Chitin Nanocrystals for Pickering High Internal Phase Emulsions

Chitin is a natural polymer of glucosamine bearing N-acetyl groups. Chitin nanocrystals (ChiNCs), resulting from the acid hydrolysis of amorphous regions of chitin, are crystalline positively charged rod-like particles. ChiNCs show some interfacial properties and very efficiently stabilize oil/water interfaces, leading to the so-called Pickering emulsions. In accordance with the irreversible adsorption of particles, these Pickering emulsions proved stable over time, with constant emulsion volume for several months, even though natural creaming may occur. The emulsions produced are not clearly susceptible to ionic strength or pH in terms of average droplet diameter. However, when mixed with a large amount of oil, high internal phase emulsions (HIPE) containing up to 96% of internal phase are formed as a gel with a texture that can be modulated from soft to solid gel by adjusting concentration, pH, and ionic strength.