Nanobubbles at Hydrophilic Particle-Water Interfaces

Area of Science:

• Surface science
• Nanotechnology
• Physical chemistry

Background:

• Nanobubbles persist anomalously, defying Laplace's law, with potential applications in various fields.
• Characterizing nanobubbles on irregular surfaces is challenging due to limitations in existing techniques.
• Previous studies primarily focused on nanobubbles on flat, hydrophobic surfaces.

Purpose of the Study:

• To develop and apply a novel in situ technique for characterizing nanobubbles on hydrophilic particle-water interfaces.
• To investigate the morphology and chemical composition of nanoscopic gas bubbles under ambient conditions.
• To demonstrate the presence and stability of oxygen nanobubbles at particle-water interfaces.

Main Methods:

• Utilized synchrotron-based scanning transmission soft X-ray microscopy (STXM) for nanometer-resolution imaging.
• Performed in situ analysis of nanobubbles at hydrophilic particle-water interfaces.
• Investigated nanobubbles formed on diatomite particles after oxygen aeration and temperature variation.

Main Results:

• Successfully discerned nanoscopic gas bubbles larger than 25 nm.
• Provided direct in situ proof of molecular oxygen (O2) within individual nanobubbles.
• Observed a stable cloud of O2 nanobubbles at the diatomite particle-water interface for extended periods.

Conclusions:

• The developed STXM technique enables the detection of nanobubbles and their internal composition on complex interfaces.
• Stable oxygen nanobubbles can form and persist at hydrophilic particle-water interfaces, impacting interfacial properties.
• These findings open new avenues for understanding nanobubble behavior and developing advanced oxygen delivery technologies.