TRPM4-Inspired Polymeric Nanochannels with Preferential Cation Transport for High-Efficiency Salinity-Gradient Energy...

Area of Science:

• Materials Science
• Nanotechnology
• Electrochemistry

Background:

• Biological ion channels, like TRPM4, demonstrate highly selective cation transport crucial for energy conversion.
• Artificial nanochannels struggle to replicate the selectivity and efficiency of biological counterparts.
• Cation-π interactions are key to the selectivity mechanism in biological channels.

Purpose of the Study:

• To design and fabricate a TRPM4-inspired artificial nanochannel (CN) with enhanced cation selectivity.
• To investigate the mechanism of Na+/Cl- selectivity using ionic and cation-π interactions.
• To evaluate the performance of the CN for salinity-gradient energy harvesting.

Main Methods:

• Assembled nanochannels using poly(ether sulfone)s with sulfonate acid and indole moieties.
• Investigated cation selectivity and transference numbers for Na+, K+, and Li+ ions.
• Measured salinity-gradient power density and energy conversion efficiency.

Main Results:

• Achieved highly selective Na+ transport with a transference number improving from 0.720 to 0.982.
• Demonstrated a Na+/Cl- selectivity ratio of 54.6, surpassing other alkali metal ions.
• Attained a maximum output power density of 5.7 W m-2 and a record energy conversion efficiency of 46.5%.

Conclusions:

• The TRPM4-inspired nanochannel effectively mimics biological selectivity for cation transport.
• The developed nanochannel offers a novel strategy for efficient salinity-gradient energy conversion.
• This research advances the development of high-performance artificial nanochannel membranes.