ISO 19810:2023

INTERNATIONAL ISO
STANDARD 19810
Second edition
2023-07
Fine ceramics (advanced ceramics,
advanced technical ceramics) — Test
method for self-cleaning performance
of semiconducting photocatalytic
materials under indoor lighting
environment — Measurement of water
contact angle
Céramiques techniques — Méthode d'essai relative aux propriétés
autonettoyantes des matériaux photocatalytiques semiconducteurs
dans un environnement d'éclairage intérieur — Mesurage de l'angle
de contact de l'eau
Reference number
© ISO 2023
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ii
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 3
5 Test apparatus .3
5.1 Instruments and apparatus . 3
5.2 Reagents . 4
5.3 Laboratory temperature and humidity . 4
6 Test piece preparation .4
7 Test procedures . 5
7.1 Measurement of water contact angle . 5
7.2 Test piece pretreatment . 5
7.3 Visible light irradiation and measurement of contact angle after n h of visible light
irradiation, θ (n) . 6
7.3.1 Measurement of illuminance and preparation of test piece placement
location . . 6
7.3.2 Measurement of contact angle after n h of visible light irradiation, θ (n) . 6
8 Calculation of test results . 8
8.1 Guide to the rounding of numbers . 8
8.2 Calculation of contact angle . 8
8.3 Conditions for a valid test . 9
8.4 Initial contact angle halving time, n . 9
1/2
8.5 Contact angle reduction time, n . 10
10°
9 Reporting of test results .10
10 Test measurement examples .11
Bibliography .12
iii
Foreword
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This document was prepared by Technical Committee ISO/TC 206, Fine ceramics.
This second edition cancels and replaces the first edition (ISO 19810:2017), of which it constitutes a
minor revision. The changes are as follows:
— definitions of 3.1, 3.2 and 3.4 corrected;
— minor editorial changes.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
iv
INTERNATIONAL STANDARD ISO 19810:2023(E)
Fine ceramics (advanced ceramics, advanced technical
ceramics) — Test method for self-cleaning performance
of semiconducting photocatalytic materials under indoor
lighting environment — Measurement of water contact
angle
1 Scope
This document specifies a test method for the determination of the self-cleaning performance of
sheet-form materials that contain an indoor-light-active photocatalyst or have indoor-light-active
photocatalytic films on the surface, under indoor lighting environment.
This method is used to measure the change of water contact angle under indoor lighting environment,
which is one of the indices reflecting the self-cleaning performance of semiconducting photocatalytic
materials.
This document is not applicable to permeable materials on which water droplets cannot hold and rough
materials which obscure water droplets. This document is not applicable to materials of which the
changes in the water contact angle due to decomposition of adhered organic matter cannot be evaluated
because even if the surface is clean, the water contact angle is remarkably large or the water contact
angle cannot be sufficiently increased by attaching organic matter to the surface.
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
ISO 14605, Fine ceramics (advanced ceramics, advanced technical ceramics) — Light source for testing
semiconducting photocatalytic materials used under indoor lighting environment
ISO 27448, Fine ceramics (advanced ceramics, advanced technical ceramics) — Test method for self-
cleaning performance of semiconducting photocatalytic materials — Measurement of water contact angle
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 27448 and the following apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
photocatalyst
substance that performs one or more catalytic functions based on oxidation or reduction reactions
under photoirradiation
Note 1 to entry: The functions include decomposition and removal of air and water contaminants, deodorization,
antibacterial, self-cleaning and antifogging actions. A photocatalyst can also be used for light energy conversion.
[SOURCE: ISO 20507:2022, 3.1.62]
3.2
photocatalytic materials
material in which or on which the photocatalyst is added by coating, impregnation or mixing
Note 1 to entry: Materials include ceramic, metal, plastic, paper and cloth for general purposes.
3.3
semiconducting photocatalyst
substance that displays photocatalytic action based on its electronic band structure
Note 1 to entry: This applies to metal oxides like titanium dioxide, and sulphides. Photocatalysts which are not
semiconducting includes metal complexes.
