Implementation of design strategies to reach the desired SSbD performance attributes: Functional textile coatings case study

Coupling textile with nanoparticles-based coating is a design strategy successfully exploited to improve the textile technical and functional performances and, at the same time, to stabilize over a versatile, flexible, low-cost supporting material, active nano-phases that can positively impact in healthcare and environmental remediation applications. Nevertheless, the increasing use of nanoenabled products (NEPs) in everyday life applications raises questions about their safety. To answer, it is necessary to promote and implement a safe-and-sustainable-by-design (SSbD) approach through the whole products life cycle: nanomaterials synthesis, substrate functionalization, use phase, and end of life. At this purpose, a careful data collection and FAIRification strategy need as well as decisional computational tools able to identify design solutions that meet the SSbD key performance indicators (KPIs) in all dimensions: functionality, safety, life-cycle environmental impact and life-cycle costs. In the collaborative research project ASINA we tested different design strategies, across two main lifecycle value chains. In this work we present the results of Value Chain 1 case studies for the production of textile with antimicrobial and depolluting activity, in particular, antimicrobial textiles functionalized with silver NPs as personal protective equipment and photocatalytic filters based on titania NPs deposited on textile or polymeric substrate, for air purification treatment. The starting materials, identified as Tier 1, were: AgHEC, a sustainable synthesis of AgNPs nucleated at room temperature on hydroxyethylcellulose (patented by CNR-ISSMC); TiO2@SiO2, a nanophase of titania coupled with silica (optimized by CNR-ISSMC); and TiO2-N, a nitrogen-doped titania commercial benchmark nanophase provided by Colorobbia. An extensive p-chem and functional characterization of Tier 1 materials allowed us to define some key decision factors (KDFs) such as synthesis parameters and nanophase coatings and link them to KPIs such as antimicrobial and photocatalytic activity. We so developed a new set of Tier 2 materials, exploring the material design space (KDF values) and evaluating how and if the design alternatives impacted on KPIs in the performance space to attain SSbD solutions. In this work, we focused on the workflow and results surrounding the preparation and characterization of Tier 1 and Tier 2 material and their incorporation into products (antimicrobial and photocatalytic textile coating). Once the design hypothesis referred to the nano-phases synthesis were investigated to obtain the addressed SSbD solutions (first NMs life cycle phase), we proceeded investigating the second life cycle phase (incorporation) with the integration of nanoforms (NFs) into NEPs.Thus the integration of second and third level SSbD case study was implemented by defining a further design space with selection of appropriate KDFs referred to the type of incorporation process and related and KDFs values range referred to the specific NFs deposition parameters. The second (KPIs) performance space has also been defined accordingly addressing the product functional activity, the worker exposure, and the NFs release during the use phase. The data collected at each stage of the SSbD case studies provided inputs for the ASINA ES (the ASINA multi-objective-optimisation tool) for the identification of the most promising SSbD alternatives.