Asymmetrical Janus Particles and symmetrical “Core-Shell” Colloids

Dr. Alla Synytska

Over the last decade there have been immense efforts to fabricate monolith and core-shell colloidal materials with tailored structural, optical, and surface properties. The “core-shell” concept is particularly interesting and provides a variety of opportunities to change properties of colloidal particles. The “core-shell” concept typically implies tailoring the surface properties of particles, often accomplished by coating or encapsulating them within a shell of a preferred material.

There are plenty of methods for modification of particles by using of different surfactants, silanes and polymers. Most of conventional methods allow uniform or homogenous coating of the particles. On the other hand, one can expect interesting properties from the asymmetrically coated particles i.e. the particles whose surface chemical composition differs on two sides. These particles are often called “Janus” particles and were suggested by de Genne for the first time. 

Janus particles (JPs) i.e. the colloidal particles having different properties (such as charge, polarity, optical and magnetic properties) at opposite sides are an example of synthetic asymmetrical systems. Due to anisotropy of properties, the JPs are unique among other micro- and nanoparticles. Recently, the JPs demonstrated huge potential as drug-carriers, emulsion stabilizers, micro rheological probes and functional elements for design of electronic paper. Moreover, due to asymmetrical structures, the JPs are able to aggregate into fascinating hierarchical structures, thereby, building blocks for complex superstructures.

Publications on Topics

Janus Particles

  • Kirillova, A. ; Stoychev, G. ; Ionov, L. ; Synytska, A. Self-Assembly behavior of hairy colloidal particles with different architectures: mixed versus Janus more Langmuir 30 (2014) 12765-12774
  • Kirillova, A. ; Stoychev, G. ; Ionov, L. ; Eichhorn, K.-J. ; Malanin, M. ; Synytska, A. Platelet Janus particles with hairy polymer shells for multifunctional materials more ACS Applied Materials & Interfaces 6 (2014) 13106-13114
  • Synytska, A. ; Kirillova, A. ; Isa, L. Synthesis and contact-angle measurements of Janus particles more ChemPlusChem 79 (2014) 656-661
  • Synytska, A. ; Ionov, L. Stimuli-responsive Janus particles more Particle and Particle Systems Characterization 30 (2013) 922-930
  • Synytska, A. ; Svetlichny, V. ; Martina, D. ; Bellmann, C. ; Simon, F. ; Ionov, L. ; Stamm, M. ; Creton, C. Intelligent materials with adaptive adhesion properties based on comb-like polymer brushes more Langmuir 28 (2012) 16444-16454
  • Puretskiy, N. ; Stoychev, G. ; Synytska, A. ; Ionov, L. Surfaces with self-repairable ultrahydrophobicity based on self-organizing freely-floating colloidal particles more Langmuir 28 (2012) 3679-3682
  • Svetushkina, E. ; Puretskiy, N. ; Ionov, L. ; Stamm, M. ; Synytska, A. A comparative study on switchable adhesion between thermoresponsive polymer brushes on flat and rough surfaces more Soft Matter 7 (2011) 5691-5696
  • Berger, S. ; Ionov, L. ; Synytska, A. Engineering of ultra-hydrophobic functional coatings using controlled aggregation of bicomponent core/shell janus particles more Advanced Functional Materials 21 (2011) 2338-2344
  • Synytska, A. ; Khanum, R. ; Ionov, L. ; Cherif, C. ; Bellmann, C. Water-Repellent Textile via Decorating Fibers with Amphiphilic Janus Particles more ACS Applied Materials & Interfaces 3 (2011) 1216-1220
  • Berger, S. ; Synytska, A. ; Ionov, L. ; Eichhorn, K.-J. ; Stamm, M. Stimuli-responsive bicomponent polymer janus particles by "grafting from"/"grafting to" approaches more Macromolecules 41 (2008) 9669-9676