Chitin nanocrystal-stabilized Pickering emulsion for multimodal sensing.

Area of Science:

• Materials Science
• Polymer Chemistry
• Nanotechnology

Background:

• Hydrogels are versatile materials with applications in various fields.
• Improving hydrogel mechanical properties and ionic conductivity is crucial for advanced applications.
• Chitin nanocrystals (ChNCs) offer unique properties for material reinforcement.

Purpose of the Study:

• To develop a Pickering emulsion-templating method for composite hydrogels.
• To enhance the mechanical properties and ionic conductivity of hydrogels.
• To create advanced hydrogel-based strain sensors with improved performance.

Main Methods:

• Preparation of ChNC-coated poly(trimethylolpropane triacrylate) microspheres.
• Utilizing a Pickering emulsion template for photo-cross-linking.
• Incorporation of poly(vinyl alcohol) (PVA) and borax followed by freeze-thawing.

Main Results:

• Composite hydrogels exhibited dual cross-linking: PVA crystallization and boronic ester bonds.
• Microspheres significantly improved hydrogel strength (676 kPa vs 350 kPa) and elongation (600% vs 350%).
• Enhanced ionic conductivity and improved strain and thermal resistances were observed.

Conclusions:

• The Pickering emulsion-templating method effectively enhances hydrogel mechanical properties and ionic conductivity.
• ChNC-stabilized Pickering emulsions provide a novel approach for designing high-performance hydrogel materials.
• The developed hydrogel sensors are suitable for large-strain deformation probing.