- 2:10 PM

Elasticity of Chains of Paramagnetic Colloidal Particles

Dichuan Li and Sibani Lisa Biswal. Chemical and Biomolecular Engineering, Rice University, MS 362, Main 6100, Houston, TX 77005

A key obstacle in assembling colloidal structures is understanding the fundamental chemistry and physics of the assembly process. In this talk, we will focus on the influence of variable flexibility on the shape and morphology of linked colloidal chains. These multilink chains are comprised of magnetic colloidal particles which have been “glued” together with various linker molecules.

The flexural rigidity, or bending stiffness, is used to describe the chain's resistance to bending forces. We have previously shown that the properties of the linker molecules greatly influence the overall chain flexibility 1. In particular, by adjusting the length of the linker molecule, we can tune the overall flexibility of the chain. We have recently constructed a simplistic model using single linker molecule elasticity to estimate the overall flexural rigidity of the chain. The calculated results of particle chains linked by different linker molecules from the model are compared with the measured overall flexural rigidity values in Ref [1].

In this talk we will elucidate how the properties of the linker molecules affect the overall chain elasticity. Also, we will show that the overall chain flexural rigidity is a non-linear function of bending angle, instead of a constant independent of bending angle as in a linear homogenous elastic filament assumed by other researchers2-4.

1. Biswal SL, Gast AP. Mechanics of semiflexible chains formed by poly(ethylene glycol)-linked paramagnetic particles. Physical Review E 2003; 68: 021402/1-/9.

2. Goubault C, Jop P, Fermigier M et al. Flexible magnetic filaments as micromechanical sensors. Phys Rev Lett 2003; 91: 4.

3. Cebers A. Flexible magnetic filaments. Current Opinion in Colloid & Interface Science 2005; 10: 167-75.

4. Cebers A, Cirulis T. Magnetic elastica. Phys Rev E 2007; 76.