Study of Water Diffusion through Hydrogels
This research focuses on understanding the properties of hydrogels, characterizing the diffusion flow of water and its transport properties across the membrane. This experiment tries to explain how the human skin acts as a transport barrier when exposed to the environment. It mirrors the transient change in transepidermal water loss after a change in relative humidity which can result in the damage to the skin. Agar-agar hydrogel is used as a poroelastic model that has similar hydration/dehydration properties simulating fluid and ion flow as that of the human skin. This poroelastic model mimics the swelling of the stratum corneum, owing to the water distribution across the hydrogel. To facilitate this analysis, thin layer of the hydrogel is partially submerged in water while the other side is exposed to a dry air flow. The differences allow us to characterize the chemical gradient needed for mass transfer of water across the membrane and be able to have measurable flow using MRI which reveals the local variation of the water content inside the hydrogel, consistent with the air boundary layer developing on the exposed side. If the steady state is reached and velocity of water diffusion is constant in one direction, the value of the chemical potential of water in the gel as a function of its volume fraction of water can then be calculated.
School:
Texas A&M University-Corpus Christi
Department:
Chemistry
Research Advisor:
John G. Georgiadis
Department of Research Advisor:
Mechanical and Industrial Engineering
Year of Publication:
2005