《BS-ISO-22412-2008.pdf》由会员分享，可在线阅读，更多相关《BS-ISO-22412-2008.pdf（26页珍藏版）》请在三一文库上搜索。
1、BRITISH STANDARD BS ISO 22412:2008 Particle size analysis Dynamic light scattering (DLS) ICS 19.120 ? Copyright British Standards Institution Provided by IHS under license with BSI - Uncontrolled Copy Licensee=Boeing Co/5910770001 Not for Resale, 08/14/2008 22:25:32 MDTNo reproduction or networking
2、permitted without license from IHS -,-,- BS ISO 22412:2008 This British Standard was published under the authority of the Standards Policy and Strategy Committee on 30 June 2008 BSI 2008 ISBN 978 0 580 56196 2 National foreword This British Standard is the UK implementation of ISO 22412:2008. The UK
3、 participation in its preparation was entrusted to Technical Committee LBI/37, Particle characterization including sieving. A list of organizations represented on this committee can be obtained on request to its secretary. This publication does not purport to include all the necessary provisions of
4、a contract. Users are responsible for its correct application. Compliance with a British Standard cannot confer immunity from legal obligations. Amendments/corrigenda issued since publication DateComments Copyright British Standards Institution Provided by IHS under license with BSI - Uncontrolled C
5、opy Licensee=Boeing Co/5910770001 Not for Resale, 08/14/2008 22:25:32 MDTNo reproduction or networking permitted without license from IHS -,-,- Reference number ISO 22412:2008(E) INTERNATIONAL STANDARD ISO 22412 First edition 2008-05-01 Particle size analysis Dynamic light scattering (DLS) Analyse g
6、ranulomtrique Dispersion lumineuse dynamique (DLD) BS ISO 22412:2008 Copyright British Standards Institution Provided by IHS under license with BSI - Uncontrolled Copy Licensee=Boeing Co/5910770001 Not for Resale, 08/14/2008 22:25:32 MDTNo reproduction or networking permitted without license from IH
7、S -,-,- ii Copyright British Standards Institution Provided by IHS under license with BSI - Uncontrolled Copy Licensee=Boeing Co/5910770001 Not for Resale, 08/14/2008 22:25:32 MDTNo reproduction or networking permitted without license from IHS -,-,- iii Contents Page Foreword iv Introduction v 1 Sco
8、pe . 1 2 Normative references. 1 3 Terms and definitions. 1 4 Symbols, abbreviated terms and units. 2 5 Principle. 3 5.1 General. 3 5.2 DLS optical detection. 3 6 Calculation of mean particle size and PI 4 7 Apparatus 4 8 Preliminary procedures 5 8.1 Instrument location. 5 8.2 Test sample preparatio
9、n 5 9 Measurement procedure 5 10 System qualification. 6 11 Repeatability 6 12 Test report . 6 Annex A (informative) Correlation function and frequency analysis 8 Annex B (informative) Concentration effects 13 Bibliography. 16 BS ISO 22412:2008 Copyright British Standards Institution Provided by IHS
10、 under license with BSI - Uncontrolled Copy Licensee=Boeing Co/5910770001 Not for Resale, 08/14/2008 22:25:32 MDTNo reproduction or networking permitted without license from IHS -,-,- iv Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards
11、 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 that committee. International organiza
12、tions, 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 in accordance with the rules given in t
13、he ISO/IEC Directives, Part 2. 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 Standard requires approval by at least 75 % of
14、 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 be held responsible for identifying any or all such patent rights. ISO 22412 was prepared by Technical Committee ISO/TC 24, Particle
15、characterization including sieving, Subcommittee SC 4, Sizing by methods other than sieving. BS ISO 22412:2008 Copyright British Standards Institution Provided by IHS under license with BSI - Uncontrolled Copy Licensee=Boeing Co/5910770001 Not for Resale, 08/14/2008 22:25:32 MDTNo reproduction or ne
16、tworking permitted without license from IHS -,-,- v Introduction Particle1) sizing in the submicrometer size range is nowadays performed on a routine basis using the dynamic light scattering (DLS) method. The success of the technique is mainly based on the fact that it provides estimates of average
17、size and its distribution in a measurement time of a few minutes, and user-friendly commercial instruments are available. Nevertheless, proper use of the instrument and interpretation of the result require certain precautions. To this end, ISO 13321 was developed. ISO 13321 provides the procedures n
