Mask4Life – Controlled pattern of electrostatically charged polymeric nanofibers to confer virus filtering capacity to protection masks

Paola Motetti
University of Bologna

Maria Letizia Focarete
University of Bologna

Andrea Zucchelli

The project aims at producing polymeric nanofibers with high residual electrostatic charge to coat common mask filter materials through a controlled nanofiber deposition. This will give the mask the protective capacity against bacteria and viruses.
The project consists of two parallel activities: (1) the first one concerns the realization of an adaptable equipment for the mass production of nanofibers with high residual electric charge, (2) the second one deals with the controlled optimization of nanofiber deposition to obtain a high filtering capacity against virus and bacteria. The first activity aims at realizing a multi-nozzle electro-drawing system, with high corona effect that allows to treat several polymers even at the same time. The second activity aims to obtain, on an industrial scale, the deposition of nanofibers on the substrate with a controlled pattern, so as to improve the filtering of virus particles and aerosols without inducing excessive pressure drops.

The expected benefits of the Mask4Life project are as follows:
1. Increased electrostatic filtration compared to conventional mask materials, which makes them suitable to retain aerosols containing viruses and bacteria;
2. High filtering power of the particulate matter thanks to the porosity characteristics obtained from the controlled deposition of nanofibers;
3. Versatility and adaptability in the production of masks, as nanofiber deposition can be carried out on nonwoven tissues that have not traditionally been used to make the protection masks.
4. The intrinsic antibacterial properties conferred to the masks by the presence of nanofibers made of polymers with natural antibacterial power, in addition to the charged polymer functional for filtration.
5. Reduced consumption of raw materials for the realization of the nanofiber coating thanks to the orderly collection of nanofibers on the fabric to be functionalized.

For this purpose, the research group is working in a recently expanded laboratory for the pilot production of nanostructured materials and it cooperates with two companies: (1) GVS (based in Zola Predosa, Bologna, Italy), one of the world leaders in the production of filters and filter materials, which actively participates in the project by sharing its know-how on personal protective equipment, its production capacities, its laboratories for masks characterization, and its network of suppliers for the procurement of raw materials; (2) Marchesini Group (based in Pianoro, Bologna, Italy) involved in the development of a machine for nanofiber mass production to coat common filter materials.

A prototype production has already demonstrated the feasibility of the project.