1、DRAFT FOR DEVELOPMENT DD ISO/TS 13762:2001 Particle size analysis Small angle X-ray scattering method ICS 19.120 DD ISO/TS 13762:2001 This Draft for Development, having been prepared under the direction of the Materials and Chemicals Sector Policy and Strategy Committee, was published under the auth
2、ority of the Standards Policy and Strategy Committee on 4 December 2002 BSI 4 December 2002 ISBN 0 580 40601 6 National foreword This Draft for Development reproduces verbatim ISO/TS 13762:2001 This publication is not to be regarded as a British Standard. It is being issued in the Draft for Developm
3、ent series of publications and is of a provisional nature because it deals with emerging technology, in which insufficient experience has been gained for a full ISO standard to be appropriate. It should be applied on this provisional basis, so that information and experience of its practical applica
4、tion may be obtained. Comments arising from the use of this Draft for Development are requested so that UK experience can be reported to the international organization responsible for the Technical Specification. A review of this publication will be initiated not later than 3 years after its publica
5、tion by the international organization so that a decision can be taken on its status at the end of its 3-year life. Notification of the start of the review period will be made in an announcement in the appropriate issue of Update Standards. According to the replies received by the end of the review
6、period, the responsible BSI Committee will decide whether to support the conversion into an international standard, to extend the life of the Technical Specification for another 3 years or to withdraw it. Comments should be sent in writing to the Secretary of BSI Subcommittee LBI/37/4, Sizing by met
7、hods other than sieving, at British Standards House, 389 Chiswick High Road, London W4 4AL, giving the document reference and clause number and proposing, where possible, an appropriate revision of the text. A list of organizations represented on this committee can be obtained on request to its secr
8、etary. Cross-references The British Standards which implement international publications referred to in this document may be found in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of B
9、ritish Standards Online. Summary of pages This document comprises a front cover, an inside front cover, the ISO/TS title page, pages ii to v, a blank page, pages 1 to 22, an inside back cover and a back cover. The BSI copyright date displayed in this document indicates when the document was last iss
10、ued. Amendments issued since publication Amd. No. Date CommentsReference number ISO/TS 13762:2001(E) TECHNICAL SPECIFICATION ISO/TS 13762 First edition 2001-03-15 Particle size analysis Small angle X-ray scattering method Analyse granulomtrique Mthode de dispersion par rayons X sous angle faible DDI
11、SO/TS13762:2001DDISO/TS13762:2001iiIS/OTS :26731(1002)E ISO 1002 All rights rsedevre iii Contents Page Foreword.iv Introduction.v 1 Scope 1 2 Normative references 1 3 Symbols and abbreviations2 4 Principle2 5 Sample preparation and requirement4 6 Apparatus .4 7 Procedure .5 8 Calculation and express
12、ion of results.5 9 Verification .7 10 Reporting of results.7 Annex A (normative) Determination of slit-height weighting function F(t) .8 Annex B (normative) Calculation of coefficient, a ij .9 Annex C (informative) Equipment for SAXS measurement 10 Annex D (informative) Reproducibility and accuracy1
13、2 Annex E (informative) Verification and examples for determination of particle size distribution of ultra-fine powders by SAXS method15 Bibliography22 DDISO/TS13762:2001iiiIS/OTS :26731(1002)E vi ISO 1002 All rights rsedevre Foreword ISO (the International Organization for Standardization) is a wor
14、ldwide 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 subject for which a technical committee has been established has the right to be represented on
15、 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 (IEC) on all matters of electrotechnical standardization. International Standards are drafted
16、in accordance with the rules given in the ISO/IEC Directives, Part 3. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standar
17、d requires approval by at least 75 % of the member bodies casting a vote. In other circumstances, particularly when there is an urgent market requirement for such documents, a technical committee may decide to publish other types of normative document: an ISO Publicly Available Specification (ISO/PA