18、ecessary to allow determination of the correct particle size using the photon correlation technique. The instruments specified in ISO 13321 are restricted to low particle concentrations in order to avoid disturbances due to multiple scattering. Instruments that seek to minimize this restriction are
19、now available. Therefore, there is a need for an International Standard for the determination of particle size by DLS suitable for a wide concentration range of dispersions that will enable users to obtain good interlaboratory agreement on accuracy and reproducibility. Several techniques have been d
20、eveloped for DLS2). These techniques can be classified in two ways: a) by the difference in data analysis (correlation method and frequency analysis method); b) by the difference in optical set-up (homodyne and heterodyne detection optics). Instruments are now available with a range of fixed and mov
21、able cell options. Although DLS allows the determination of particle-size distribution, this International Standard is limited to the description of size distribution by means of only two robust descriptors: an average size and a polydispersity index. Many different methods for the calculation of fu
22、ll size distributions are used. However, reproducibility of the different methods of calculation for full distributions is, at present, not good enough to include in an International Standard. Therefore, today, there is no standardized algorithm that may be included in an International Standard. 1)
23、The NIST definition of a particle is: “Any condensed-phase tridimensional discontinuity in a dispersed system may generally be considered a particle” (Reference 19). 2) DLS probes the dynamics of time-dependent phenomena such as particle motions. DLS combined with the correlation method of data anal
24、ysis is often referred to as photon correlation spectroscopy. BS ISO 22412:2008 Copyright British Standards Institution Provided by IHS under license with BSI - Uncontrolled Copy Licensee=Boeing Co/5910770001 Not for Resale, 08/14/2008 22:25:32 MDTNo reproduction or networking permitted without lice
25、nse from IHS -,-,- blank Copyright British Standards Institution Provided by IHS under license with BSI - Uncontrolled Copy Licensee=Boeing Co/5910770001 Not for Resale, 08/14/2008 22:25:32 MDTNo reproduction or networking permitted without license from IHS -,-,- 1 Particle size analysis Dynamic lig
26、ht scattering (DLS) 1 Scope This International Standard specifies a method for the application of dynamic light scattering (DLS) to the estimation of an average particle size and the measurement of the broadness of the size distribution of mainly submicrometre-sized particles or droplets dispersed i
27、n liquids. This International Standard is applicable to the measurement of a broad range of dilute and concentrated suspensions. The principle of DLS is the same as for a dilute dispersion. However, specific requirements for the instrument set-up and specification of test sample preparation, as well
28、 as some advice on the correct interpretation of the results of measurements for concentrated dispersions, are required. NOTE A photon correlation spectroscopy method for dilute dispersions is specified in ISO 13321. 2 Normative references The following referenced documents are indispensable for the
29、 application 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 13321:1996, Particle size analysis Photon correlation spectroscopy 3 Terms and definitions For the purpos
30、es of this document, the following terms and definitions apply. 3.1 average particle diameter DLS x dynamic light scattering harmonic intensity-weighted arithmetic average particle diameter NOTE Average particle diameter is expressed in nanometres. Typical average particle diameters are in the range
31、 1 nm to about 1 000 nm. 3.2 polydispersity index PI dimensionless measure of the broadness of the size distribution NOTE 1 Adapted from ISO 13321:1996, 2.2. NOTE 2 The PI typically has values less than 0,1 for a monodisperse test sample. 3.3 scattering volume V section of the incident laser beam vi
32、ewed by the detector optics NOTE Adapted from ISO 13321:1996, 2.3. BS ISO 22412:2008 Copyright British Standards Institution Provided by IHS under license with BSI - Uncontrolled Copy Licensee=Boeing Co/5910770001 Not for Resale, 08/14/2008 22:25:32 MDTNo reproduction or networking permitted without
33、 license from IHS -,-,- 2 3.4 scattered intensity count rate photocurrent Is intensity of the light scattered by the particles in the scattering volume; in practice, a number of photon pulses per unit time or a photodetector current which is proportional to the scattered intensity as measured by a d
