Fabrication of chitosan colloidal gels via pH-mediated self-association

The development of biopolymer-based colloidal systems is of great interest in the food science and pharma-ceutical fields. Here, we report a simple process to fabricate chitosan colloidal gels though self-assembly of chitosan in solution. In the first step, insoluble chitosan aggregates formed at close to neutral pH (6.6-7.0) were transformed into nano-sized particles (20-100 nm) via shear homogenization. These nanoparticles then spon-taneously aggregated and assembled to form a 3D space-spanning network upon storage. The chitosan particle size as well as the formation, viscoelasticity and microstructure of the corresponding gels were highly affected by pH. Findings from this study are of interest for the fabrication of tunable colloidal gel materials using chitosan alone.

Automated summary

This study reports a simple process to fabricate chitosan colloidal gels through self-assembly of chitosan in solution. The particle size, gel formation, viscoelasticity, and microstructure of the gels were found to be highly affected by pH.