Synthesis and characterization of anisotropic colloidal particles

Viac o knihe

Anisotropic colloids, with their non-spherical shapes and heterogeneous compositions, have garnered attention in chemistry and physics research. Their preparation and characterization present challenges in fundamental research and material science. The author explores the synthesis and characterization of two colloidal systems featuring dumbbell-shaped core-shell morphologies, where the core is made of poly(methyl methacrylate) and poly(styrene). A notable aspect of these systems is that the attached shell layer allows for alterations in particle size and aspect ratio through changes in ionic strength or temperature. Depolarized dynamic light scattering (DDLS) is employed to examine how these stimuli influence translational and rotational diffusion in a highly diluted state. The hydrodynamics are effectively described using stick-boundary conditions and analytical models for double spheres, prolate ellipsoids, and cylinders. Imaging techniques such as electron and scanning force microscopy reveal the particle morphology. The second part of the work focuses on the hydrodynamics of monodisperse, submicron-sized colloidal clusters composed of one to four spherical building blocks. The author illustrates the effectiveness of the shell model in identifying the rotational relaxations accessible via DDLS.