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Click-active Janus particles


Scalable synthesis and functionalization of clickable Janus particles via seeded emulsion polymerization



Kathleen Stebe, Deputy Dean for Research & Innovation and Richer & Elizabeth Goodwin Professor of Chemical & Biomolecular Engineering and Daeyeon Lee, Professor of Chemical & Biomolecular Engineering



Amphiphilic Janus particles are biphasic colloids, where each face has distinct chemical properties.  Janus particles are useful for stabilizing multiphasic fluid mixtures, such as emulsions.  Current methods to make Janus particles rely on surface functionalization or phase separation, which have low throughput or require stringent synthesis conditions.  Incorporating a secondary monomer is technically challenging for Janus particles and has been previously demonstrated only for seed/core particles.



Researchers in the Stebe and Lee labs have developed a bulk synthesis method for generating click-active polystyrene-poly(propargyl acrylate) Janus particles using phase separation with seeded emulsion polymerization to obtain seed particles.  Functionalization is achieved through cross-linking and thiol-alkyne click chemistry.  This technique has been demonstrated with 3 different click reactions, and the morphology has been characterized with scanning electron microscopy.  The method can be expanded to seed particles with hydrophobic monomers and a variety of click-active monomers.  Particle morphology, composition, and surface charge can all be controlled, achieving chemical flexibility; furthermore, click reactions can occur throughout the bulk of particles or only at the particle surface.




•       Bulk synthesis from commercially available reagents

•       Rapid functionalization of a single clickable Janus particle via click-reactions with pendant groups to transform the chemical composition, surface charge, and particle shape in a matter of minutes.

•       Functionalization without harsh conditions

•       Tailor particles for particular chemical properties, such as wetting, adhesion, catalysis, and biological recognition

•       Fabricate stable particles with diverse compositions

•       Sequential click chemistry can be performed



•       Stabilize emulsions

•       Tunable materials



Stage of Development

•       Proof-of-principle


Intellectual Property

Provisional Pending


Reference Media

Bradley L.C. et al.  JACS, 2016.

Highlight in Nature Chemistry.


Desired partnerships

• License



Download PDF


Docket #  16-7872 

Patent Information:
For Information, Contact:
Joshua Jeanson
Associate Director, SEAS/SAS Licensing Group
University of Pennsylvania
Kathleen Stebe
Daeyeon Lee