colloids; particles; directed-assembly; structure; materials; complex materials; self-assembly; aggregation
Sander J. S., Isa L., Rühs P., Fischer P., Studart A. R. (2012), Stabilization mechanism of double emulsions made by microfluidics, in Soft Matter
, 8, 11471-11477.
Sander JS, Erb RM, Denier C, Studart AR (2012), Magnetic Transport, Mixing and Release of Cargo with Tailored Nanoliter Droplets, in ADVANCED MATERIALS
, 24(19), 2582-2587.
Sander JS, Studart AR (2011), Monodisperse Functional Colloidosomes with Tailored Nanoparticle Shells, in LANGMUIR
, 27(7), 3301-3307.
The systematic study of colloids has led to major scientific discoveries over the past two centuries, including for example the observation of the jittery, random motion of particulate matter in liquids by Robert Brown in 1827, and the theoretical and experimental findings of Albert Einstein and Jean-Baptiste Perrin that helped to prove the real existence of molecules in the early 1900s. Current investigations on this field are mainly focused on the use of colloidal particles as analogs of atoms and molecules to investigate open questions in condensed matter physics or as building blocks for the assembly of materials with new, unusual structures and properties. The assembly of spherical colloidal particles under external stimuli, such as gravity, confining walls and electromagnetic fields, has been extensively exploited to fabricate structures of fundamental and technological interest that cannot be obtained through self-assembly processes. While a wide variety of structures have been achieved, the use of non-spherical anisotropic particles as colloidal building blocks and chemical external stimuli to control the assembly process remains largely unexplored. Chemical triggering is likely to be the major mechanism used for the assembly of inorganic building blocks in biological structures, whereas the use of non-spherical anisotropic particles should substantially expand the possible structures that can be formed. In this context, the aim of this project is to investigate the assembly of spherical and non-spherical anisotropic colloidal particles under the influence of external chemical stimuli as a means to obtain materials with new structures and properties. To achieve this goal, we will first synthesize non-spherical particles with well defined shape and surface chemistry to be used as anisotropic building blocks. An experimental apparatus will then be set-up to investigate the assembly of these building blocks under static and dynamic external chemical stimuli. Particular attention will be given to the effect of particle size, geometry and surface chemistry on the assembly process and to the conditions required to reversibly self-assemble the particles onto a variety of different structures. Understanding the effect of external stimuli on the assembly of anisotropic particles should help the design and manufacture of novel structured materials for biomedical, sensing, optical, magnetic and electronic applications.