Capillary negative pressure measured by nanochannel collapse.

Area of Science:

• Physics
• Materials Science
• Physical Chemistry

Background:

• Capillarity plays a crucial role in various physical and chemical phenomena.
• Measuring negative pressure, particularly in confined geometries, presents significant experimental challenges.

Purpose of the Study:

• To introduce and validate a novel method for quantifying capillarity-induced negative pressure.
• To investigate negative pressure in different liquids under varying surface tension conditions.

Main Methods:

• Developed a technique based on the critical channel width for elastocapillary collapse.
• Utilized silica nanochannels with a precise width of 79 ± 3 nm.
• Measured negative pressures for ethanol, acetone, cyclohexane, aniline, and water.

Main Results:

• Successfully measured negative pressures of several bars for five distinct liquids.
• Demonstrated the method's effectiveness across a range of surface tensions.
• Observed results consistent with the predictions of the Young-Laplace equation.

Conclusions:

• The presented method provides a reliable way to measure capillarity-induced negative pressure.
• Experimental findings align with theoretical models, validating the Young-Laplace equation in this context.
• This work offers new insights into fluid behavior under confinement.