Abstract
The detachment of polystyrene particles adhering to collector surfaces with different electrostatic charge and hydrophobicity by attachment to a passing air bubble has been studied in a parallel plate flow chamber. Particle detachment decreased linearly with increasing air bubble velocity and decreasing liquid/vapour interfacial tension, regardless of the collector surface properties. However, particle detachment from hydrophilic, positively charged surfaces [3-(2-aminoethylamino)propyldimethoxysilane-coated glass, water contact angle 33°] was most sensitive to variations in air bubble velocity and liquid/vapour interfacial tension, while detachment from hydrophobic, negatively charged surfaces (dimethyldichlorosilane-coated glass, water contact angle 96°) was affected least. The influence of air bubble velocity was predominantly through the bubble/particle contact time, which needs to be long enough to allow sufficient thinning of the liquid film between the bubble and the particle for the detachment forces to become effective. On the hydrophobic collector surfaces, this thinning is assisted by a nearly spontaneous de-wetting of the collector surface, therewith decreasing the influence of other factors, such as air bubble velocity or liquid/vapour interfacial tension. Upon multiple passages of air bubbles approximately 80% of the particles were eventually detached, regardless of the properties of the collector surfaces, illustrating that the probabilities of detachment by multiple air bubble passages are additive.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.