Liquid-Liquid Phase Separation, Crystallization, and Solvent Evaporation in Relation to Microsphere Formation from...

Area of Science:

• Polymer Science
• Materials Science
• Chemical Engineering

Background:

• Thermally induced phase separation (TIPS) is a widely used technique for synthesizing polymer micro/nanoparticles.
• A clear understanding of the relationship between phase separation dynamics and the resulting particle morphology is currently lacking.

Purpose of the Study:

• To establish the correlation between polymer/solvent phase separation dynamics and the morphological characteristics of the resultant polymer micro/nanoparticles.
• To elucidate the microsphere formation mechanism during the evaporation process.

Main Methods:

• Characterization of polymer/solvent systems using UV-vis spectroscopy and Differential Scanning Calorimetry (DSC) to determine phase separation and crystallization temperatures.
• Innovative application of rotational rheometry to study the TIPS process dynamics under sealed conditions.
• Analysis of solid-liquid separation methods (opening vs. restricted evaporation) to investigate product properties.

Main Results:

• Detailed analysis of TIPS evolution in polymer/solvent systems under various conditions.
• Investigation of size distribution, morphology, crystallization, and thermal properties of TIPS products.
• Successful summarization of the microsphere formation mechanism for isotactic polypropylene (iPP)/decalin solutions.

Conclusions:

• The study successfully links phase separation dynamics to nanoparticle morphology in TIPS.
• The findings provide a mechanistic understanding of microsphere formation in polymer solutions.
• This research facilitates the controlled preparation of polymer micro/nanoparticles with desired properties.