| Autor: |
Benke D; Department of Chemistry, Chair of Physical Chemistry 1, University Bayreuth, Germany. retsch@uni-bayreuth.de., Feller T; Department of Chemistry, Chair of Physical Chemistry 1, University Bayreuth, Germany. retsch@uni-bayreuth.de., Krüsmann M; Chair of Colloids and Nano Optics, Heinrich-Heine-University Düsseldorf, D-40225 Düsseldorf, Germany., Neuhöfer AM; Department of Chemistry, Chair of Physical Chemistry 1, University Bayreuth, Germany. retsch@uni-bayreuth.de., Ganster F; Department of Chemistry, Chair of Physical Chemistry 1, University Bayreuth, Germany. retsch@uni-bayreuth.de., Karg M; Chair of Colloids and Nano Optics, Heinrich-Heine-University Düsseldorf, D-40225 Düsseldorf, Germany., Retsch M; Department of Chemistry, Chair of Physical Chemistry 1, University Bayreuth, Germany. retsch@uni-bayreuth.de.; Bavarian Polymer Institute, Bayreuth Center for Colloids and Interfaces, Bavarian Center for Battery Technology (BayBatt), Universitätsstraße 30, 95447 Bayreuth, Germany. |
| Abstrakt: |
Shape-anisotropic colloids are increasingly attracting attention for the fabrication of nano- and mesostructured materials. Polymer-based prolate spheroids are typically accessible through a two-step fabrication procedure comprising the synthesis of monodisperse particles of initially spherical shape and their stretching into elongated, ellipsoidal-like objects. The particle stretching is conducted within a matrix polymer, most commonly polyvinylalcohol, which allows heating beyond the glass transition temperature of the polymer particles, e.g. polystyrene. Here, we investigate various aspects of the synthesis and their consequences for the resulting colloids. Loading the stretching matrix with a high amount of polymer particles results in small particle clusters, which are separated during the mechanical stretching step. At the same time, the matrix polymer physisorbs at the particle surface which can be removed via a rigorous work-up procedure. Overall, this process allows for a precise adjustment of the aspect ratio of the prolate spheroids with a small size distribution and retained electrostatic stabilization. We analyse these particles with a range of microscopic and scattering techniques, including depolarized dynamic light scattering that gives access to the rotational diffusion coefficients. |
