Spherical colloidal crystals are three-dimensional periodic arrays of monodisperse colloidal particles with a spherical geometry. The spatial periodicity of the refractive index of the colloidal crystalline arrays results in an optical stop band and, hence, they act as photonic crystals in the optical regime. In contrast to conventional film-type colloidal crystals where the crystals are aligne...

A controlled greenhouse experiment was conducted to study the fraction, uptake and fixation of phosphorus (P) and potassium (K) in three soils with contrasting characteristics. The experiment was carried out in two phases, viz., sorghum-Sudangrass depletion and test crop experiment with maize with three levels of fertility status (depleted, original and fertilized with 40 mg kg-1 P and K) and t...

A method to prepare monodisperse and simultaneously NMR-visible and fluorescent colloidal particles is described, and a systematic approach to obtain spectrally resolved diffusion coefficient for every component in a monodisperse colloidal suspension is presented. We also prepared bidisperse colloidal suspensions, where each colloid component has a distinct NMR spectral signature, and obtained ...

Ordered two-dimensional (2D) superstructures of colloidal nanocrystals (NCs) can be tailored by the size, shape, composition, and surface chemistry of the NC building blocks, which can give directionality to the resulting superstructure geometry. The exact formation mechanism of 2D NC superstructures is however not yet fully understood. Here, we show that oleic acid (OA) ligands induce atomic a...

Colloidal Gas Aphron as a mobility control in enhanced oil recovery is becoming attractive; it is also designed to block porous media with micro-bubbles. In this paper, the effects of surfactant concentration, polymer concentration, temperature and salinity on the bubble size of the Colloidal Gas Aphron were studied. Effects of injection rates, Colloidal Gas Aphron fluid composition, heterogene...

Fertilization exceeding crop requirements causes an accumulation of phosphorus (P) in soils, which might increase concentrations of dissolved and colloidal P in drainage. We sampled soils classified as Typic Haplorthods from four fertilization experiments to test (i) whether increasing degrees of phosphorus saturation (DPS) increase concentrations of dissolved and colloidal P, and (ii) if criti...

Evaporation-driven colloidal self-assembly is a promising family of routes to large-area, low-cost, if imperfect, photonic crystals. The simplest example occurs at the surface of a stagnant, evaporating colloidal suspension. For an evaporating colloidal suspension in which the interface falls faster than the particles sediment, particles will accumulate at the solvent-air interface. If neither ...

solar cells, [ 4 ] and photonic crystals, [ 5 ] 2D hexagonal structures and 3D inverted opal (IO) structures have recently been intensively studied. In order to fabricate uniform IO structures consisting of regular arrangements of spherical void spaces surrounded by solid walls, 2D and 3D colloidal crystals consisting of a regular arrangement of uniform spherical particles are required. To date...

For an evaporating colloidal suspension in which the evaporation velocity exceeds the sedimentation velocity, particles will accumulate at the solvent-air interface. If neither diffusion nor convection can disperse this accumulation, it is expected to grow into a colloidal multilayer several microns thick. We observe that the thickness of colloidal crystals vertically deposited from 1 mum diame...

The structure of a ferrofluid under the influence of an external magnetic field is expected to become anisotropic due to the alignment of the dipoles into the direction of the external field, and subsequently to the formation of particle chains due to the attractive head to tail orientations of the ferrofluid particles. Knowledge about the structure of a colloidal ferrofluid can be inferred fro...