.org/user/kedmond/article/1205584 <i>Science, Vol. 301, No. 5632. (25 July 2003), pp. 470-471.</i><br /><br />10.1126/science.1087140 CHEMISTRY: Colloidal Molecules and Beyond Alfons van Blaaderen doi:10.1126/science.1087140 Science, Vol. 301, No. 5632. (25 July 2003), pp. 470-471. 2007-04-04T08:25:28-00:00 2003 Science 301 5632 470 471 colloidal microscopy monodisperse qualifier rotation self-assembly structure http://www.citeulike.org/user/kedmond/article/1869305 <i>Advanced Materials, Vol. 13, No. 6. (2001), pp. 415-420.</i><br /><br />This paper discusses the potential use of non-spherical colloids (see Figure) as the building blocks in self-assembly to fabricate three-dimensional photonic crystals with bandgaps located in the optical regime. The methods of producing non-spherical colloids as monodisperse samples, and with well-defined shapes and tightly controlled dimensions are presented, and the methods employed to organize these non-spherical colloids into 3D crystalline lattices are discussed. Three-Dimensional Photonic Crystals with Non-spherical Colloids as Building Blocks Y Lu Y Yin Y Xia doi:10.1002/1521-4095(200103)13:6<415::AID-ADMA415>3.0.CO;2-O Advanced Materials, Vol. 13, No. 6. (2001), pp. 415-420. 2007-11-05T17:09:20-00:00 2001 Advanced Materials 13 6 415 420 colloidal monodisperse self-assembly synthesis http://www.citeulike.org/user/kedmond/article/1219663 <i>Langmuir, Vol. 21, No. 6. (15 March 2005), pp. 2113-2116.</i><br /><br />Abstract: The controlled synthesis of nonspherical microparticles using microfluidics processing is described. Polymer droplets, formed by shearing a photopolymer using a continuous water phase at a T-junction, were constrained to adopt nonspherical shapes by confining them using appropriate microchannel geometries. Plugs were obtained by shearing the polymer phase at low shear rates, while disks were obtained by flattening droplets using a channel of low height. The nonspherical shapes formed were permanently preserved by photopolymerizing the constrained droplets in situ using ultraviolet light. Monodisperse plugs and disks of different lengths and diameters were obtained by varying the flow rates of the two phases. Controlled Synthesis of Nonspherical Microparticles Using Microfluidics D Dendukuri K Tsoi TA Hatton PS Doyle doi:10.1021/la047368k Langmuir, Vol. 21, No. 6. (15 March 2005), pp. 2113-2116. 2007-04-11T03:07:39-00:00 2005 Langmuir 21 6 2113 2116 colloidal droplets fluid fluorescence microscopy monodisperse http://www.citeulike.org/user/kedmond/article/1575814 <i>Journal of Polymer Science Part A: Polymer Chemistry, Vol. 30, No. 7. (1992), pp. 1463-1475.</i><br /><br />Monodisperse crosslinked polystyrene (PS) and polymethacrylate (PMA) beads of sizes greater than 1 ?m in diameter are prepared by particle nucleation onto pre-existing polymer seeds in a multistage emulsion polymerization, in the absence of emulsifier. An adequate seed number concentration, which decreases with increasing seed size, is necessary to achieve monodisperse beads. Monodisperse multicomposition beads are prepared by polymerizing styrene onto PMA seeds, but not by polymerizing methyl methacrylate onto PS seeds. Phase separation in growing seed particles or surface polymerization following free radical capture may lead to the formation of asymmetric shaped particles. Model filled polymers. VIII. Synthesis of crosslinked polymeric beads by seed polymerization Dezhong Zou Liquing Sun JJ Aklonis R Salovey doi:10.1002/pola.1992.080300726 Journal of Polymer Science Part A: Polymer Chemistry, Vol. 30, No. 7. (1992), pp. 1463-1475. 2007-08-19T22:38:38-00:00 1992 Journal of Polymer Science Part A: Polymer Chemistry 30 7 1463 1475 colloidal monodisperse synthesis 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/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/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/2030059 <i>Science, Vol. 304, No. 5673. (14 May 2004), pp. 987-990.</i><br /><br />We report on a microfluidic particle-separation device that makes use of the asymmetric bifurcation of laminar flow around obstacles. A particle chooses its path deterministically on the basis of its size. All particles of a given size follow equivalent migration paths, leading to high resolution. The microspheres of 0.8, 0.9, and 1.0 micrometers that were used to characterize the device were sorted in 40seconds with a resolution of [~]10nanometers, which was better than the time and resolution of conventional flow techniques. Bacterial artificial chromosomes could be separated in 10 minutes with a resolution of [~]12%. 10.1126/science.1094567 Continuous Particle Separation Through Deterministic Lateral Displacement Lotien Huang Edward Cox Robert Austin James Sturm doi:10.1126/science.1094567 Science, Vol. 304, No. 5673. (14 May 2004), pp. 987-990. 2007-11-30T17:48:27-00:00 2004 Science 304 5673 987 990 colloidal fluid monodisperse http://www.citeulike.org/user/kedmond/article/1205550 <i>Science, Vol. 301, No. 5632. (25 July 2003), pp. 483-487.</i><br /><br />When small numbers of colloidal microspheres are attached to the surfaces of liquid emulsion droplets, removing fluid from the droplets leads to packings of spheres that minimize the second moment of the mass distribution. The structures of the packings range from sphere doublets, triangles, and tetrahedra to exotic polyhedra not found in infinite lattice packings, molecules, or minimum-potential energy clusters. The emulsion system presents a route to produce newcolloidal structures and a means to study howdifferent physical constraints affect symmetry in small parcels of matter. 10.1126/science.1086189 Dense Packing and Symmetry in Small Clusters of Microspheres Vinothan Manoharan Mark Elsesser David Pine doi:10.1126/science.1086189 Science, Vol. 301, No. 5632. (25 July 2003), pp. 483-487. 2007-04-04T07:42:56-00:00 2003 Science 301 5632 483 487 clusters colloidal monodisperse qualifier self-assembly structure synthesis 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/ahe/article/1675941 <i>Colloids and Surfaces A: Physicochemical and Engineering Aspects, Vol. 309, No. 1-3. (1 November 2007), pp. 117-124.</i><br /><br />Monodisperse liquid foams consisting of equal-sized bubbles with diameters of a few hundred microns exhibit crystalline order, with a predominance of the fcc structure. This is inferred from observations at both bottom (foam-water) and top (foam-air) interfaces, together with supporting ray-tracing simulations. Diffusion of gas from the top layer into the atmosphere results in the formation of an ordered bidisperse top layer within a few minutes. In foam samples with a height of about 100 bubbles we have found a transition from mainly fcc packing at the (wet) bottom to the (bcc) Kelvin structure at the (dry) top. The issue of templating for the ordering in wet foams is addressed in soft sphere computer simulations. Crystalline arrangements of microbubbles in monodisperse foams Antje van der Net Gary Delaney Wiebke Drenckhan Denis Weaire Stefan Hutzler doi:10.1016/j.colsurfa.2006.11.056 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Vol. 309, No. 1-3. (1 November 2007), pp. 117-124. 2007-09-19T12:59:26-00:00 2007 Colloids and Surfaces A: Physicochemical and Engineering Aspects 309 1-3 117 124 foam microbubble monodisperse