Measuring colloidal forces with the magnetic chaining technique.
In 1994 Leal Calderon et al. (Phys. Rev. Lett. 72, 2959 (1994)) introduced the magnetic chaining technique to directly probe the force-distance profile between colloidal particles. In this paper, we revisit this approach in two ways. First, we describe a new experimental design which allows us to utilize sample volumes as low as a few microliters, involving femtomoles of surface active macromolecules. Secondly, we extensively describe the characterization and preparation of the magnetic colloids, and we give a quantitative evaluation of performance and resolution of the technique in terms of force and interparticle separation.
Dreyfus
R
R
Center for Soft Matter Research, 4 Washington Place, New York University, New York, NY 10003, USA. dreyfus@nyu.edu
Lacoste
D
D
Bibette
J
J
Baudry
J
J
D003102:Colloids / Q000737:chemistry*; D008027:Light; D008280:Magnetics; D055620:Optical Phenomena; D012542:Scattering, Radiation; D055672:Static Electricity
D003102:Colloids