Ultra-strong thermoresponsive double network hydrogels.
Ruochong Fei1, Jason T George1, Jeehyun Park1
1Department of Biomedical Engineering, Materials Science & Engineering Program, Texas A&M University, 3120 TAMU, College Station, TX, USA.
Soft Matter
|December 18, 2020
Summary
This study introduces robust double network hydrogels using poly(N-isopropylacrylamide) (PNIPAAm) and AMPS. The novel hydrogels exhibit enhanced mechanical strength and tunable thermosensitivity for advanced applications.
Area of Science:
- Polymer Science
- Materials Science
- Biomedical Engineering
Background:
- Thermoresponsive poly(N-isopropylacrylamide) (PNIPAAm) hydrogels are promising smart materials.
- Their application is limited by poor mechanical strength.
Purpose of the Study:
- To enhance the mechanical properties of PNIPAAm hydrogels.
- To investigate the effect of incorporating an electrostatic co-monomer, AMPS, into a double network (DN) hydrogel structure.
- To evaluate the impact of AMPS content on hydrogel properties.
Main Methods:
- Preparation of P(NIPAAm-co-AMPS)/PNIPAAm DN hydrogels with asymmetric crosslinking.
- Sequential formation of a tightly crosslinked first network (variable NIPAAm:AMPS ratios) and a loosely crosslinked second network (PNIPAAm).
- Evaluation of volume phase transition temperature (VPTT), morphology, kinetics, and mechanical properties.
Main Results:
- DN hydrogels maintained PNIPAAm's VPTT while improving thermosensitivity.
- The hydrogel with a 25:75 wt% NIPAAm:AMPS ratio demonstrated exceptional strength.
- High modulus and high %strain at break were achieved in the optimized DN hydrogel.
Conclusions:
- Asymmetric crosslinking and AMPS incorporation significantly enhance PNIPAAm hydrogel mechanical properties.
- The developed DN hydrogels offer a promising platform for advanced biomedical applications requiring both responsiveness and durability.
