Cavitation effects versus stretch effects resulted in different size and polydispersity of ionotropic gelation chitosan-sodium tripolyphosphate nanoparticle

The objectives of the study are to compare different modes and input-energy levels of ultrasonic radiation and mechanical shearing on the changes in mean diameter of resulted ionotropic gelation chitosan-sodium tripolyphosphate (TPP) nanoparticles, and to elucidate the different effects on the size and polydispersity difference caused by cavitation effects versus stretch effects owing to using different modes of mechanical energy. The results obtained were as follows: the particle size and reduction rate of ionotropic gelation chitosan-TPP can be manipulated by varying different mechanical energy of ultrasonic radiation or mechanical shearing. Effects of solution temperature on resulted nanoparticle size by ultrasonic treatment or by mechanical shearing were different. The higher the solution temperature, the lower the solution viscosity that facilitates the sporadic cavitation effect exerted on the chitosan molecules producing smaller molecular weight fragments than that produced by stretching effects. Mean diameter of nanoparticle decreased with increasing solution temperature in ultrasonic radiation samples. (C) 2007 Elsevier Ltd. All rights reserved.