CO₂-responsive gels

Area of Science:

• Materials Science
• Polymer Chemistry
• Chemical Engineering

Background:

• Carbon dioxide (CO2) is an abundant, inexpensive, and environmentally benign stimulus.
• CO2-responsive materials exhibit property changes upon CO2 introduction or removal.
• CO2-responsive gels, a subset of CO2-responsive polymers, show unique swelling and morphological changes.

Purpose of the Study:

• To review the preparation, properties, and applications of CO2-responsive gels.
• To classify CO2-responsive gels by particle size: nanogels, microgels, aerogels, and macrogels.
• To highlight CO2-induced self-assembled gels, including poly(ionic liquid) gels.

Main Methods:

• Literature review of 90 peer-reviewed publications over the past 15 years.
• Classification of CO2-responsive gels based on particle size.
• Categorization of applications based on exploited properties.

Main Results:

• CO2-responsive gels are investigated for applications in Enhanced Oil Recovery (EOR) and CO2 sequestration.
• Key properties exploited include CO2-triggered aggregation for fluid flow control and reversible CO2 absorption-desorption.
• The review covers nanogels, microgels, aerogels, macrogels, and CO2-induced self-assembled gels.

Conclusions:

• CO2-responsive gels represent a significant area of research with diverse applications.
• Their tunable nature and response to CO2 make them promising for advanced material technologies.
• Further development in CO2-responsive gel technology is expected for industrial and environmental solutions.