1、BS ISO27448:2009ICS 81.060.30NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBRITISH STANDARDFine ceramics(advanced ceramics,advanced technicalceramics) Testmethod for self-cleaning performanceof semiconductingphotocatalyticmaterials Measurement of watercontact angleThis Britis
2、h Standardwas published under theauthority of the StandardsPolicy and StrategyCommittee on 31 August2009 BSI 2009ISBN 978 0 580 67214 9Amendments/corrigenda issued since publicationDate CommentsBS ISO 27448:2009National forewordThis British Standard is the UK implementation of ISO 27448:2009.The UK
3、participation in its preparation was entrusted to TechnicalCommittee RPI/13, Advanced technical ceramics.A list of organizations represented on this committee can be obtained onrequest to its secretary.This publication does not purport to include all the necessary provisionsof a contract. Users are
4、responsible for its correct application.Compliance with a British Standard cannot confer immunityfrom legal obligations.BS ISO 27448:2009Reference numberISO 27448:2009(E)ISO 2009INTERNATIONAL STANDARD ISO27448First edition2009-07-15Fine ceramics (advanced ceramics, advanced technical ceramics) Test
5、method for self-cleaning performance of semiconducting photocatalytic materials Measurement of water contact angle Cramiques techniques Mthode dessai de la performance auto nettoyante des matriaux photocatalytiques semiconducteurs Mesurage de langle de contact de leau BS ISO 27448:2009ISO 27448:2009
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9、PYRIGHT PROTECTED DOCUMENT ISO 2009 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address bel
10、ow or ISOs member body in the country of the requester. ISO copyright office Case postale 56 CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland ii ISO 2009 All rights reservedBS ISO 27448:2009ISO 27448:2009(E) ISO 2009 All
11、rights reserved iiiForeword 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 through ISO technical committees. Each member body interested in a su
12、bject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (
13、IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical commi
14、ttees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not b
15、e held responsible for identifying any or all such patent rights. ISO 27448 was prepared by Technical Committee ISO/TC 206, Fine ceramics. BS ISO 27448:2009ISO 27448:2009(E) iv ISO 2009 All rights reservedIntroduction Under the illumination of ultraviolet (UV) light, photocatalysts show diverse func
16、tions, such as the decomposition of air and water contaminants, as well as deodorization, self-cleaning, antifogging and antibacterial actions. These functions of photocatalysts are generally based on the action of active oxygen species such as hydroxyl (OH) radicals formed on the surface of photoca
17、talysts. The energy- and labour-saving nature of photocatalysis has attracted keen interest when the photocatalyst is activated by sunlight (or artificial lighting). Practical applications of photocatalysts, for both indoor and outdoor use, have rapidly expanded in recent years. Many kinds of photoc
18、atalytic materials have been proposed or are already commercialized, based on ceramics, glass, concrete, plastics, paper, etc. Such materials are produced by either coating or mixing of a photocatalyst, in most cases, titanium dioxide (TiO2). However, the effect of photocatalysis is not easily inspe
19、cted visually, and no appropriate and official evaluation methods have been available to date. Some confusion has thus arisen as photocatalytic products have been introduced. Furthermore, the above-mentioned diverse functions of photocatalysts cannot be evaluated with a single method; thus, differen
20、t evaluation methods are provided for self-cleaning, water decontamination, air purification and anti-bacterial actions, respectively. As a result of continuing efforts to provide test methods for photocatalytic materials, this International Standard (covering the measurement of the water contact an
21、gle) for self-cleaning performance was prepared. For permeable, rough, or highly hydrophobic surfaces, etc., other test methods are required and are being developed. It must be noted that self-cleaning performance could be evaluated with photo-induced hydrophylic property and photocatalytic decompos
22、ition ability, because many field test results concerning the self-cleaning properties of TiO2-coated materials are in good agreement with the indexes obtained by measurement of the water contact angle and degradation of methylene blue. BS ISO 27448:2009INTERNATIONAL STANDARD ISO 27448:2009(E) ISO 2
23、009 All rights reserved 1Fine ceramics (advanced ceramics, advanced technical ceramics) Test method for self-cleaning performance of semiconducting photocatalytic materials Measurement of water contact angle 1 Scope This International Standard deals with fine ceramics. This International Standard sp
24、ecifies a test method for the determination of the self-cleaning performance of materials that contain a photocatalyst or have photocatalytic films on the surface, and which are usually made from semiconducting metal oxides such as titanium dioxide. This method is used to measure the water contact a
25、ngle under illumination with ultraviolet light, which is one of the indices influencing the self-cleaning performance of photocatalytic materials. This International Standard does not include water-permeable substrates, rough surfaces which do not have exposed water droplets, highly hydrophobic, pow
26、der or granular materials, or visible light-sensitive photocatalysts. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced d
27、ocument (including any amendments) applies. ISO 3534-1:2006, Statistics Vocabulary and symbols Part 1: General statistical terms and terms used in probability ISO 80000-1, Quantities and units Part 1: General 3 Terms and definitions For the purposes of this document, the following terms and definiti
28、ons apply. 3.1 photocatalyst substance that carries out one or more functions based on oxidization and reduction reactions under photoirradiation, including decomposition and removal of air and water contaminants, deodorization, and antibacterial, self-cleaning and antifogging actions 3.2 photocatal
