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pH-responsive, shape changing amphiphilic Janus particles

Description:

Stimuli-responsive colloid surfactants for thermodynamically stable emulsions and phase inversion emulsification

 

Inventor

Daeyeon Lee, Professor of Chemical & Biomolecular Engineering

 

Problem

Janus particles are biphasic colloids that have distinct chemistries and contrasting properties on each side.  Because of their amphiphilicity, Janus particles have the unique ability to stabilize multiphasic fluid mixtures, such as emulsions.  Janus particles have a strong tendency to segregate to and remain at fluid interfaces, leading to highly stable emulsions.  However, current synthesis techniques generate only one type of emulsion, so a method where the chemical environment can be tuned on demand to generate different types of emulsions is desirable.

 

Solution

Researchers in the Lee lab have designed a new approach to synthesize a new class of colloidal materials, highly uniform, pH-responsive Janus particles in emulsions, via seeded emulsion polymerization and acid hydrolysis.  The hydrolysis of the composite particles leads to a drastic change in particle morphology.  Janus particles with varying surface properties can be controlled by manipulating the chemical environment.  The pH-dependent aggregation/dispersion behavior of the Janus particles generates both attractive and repulsive emulsions at low and high pH conditions, respectively.  The ability to enable phase inversion allows for the generation of novel emulsions that cannot be achieved by traditional emulsion bulk synthesis methods.

 

 

Caption: Schematic illustration for synthesis of amphiphilic Janus particles and scanning electron microscopy images.  From Tu et al, JACS, 2014.

 

Advantages

•       Generate highly uniform, pH-responsive Janus particles

•       Completely reverse amphiphilicity in response to changes in solution pH

•       Dynamically tunable

•       Easier separation than amphiphilic surfactants to remove particles from products

 

Applications

•       Solid surfactants

•       Stable, industrial emulsions; water-in-oil and oil-in-water

•       Paints, coatings

•       Oil recovery

•       Emulsion-based reactions

 

 

Stage of Development

•       Proof-of-principle testing

 

Intellectual Property

US pending (14/687,266)

 

Reference Media

Tu and Lee.  JACS, 2014, 136, p. 9999 – 10006.

Tu and Lee.  Chemical Communications, 2014, 50, p. 15549-15552.

 

Desired partnerships

• License

Co-development

 

 

Download PDF

 

Docket #  14-7092 


Patent Information:
For Information, Contact:
Joshua Jeanson
Associate Director, SEAS/SAS Licensing Group
University of Pennsylvania
jeanson@upenn.edu
Inventors:
Daeyeon Lee
Keywords:
Engineering