Probing molecular motion and microstructure into emulsion gels by PFG NMR and advanced microscopy for microstructural...

Area of Science:

• Colloid and Surface Science
• Materials Science
• Biophysics

Background:

• Emulsion gels are composite materials with oil phases in gel matrices, gaining interest in food and pharmaceutical industries.
• Their tunable properties and controlled release capabilities are valuable, but water diffusion remains poorly understood.
• Understanding water dynamics is crucial for optimizing emulsion gel functionality.

Purpose of the Study:

• To investigate the dynamic behavior of water molecules in agarose gel-based systems using pulsed-field gradient (PFG) NMR.
• To elucidate the complex effects of oil phases on water diffusion within emulsion gels.
• To differentiate water diffusion environments in pure agarose gels versus emulsion gels.

Main Methods:

• Utilized pulsed-field gradient (PFG) NMR spectroscopy with a low-field benchtop instrument.
• Combined PFG NMR with advanced microscopy techniques for comprehensive analysis.
• Analyzed signal attenuation data using a two-compartment exchange model.

Main Results:

• Pure agarose gels exhibited a single water diffusion environment, indicating free water.
• Agarose emulsion gels showed multi-component water diffusion behavior.
• A two-compartment model successfully described water exchange between free and bound states.

Conclusions:

• The oil phase in emulsion gels significantly alters water diffusion dynamics.
• A complex microstructure, influenced by surfactant interactions, creates distinct water environments.
• PFG NMR is effective in characterizing water mobility within complex emulsion gel systems.