GAiA’s long-term objective is to develop fibres for filtering face pieces, known as FFPs, using sustainable electrospinning processes and materials designed for compostability at the end of use. The aim is not only to help protect users from pathogens, but also to reduce cross-contamination risks and avoid generating polluting, potentially hazardous waste from disposable protective equipment.
This first reporting period therefore concentrated on the foundations of the material platform. The team reviewed the scientific and regulatory state of the art for facial filtering systems, with particular attention to the structure and properties of the layers that make up FFP filters. This work was formalised through deliverable D2.1, dedicated to the state of the art on filtration systems for FFP applications.
In parallel, the researchers began validating the polymer solutions proposed for the production of electrospun fibres. The selected starting approach was based on polyvinyl alcohol, or PVA, and polyacrylic acid, or PAA: two water-soluble polymers used as precursors for the fabrication of nonwoven electrospun materials. This choice reflects GAiA’s green-chemistry strategy, because the project is designed to minimise environmental impact across the whole process, from fibre production to end-of-life management.
A particularly important aspect of this early work was the decision to work directly with water-based solutions. The technical report explains that, although ethanol could also be used as a solvent, the team started from bidistilled water in order to reduce the environmental impact of the materials and processes used. Different polymer-to-water ratios were tested to tune the viscosity of the solutions and identify conditions suitable for electrospinning.
The first electrospun mats were then produced and characterised. These preliminary nonwoven fibres represented the first physical step toward GAiA’s future antimicrobial filter concept. At this stage, the goal was not yet to produce the final functional filter, but to prove that the polymeric base could be processed into fibrous materials with the right potential for later development. The first report records the preparation and optimisation of PVA/PAA solutions in water, the production of preliminary electrospun materials, hot esterification and the preliminary characterisation of the resulting fibres.
The esterification step was especially important because it transformed the electrospun fibres into a more stable material. After electrospinning, the fibres were thermally cross-linked through heat-induced esterification; the technical report describes heating at 130°C for 30 minutes and then checking the result by immersing a fibrous sample in water. The cross-linking was considered successful when the fibres did not dissolve after 24 hours of immersion.
This early phase also established the experimental logic for the following stages of GAiA. The research did not simply produce first samples: it began building a reproducible relationship between polymer formulation, rheological behaviour, electrospinning processability and fibre morphology. This relationship would later become essential for incorporating antimicrobial bioactive glass particles into the fibres without compromising the material structure.
By the end of the first reporting period, GAiA had achieved a solid starting point: a documented analysis of existing FFP filtration systems, first water-based polymer formulations, preliminary electrospun nonwoven mats, a heat-based cross-linking strategy and initial material characterisation. The project was also reported as proceeding according to schedule, with no factors suggesting deviations from the original plan or expected results.
This milestone laid the green-material foundation for the entire GAiA pathway. From this base, the project could move forward toward validated electrospinning, antimicrobial bioactive glass development, loaded composite fibres and, ultimately, safer and more sustainable filter materials for future respiratory protection.
