Exceptionally fast temperature-responsive, mechanically strong and extensible monolithic non-porous hydrogels: poly(N-isopropylacrylamide) intercalated with hydroxypropyl methylcellulose

0580772 - ÚMCH 2024 RIV CH eng J - Journal Article
Strachota, Beata - Strachota, Adam - Vratović, Leana - Pavlova, Ewa - Šlouf, Miroslav - Kamel, S. - Cimrová, Věra
Exceptionally fast temperature-responsive, mechanically strong and extensible monolithic non-porous hydrogels: poly(N-isopropylacrylamide) intercalated with hydroxypropyl methylcellulose.
Gels. Roč. 9, č. 12 (2023), č. článku 926. E-ISSN 2310-2861
Grant - others:AV ČR(CZ) ASRT-22-01
Program: Bilaterální spolupráce
Institutional support: RVO:61389013
Keywords : hydrogels * drug release * smart materials
OECD category: Polymer science
Impact factor: 4.6, year: 2022
Method of publishing: Open access
https://www.mdpi.com/2310-2861/9/12/926

Exceptionally fast temperature-responsive, mechanically strong, tough and extensible monolithic non-porous hydrogels were synthesized. They are based on divinyl-crosslinked poly(N-isopropyl-acrylamide) (PNIPAm) intercalated by hydroxypropyl methylcellulose (HPMC). HPMC was largely extracted after polymerization, thus yielding a ‘template-modified’ PNIPAm network intercalated with a modest residue of HPMC. High contents of divinyl crosslinker and of HPMC caused a varying degree of micro-phase-separation in some products, but without detriment to mechanical or tensile properties. After extraction of non-fixed HPMC, the micro-phase-separated products combine superior mechanical properties with ultra-fast T-response (in 30 s). Their PNIPAm network was highly regular and extensible (intercalation effect), toughened by hydrogen bonds to HPMC, and interpenetrated by a network of nano-channels (left behind by extracted HPMC), which ensured the water transport rates needed for ultra-fast deswelling. Moreover, the T-response rate could be widely tuned by the degree of heterogeneity during synthesis. The fastest-responsive among our hydrogels could be of practical interest as soft actuators with very good mechanical properties (soft robotics), while the slower ones offer applications in drug delivery systems (as tested on the example of Theophylline), or in related biomedical engineering applications.
Permanent Link: https://hdl.handle.net/11104/0349542