Kinetics of 12-Hydroxyoctadecanoic Acid SAFiN Crystallization Rationalized Using Hansen Solubility Parameters

Area of Science:

• Materials Science
• Physical Chemistry
• Supramolecular Chemistry

Background:

• Organogelators self-assemble into supramolecular structures, with properties influenced by solvent interactions.
• Controlling crystallization kinetics and morphology is crucial for tailoring material properties.

Purpose of the Study:

• To investigate how solvent chemistry affects the nucleation and crystallization kinetics of 12-hydroxyoctadecenoic acid (12HOA).
• To establish a relationship between solvent properties, gelator compatibility, and the resulting crystal structure and length.

Main Methods:

• Differential scanning calorimetry (DSC) was employed to study thermal transitions.
• A modified Avrami model was applied to DSC data to analyze crystallization kinetics.
• Hansen solubility parameters were used to quantify solvent-gelator interactions.

Main Results:

• Solvent changes significantly altered the nucleation and crystallization kinetics of 12HOA.
• Solvent-gelator compatibility, influenced by solvent properties, affected the chemical potential at crystallization onset.
• A linear correlation was found between chemical potential and Hansen solubility parameters (hydrogen-bonding) and Hansen space distance (Ra).

Conclusions:

• Solvent properties can be modulated to control 12HOA solubility, influencing crystallization kinetics and self-assembly into supramolecular structures.
• Modulating solvent properties during organogelation offers a method to control fiber length and engineer the physical properties of 12HOA gels.