ISO 19810:2017

INTERNATIONAL ISO
STANDARD 19810
First edition
2017-04
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 19810:2017(E)
©
ISO 2017

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ISO 19810:2017(E)

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© ISO 2017, Published in Switzerland
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ISO 19810:2017(E)

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 . 4
7.1 Measurement of water contact angle . 4
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
4
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 .
1/2 9
8.5 Contact angle reduction time, n .
10° 10
9 Reporting of test results .10
10 Test measurement examples .11
Bibliography .12
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ISO 19810:2017(E)

Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
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ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
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This document was prepared by Technical Committee ISO/TC 206, Fine ceramics.
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INTERNATIONAL STANDARD ISO 19810:2017(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 terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at http:// www .electropedia .org/
— ISO Online browsing platform: available at http:// www .iso .org/ obp
3.1
photocatalyst
material in which or on which the photocatalyst is added by coating, impregnation, mixing, etc.
Note 1 to entry: Materials include ceramic, metal, plastic, paper, cloth, etc. for general purposes.
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ISO 19810:2017(E)

3.2
photocatalytic materials
material in which or on which the photocatalyst is added by coating, impregnation, mixing, etc.
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 sulfides. 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 redox 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
1
water contact angle before pretreatment by UV irradiation and coating with organic matter
3.8
contact angle after UV irradiation and before coating
θ
2
water contact angle after pretreatment by UV irradiation and before coating with organic matter
3.9
initial contact angle
θ
3
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)
4
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.
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ISO 19810:2017(E)

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
3
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 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, as specified by ISO 10677.
NOTE 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, as specified by ISO 27448.
5.1.3 Ultraviolet light radiometer, as specified by 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
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ISO 19810:2017(E)

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, as specified by ISO 14605.
5.1.7 Contact angle measurement apparatus, as specified by ISO 27448.
5.2 Reagents
5.2.1 Stearic acid, of assay (cGC) 60,0 % or higher.
5.2.2 n-Heptane, of assay (cGC) 99,0 % or higher.
5.2.3 Water, distilled water or water of equivalent purity.
5.3 Laboratory temperature and humidity
+20
The laboratory should be preferably kept at a temperature (23 ± 5) °C, relative humidity (50 ) % or a
−10
temperature (20 ± 5) °C, relative humidity (65 ± 10) %. The laboratory temperature and humidity in
use shall be documented in the reports of test results.
6 Test piece preparation
Preparation of test pieces shall be as follows.
a) Test
...