Project Details Nomenclature and Associated Terminology for Inorganic Nanoscale Particles

Project No.:
Start Date:
15 November 2019
End Date:


Nanoscale particles are receiving increased attention worldwide, with numerous commercial and technological applications leading to significant societal impact. There is a steady increase of publications on such materials, and a growing interest in the application of these materials and their associated chemistries to new fields. Particles, in general, are an enormous contributor to international commerce, advanced technologies, science, and the chemical industry at large. Almost all chemical and manufacturing processes include the use of, or creation of particles.

Currently there is not an established nomenclature system for describing particulate materials. Particles, much like polymers, can have similar chemical identities, but due to particle structure, size, and distribution of properties they can have distinct behaviors. The lack of proper naming conventions frequently leads to confusion regarding the type of particle being described or used in literature and in commerce. Particles are extensively exploited in the chemical and material science industries, and growing regulatory monitoring activities predicate a need for procedures for naming particulate materials in a meaningful and systematic manner. Notably, these materials lie in an area that is not explicitly covered by the nomenclature rules for inorganic or organic compounds. Hence, there is a need to develop IUPAC recommendations for the nomenclature and associated terminology for particles and populations of particles.

This project will begin the development a framework for the nomenclature of inorganic particles, building upon and refining existing principles derived from polymers, ongoing efforts on carbon nanotubes, ISO terminology, and opportunities with InChI, in addition to developing new frameworks for future materials. The intent is to develop conventions for the clear description of inorganic particles, their modifications (surface and bulk) and populations.


Particles are of fundamental importance in basic science, in emerging technologies and in the current marketplace. There are many different types of inorganic particles, each presenting different challenges associated with definition, nomenclature and delineation, and legislative impact.

This project follows on an informal one-day scoping meeting that took place between the ISO and IUPAC (Division VIII) in 2015 regarding nomenclature/terminology of inorganic nanoparticles. The outcomes from the scoping meeting were discussed in the IUPAC General Assembly in 2015 (Busan) and there was an agreement that projects should proceed in three targeted areas:
1. Developing proper definitions for the symbology that is used to represent the different kinds of materials;
2. Full nomenclature procedures for “magic number” clusters; and
3. Nanoscale materials containing crystallographically characterized phases

It has been nearly five years since the original scoping activity. Resulting nanoscale material-related projects have and are proceeding with different levels of progress. The complexities surrounding the development of nomenclature for nanomaterials has become evident and new approaches that address inorganic nanomaterials, but generally deal with “particles”, may be required to deal with the diversity and complexity of these systems. To this effect, we propose to focus on the practicalities of developing an inorganic particle nomenclature system that would be valid for both nanoscale and larger particles. It is anticipated that the nomenclature systems for particles will largely depend on (1) compatibility with practical and established measurement methods as well as (2) the delineation of realistic levels of discrimination between and within different general classes along with identifiable breakpoints for various forms of particles with predominantly inorganic cores. Such classes (to be determined) may involve “advanced” particles that are fabricated in ways whereby size, structure (e.g., morphology, shape, porosity) and composition are tightly controlled, versus “industrial” particles that are largely irregular in shape, size and sometimes composition. Methods for addressing inorganic nanomaterials may require further advances to describe complex populations (e.g., core-shell morphologies). Additionally, considerations for the inclusion of informatics approaches for naming and identifying this class of materials will be of practical importance.

This project will primarily address target area 1 from the informal scoping activity, building on experiences within ISO TC229 and will work through appointed liaisons with ISO TC229 JWG1/TG1 and ASTM International E56.01. Initial efforts will focus on determining the appropriate level of granularity needed to build a general nomenclature system and associated terminology for predominantly inorganic particles. As identified and refined during the scoping activity, this will include core aspects related to shape, size, surface properties, and chemical composition and also will take into account recent international activities related to nanoscale material identification. In the short time available, the project will identify logical and practical classes and breakpoints for discriminating between different types of inorganic particles that may result in different levels of practical definition within and between different identified groups or classes of nanoparticles This information will be further informed by (and will also help define) methodologies for describing particle populations. For polymer systems similar efforts have been made to describe polydispersity. These systems are not directly adaptable to particles; however a similar approach will need to be taken here. Collectively this exercise will integrate capabilities from existing measurement systems, knowledge from industrial performance classifications, and regulatory concerns. Scoping will include atomistic as well as non-atomistic connectivity, topological and topographical approaches and will be driven with a view to usability and acceptability in the stakeholder communities. Additionally, gaps that need to be addressed will be identified and a related roadmap document will be generated to encourage work in areas to improve upon these initial efforts.

A team of experts comprising participants from academia, government, and industry has been assembled to begin establishing a generalized framework for naming inorganic particle systems including nano-particles Team members represent a range of organizations and will build upon past and ongoing nanomaterial nomenclature activities in IUPAC and activities in terminology, nomenclature and measurement sciences in ISO TC229 and ASTM International E56. Additionally, the team has technical expertise in macromolecular, polymer and inorganic complex nomenclature, nanomaterial informatics, and nanotechnology terminology. Special attention will be paid to correlating the different classes to other areas of IUPAC activities for post-scoping projects, e.g. composition may align with alloys and glasses; coatings with adsorption, coatings and surface treatment.


Project announcement published in Chem Int Jan 2020, p. 30

Page last updated 12 Feb 2020