The International Organization for Standardization (ISO) recently published a standard that offers significant guidance to the nanotechnology community, specifically in the use of scanning electron microscopes (SEMs): ISO 19749:2021, Nanotechnologies — Measurements of particle size and shape distributions by scanning electron microscopy.
Measurement of nanoparticle size and shape is critical in understanding their behavior and potential use in many applications. This International Standard details data collection and analysis using scanning electron microscopy (SEM) to determine the size and shape of nanoparticles with highly reproducible results. SEMs create images by scanning a focused electron beam over a surface and delivering various signals to indicate how the electrons in the beam interacted with the material, which offers important information about the composition and topography of the material's surface. SEMs are indispensable and widely used in many fields of research, development, and manufacturing, including nanotechnology.
The new standard deals with two attributes of morphology – size and shape – for discrete and aggregated nano-objects (materials with at least one dimension in the nanometer-scale, i.e., within 1 nm to 100 nm). Furthermore, the ISO standard will be widely used as there are many SEMs utilized worldwide, making them the indispensable "workhorse" for nanometer-scale measurements.
ISO 19749 was developed by ISO Technical Committee (TC) 229, Nanotechnologies, Joint Working Group (JWG) 2, Measurement and characterization. The project was led by Dr. Andras Vladar of NIST (of the U.S.) and Dr. Tomoshige Sato of JEOL (of Japan), with significant contributions from international experts from France, Germany, Japan, and Mexico.
"With the publication of ISO 19749:2021, the United States Technical Advisory Group (TAG) to ISO TC 229 continues its leadership in developing foundational standards for rigorous characterization of two of the most fundamental characteristics of nanoparticles, their size and shape," said Dr. Vladimir Murashov, chair of the ANSI-Accredited U.S. TAG to ISO TC 229, Nanotechnologies. "Such foundational standards are necessary to further advance research and development with the ultimate goal of unleashing the enormous potential of nanotechnologies to solve most pressing challenges that the world is facing."
This standard serves as a companion document to ISO 21363, Nanotechnologies — Measurements of particle size and shape distributions by transmission electron microscopy, published in 2020 and led by the late Dr. Eric Grulke.