Effect of Formulation and Process Parameters on Chitosan Microparticles Prepared by an Emulsion Crosslinking Technique.

There are many studies about the synthesis of chitosan microparticles; however, most of them have very low production rate, have wide size distribution, are difficult to reproduce, and use harsh crosslinking agents. Uniform microparticles are necessary to obtain repeatable drug release behavior. The main focus of this investigation was to study the effect of the process and formulation parameters during the preparation of chitosan microparticles in order to produce particles with narrow size distribution.

Elastic properties and morphology of individual carbon nanofibers.

The structural complexity of vapor-grown carbon nanofibers means that they require a method that determines both their elastic properties and their corresponding morphology. A three-point bending test method was developed combining atomic force microscopy, transmission electron microscopy (TEM) and focused ion beam techniques to suspend individual nanofibers and measure their deflection coupled with accurate determinations of inner and outer diameters and morphology using high resolution TEM. This resulted in much improved accuracy and reproducibility of the measured values of the elastic modulus which ranged from 6 to 207 GPa.