Characterization of Hydrogel Porous Structure By Using the Differential Scanning Calorimetry Technique

Over the past decades hydrogels have been used widely in various pharmaceutical and biomedical applications such as drug delivery systems, engineering tissue scaffolds, and health care products. As many applications of hydrogels require very accurate measurement and control of the pore network structure i.e. pore size and pore-size distribution, it is important to understand the nature of the hydrogel pore structure and the methods used for the characterization of its network structure. Therefore, numerous techniques have been developed to characterize the internal morphology of pores including swelling, scattering and mercury intrusion porosimetry, among others.

Characterization of the hydrogel pore structure is very important for selecting the gel type for a particular application. In this research we will try to gain a better understanding of hydrogel morphology by using Thermoporometry by “Differential Scanning Calorimetry” (DSC). This technique will be used in this research to characterize both pore size and pore-size distribution for nano-templated hydrogel materials for the applications mentioned above; in particular, we are interested in the separation of bio-pharmaceutical drugs and scaffolds for tissue engineering. Thermoprometry is one of the few techniques available now for determining both pore size and pore-size distribution at the same time. The DSC will take measurements of the temperature shift that occurs between the water confined within the pores of the gel and the bulk water. The temperature difference will be used to generate a heat flow curve. We will present the fundamental aspects of the technique for its adaptation for hydrogel’s measurements. We will also present preliminary results for hydrogels and a strategy for its validation with previous results in the literature for regular gels.