ISO TS 21975-2020 pdf download.Nanotechnologies一Polymeric nanocomposite films for food packaging with barrier properties一 Specification of characteristics and measurement methods. 4.2.1.4 PartIcle tracking analysis The size of nano-objects in a liquid can also be measured by PTA where the Brownian motion of nanoobjects is traced optically. ISO 19430:2016 describes the evaluation of the number-based nano-object size distribution in liquid dispersions (solid, liquid or gaseous particles suspended in liquids) using the PTA method for diffusion velocity measurements. 4.2.1.5 Dynamic light scattering The size of nano-objects in a liquid can also be measured by DLS. Particle size analysis is performed using the DLS method, which probes the hydrodynamic mobility of the particles. ISO 22412:2017 provides estimates of the average particle size and size distribution. 4.2.1.6 Atomic force microscopy The size of nano-objects in dry form on a flat substrate can also be measured by AFM using height measurement (z-displacement). AFM provides a three-dimensional surface profile. While the lateral dimensions are influenced by the shape of the probe, displacement measurements can provide the height of nanoparticles with a high degree of accuracy and precision (see ASTM E2859-11). 4.2.1.7 Laser diffraction The size of nano-objects and size distribution in many two-phase systems (e.g. powders, sprays, aerosols, suspensions, emulsions and gas bubbles In liquids) can be measured through the analysis of their light-scattering properties. In laser diffraction measurement, a laser beam is passed through a well-dispersed particle sample and particle size is measured by detecting the intensity of the scattered light produced (see ISO 13320). The laser diffraction method is often applied to nanoplates the lateral size of which is larger than 100 nm. 4.2.2 Chemical composition content 4.2.2.1 General A test specimen for measurements of chemical composition content is taken from the nano-object raw material sample and a dried powder is prepared. The chemical composition of nano-objects, i.e. elemental and compound compositions, of a nano-object raw material sample is one of the essential characteristics because it can influence the final products properties. The chemical composition includes major composition and minor composition (impurities). The chemical composition content is the ratio of the mass ofan element or compound contained in a dried powder sample of nano-object raw material to that of the dried powder sample. The chemical composition content shall be measured using an appropriate method. XRD, XRF, energy dispersive X-ray analysis, inductively coupled plasma/optical emission spectroscopy (ICP/OES) and /mass spectroscopy (ICP/MS) are recommended to be used...
Download Address
Download