Biodegradable polymers and sustainable pathways for membrane separation applications and packaging flexible films:

• Membrane applications: Bio renewable and biodegradable polymers, fully dissolvable in seawater, are tested for the gas separation performances.  Membrane technology is a valid alternative to traditional gas separation processes and a promising solution for Carbon Capture. Even though membrane materials are usually polymer-based, end-of-life treatment planning seldom enters process design considerations. Using degradable biopolymers could increase the sustainability of membrane technology, which is conquering market shares owing to its positive environmental impact. The ultimate purpose of this project is to promote a circular economy mindset through the analysis of potential applicability of bio-based polymers in typical industrial applications. Membranes are produced replacing traditional toxic solvents with greener ones, and the films obtained are tested for potential use in gas separation and CO₂ capture applications. The activity developed covers: Optimization of the preparation protocol and solvent; measurement of gas solubility, permeability and selectivity of the membrane; molecular simulation of the polymeric materials and of the gas sorption and transport therein; evaluation of key structural parameters to improve separation performance.  See projects EPSRC IAA 
  • Modelling across Multiple Scales to Design Biopolymer Membranes for Sustainable Gas Separations: 1—Atomistic Approach, 2023, Open Access 
  • New sustainable routes for gas separation membranes: The properties of poly(hydroxybutyrate-co-hydroxyvalerate) cast from green solvents, 2022, Open Access
• ​Packaging applications: 
  • ​Fully Biobased Polyhydroxyalkanoate/Tannin Films as Multifunctional Materials for Smart Food Packaging Applications, 2023, Open access

Multiscale modeling of fluid sorption and transport in polymeric materials - including Machine Learning

• Polymeric membranes for gas separation: Multiple scale approaches can combine the computational efficiency of macroscopic methods with the accuracy and predictive power of atomistic ones, especially when complex materials such as those including crystalline structures and nanofillers with enhanced selective properties are concerned (e.g. graphene, MOFs etc.). The separation of interest in this project is mainly CO₂ capture and natural gas/biogas purification, but other processes such as water purification are not excluded a priori. The modeling strategies developed are validated against experimental data.  
  • ​​Estimating Gas Sorption In Polymeric Membranes From The Molecular Structure: A Machine Learning Based Group Contribution Method For The Non-Equilibrium Lattice Fluid Model (ML-GC-NELF), 2024 Open Access
  • A perspective on data-driven screening and discovery of polymer membranes for gas separation, from the molecular structure to the industrial performance, 2024
  • Simple lattice model explains equilibrium separation phenomena in glassy polymers, 2024
  • Modelling across Multiple Scales to Design Biopolymer Membranes for Sustainable Gas Separations: 1—Atomistic Approach, 2023 Open Access
  • Modelling Sorption and Transport of Gases in Polymeric Membranes across Different Scales: A Review, 2022 Open Access
  • A multiscale approach to predict the mixed gas separation performance of glassy polymeric membranes for CO₂ capture: the case of CO₂/CH₄ mixture in Matrimid^®, 2017

• Barrier materials, e.g. for hydrogen or supercritical CO₂. This activity, in collaboration with the Dutch Polymer Institute and several companies, is devoted to developing hierarchical simulation strategies to predict the behavior of barrier materials in extreme conditions during H₂ handling.  The project develops an integrated simulation chain for the sorption and transport properties of high performance, multiphase materials, such as semi crystalline polymers or nanocomposites for challenging industrial applications. A Molecular Dynamics (MD) simulation of the phases is bridged with macroscopic methods in a hierarchical approach adopting key material parameters and producing structure-property correlations useful to guide the design and the optimization of such materials, as well as to reduce the number of experimental tests required. A comprehensive, dedicated experimental campaign is designed and performed to validate and integrate the simulation approach.

  • Molecular Simulations of Hydrogen Sorption in Semicrystalline High-Density Polyethylene: The Impact of the Surface Fraction of Tie-Chains, 2024 Open Access

  • Multi-scale modeling of gas solubility in semi-crystalline polymers: bridging Molecular Dynamics with Lattice Fluid Theory, 2023 Open access

  • Modelling solubility in semi-crystalline polymers: a critical comparative review, 2022 Open Access

  • A comprehensive theoretical framework for the sub and supercritical sorption and transport of CO₂ in polymers, 2022

  • An equation of state (EoS) based model for the fluid solubility in semicrystalline polymers, 2014 