34、etector 3.5 qualification dynamic light scattering proof with reference material that an instrument is operating in agreement with its specifications 3.6 validation dynamic light scattering proof with reference material that a procedure is acceptable for all elements of its scope 4 Symbols, abbrevia
35、ted terms and units C() distribution function of decay rates or inverse characteristic frequencies arbitrary units D translational diffusion coefficient metres squared per second m2/s Dc collective diffusion coefficient metres squared per second m2/s Ds self-diffusion coefficient metres squared per
36、second m2/s g(1)() normalized electric field correlation function arbitrary units G(2)() intensity correlation function arbitrary units Is scattered intensity, count rate, photocurrent n refractive index of the dispersion medium dimensionless P() power spectrum arbitrary units PI polydispersity inde
37、x Qint,i intensity-weighted amount of particles with size xi arbitrary units V scattering volume x diameter of a spherical particle nanometres nm DLS x average particle diameter nanometres nm decay rate and characteristic frequency reciprocal seconds s1 intensity-weighted average value of the decay
38、rate reciprocal seconds s1 viscosity of the dispersion medium millipascal seconds mPas scattering angle degrees 0 wavelength of the laser in a vacuum nanometres nm BS ISO 22412:2008 Copyright British Standards Institution Provided by IHS under license with BSI - Uncontrolled Copy Licensee=Boeing Co/
39、5910770001 Not for Resale, 08/14/2008 22:25:32 MDTNo reproduction or networking permitted without license from IHS -,-,- 3 2 second cumulant of the intensity-weighted size distribution arbitrary units particle density grams per cubic centimeter g/cm3 correlation time seconds s particle volume fracti
40、on arbitrary units angular frequency reciprocal seconds Hz 5 Principle 5.1 General Submicrometre-sized particles suspended in a fluid are in constant random Brownian motion as the result of the interaction with the molecules of the suspending fluid. In the Stokes-Einstein theory of Brownian motion (
41、Reference 16), particle motion at very low concentration is determined by the suspending fluid viscosity and temperature, and the size of the particle. From a measurement of the particle motion in a fluid of known temperature and viscosity, the particle size can be determined. At low particle concen
42、trations, this is a hydrodynamic particle size (see ISO 13321). At increased concentrations, multiple scattering and particle-particle interactions are relevant. The influence of multiple scattering can be suppressed by the measurement setup. Particle-particle interactions mean that only an apparent
43、 particle size can be measured (see Annex B). The DLS technique (References 15, 17, 18) probes the motion optically. The suspended particles are illuminated with a coherent light source. The light scattered from the moving suspended particles has a time-dependent phase imparted to it from the time-d
44、ependent position. The time-dependent phase of the scattered light can be considered as either a time-dependent phase shift or as a spectral frequency shift from the central frequency of the light source. Measured over time, random particle motion forms a distribution of optical phase shifts or spec
45、tral frequency shifts. 5.2 DLS optical detection 5.2.1 The use of a coherent optical reference allows, through optical wave interference, the conversion from spectral central frequencies to the difference between light frequencies (the shift frequencies). For DLS the shift frequencies are on the sca
46、le 1 Hz to 100 kHz, readily detected by modest frequency electronics. Two methods of referencing are commonly used and are illustrated in Figure 1. a) homodyne b) heterodyne Key 1 scattered light 2 portion of unscattered beam 3 detector 4 autocorrelator or spectrum analyser Figure 1 Optical arrangem
47、ent for DLS 5.2.2 Homodyne detection see Figure 1 a) is also referred to as self-referencing or self-beating detection. The mixing at the optical detector of all of the collected scattered light provides the reference for frequency- or phase-difference measurement. BS ISO 22412:2008 Copyright British Standards Institution Provided by IHS under license with BSI - Uncontrolled Copy Licensee=Boeing Co/5910770001 Not for Resale, 08/14/2008 22:25:32 MDTNo reproduction or networking permitted without license from IHS -,-,- 4 5.2.3 Heterodyne detection see Figure 1 b)