Kinetic arrest in colloidal dispersions with isotropic attractive interactions usually occurs through the destabilization of the homogeneous phase and the formation of a non-equilibrium network of jammed particles. Theory and simulations predict that a different route to gelation should become available when the valence of each colloidal particle is suitably reduced. Under these conditions, gel...

Previously we have reported a family of convective patterns formed by charge-stabilized aqueous colloidal suspensions under constant (dc) vertical electric fields [Y. Han and D. G. Grier, J. Chem. Phys. 122, 164701 (2005); and ibid. 125, 144707 (2006)]. These patterns form in the bulk when electrokinetic forces act in the opposite direction to gravity. Here, we report on cellular patterns that ...

In summary, we have developed a new strategy for the fabrication of arrayed colloidal particles well-ordered nanometric holes of three or four fold symmetry by anisotropic reactive ion (plasma) etching of self-organized layers of colloidal spheres. We demonstrated that a mesoporous silica matrix with regular open windows could be used as a lithographic mask and the resulting arrangement of pore...

A high-resolution calorimetric spectroscopy study has been performed on pure glycerol and colloidal dispersions of an aerosil gel in glycerol covering a wide range of temperatures from 300 to 380 K, deep in the liquid phase of glycerol. The colloidal glycerol+aerosil samples with 0.07, 0.14, and 0.32 g of silica per cm3 of glycerol reveal activated energy (thermal) dynamics at temperatures well...

Hydrophobic particles based on dodecyl 3,4,5-trihydroxybenzoate (LG) were coupled onto the surface of cellulose nanofibrils (CNFs) and silica by treatment with a multicomponent colloidal system (MCS) derived from the laccase-mediated reaction of LG in the presence of a sulfonated lignin (SL). Surface modification upon treatment with MCS was monitored in situ and in real time by quartz crystal m...

Studies on colloidal aggregation have brought forth theories on stability of colloidal gels and models for aggregation dynamics. Still, a complete link between developed frameworks and obtained laboratory observations has to be found. In this work, aggregates of silica nanoparticles (20 nm) are studied using diffusion limited cluster aggregation (DLCA) and reaction limited cluster aggregation (...

This contribution highlights some recent advances in the synthesis of monodispersed colloidal spheres loaded with superparamagnetic components for external manipulation. We firstly discuss how Fe3O4 nanoparticles can be directly coated with silica to form core–shell particles using a sol–gel approach. We then focus on the demonstration of new materials for such an application, with Pb and amorp...

approved by: Circular dichroism (CD) spectra were obtained for bacteriophage T4 lysozyme and three of its mutants in the presence and absence of colloidal silica nanoparticles. Mutant lysozymes were produced by substitution of the isoleucine at position 3 with tryptophan, cysteine and leucine. Each substitution resulted in an altered structural stability, quantified by a difference in free ener...

The trajectories of colloidal particles driven through a periodic potential energy landscape can become kinetically locked in to directions dictated by the landscape’s symmetries. When the landscape is realized with forces exerted by a structured light field, the path a given particle follows has been predicted to depend exquisitely sensitively on such properties as the particle’s size and refr...

Silica is a very common material that can be found in both crystalline and amorphous forms. Well-known toxicities of the lung can occur after exposure to the crystalline form of silica. However, the toxicities of the amorphous form of silica have not been thoroughly studied. The majority of in vivo studies of amorphous silica nanoparticles (NPs) were performed using an inhalation exposure metho...