Tailoring Architecture of Nanothin Hydrogels: Effect of Layering on pH-Triggered Swelling

We have tailored the internal architecture of ultrathin poly(methacrylic acid) (PMAA) hydrogels from well stratified to highly intermixed by controlling the internal structure in layer-by-layer templates used for hydrogel fabrication. We have found pH-triggered swelling properties of these hydrogels to be significantly affected by hydrogel architecture. Well-stratified hydrogels exhibited a dramatic 10-fold increase in thickness when transitioned between pH = 5 and 7.5, unlike the 2-fold swelling observed in less-organized hydrogels.