Mariela Martins Nolasco (University of Aveiro, Portugal) has developed the ability to characterise polymer structure and dynamics, embracing both natural polymers (e.g. cellulose and bacterial cellulose) and bio-based synthetic polymers. This knowledge is critical in developing new functionalized or composite materials for use in emerging technologies such as medical devices or fuel cells.
Her approach took advantage of inelastic neutron scattering (INS) combined with discrete and periodic density functional theory (DFT) calculations to delve deeper into the structure−property correlations in polymeric materials. This combination is ideal either to assist the elucidation of measured data or, conversely, as method of validating theoretical models. The scientific impact of these projects arises from the recognition of the potential of INS spectroscopy to give answers to the questions relating the micro-structure and dynamics of polymer chains and the macroscopic properties of polymeric materials, including nano-structured and composite materials.
One class of polymers studied using INS was bio-based synthetic polymers (furandicaboxylate polyesters). These polymers are a new class of sustainable materials derived from renewable resources which are intended to gradually phase out their petrochemical counterparts. They could replace poly(ethylene terephthalate) (PET), a petro-based high performance polyester widely used as packaging material, offering good mechanical performance, comparable thermal stability, and increased barrier properties (ca. 10 times less permeable to oxygen and 20 times less permeable to carbon dioxide). Their industrial and commercial potential is already being implemented by industry stakeholders.
In addition, her comprehensive study of celluloses – in which the periodic-DFT calculations provide a detailed description of the vibrational spectra of bacterial and vegetal cellulose with different wet contents – set the grounds for the understanding of subtle interactions in cellulose-based composites and to assist the characterization of bacterial cellulose membranes in microbial fuel cells. The comprehensive character and clarifying nature concerning the vibrational spectra of celluloses makes it possible to assess not only domains within the supramolecular structure, but also to identify the sample origin (bacterial, kraft pulp, etc), with high accuracy, a result of the resolution power of the INS technique.
Evidence of impact
- Hydrogen Bond Dynamics of Cellulose through Inelastic Neutron Scattering Spectroscopy, Biomacromolecules, 19 (2018) 1305-1313
- Inside PEF: Chain Conformation and Dynamics in Crystalline and Amorphous Domains Macromolecules, 51 (2018) 3515–3526
- Asymmetric Monomer, Amorphous Polymer? Structure–Property Relationships in 2,4-FDCA and 2,4-PEF, Macromolecules, 53 (2020) 1380-1387
- Understanding the Structure and Dynamics of Nanocellulose-Based Composites with Neutral and Ionic Poly(methacrylate) Derivatives Using Inelastic Neutron Scattering and DFT Calculations, Molecules, 25 (2020) 1689;
- Poly(4-styrene sulfonic acid)/bacterial cellulose membranes: Electrochemical performance in a single-chamber microbial fuel cell, Bioresource Technology Reports, 9 (2020) 100376.