BS ISO 21066:2018 pdf download

BS ISO 21066:2018 pdf download.Fine ceramics (advanced ceramics, advanced technical ceramics) — Qualitative and semiquantitative assessment of the photocatalytic activities of surfaces by the reduction of resazurin in a deposited ink film
1 Scope
This document specifies a method, the Resazurin (Rz) ink test, for the qualitative assessment of the activity of a photocatalytic surface, and its classification as below, within, or above the applicable range of the test. The method then allows for the subsequent semiquantitative evaluation of the activities of photocatalytic surfaces that are within the applicable range of the test. In all cases, artificial ultraviolet (UV) radiation is used. The test method specified is appropriate for use with all flat, smooth, photocatalytic surfaces, which are not macroporous, examples of which include: commercial photocatalytic glass, paint, tiles and awning materials. The method is not applicable to assessing the visible-light activity of photocatalytic surfaces, nor their ability to effect: air purification, water purification, self-cleaning or disinfection, although some relevant correlations have been reported [4][5] .
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 10677, Fine ceramics (advanced ceramics, advanced technical ceramics) — Ultraviolet light source for testing semiconducting photocatalytic materials
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www.iso.org/obp
— IEC Electropedia: available at http://www.electropedia.org/
3.1 photocatalyst
substance that performs one or more functions based on coupled oxidation and reduction reactions under photo-irradiation, including decomposition and removal of air and water contaminants,deodorization, and antibacterial, self-cleaning and antifogging actions
[SOURCE: ISO 22197-1:2016, 3.1, modified — The definition has been slightly rephrased.]
3.2 photocatalytic material
material in which, or on which, a photocatalyst (3.1) is added by coating, impregnation, mixing, etc.
[SOURCE: ISO 20507:2014, 2.1.60, modified — Note 1 to entry removed.]
5.1 General
A photocatalyst activity indicator ink is deposited, using a K-bar, onto samples, 25 mm × 25 mm square, of the photocatalytic material under test, which have previously been wiped-clean and possibly UV- conditioned. If upon depositing the ink film on the material under test, but before irradiation, the ink changes from blue to pink or colourless, the sample is reactive (usually due to a highly alkaline surface) and the ink test is unsuitable for evaluating the photocatalytic material. Assuming the sample is not reactive and is photocatalytically active, then there are two possible tests the material under test can be subjected to as part of this method: a precursor qualitative test and then, for samples found to be within the applicable range of the test, a semiquantitative activity test. The Rz ink test is an example of reductive photocatalysis based on the photocatalysed reduction of Rz and concomitant oxidation of glycerol in an ink coating [5] .