18、S) represents an agreement between technical experts in an ISO working group and is accepted for publication if it is approved by more than 50 % of the members of the parent committee casting a vote; an ISO Technical Specification (ISO/TS) represents an agreement between the members of a technical c
19、ommittee and is accepted for publication if it is approved by 2/3 of the members of the committee casting a vote. An ISO/PAS or ISO/TS is reviewed every three years with a view to deciding whether it can be transformed into an International Standard. Attention is drawn to the possibility that some o
20、f the elements of this Technical Specification ISO/TS 13762 may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO/TS 13762 was prepared by Technical Committee ISO/TC 24, Sieves, sieving and other sizing methods, Subcommittee SC 4, S
21、izing by methods other than sieving. Annexes A and B form a normative part of this Technical Specification. Annexes C to E are for information only. DDISO/TS13762:2001ivIS/OTS :26731(1002)E ISO 1002 All rights rsedevre v Introduction The size range for which the small angle X-ray scattering (SAXS) m
22、ethod is applicable is approximately in the range of 1 nm to 300 nm. The success of the technique is mainly based on the fact that SAXS effect results from the difference of electron density between particles and their surroundings so that size X SAXS always indicates the size of a primary particle
23、rather than the internal crystallite or external agglomerate size; in other words, the requirement of particle dispersion of a sample for SAXS analysis is not as strict as that for other methods. However, the SAXS method has its limitations: firstly, it cannot distinguish pores from particles; secon
24、dly, the interference effect between particles will arise as the sample is available only in concentrated form. SAXS measurements and the interpretation of the data are currently not uniform. The purpose of this Technical Specification is to facilitate comparisons of size analysis made in different
25、laboratories. It is well known that X-rays can kill human tissue. However, this Technical Specification does not purport to address all the safety problems associated with the use of the SAXS method; it is the responsibility of the user to establish appropriate safety and health practices prior to i
26、ts use. DDISO/TS13762:2001vTECINHCAL ICEPSFICATION IS/OTS :26731(1002)E ISO 1002 All rights rsedevre 1 Particle size analysis Small angle X-ray scattering method 1 Scope This Technical Specification specifies the method for determining particle size distribution of ultra-fine powders by the small an
27、gle X-ray scattering technique. It is applicable to particle sizes ranging from 1 nm to 300 nm. In the data analysis, it is assumed that particles are isotropic and spherically shaped. The method described in this Technical Specification is also applicable to particle suspensions. This Technical Spe
28、cification does not apply to: a) powders containing particles whose morphology is far from spherical, except by special agreement; b) powders consisting of porous particles; c) mixtures of powders. 2 Normative references The following normative documents contain provisions which, through reference i
29、n this text, constitute provisions of this Technical Specification. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. However, parties to agreements based on this Technical Specification are encouraged to investigate the possibility of applying
30、the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies. Members of ISO and IEC maintain registers of currently valid International Standards. ISO 9276-1, Representation of results of particle size
31、analysis Part 1: Graphical representation. ISO 9276-2: 1) , Representation of results of particle size analysis Part 2: Calculation of average particle sizes/diameters and moments from particle size distributions. 1) To be published. DDISO/TS13762:20011IS/OTS :26731(1002)E 2 ISO 1002 All rights rsed
32、evre 3 Symbols and abbreviations SAXS small angle X-ray scattering x particle size, diameter of a sphere i x length of particle size interval, 1 iii xxx n total number of size classes 3,i q average density distribution of the class i x by volume or mass 3,i q average density distribution in a repres
33、entation with logarithmic abscissa 3,i Q cumulative volume fraction of particle sizes i xx u scattering angle 3,i Q volume fraction within the class , i x 3, 3, i ii x Qq () scattering function of a spherical particle: 32 2 1 / 2 ()3 ( s i n c o s) / , ( ) x t wavelength of incident X-ray beam t ang
