Melanin-Inspired Stable Dispersion of Molten Salt Nanofluids

Area of Science:

• Materials Science
• Nanotechnology
• Chemical Engineering

Background:

• Inorganic molten salt nanofluids offer potential for thermal applications but face challenges with nanoparticle aggregation.
• Existing methods struggle to achieve stable, long-term dispersion of nanoparticles in molten salts.

Purpose of the Study:

• To develop a stable dispersion method for nanoparticles in molten salts inspired by melanin.
• To enhance the properties of molten salt nanofluids for solar-thermal energy applications.

Main Methods:

• Utilized in situ polymerization of l-dopa in the presence of inorganic salt ions (Li+, K+, Na+).
• Leveraged molten salt cations to enhance polymerization kinetics and self-assembly into melanin-like poly(l-dopa) (PLD) particles.
• Investigated the formation of a charge distribution layer on PLD particles for stable dispersion.

Main Results:

• Achieved stable, uniform dispersion of various nanoparticles within molten salts using poly(l-dopa) (PLD).
• Molten salt cations (Li+, K+, Na+) promoted PLD formation and surface functionalization, creating rough-surfaced particles.
• Resultant nanofluids exhibited boosted solar absorptance and enhanced specific heat capacity.

Conclusions:

• A melanin-inspired in situ polymerization strategy effectively disperses nanoparticles in molten salts.
• The developed molten salt nanofluids are suitable for medium-temperature solar-thermal energy harvesting.
• This approach facilitates the controlled fabrication of functional materials in ionic fluids.