In: Nanotechnology, 2010, vol. 21, no. 18, p. 185603
We report on the synthesis of nanocomposites with integrated ellipsoidal silica-coated hematite (SCH) spindle type nanoparticles which can act as crosslinking agents within an elastomeric matrix. Influence of the surface chemistry of the hematite, leading either to dispersed particles or crosslinked particles to the elastomer matrix, was studied via swelling, scattering and microscopy...
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In: Journal of the American Chemical Society, 2008, vol. 130, no. 44, p. 14434–14435
Supramolecular principles have been applied for improving the spin crossover activity of metal centers due to cooperative effects in solution. Thus, incorporation of alkyloxy tails at the phenyl group of Fe(sal₂trien) 2a provides amphiphilic complexes Fe(sal-OR₂trien) 2b−d (b, R = C₆H₁₃; c, R = C₈H₁₇; d, R = C₁₈H₃₇) comprising an apolar...
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In: Physical Review Letters, 2007, vol. 99, no. 19, p. 198103
Small-angle neutron scattering experiments and molecular dynamics simulations combined with an application of concepts from soft matter physics to complex protein mixtures provide new insight into the stability of eye lens protein mixtures. Exploring this colloid-protein analogy we demonstrate that weak attractions between unlike proteins help to maintain lens transparency in an extremely...
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In: Langmuir, 2007, vol. 23, no. 7, p. 3570 -3580
We have systematically investigated the phase diagram of clay particles in water to understand the relation between the local and macroscopic properties and the structures of clay suspensions. We focused, in particular, on sodium Cloisite (CNa) particles at concentrations typically used in nanocomposites (concentrations from 1 to 4 wt %) and at an extended range of ionic strengths (10⁻⁵ to...
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In: Physical Review Letters, 2007, vol. 99, no. 11, p. 118301
We investigate the competition between spinodal decomposition and dynamical arrest using aqueous solutions of the globular protein lysozyme as a model system for colloids with short-range attractions. We show that quenches below a temperature Ta lead to gel formation as a result of a local arrest of the protein-dense phase during spinodal decomposition. The rheological...
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In: Europhysics Letters, 2007, vol. 77, no. 4, p. 48004
We present a combined experimental and numerical study of the equilibrium cluster formation in globular-protein solutions under no-added salt conditions. We show that a cluster phase emerges as a result of a competition between a long-range screened Coulomb repulsion and a short-range attraction. A simple effective potential, in which electrostatic repulsion is fixed by experimental conditions...
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In: Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2006, vol. 291, no. 1-3, p. 110-116
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In: Journal of Physics: Condensed Matter, 2006, vol. 18, p. L339–L346
We investigate phase separation and structural evolution in a complex food colloid (casein micelles) and biopolymer (xanthan) mixture using small-angle light scattering. We demonstrate that phase separation is induced by a depletion mechanism, and that the resulting coexistence curve can be described by osmotic equilibrium theory for mixtures of colloids and polymer chains in a background...
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In: Journal of Physics: Condensed Matter, 2006, vol. 18, p. L363-L369
The static structure factor S(q) is measured for a set of deionized latex dispersions with different numbers of ionizable surface groups per particle and similar diameters. For a given volume fraction, the height of the main peak of S(q), which is a direct measure of the spatial ordering of latex particles, does not increase monotonically with the number of ionizable...
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In: Langmuir, 2005, vol. 21(23), p. 10835
Small-angle neutron scattering (SANS) measurements are reported on a sterically stabilized, core-shell colloidal system using contrast variation. Aqueous dispersions of polystyrene particles bearing grafted poly(ethylene glycol) (PEG) have been studied over a large range of particle concentrations and two different solvent conditions for the PEG polymer. SANS data are analyzed quantitatively by...
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