2014 The gelification process by polycondensation leading to self similar clusters of polyurethane is studied, near and below the gelation threshold. In dilute solutions, where light scattering experiments are performed, the interaction between clusters is a function of 03B5, the distance to the gelation threshold. This is a direct evidence of the swelling of the clusters. Thus, the experimenta...

Motile extracts have been prepared from Dictyostelium discoideum by homogenization and differential centrifugation at 4 degrees C in a stabilization solution (60). These extracts gelled on warming to 25 degrees Celsius and contracted in response to micromolar Ca++ or a pH in excess of 7.0. Optimal gelation occurred in a solution containing 2.5 mM ethylene glycol-bis (beta-aminoethyl ether)N,N,N...

the present study deals with the formulation and evaluation of chitosan nanoparticles containing donepezil hydrochloride for the targeted delivery to the brain. nanoparticles were prepared by ionic gelation method using sodium tripolyphos-phate (tpp) as a cross linking agent followed by sonication. nanoparticles were obtained in the average size ranging from 116.8 to 227.5 nm. particle morpholo...

We study gelation in suspensions of model colloidal particles with short-ranged attractive and long-ranged repulsive interactions by means of three-dimensional fluorescence confocal microscopy. At low packing fractions, particles form stable equilibrium clusters. Upon increasing the packing fraction the clusters grow in size and become increasingly anisotropic until finally associating into a f...

Many small molecules can self-assemble by non-covalent interactions into fibrous networks and thereby induce gelation of organic liquids. However, no capability currently exists to predict whether a molecule in a given solvent will form a gel, a low-viscosity solution (sol), or an insoluble precipitate. Gelation has been recognized as a phenomenon that reflects a balance between solubility and ...

bioedegradable nanoparticles are intensively investigated for their potential applications in drug delivery systems. being a biocompatible and biodegradable polymer, chitosan holds great promise for use in this area. this investigation was concerned with determination and optimization of the effective parameters involved in the production of chitosan nanoparticles using ionic gelation method. s...

Alginate hydrogels are commonly used in biomedical applications such as scaffolds for tissue engineering, drug delivery, and as a medium for cell immobilization. Multivalent cations are often employed to create physical crosslinks between carboxyl and hydroxyl moieties on neighbouring polysaccharide chains, creating hydrogels with a range of mechanical properties. This work describes the manufa...

The aim of this study was to examine the effect of D-sorbitol on the gelation characteristics of methylcellulose in aqueous solution. The addition of D-sorbitol at concentrations of between 25 and 30% (w/v) to 1.0-2.0% (w/v) methylcellulose solutions reduced the gelation temperature from approximately 53 degrees Celsius to values between ambient and 37 degrees Celsius and increased the strength...

The physical properties of agarose gel prepared under strong magnetic fields were investigated. The storage modulus was measured by the reflection method with an ultrasonic pulse. The measurement results of the gel's elasticity indicate that agarose gel has anisotropic properties. The elasticity and its anisotropy depend on the concentration of the gel and the magnetic field to which it is expo...