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Measuring particle-bubble interactions using optical tweezers

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dc.contributor.authorSchulz, J.R.
dc.contributor.authorConnor, J.N.
dc.contributor.authorSedev, R.
dc.contributor.authorWedding, B.
dc.contributor.authorMiklavcic, S.J.
dc.contributor.conferenceChemeca conference 2016 (25 Sep 2016 - 28 Sep 2016 : Adelaide, Australia)
dc.date.issued2016
dc.description.abstractFroth flotation is a key pre-concentration process in many minerals processing operations and also in wastewater treatment. At its heart is the interaction between micrometer-sized particles and air bubbles. An understanding of the factors affecting such interactions can be used to enhance process optimization. Al- though instruments such as the atomic force microscope and surface force apparatus have been used to explore these interactions, they are limited by the mechanical constraint placed on the particle and the sensitivity to stronger short-range (< 100 nm) forces. Optical tweezers provide an alternative method that uses tightly focused laser light to hold and manipulate the particle.As a result, the particle is only partially constrained in space, and can undergo Brownian motion. The optical trap also behaves as a very weak spring and is sensitive to the weak long-range forces that often account for particle capture in real flotation processes. In this paper we give the first-ever report of force −vs− distance measurements using optical tweezers of the interactions between air bubbles and micrometer-sized silica spheres across a range of electrolyte solutions. In addition to force profiles, adhesive forces of the bubble-particle systems were also measured and found to increase significantly with increasing salt concentration. To benchmark the experimental procedure we also measured forces between a silica sphere and a glass fibre. The results were compared with calculations based on DLVO theory and found to be in qualitative agreement.
dc.identifier.citationChemeca 2016: Chemical engineering - regeneration, recovery and reinvention, 2016, iss.3407088, pp.373-380
dc.identifier.isbn9781922107831
dc.identifier.urihttps://hdl.handle.net/11541.2/122676
dc.language.isoen
dc.publisherChemeca
dc.publisher.placeAustralia
dc.rightsCopyright 2016 Institution of Chemical Engineers
dc.subjectoptical tweezers
dc.subjectsurface forces
dc.subjectcolloid particle
dc.subjectbubble-solid interactions
dc.subjectflotation
dc.titleMeasuring particle-bubble interactions using optical tweezers
dc.typeConference paper
pubs.publication-statusPublished
ror.mmsid9916097589701831

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