Micro-rheology on (polymer-grafted) colloids using optical tweezers.

Forces within Single Pairs of Charged Colloids in Aqueous Solutions of Ionic Liquids As Studied by Optical Tweezers Forces of interaction within single pairs of negatively charged micro-sized blank colloids

Microrheology and the fluctuation theorem in dense colloids

We present experiments and computer simulations of a “tracer” (or “probe”) particle trapped with optical tweezers and dragged at constant speed through a bath of effectively hard colloids with approximately the same size as the probe. The results are analyzed taking the single-particle case and assuming effective parameters for the bath. The effective microscopic friction coefficient and effect...

Probing Thermodynamics of Small Systems over Small Timescales Using Optical Tweezers

In the past decade, Atomic Force Microscopy (AFM) and Optical Tweezers (OT) have revolutionised molecular science by measuring picoNewton forces over lengthscales from 1 to 104 Å. In our laboratory, we have an Optical Tweezer Apparatus which has been extensively modified for our force measurement experiments in polymer and colloids science. The apparatus consists of an optical trap that weakly ...

Force measurements on oil and liposomes with the NanoTrackerTM 2 optical tweezers system

The versatile NanoTrackerTM 2 system is designed for the optical trapping of dielectric particles and optically refractive objects. Sizes range from sub-micrometer polystyrene and silica particles (beads) to living cells with diameters of >10μm. After automated calibration of the trap-particle system, the precise and reliable measurement of piconewton forces is possible. Applications include si...

Effect of Micro Glass Flake on Morphological and Rheological Behaviour of Epoxy Vinyl Ester Composite Coatings

In the present work, attempts were made to investigate the reinforcement and treatment effect of GF on morphological and rheological behaviour of GF/epoxy vinyl ester composites. GF was incorporated into epoxy vinyl ester resin by sonication, and mechanical agitation. Rheological and morphological properties were studied as a function of particle treatment and size distributions. The dispersion...