3.4
self-cleaning effect
maintenance of surface cleanliness of a material by employing a photocatalyst loaded onto the surface
Note 1 to entry: Self-cleaning using photocatalysis is achieved through decomposition of surface contaminants
by oxidation and reduction reactions, and/or hydrophilicity that allows stains or dirt to be easily removed by the
flow of (rain)water over the surface.
Note 2 to entry: Examples include glass, tiling and other facings for buildings, and plastics and coatings for
general purposes.
3.5
indoor lighting environment
indoor lighting environment with an artificial light source for general lighting service that does not
include sunlight
Note 1 to entry: For the purposes of photocatalytic activity characterization, a clear definition of spectral range
and intensity is normally required.
3.6
indoor-light-active photocatalyst
substance that carries out many functions based on oxidization and reduction reactions produced by
an artificial light source for general lighting service, including decomposition and removal of air and
water contaminants, deodorization, and antibacterial, antifungal, self-cleaning and antifogging actions
3.7
contact angle before pretreatment
θ
water contact angle before pretreatment by UV irradiation and coating with organic matter
3.8
contact angle after UV irradiation and before coating
θ
water contact angle after pretreatment by UV irradiation and before coating with organic matter
3.9
initial contact angle
θ
water contact angle after pretreatment by UV irradiation and coating with organic matter and
immediately before starting visible light irradiation (water contact angle after 0 h of visible light
irradiation)
3.10
contact angle after n h of visible light irradiation
θ (n)
water contact angle after applying visible light irradiation for n h
Note 1 to entry: The unit of time may also be in days, minutes, and seconds in addition to hours.
3.11
initial contact angle halving time
n
1/2
time required for water contact angle to reach half the value of the initial contact angle θ due to visible
light irradiation
3.12
contact angle reduction time (10°)
n
10°
time required for water contact angle to reach 10° due to visible light irradiation
3.13
test piece set
multiple test pieces of the same material, treated under the same conditions, to investigate time-series
changes in a water contact angle by sequential measurement under identical visible light irradiation
conditions
4 Principle
This test method measures the time until a water contact angle increased by attaching organic matter to
a test piece is reduced due to decomposition of the organic matter by the photocatalytic effect of visible
light irradiation, thus provides an index of the self-cleaning effect performance of an indoor-light-active
photocatalytic material. First, the test piece is irradiated with UV light to remove any organic matter
adsorbed to its surface, and organic matter for test purposes (stearic acid) is then applied to the test
piece by a previously established method. Next, the initial contact angle is measured, and the test piece
is then irradiated with a given amount of visible light. The time-series changes in the contact angle due
to visible light irradiation are measured, and the elapsed time from the start of visible light irradiation
until the contact angle reaches half of the initial value and until the contact angle reaches 10° or lower
are determined.
5 Test apparatus
5.1 Instruments and apparatus
5.1.1 Black light blue fluorescent lamp, in accordance with ISO 10677.
In general, the lamp recommended for use is an ultraviolet fluorescent lamp which produces ultraviolet
rays termed UVA and has a peak emission at 351 nm, employing blue glass which absorbs visible light.
5.1.2 Ultraviolet light irradiation apparatus, in accordance with ISO 27448.
5.1.3 Ultraviolet light radiometer, in accordance with ISO 10677.
5.1.4 Visible light source (fluorescent lamp and UV cut filter).
Indoor illumination environment condition (Condition A) shall be used with a cool white halophosphate
fluorescent lamp and a UV sharp cut filter designated as Type A from among those specified by
ISO 14605, with an attached cover which transmits light longer than wavelengths of 400 nm. Fluorescent
lamps shall be warmed up for 15 min before use to stabilize output.
5.1.5 Visible light irradiating apparatus.
To ensure uniform irradiation of test piece sets by light produced by the lamp, allow for blocking of light
from surroundings, and allow for adjustment of illuminance, the test piece or the position of the lamp
shall be movable. If a lamp reflector is attached, it shall employ a material with little absorption of visible
light and degradation under visible light conditions and the structure shall allow for measurement of
illuminance where the test piece is located. Illuminance at the test piece surface shall be adjustable over
a threefold or greater range.
5.1.6 Illuminometer, in ac
...