Downward and upward ultrafiltration (UF) was performed using the suspensions of nanosized colloidal silica with different particle diameters and their filtration rates were compared. In downward UF, the filtration rate decreases as the particle diameter decreases because the specific filtration resistance of the filter cake becomes significantly higher. In contrast, the filtration rate in upwar...

Colloidal nanosilica is currently being produced by various methods which are mainly high energy intensive and/or not environmentally friendly. It is therefore essential to develop new energy-efficient and environmentally friendly technologies. This paper introduces a new ultrasound assisted route based on alkali leaching of silica fume for synthesis of colloidal silica nanoparticles. The ef...

Fluorescence enhancement was studied on silver colloidal metal films (CMFs) using two systems: (1) Langmuir--Blodgett monolayers of fluorescein-labeled phospholipids separated from the surface of the films by spacer layers of octadecanoic acid and (2) biotin--fluorescein conjugates captured by avidin molecules adsorbed on top of a multilayer structure formed by alternating layers of bovine seru...

The colloidal dimer particles are templated from sacrificial α-Fe2O3 (hematite) core particles prepared via aging of a condensed Fe(OH)3 gel as described in [1]. In a typical synthesis, 50 mL of FeCl3 (2.0 M) is mixed with 45 mL of NaOH (6.0 M) and 5 mL of the shapemodifier, Na2SO4 (0.6 M), before being placed in an oven set at 100°C for 8 days. To make the nonmagnetic particles investigated in...

Interaction between anionic (and cationic) colloidal particles of silica having the particles diameters 12 and 22 nm with synthetic cationic (and anionic) polyelectrolytes of various nature and structure was studied by potentiometric, conductimetric spectroturbidimetric and viscometric methods in aqueous solution. It was shown that the complexation of silica nanoparticles with linear polyelectr...

Composite colloidal particles with a silica core and a synthetic, homopolypeptide shell have been produced by initiation of benzyl-L-glutamate N-carboxyanhydride monomer from primary amine functionalized silica particles. The resulting poly(γ-benzyl-R,L-glutamate)-coated spheres were characterized by electron microscopy, dynamic light scattering, infrared spectroscopy, and thermogravimetry. The...

Here we report a simple and scalable bottom-up technology for assembling close-packed nanoparticle monolayers on both sides of a glass substrate as high-quality antiglare coatings. Optical measurements show that monolayer coatings consisting of 110 nm silica nanoparticles can significantly reduce optical reflectance and enhance specular transmittance of the glass substrate for a broad range of ...

Polymerization conditions in the Pickering emulsion of colloidal silica-stabilized polystyrene latex were optimized. The influence process on various parameters, including particle size and distribution was investigated. Monomodal particles obtained by conducting at a temperature 80°C slightly acidic environment (pH = 5), while maintaining fast monomer conversion. It has been shown that amount ...

We propose an adaptation of the osmotic stress technique for determining equations of state of colloids covered by polymer films. We describe here the case of silica particles covered by 6 or 7 layers of polyelectrolyte multilayers. The establishment of a pressure-distance curve allows the interpretation of colloidal interactions over more than four orders of magnitude in pressure. This large r...

Rings and split rings of sub-micrometer size are prepared by the infiltration of colloidal crystals of spherical silica particles with diameters of about 1 lm by diluted solutions of tetrachloroauric acid in butanone, followed by the evaporation of the butanone, the annealing of the samples at elevated temperatures and the removal of the silica spheres with hydrofluoric acid. X-ray photoelectro...