29、ytic materials materials in which, or on which, the photocatalyst is added by coating, impregnation, mixing, etc. NOTE Such photocatalytic materials are intended for use as building and road construction materials to obtain the functions mentioned in 3.1. BS ISO 27448:2009ISO 27448:2009(E) 2 ISO 200
30、9 All rights reserved3.3 fluorescent UV lamp lamp that provides UV-A irradiation within a wavelength range of 300 nm to 400 nm NOTE A suitable lamp is the so-called black light blue (BLB) fluorescent lamp, with a maximum wavelength of 351 nm, as described in ISO 4892-3. 3.4 hydrophilicity property i
31、n which the surface of the photocatalytic material shows a strong affinity for water 3.5 self-cleaning function whereby a photocatalyst, attached to a surface like a building material, prevents fouling of the surface by utilizing at least one of the following: the phenomenon where fouling substances
32、 attached to the surface are broken down by oxidation and reduction when irradiated with light, and/or the phenomenon where fouling is washed away when the surface is exposed to rain or rinsed with water, due to the hydrophilicity which manifests itself at the same time 3.6 contact angle when a tang
33、ent line is drawn from the contact point of the solid, liquid and vapour phases (normally air) along the curve of the liquid on the solid, the angle between the line and the solid surface is referred to as the contact angle 3.7 initial contact angle contact angle immediately before starting UV irrad
34、iation 3.8 contact angle after n h of UV irradiation contact angle after applying UV irradiation for n h NOTE The unit of time may also be days, minutes or seconds, in addition to hours. 3.9 final contact angle contact angle at the highest water affiliation after irradiation at a constant intensity
35、on a photocatalytic material 3.10 pretreatment of test piece preparation of a test piece by irradiating it with UV and then applying organic substances such as oleic acid 3.11 coefficient of variation ratio of the standard deviation to the arithmetic mean 4 Symbols iinitial contact angle, in degrees
36、 ncontact angle after n h, in degrees x average of the three consecutive points, in degrees s standard deviation of the three consecutive points, in degrees ffinal contact angle, in degrees BS ISO 27448:2009ISO 27448:2009(E) ISO 2009 All rights reserved 35 Principle This International Standard is fo
37、r the development, comparison, quality assurance, characterization, reliability, and design data generation of photocatalytic materials. This International Standard defines the test method, which provides a performance correlated with the contamination that occurred during the exposure test. This te
38、st method is to evaluate the self-cleaning performance of a photocatalytic material by obtaining the final contact angle of a test piece on which organic substances are applied. The organic substance is first applied to a test piece (pretreatment), which is then irradiated by UV at a constant intens
39、ity. The water contact angle after n h can be measured during the process. This test simultaneously evaluates the decomposition of the organic substance and change of water affiliation. When the pretreatment of a certain test piece is impossible and the initial contact angle before UV irradiation is
40、 20 or greater, the final contact angle can be obtained without pretreatment. 6 Apparatus 6.1 Black light fluorescent lamp The fluorescent UV lamp shall be a black light blue (BLB) lamp with a peak wavelength of 351 nm and blue glass for absorbing visible light. 6.2 Ultraviolet irradiator The equipm
41、ent shall provide uniform irradiation from the lamp to the test piece and the irradiation intensity shall be adjustable by moving the position of the lamp or test piece. 6.3 Ultraviolet light radiometer The irradiation intensity shall be measurable at the test sample position. The photoelectric sens
42、or shall have good cosine characteristics. The irradiation-measuring instrument shall be calibrated with the light source to be used, or corrected to a certain sensitivity within the wavelength range to be absorbed by the photocatalytic test piece. 6.4 Contact angle meter The instrument shall have a
43、 measurement range of 0 to 180, a readout accuracy of 0,1 and a measurement accuracy of 1. The instrument shall be capable of measuring the contact angle from the image of a liquid drop attached to a test sample by using the /2 method after the dropping attachment has been used for a certain time. 7
44、 Test chemicals 7.1 Oleic acid, of assay (cGC) 60,0 % or higher. 7.2 n-Heptane, of assay (cGC) 99,0 % or higher. 8 Temperature and humidity of test laboratory The test laboratory should preferably be controlled at a temperature range of 23 C 5 C, and a relative humidity range of 40 % to 70 %. BS ISO
45、 27448:2009ISO 27448:2009(E) 4 ISO 2009 All rights reserved9 Test piece Cut out a 100 mm 2 mm square flat piece of a product as the standard-size test piece. Use caution not to contaminate the test piece with organic substances or other test pieces. It is recommended to obtain test pieces from the p
46、roduct but, if it is impossible to prepare test pieces due to the products shape, then the test pieces may be created from a separate flat plate made from the same raw material and by using the same process. If it is impossible to cut a product into 100 mm 2 mm square pieces, then the test piece may
47、 have a different shape or size, as long as its shape and size allow the measurement of the contact angle at five different points. Test pieces shall be prepared in quantities of five. 10 Procedure 10.1 Pretreatment of test piece 10.1.1 Procedure of pretreatment The following procedure shall be used
48、 for pretreatment of the test piece. When the test pieces are not used immediately after this pretreatment, store them in a sealed container. This pretreatment can be omitted if it is impossible to apply oleic acid and if the contact angle before pretreatment is not less than 20. In the case of a te
49、st in which the procedures in 10.1.2 and 10.1.3 were eliminated, in addition to the procedures in 10.2.3 and 10.2.4, the dark field test without any UV exposure shall be conducted. The dark field test shall be performed in accordance with the same procedure as that in 10.2.3 and 10.2.4 by taking the number of test pieces as five, except for the procedure of performing UV irradiation. When the dark field test shall be performed simultaneously with the UV irradiation test, “the contact angle after n h without
