Ca2+ ion responsive pickering emulsions stabilized by PSSMA nanoaggregates

Area of Science:

• Materials Science
• Colloid and Surface Chemistry
• Polymer Science

Background:

• Emulsion stability is crucial in many industrial processes.
• Developing responsive emulsifiers allows for controlled emulsion properties.
• Copolymer nanoaggregates offer tunable characteristics for interfacial applications.

Purpose of the Study:

• To synthesize and characterize novel Ca(2+) ion responsive copolymer nanoaggregates.
• To investigate the formation and properties of these nanoaggregates in response to Ca(2+) concentration.
• To prepare and evaluate Ca(2+) ion responsive Pickering emulsions using these nanoaggregates.

Main Methods:

• Dynamic light scattering (DLS) for aggregate and emulsion size analysis.
• Cryo-transmission electron microscopy (cryo-TEM) for visualizing nanoaggregate structure.
• Dynamic interfacial tension measurements to confirm interfacial adsorption.
• Preparation and stability testing of Pickering emulsions.

Main Results:

• Poly (4-styrenesulfonic acid-co-maleic acid) sodium salt (PSSMA) nanoaggregates form above a critical Ca(2+) concentration (0.2 M).
• PSSMA nanoaggregates are stable at high Ca(2+) concentrations but redissolve upon dilution.
• Ca(2+) responsive Pickering emulsions with submicrometer sizes and high stability were prepared, exhibiting rapid demulsification upon dilution.

Conclusions:

• PSSMA nanoaggregates act as effective, Ca(2+) responsive emulsifiers.
• The ability to control emulsion stability and demulsification via Ca(2+) concentration and dilution is demonstrated.
• This work provides a new method for manipulating emulsion stability with potential applications in oil recovery, food science, and environmental protection.