Modelling Across Multiple Scales to Design Biopolymer Membranes for Sustainable Gas Separations: 2-Multiscale...

Area of Science:

• Materials Science
• Chemical Engineering
• Computational Chemistry

Background:

• Current membrane materials for gas separation are often non-renewable and non-biodegradable.
• Assessing new bio-based polymers typically involves costly and time-consuming experiments.
• Modeling approaches can reduce the experimental burden for evaluating alternative materials.

Purpose of the Study:

• To develop and validate a multiscale modeling methodology for assessing the CO2/CH4 separation performance of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) copolymers.
• To compare the multiscale approach with fully atomistic simulations and experimental data.
• To establish a time-efficient method for predicting the gas sorption behavior and selectivity of bio-based polymers.

Main Methods:

• Simulated PHBV structures using Molecular Dynamics (MD) to generate pressure-volume-temperature (PVT) data.
• Parametrized the Sanchez-Lacombe Equation of State using the PVT data.
• Evaluated CO2 and CH4 solubility and sorption-based selectivity in PHBV copolymers at various conditions.

Main Results:

• The multiscale model accurately predicted CO2 and CH4 solubility in PHBV copolymers.
• The sorption-based selectivity for CO2/CH4 mixtures showed reasonable agreement with fully atomistic models and experimental results.
• The multiscale method required significantly less computational effort compared to fully atomistic simulations.

Conclusions:

• The proposed multiscale modeling approach is a time-efficient and accurate alternative to extensive experimental studies and fully atomistic simulations.
• This method can significantly accelerate the development and adoption of renewable materials for gas separation applications.
• The study highlights the potential of bio-based PHBV copolymers for CO2/CH4 separation.