Sensitivity to pH is the property of a polymer system whose ionisation, swelling or assembly state changes with the acidity of the surrounding medium [1]. Zwitterionic hydrogels reinforced with aramid nanofibers resist swelling while remaining responsive, a balance exploited in strain sensors [1]. Chitosan-based hydrogels swell and bend as pH shifts, and the response has been followed experimentally [2]. Bilayer hydrogel strips convert the same swelling mismatch into bending, analysed by both analytical and finite-element treatment [3]. Dual pH- and thermo-sensitive nanogels of poly(N-isopropylacrylamide-co-allylamine) show swelling-deswelling behaviour with a defined phase transition [4]. Nanosilica/poly(acrylic acid) macroporous hydrogels swell strongly and release amoxicillin as the pH changes [5].
- ph-triggered swelling
- swelling
- hydrogel
- responsive polymer
- nanogel
- drug release
Hydrogels: synthesis, properties, applications·Molecular Medicine·Biochemistry, Genetics and Molecular Biology·Life Sciences
References
- Chen, Z.; Zhong, W.; Anti-Swelling Aramid-Nanofiber-Reinforced Zwitterionic Polymer Hydrogel for Strain Sensors. Materials 2025, 18, 1800, 10.3390/ma18081800.
- Mehr, J.A.; Hatami-Marbini, H.; Investigating Swelling and Bending Response of pH-Sensitive Chitosan-Based Hydrogels. Macromol 2025, 5, 57, 10.3390/macromol5040057.
- Askari-Sedeh, M.; Baghani, M.; pH-Sensitive Hydrogel Bilayers: Investigation on Transient Swelling-Induced Bending through Analytical and FEM Approaches. Gels 2023, 9, 563, 10.3390/gels9070563.
- Santhamoorthy, M.; Kim, S.C.; Dual pH- and Thermo-Sensitive Poly(N-isopropylacrylamide-co-allylamine) Nanogels for Curcumin Delivery: Swelling–Deswelling Behavior and Phase Transition Mechanism. Gels 2023, 9, 536, 10.3390/gels9070536.
- Sorkhabi, T.S.; Samberan, M.F.; Ostrowski, K.A.; Majka, T.M.; Novel Synthesis, Characterization and Amoxicillin Release Study of pH-Sensitive Nanosilica/Poly(acrylic acid) Macroporous Hydrogel with High Swelling. Materials 2022, 15, 469, 10.3390/ma15020469.