Mechanical and physicochemical characteristics of sub-millimeter and macrobubbles: Insights from AFM analysis, zeta potential measurements and rise velocity

• DOI: 10.1016/j.rsurfi.2024.100262
• Publication Date: 2024-08-02T10:06:29Z
• Authors: A.M. Joshua; E.H. Ooi; W.S. Chang; E.V. Lau
• Keywords: Zeta potential; Streaming current

This study presents the change in mechanical and physicochemical behaviour of macrobubbles sub-millimeter bubbles with respect to pH. While conventionally range from 100 μm 2 mm diameter, this focuses on comparatively less-explored bubble range, centered around a median diameter 500 μm. The difference (500 μm) compared their larger counterparts (1100 within macrobubble size were evidenced through atomic force microscopy (AFM) analysis, zeta potential measurements, rise velocity experiments. adhesion energy between silicon nitride cantilever tip showed decreasing trend increasing pH, notably diminishing by about 50% beyond pH 9. Although no significant differences statistically revealed two sizes at lower consistently smaller for higher finding suggests that electrical double layer (EDL) interactions are influenced specific surface area, particularly alkaline region. Zeta measurements exhibited cubic trend, an isoelectric point 3.5 minimum 11. also depicted similar bubbles, suggesting direct relationship stiffness its velocity. Therefore, changes affected bubbles' properties, while other hand, certain properties sizes.