Nanostructured fluids from pluronic® mixtures.

Area of Science:

• Polymer Science
• Materials Science
• Physical Chemistry

Background:

• Pluronic(®) block copolymers form micelles and gels in aqueous solutions.
• Binary mixtures of Pluronics can exhibit complex phase behaviors.
• Understanding these behaviors is crucial for developing advanced materials.

Purpose of the Study:

• Investigate the interplay between micellization and gelation in binary Pluronic(®) mixtures.
• Characterize the distinct contributions of Pluronic(®) F127 and Pluronic(®) F68 to mixture properties.
• Determine the influence of temperature and maturation on the rheological behavior of these mixtures.

Main Methods:

• Micro-differential scanning calorimetry (Micro-DSC) to study thermal transitions.
• Rheology to measure mechanical properties and gelation transitions.
• Systematic variation of Pluronic(®) F127 and Pluronic(®) F68 ratios at a fixed total concentration (20 wt%).

Main Results:

• Micro-DSC confirmed two independent micellization processes for F127 and F68.
• F127 exhibited a distinct crystallization transition that persisted in mixtures.
• Rheology revealed two gelation types: F127 crystallization-induced and jamming transitions.
• Maturation significantly impacted rheological properties, suggesting phase rearrangements.

Conclusions:

• Binary Pluronic(®) mixtures display unique micellization and gelation phenomena distinct from single-component systems.
• The interplay between micellization and gelation is governed by the specific copolymer interactions and phase behaviors.
• These findings offer insights into the design and application of Pluronic(®) based hydrogels.