• Screening nanoporous adsorbents for wearable hemodialysis (removal of urea from water). Hemodialysis is a life-saving treatment which requires an exceptional amount of water. Ultrapure water is required to remove toxins from the blood of patients. The development of materials usable as membranes or adsorbent with purification ability for spent dialysate streams allows to reduce the amount of water required and to render the treatment available to more people and in remote places. We aim to fiscover novel materials which allow miniaturisation of the HD device and reduction of water consumed. Research featured on BBC news. This project is carried out thanks to funds from the Royal Society of Edinburgh and Kidney Research UK

  • In silico screening of nanoporous materials for urea removal in hemodialysis applications, 2023 

  • Mixed Matrix Membranes Adsorbers (MMMAs) for the Removal of Uremic Toxins from Dialysate, 2022 Open Access

Novel materials for membrane separations: mixed matrix membranes and others

In recent years a number of new materials has entered the picture into the membrane world: new high performance polymers, 2d nanomaterials like graphene, crystalline porous materials like Metal Organic Frameworks, etc. Due to polymer flexibility and processability, a feasible solution seems the one of incorporating variable percentages of such fillers in the polymer and produce thin films out of them.  
The activity regards the addition of graphene and graphene oxide to polymers, as well as the addition of Zeolite and ZIF-8. The aim is to provide emerging separation processes, like CO₂ capture, with improved materials and possibly provide also an explanation to the observed behavior with the use of models.  

• Related papers :
  • Mixed matrix membranes based on TORLON® and ZIF-8 for high-temperature, size-selective gas separations, 2022, Open Access
  • An analysis of the effect of ZIF-8 addition on the separation properties of polysulfone at various temperatures, 2021, Open Access
  • Enhancing the separation performance of glassy PPO with the addition of a molecular sieve (ZIF-8): Gas transport at various temperatures 2020   Open Access
  • Evaluation of electrospun nanofibrous mats as materials for CO₂ capture: A feasibility study on functionalized poly(acrylonitrile) (PAN), 2018
  • Reducing ageing of thin PTMSP films by incorporating graphene and graphene oxide: Effect of thickness, gas type and temperature 2018
  • Permeability and selectivity of PPO/graphene composites as mixed matrix membranes for CO2 capture and gas separation 2018 Open Access
  • Effect of relative humidity on the gas transport properties of zeolite A/PTMSP mixed matrix membranes 2015
  • Effect of Graphene and Graphene Oxide Nanoplatelets on the Gas Permselectivity and Aging Behavior of Poly(trimethylsilyl propyne) (PTMSP) 2015

Evaluation of polymeric membranes performance in multicomponent conditions
Polymeric membranes are a sustainable alternative to traditional, energy-intensive separation methods in many applications such as gas separation and Carbon Capture. A precise evaluation of the membrane performance in realistic conditions and in the presence of impurities is required to cut the process costs and extend the membranes lifetime.  
One of the main issues is associated, especially in the process of natural gas and biogas purification, to the presence of CO2, which promotes membrane softening and exhibits a non-ideal behavior engaging competition with the other gases. Such aspects require tailored and time consuming experiments.  
In this activity, experimental data are collected with a sophisticated equipment which allows to monitor the behavior of binary and ternary mixtures (for the first time!) in high performance membranes. The data are used to generate generalized relationships and provide validation to  predictive thermodynamic and molecular models which can extend the experimental results in wide operative ranges and offer a fundamental insight of the process.  
The results of such project will allow engineers to design and select more efficient membrane process conditions and materials, and expand the range of application of membrane technologies.  

• Related Papers:
  • Mixed gas diffusion and permeation of ternary and quaternary CO₂/CO/N₂/O₂ gas mixtures in Matrimid®, polyetherimide and poly(lactic acid) membranes for CO₂/CO separation, 2022
  • Enabling experimental characterization and prediction of ternary mixed-gas sorption in polymers: C₂H₆/CO₂/CH₄ in PIM-1, 2021
  • Towards a systematic determination of multicomponent gas separation with membranes: the case of CO2/CH4 in cellulose acetates, 2021 
  • The influence of propane and n-butane on the structure and separation performance of cellulose acetate membranes, 2021 
  • Competitive sorption in CO₂/CH4 separations: the case of HAB-6FDA polyimide and its TR derivative and a general analysis of its impact on the selectivity of glassy polymers at multicomponent conditions 2020
  • Sorption of CO₂/CH₄ mixtures in TZ-PIM, PIM-1 and PTMSP: Experimental data and NELF-model analysis of competitive sorption and selectivity in mixed gases, 2020
  • Modelling Mixed-Gas Sorption in Glassy Polymers for CO2 Removal: A Sensitivity Analysis of the Dual Mode Sorption Model, 2019, Open Access