introduction
ISO (International Organization for Standardization) is a global alliance of national standards bodies (ISO member bodies). The development of international standards is usually carried out through ISO technical committees. Each member institution interested in a subject on which a technical committee has been established has the right to be represented on that committee. International governmental and non-governmental organizations liaising with ISO are also involved in this work. ISO works closely with the International Electrotechnical Commission (IEC) on all matters of electrical standardization.

The procedures used to develop this document and those used for further maintenance are described in Part 1 of the ISO/IEC Directive. In particular, attention should be paid to the different approval criteria required for different types of ISO documents. This document has been drafted in accordance with the editing rules of ISO/IEC Directive Part 2 (see iso.org/directives).

ISO 18473-4-2022 “Functional pigments and fillers for special purposes – Part 4: nano-scale titanium dioxide for photocatalytic applications”

Please note that certain elements of this document may be subject to patent rights. ISO is not responsible for identifying any or all such patents. Details of any patent rights identified during the preparation of the document will be found in the introduction and/or in the list of patent claims received by ISO (see iso.org/patents).

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This document was prepared by the ISO/TC 256 Technical Committee on Pigments, Dyes and Fillers.

A list of all the components in the ISO 18473 series can be found on the ISO website.

Any feedback or questions regarding this document should be directed to the user’s national standards body. A complete list of these institutions is available at so.org/members.html

ISO 18473-4-2022 “Functional pigments and fillers for special purposes – Part 4: nano-scale titanium dioxide for photocatalytic applications”

introduce
Metal nanoparticles are promising materials that can be used as heterogeneous catalysts in various organic transformations. Their catalytic properties are a function of their size and lattice parameters, and show amazing levels of performance in terms of selectivity, activity, and increased product yield. Nanoscale titanium dioxide (TiO2) particles, in particular, exhibit many special properties because the band gap of the nanoparticle increases with the decrease in size. TiO2 nanoparticles have received considerable attention for their applications in green synthetic organic chemistry, decomposition and removal of air and water pollutants, deodorization, and antibacterial, antifungal, self-cleaning, and anti-fogging effects.

1 Range
This document specifies the requirements and corresponding test methods for nanoscale titanium dioxide (TiO2) in powder or suspension form for photocatalytic applications.

This document is intended for modified nanoscale titanium dioxide for photocatalytic applications.

Note that this modification can be surface treatment, coating, doping or a combination.

ISO 18473-4-2022 “Functional pigments and fillers for special purposes – Part 4: nano-scale titanium dioxide for photocatalytic applications”

2 Normative references
The following files are referenced in text in a manner that constitutes part or all of the requirements of this document. For dated references, only the cited version applies. For undated references, a new version of the reference (including any revisions) applies.

ISO 591-1:2000, titanium dioxide pigments for paints. Part 1: Specifications and test methods

ISO 787-2, General test methods for pigments and fillers – Part 2: Determination of volatiles at 105°C

ISO 787-9, Common test methods for pigments and fillers – Part 9: Determination of the pH value of water suspensions

ISO 787-11, General test methods for pigments and fillers – Part 11: Determination of compaction volume and apparent density after compaction

ISO 787-18, General test methods for pigments and fillers – Part 18: Determination of residues on screens – mechanical flushing procedure

ISO 18473-4-2022 “Functional pigments and fillers for special purposes – Part 4: nano-scale titanium dioxide for photocatalytic applications”

ISO 3262-1, Extenders – Test specifications and methods – Part 1: Introduction and general test methods

ISO 6227, chemical products for industrial use – Common method for determination of chloride ions – potentiometric method

ISO 9277, Determination of specific surface area of solids by gas adsorption – BET method

ISO 15528, Paints, varnishes and raw materials for paints and varnishes – Sampling

ISO 18451-1, pigments, dyes and fillers – terminology – Part 1: General terminology

ISO 20814, Nanotechnology – Testing the photocatalytic activity of nanoparticles for NADH oxidation

ISO 22197-1, Fine ceramics (advanced ceramics, outstanding technical ceramics) – Test methods for air purification properties of semiconductor photocatalytic materials – Part 1: Removal of nitric oxide

3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 18451-1 and the following articles apply.

ISO 18473-4-2022 “Functional pigments and fillers for special purposes – Part 4: nano-scale titanium dioxide for photocatalytic applications”

3.1 Nanometer scale

The length ranges from about 1 nm to 100 nm

Note 1: Features that are not extrapolated from larger dimensions are mainly present in this length range.

[Source: ISO/TS 80004-1:2015, 2.1]

3.2 Optical contact media

A substance that performs one or more functions, such as self-cleaning, based on oxidation and reduction reactions under light exposure

[Source: ISO 17094:2014 3.1, modified – examples other than self-cleaning in definition removed]

3.3 Titanium dioxide photocatalyst

Photocatalyst (3.2), mainly composed of anatase type titanium dioxide (TiO2) and/or rutile crystal structure

3.4 Suspension

A heterogeneous mixture of liquid and finely dispersed solid materials

[Source: ISO/TS 80004-6:2012, 3.13]

ISO 18473-4-2022 “Functional pigments and fillers for special purposes – Part 4: nano-scale titanium dioxide for photocatalytic applications”

3.5 Median of the size distribution

Median dividing the distribution into two equal parts [D50]

[Source: ISO 17827-1:2016, 3.1, modified: Delete entry Note 1]

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