Optical tracking of relaxation dynamics in semi-dilute hydroxypropylcellulose solutions as a precise phase transition probe.

Phase separation of thermo-responsive polymers in solution is a complex process, whose understanding is essential to screen and design materials with diverse technological applications. Here we report on a method based on dynamic light scattering (DLS) experiments to investigate the phase separation of thermo-responsive polymer solutions and precisely define the transition temperature (T). Our results are applied on hydroxypropylcellulose (HPC) solutions as an important biosourced green water-soluble polymer.

Dehydration, dissolution, and melting of cyclodextrin crystals.

Cyclodextrins are a family of oligosaccharides with a toroid shape that exhibit a unique ability of entrapping guest molecules in their internal cavity. Water is the primary guest molecule and is omnipresent in the crystalline phases stabilizing the overall architecture. Despite the presence of water molecules inside the cavity, cyclodextrins provide a hydrophobic environment where poorly soluble molecules can easily fit.