Work Package 1

Preparation of Representative Test Materials (RTMs) and value assignment

The aim of this WP is to develop RTMs for number concentration measurements of nano‑ and sub‑micrometre particles that i) are relevant for health and personal care industries, ii) resemble semiconductor or energy materials used in commercial products, or iii) represent persistent and novel environmental pollutants such as nano‑ and micro‑plastics.

Currently, there are no RMs or RTMs that are relevant for health, personal care, or semiconductor and energy industries, or represent persistent environmental pollutants, and which are characterised for particle number concentration. Even idealised monodispersed and spherical nano‑ and microparticle RMs are scarce. Very few contain any information on density or RI, which are essential input values required by the majority of ensemble methods typically used by the industry, testing laboratories and environmental monitoring agencies for particle characterisation. Therefore, the project needs to establish its own panel of RTMs to be able to assess the influence of particle density and RI on particle concentration measurements of particles relevant for industrial applications and particle‑based pollutants, by ensemble techniques.

Tasks under WP1

Task 1.1: Material sourcing and synthesis

The aim of this task is to collate stakeholder needs and project requirements with regards to specific physicochemical properties, relevant concentration ranges, stability and required quantities of RTMs.

Based on the current needs, materials representing those most relevant to key sectors will be synthesised or sourced. These include: i) health and personal care industries, such as liposomes and silver particles with sizes of up to 1000 nm; ii) semiconductor or energy applications, such as quantum dots, hybrid plasmonic (Au, Ag, Pd) or silicon‑based materials; iii) persistent and novel environmental pollutants, such as polypropylene, polyvinyl chloride or polyethylene terephthalate nano‑/micro‑plastics. These materials will be synthesised using already established protocols or sourced from commercial suppliers, material repositories, or past and ongoing projects.

Task 1.2: RTMs homogeneity and stability testing

The aim of this task is to assess the homogeneity and monitor the stability of RTMs synthesised within the project. Different techniques will be used. Sufficiently homogeneous materials will then become candidate RTMs and will be shipped for use in WP2 and WP3.

Task 1.3: Value assignment

The aim of this task is to assign to RTMs consensus particle number‑based concentration, density and RI characterisation values, along with associated uncertainties, which will include uncertainties associated with materials homogeneity and stability. This will be done for materials synthesised and characterised within the project, or for materials sourced from commercial suppliers, repositories or other past and current projects.