20.500.12556/DKUM-100386 Thermoresponsive N-vinylcaprolactam-based PolyHIPE hydrogels with composition-controlled water uptake and volume phase transition behavior A series of thermoresponsive polyHIPE hydrogels based on N-vinylcaprolactam (NVCL) and N,N-dimethylacrylamide (DMAA) were prepared using oil-in-oil (O/O) high internal phase emulsion (HIPE) templating to investigate how copolymer composition influences porous morphology, water uptake, and volume phase transition (VPT) behavior. HIPE stability strongly depends on the NVCL/DMAA ratio, reflecting differences in monomer polarity and partitioning. Incorporating DMAA significantly improved HIPE stability and enabled the preparation of highly porous homo- and copolymeric monoliths with porosities of 92–94%. Enhanced HIPE stability reduces the pore size in polyHIPEs, with average void diameters decreasing from approximately 92 μm in NVCL-based polyHIPEs to 23 μm in DMAA-rich polymer materials. Equilibrium water uptake at 4 °C increased significantly from approximately 2 g·g–1 for NVCL polyHIPEs to 27 g·g–1 for DMAA polyHIPEs, while NVCL-co-DMAA polymer materials showed intermediate uptakes (15–24 g·g–1) depending on composition. All NVCL-containing polyHIPEs exhibited reversible thermoresponsive behavior. Water uptake decreases upon heating to 45 °C (9–21 g·g–1) due to thermally induced network collapse, as NVCL segments exceed their lower critical solution temperature. Increasing the DMAA ratio enhances water retention and suppresses deswelling of polyHIPEs, while NVCL-rich compositions exhibit pronounced, reversible volume contraction. These results demonstrate that DMAA and NVCL have complementary roles in polyHIPE architectures. DMAA segments control hydrophilicity and water uptake, while NVCL provides thermoresponsive functionality. The combination of tunable porosity, high water absorbency, and reversible thermoresponsive behavior demonstrates their potential as a platform for temperature-responsive absorbents. HIPE templating thermoresponsive polymers N-vinylcaprolactam N N-dimethyl acrylamide water uptake swelling ratio emulzije hydrogeli kopolimeri termalne lastnosti absorpcija true false true ACS Publications Angleški jezik Slovenski jezik https://pubs.acs.org/ © The Authors Članek v reviji 2026-09-16 09:08:51 2026-09-16 09:08:51 2026-09-17 03:10:57 0000-00-00 00:00:00 2026 0 0 10 str. Sep. 2026 0000-00-00 Zaloznikova Objavljeno NiDoloceno 2026-06-08 2026-09-04 2026-09-08 547.4 290358275 10.1021/acsapm.6c02452 2637-6105 https://pubs.acs.org/aapmcd/article/doi/10.1021/acsapm.6c02452/5422856/Thermoresponsive-N-Vinylcaprolactam-Based-PolyHIPE 1 795a924e-b19d-11f1-b05b-00155d0001be https://dk.um.si/Dokument.php?lang=slv&id=212558 acsapm.6c02452.pdf acsapm.6c02452.pdf 1 D4C366F7470A654699EDDF6BC38F7A52 cffcfaa9f2c78db96de4b9ffc55b74b801ffe793943eec67384a8507e04eb900 c4463231-b19d-11f1-b05b-00155d0001be https://dk.um.si/Dokument.php?lang=slv&id=212559 Fakulteta za kemijo in kemijsko tehnologijo 0 0 0