Switchable thermoresponsive fluorinated hydrogels for reversible and efficient PFAS adsorption-desorption
Jinjing Huang1, Hengzhi Liu2, Zichen Zhang1
1State Key Laboratory of Green Papermaking and Resource Recycling, School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China.
Water Research
|May 8, 2026
Summary
We developed novel thermoresponsive fluorinated hydrogels (F9-NIPAM) for efficient and reversible per- and polyfluoroalkyl substances (PFAS) removal. This sustainable method significantly reduces organic solvent use and costs for PFAS remediation.
Area of Science:
- Materials Science
- Environmental Engineering
- Polymer Chemistry
Background:
- Conventional regeneration of per- and polyfluoroalkyl substances (PFAS)-saturated adsorbents using organic solvents is expensive, complex, and environmentally harmful.
- There is a critical need for sustainable and efficient methods for PFAS removal and adsorbent regeneration.
Purpose of the Study:
- To develop novel thermoresponsive fluorinated hydrogels (F9-NIPAM) for reversible PFAS adsorption and desorption.
- To investigate the mechanisms underlying the reversible PFAS binding and release.
- To assess the economic and environmental viability of the developed F9-NIPAM hydrogels for PFAS treatment.
Main Methods:
- Synthesis of thermoresponsive fluorinated hydrogels (F9-NIPAM) by incorporating fluorophilic moieties into N-isopropylacrylamide networks.
- Characterization of hydrogel properties, including temperature-triggered hydrophilic-hydrophobic transitions and pore size changes.
- Evaluation of PFAS sorption and desorption efficiencies using various PFAS compounds and mild regenerant solutions.
- Molecular dynamics simulations to elucidate the mechanisms of PFAS desorption.
- Techno-economic and life-cycle assessments to evaluate cost efficiency and environmental impact.
Main Results:
- F9-NIPAM hydrogels demonstrated reversible PFAS adsorption-desorption across a temperature range of 25-50 °C.
- Achieved 80-100% sorption of long-chain PFAS (PFOA, PFOS, PFHxS, PFNA) and >95% desorption using mild regenerants (0.1% NaOH+20% MeOH).
- Reduced methanol consumption by 80% compared to conventional methods.
- Molecular dynamics simulations revealed thermally assisted desorption, increased PFAS diffusion, and weakened hydrogen-bond interactions.
- Techno-economic and life-cycle assessments indicated 15-20% cost efficiency improvements and substantial reductions in carbon emissions.
Conclusions:
- Thermoresponsive fluorinated hydrogels (F9-NIPAM) offer a sustainable and efficient solution for reversible PFAS removal.
- The synergistic interplay of fluorine-fluorine interactions and temperature-triggered transitions enables controlled PFAS adsorption-desorption.
- This approach presents a promising alternative to conventional PFAS treatment methods, reducing environmental burden and operational costs.
