Salt- and temperature-stable quantum dot nanoparticles for porous media flow

- Cadmium selenide nanoparticles (NPs) are colloidally stable in 1 M NaCl brine solution.
- A nonionic ethoxylated alcohol surfactant (Neodol) provides this salt stability.
- NPs are colloidally stable up to 70 °C, near the surfactant cloud point temperature.
- NPs can travel through crushed calcite and sandstone and through a sandstone core.
- NP adsorption during porous media flow can occur due to surfactant clouding.