34、le variable along the slit-height direction F(t) slit-weighting function along the slit-height direction 4P r i n c i p l e As a narrow beam of X-ray passes through a powder layer containing ultra-fine particles, it will be dispersed around the incident beam at a small angle range resulting from the
35、 electron scattering in the particles. The distribution of scattered intensity is closely related to the particle size distribution. The scattered intensity I( ) from a dilute spherical particle system can be expressed by the integral equation: 0 32 () () d () () d n x x IcF t tx x x (1) where x 0 i
36、s the size below which there are no particles; x n is the size above which there are no particles; (x)is the size distribution function by volume (without normalization); c is a synthetic constant. DDISO/TS13762:20012IS/OTS :26731(1002)E ISO 1002 All rights rsedevre 3 The size range of x 0 to x n ca
37、n be divided into n intervals and the lengths of the intervals, x, increase with x increasing. Let j represent the average distribution function of the class x j , and then measure scattering intensities at a series of chosen angles to obtain n values of I( ). The angles are specified by the equatio
38、n: 1 25 /( ) ii i xx (i = 1, 2, 3, ., n)( 2 ) Approximately, the integral equation (1) is transformed into a set of a linear equations: 1 () n ii j j j la (i = 1, 2, 3, ., n)( 3 ) where 1 32 () d ( ) d j j x ij x aF t txx (4) All the coefficients, a ij , in the set of linear equations are a group of
39、 constants for given , collimation geometry, classes and specific angles. We may calculate them one by one by using a numerical integration method as long as the slit-height weighting function, F(t), has been measured (annex B). Thus, the values of distribution function corresponding to each class c
40、an be obtained from solving equation (3). Based on the solutions, the average density distribution, volume fractions, cumulative volume fractions and the mean size x of the particles can be calculated as follows: 3, 1 / n jjkk k qx ( j = 1, 2, ., n)( 5 ) 3, 3, 100 % jjj Qqx ( j = 1, 2, ., n)( 6 ) 3,
41、 3, 0 j jk k QQ ( j = 1, 2, ., n) (7) 3, 1 1 () / 2 n jj j j xQxx ( j = 1, 2, ., n)( 8 ) The solution of equation (3) involves the inversions of an ill-conditioned problem but it can be improved through optimizing the coefficient matrix and introducing a diagonal matrix B and a stabilizer . In matri
42、x form, equation (3) can be modified as: A BI (9) where (); ij n n Aa 11 22 diag( , ,., ); nn Ba aa 0 0,3 12 (, . . . ,) n 12 (, . . . ,) n IIII DDISO/TS13762:20013IS/OTS :26731(1002)E 4 ISO 1002 All rights rsedevre 5 Sample preparation and requirement 5.1 Preparation of collodion solution The analy
43、tically pure acetone and collodion without small-angle scattering should be used to prepare the solution. In general, the concentration of the solution may be approximately 5 % to 10 %. 5.2 Requirements and preparation of the sample plate 5.2.1 Requirements of the sample plate The sample plate used
44、for scattering measurement should meet the following requirements: a) the volume concentration of the test powder in the plate should be less than 1 %; b) to achieve maximum scattering intensity, the thickness of the sample plate shall be chosen to an optimum value where the monochromatic X-ray beam
45、 will be attenuated to 37 %; c) the sample plate should be uniform, flat, crack free and should ensure that the powder particles are separated as well as possible; d) the sample plate should have suitable dimensions, for example a length of 20 mm and a width of 10 mm. 5.2.2 Preparation of the sample
46、 plate Weigh out a given mass of test powder and pour onto it an appropriate volume of collodion solution. The quantities requested for the powder and solution may be estimated from the density of each and from their X-ray absorption coefficient, in order to meet the requirements in 5.2.1. Stir the
47、suspension in a small cup. A drop of wetting agent shall be added to the suspension if the solution does not readily wet the powder. The dispersion of the powder in the suspension shall be made by the addition of dispersing agent and/or an ultrasonic treatment. Place the cup containing the suspensio
48、n into an oven at the temperature of 20 Ct o5 0 C and with a relative humidity of below 50 %, until a dry sample plate has formed. 5.3 Preparation of dry powder sample Place the dry powder in a special sample holder with a slot. If the requirements in 5.2.1 are met in this way, it shall be directly used for SAXS measurement. 5.4 Preparation of colloidal solution The concentration of the colloidal solution should be less than 1 %. An appropriate surfactant may be added to prevent the colloids from agglomerating. When preparing the sample for measurement, the method chosen shou
