Disjoining Pressure of Water in Nanochannels

Area of Science:

• Nanoscale physics
• Fluid dynamics
• Thermodynamics

Background:

• Understanding water behavior at the nanoscale is crucial for various applications.
• Disjoining pressure influences phenomena in confined geometries.
• Previous studies have lacked experimental validation of disjoining pressure models in simulations.

Purpose of the Study:

• To experimentally determine the disjoining pressure of water in silicon dioxide nanochannels.
• To implement and validate this pressure relation in computational fluid dynamics (CFD) simulations.
• To simulate and predict bubble nucleation temperature in nanochannels.

Main Methods:

• Wicking experiments were performed in 1D silicon dioxide nanochannels of varying heights (59-1015 nm).
• Disjoining pressure data was fitted to a mathematical relation and integrated into CFD.
• Bubble nucleation was simulated in a 59 nm nanochannel and experimentally verified in a 58 nm nanochannel using laser heating.

Main Results:

• Disjoining pressure of water was measured up to ~1.5 MPa, decreasing exponentially with increasing channel height.
• CFD simulations accurately predicted bubble nucleation temperature, matching experimental results.
• The study successfully validated the experimentally derived disjoining pressure relation.

Conclusions:

• The developed disjoining pressure relation is experimentally validated and applicable in CFD.
• This integrated approach allows for numerical study of nanoscale phenomena involving disjoining pressure.
• The findings enable more accurate simulations of bubble nucleation and other related processes in nanochannels.