Design of Soft Materials from Colloidal Crystals

Phonons in two-dimensional soft colloidal crystals.

The vibrational modes of pristine and polycrystalline monolayer colloidal crystals composed of thermosensitive microgel particles are measured using video microscopy and covariance matrix analysis. At low frequencies, the Debye relation for two-dimensional harmonic crystals is observed in both crystal types; at higher frequencies, evidence for van Hove singularities in the phonon density of sta...

Fabrication of tunable spherical colloidal crystals immobilized in soft hydrogels.

Highly cooperative stress relaxation in two-dimensional soft colloidal crystals.

Stress relaxation in crystalline solids is mediated by the formation and diffusion of defects. Although it is well established how externally generated stresses relax, through the proliferation and motion of dislocations in the lattice, it remains relatively unknown how crystals cope with internal stresses. We investigate, both experimentally and in simulations, how highly localized stresses re...

Quantification of protein-materials interaction by soft colloidal probe spectroscopy.

We present a robust and fast method to quantify the adhesion energy of surface anchored proteins on material surfaces using soft colloidal particles as sensors. The results obtained from studying the adhesion of fibronectin on surfaces with different hydrophobicity were in good agreement with theoretical considerations demonstrating the feasibility of the method.

Photonic crystals Fabrication of Tunable Spherical Colloidal Crystals Immobilized in Soft Hydrogels**

Spherical colloidal crystals are three-dimensional periodic arrays of monodisperse colloidal particles with a spherical geometry. The spatial periodicity of the refractive index of the colloidal crystalline arrays results in an optical stop band and, hence, they act as photonic crystals in the optical regime. In contrast to conventional film-type colloidal crystals where the crystals are aligne...