CRISTAPRESS: an optical cell for structure development in high-pressure crystallization.

Area of Science:

• Materials Science
• Polymer Science
• Physical Chemistry

Background:

• Investigating phase transitions in complex liquids like polymers requires specialized equipment.
• Existing methods may have limitations in pressure, temperature control, or pressure-transmitting medium flexibility.

Purpose of the Study:

• To introduce the CRISTAPRESS, a novel optical high-pressure cell designed for in situ microscopic observation of phase transitions.
• To demonstrate the cell's capability in studying polymer crystallization kinetics under high pressure.

Main Methods:

• Design and implementation of the CRISTAPRESS optical high-pressure cell.
• Utilizing in situ light depolarizing microscopic observations to monitor morphological changes.
• Applying pressures up to 200 MPa and temperatures up to 300°C with various pressure-transmitting media.

Main Results:

• The CRISTAPRESS cell successfully enabled time-resolved measurements of polymer crystallization induced by water pressure.
• Preliminary investigations differentiated the impact of pressure and thermal histories on polymer growth kinetics and morphology.
• Demonstrated the cell's versatility with different pressure-transmitting media, including supercritical fluids.

Conclusions:

• The CRISTAPRESS cell is a valuable tool for investigating phase transitions in complex liquids.
• The technique allows for detailed analysis of crystallization kinetics and morphology under controlled high-pressure conditions.
• Findings pave the way for developing more accurate polymer crystallization models.