Nano chitosan dispersion

Stabilization of nano chitosan dispersion can be explained on the principle of Coulombic or electrostatic repulsion. Particles in a colloid, due to smaller size, are often pushed around by the molecular collisions of the surrounding media, an effect called Brownian motion. The Brownian motion is a rather random, causing the particles to collide with each other frequently and aggregate to form larger particles, which settle down due to their weight. A... 

The viscosity of polymer solution, at the molecular level, is a direct measure of the hydrodynamic volume of the polymer molecules, which in turn is governed by the molecular size or the chain length and hence the molecular weight [32], The viscosity of nano chitosan dispersion decreases with reduction in the particle size, as reported in the literature [148], It was also reported that the... 

These additives can also be placed into microcapsules with a thin polymer skin. For example, they are filled with natural aromas and applied to the textile from a water dispersion in combination with a polyurethane or silicone binder. The ratio of micro bubbles to binder determines the efficiency and permanence of the finish. Good results after 4-12 washing cycles are reported. The encapsulated materials are released during wearing as the micro bubbles burst from rubbing caused by body movement or by diffusion through the thin layer of the capsules. A market available encapsulation in micro bubbles, built from chitosan, is described by Hampe. The incorporation and controlled release of fragrance compounds is also provided by the sol-gel nano-technique described in Section 18.4. 

An instrumental characterization of nano-hydroxyapatite was provided by Chen et al. (2002) the size of their particles was ca. 20-30 nm in width and 50-60 nm in length, with a specific surface area of 73 m /g aggregation was avoided with the use of n-butanol. The uniform dispersion of these particles in chitosan solutions was recognized as an important motif for the innovative preparation of chitosan composites in fact, nano-hydroxyapatite + chitosan composite membranes prepared by solvent casting and evaporation were found suitable for guided bone regeneration. 

Globally, the properties of CH/NFC nanocomposite films were better than those displayed by similar chitosan films reinforced with BC Nano fibrils. This behavior could be due to the better dispersion of NFC into the chitosan matrices, related to the individual fiber morphology, contrasting with the tridimensional network fibers strac-ture of BC, as well as to the higher aspect ratio of the NFC compared withBC. 

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