I've been thinking about and looking up these topics for a while, but haven't been sure of an answer. I found a number of related concepts, but can't seem to make sense of them together.
- What makes a humectant a humectant? How is humectancy related to hygroscopy (attracting water), "water holding" capacity, and the vapor pressure of an aqueous solution (escaping molecules)?
- What part of a molecule can we use to clue in on its ability to bind water? Is it the physical structure that determines the ability to bind water rather than solely the presence of polar groups on the outside? (Like EDTA with divalent metal ions; Hydroxypropyl Cyclodextrins with VOCs—the structure determines the function)
- Could humectants more effective than PCA be found? What makes PCA more effective than glycerol on a mass basis? Is there a difference in how PCA vs. glycerol vs. PEG attract water molecules?
⚠️ I have a lot of ideas, but not much experience! Please keep this in mind when reading my suggestions. ⚠️