Colloidal crystal formation: Nano-dewetting and the assembly process

3^rd International Conference and Exhibition on Materials Science & Engineering

October 06-08, 2014 Hilton San Antonio Airport, USA

Frank Marlow and Mulda Muldarisnur

Accepted Abstracts: Material Sci Eng

Abstract :

Self-assembly of colloidal particles is a promising approach for fabrication of three-dimensional periodic structures which are especially interesting for photonic crystals. This approach is simple, cheap, and applicable for a large range of particles and lattice constants. However, these big advantages are accompanied by some drawbacks namely the imperfect control of the fabrication process and of the intrinsic defects. The type and the number of defects inside colloidal crystals are widely unknown and difficult to obtain from measurements. The efforts to improve the self-assembly process have led to many proposed deposition methods with a different degree of controllability and defect concentration. In this talk we will give the results for our deposition method. In addition, our studies have been devoted to understand colloidal crystal formation. Regarding one of the details of the formation process, we will have a closer look at the drying of colloidal crystals. This lessregarded but important step is connected with a continuous shrinkage process of the lattice. However, several minutes after starting the drying, the system seems to take a breath before it shrinks monotonously until its final state after about one day. This short period we call ?v?-event because of the shape of the curve characterizing the lattice constant: a decrease followed by a counter-intuitive increase which ends after one hour. The event is found in time-dependent optical spectra. It is assigned to the start of a nano-dewetting process occurring at the colloidal particles.

Biography :

Frank Marlow has completed his PhD at the age of 28 years from Humboldt University Berlin and postdoctoral studies at the Institute of Applied Chemistry in Berlin, Delft University of Technology, and UC Santa Barbara. He is a group leader at the MPI für Kohlenforschung in Mülheim/Ruhr. He has published more than 100 papers in reputed journals.