Characterization of nano-silica vegetable grease with diffusing wave spectroscopy DWS and Raman spectroscopy

Area of Science:

• Materials Science
• Rheology
• Physical Chemistry

Background:

• Understanding the temperature-dependent behavior of vegetable grease is crucial for its application and stability.
• Grease viscoelastic properties are influenced by molecular dynamics and microstructure.
• Existing methods may not fully capture the complex interplay between temperature, microstructure, and rheological changes.

Purpose of the Study:

• To investigate the effect of temperature on the viscoelastic properties and microstructure of vegetable grease.
• To evaluate changes in particle dynamics and molecular movement within the grease as a function of temperature.
• To correlate microstructural changes with macroscopic viscoelastic parameters.

Main Methods:

• Diffusing wave spectroscopy (DWS) was employed to analyze particle dynamics and viscoelastic properties.
• Key DWS parameters such as intensity correlation function (ICF) and mean square displacement (MSD) were measured.
• Raman spectroscopy was used to assess changes in the chemical structure, specifically the ratio of unsaturated to saturated bonds.

Main Results:

• Temperature significantly affects the microstructure and viscoelastic states of vegetable grease.
• Changes in particle movement dynamics were observed with varying temperatures.
• Elastic modulus (G') and viscosity modulus (G″) shifted towards higher frequencies due to temperature-induced microstructural alterations.

Conclusions:

• Diffusing wave spectroscopy is effective in identifying temperature-induced changes in grease dynamics and viscoelasticity.
• Temperature influences the chemical structure and molecular mobility, impacting the overall rheological behavior of vegetable grease.
• The study highlights a significant relationship between temperature, microstructure, and the viscoelastic response of vegetable grease.