English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We measure interaction forces between pairs of charged PMMA colloidalparticles suspended in a relatively low-polar medium (5 $\lesssim \epsilon\lesssim$ 8) directly from the deviations of particle positions inside twotime-shared optical traps. The particles are confined to optical point traps;one is held in a stationary trap and the other particle is brought closer insmall steps while tracking the particle positions using confocal microscopy.From the observed particle positions inside the traps we calculate theinterparticle forces using an ensemble-averaged particle displacement-forcerelationship. The force measurements are confirmed by independent measurementsof the different parameters using electrophoresis and a scaling law for theliquid-solid phase transition. When increasing the salt concentration byexposing the sample to UV light, the force measurements agree well with theclassical DLVO theory assuming a constant surface potential. On the other hand,when adding tetrabutylammonium chloride (TBAC) to vary the salt concentration,surface charge regulation seems to play an important role.

Measuring Colloidal Forces from Particle Position Deviations inside an Optical Trap