WO2000014510A1 - Particle shape - Google Patents
Particle shape Download PDFInfo
- Publication number
- WO2000014510A1 WO2000014510A1 PCT/GB1999/002996 GB9902996W WO0014510A1 WO 2000014510 A1 WO2000014510 A1 WO 2000014510A1 GB 9902996 W GB9902996 W GB 9902996W WO 0014510 A1 WO0014510 A1 WO 0014510A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- measurements
- scattering angle
- sample
- measurement
- radiation
- Prior art date
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N15/00—Investigating characteristics of particles; Investigating permeability, pore-volume, or surface-area of porous materials
- G01N15/02—Investigating particle size or size distribution
- G01N15/0205—Investigating particle size or size distribution by optical means, e.g. by light scattering, diffraction, holography or imaging
- G01N15/0211—Investigating a scatter or diffraction pattern
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N15/00—Investigating characteristics of particles; Investigating permeability, pore-volume, or surface-area of porous materials
- G01N15/02—Investigating particle size or size distribution
- G01N15/0205—Investigating particle size or size distribution by optical means, e.g. by light scattering, diffraction, holography or imaging
- G01N15/0211—Investigating a scatter or diffraction pattern
- G01N2015/0216—Investigating a scatter or diffraction pattern from fluctuations of diffraction pattern
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N15/00—Investigating characteristics of particles; Investigating permeability, pore-volume, or surface-area of porous materials
- G01N15/02—Investigating particle size or size distribution
- G01N2015/0294—Particle shape
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
- G01N21/47—Scattering, i.e. diffuse reflection
- G01N2021/4792—Polarisation of scatter light
Definitions
- the present invention relates to determination of particle shape.
- Particle shape can be important in many industries, particularly for determining the suitability of materials for particular purposes.
- particle shape in an emulsion can affect flow characteristics and the area coverage obtainable by a paint.
- particle shape can affect the stability of tablets and the rate of release of the pharmaceutical when ingested.
- clay slurries may be formed, and will have characteristics which are dependent on particular shape.
- the present invention provides a method of obtaining information relating to the shape of particles in a sample, in which the sample is illuminated with polarized radiation, and scattered radiation is measured at a plurality of scattering angles to produce a set of data which is characteristic of the particle shape, the measurements including measurement of the intensity of at least two polarization states of the scattered radiation at each scattering angle.
- the intensity measurements at each scattering angle are combined to produce a data value for the corresponding scattering angle.
- Illuminating radiation is preferably polarized and preferably coherent. Measurements are preferably taken of two orthogonal polarization states and measurements at each scattering angle are preferably taken simultaneously. Measurements at each scattering angle are preferably time averaged. Measurements are preferably taken over a period sufficiently long for substantially all possible particle orientations to have been expected to be present in the sample during the measurement period.
- Measurements at a scattering angle are preferably combined by forming a correlation coefficient, preferably a normalised correlation coefficient.
- a correlation coefficient preferably a normalised correlation coefficient.
- the data value for a scattering angle is given by one of the following formulae:
- I ⁇ is the data value for the scattering angle ⁇
- I j and I. are the sampled intensity measurements for respective polarization states at the measurement angle ⁇ .
- the invention also provides apparatus for obtaining information relating to the shape of particles in a sample, comprising illumination means operable to illuminate the sample with polarized radiation, and measurement means operable to measure scattered radiation at a plurality of scattering angles, including measurement of the intensity of at least two polarization states of the scattered radiation at each scattering angle to produce a set of data which is characteristic of the particle shape.
- control means combine the intensity measurements at each scattering angle to produce a data value for the corresponding scattering angle.
- the illumination means produces polarized radiation, preferably coherent radiation.
- the measurement means are operable to take measurements of two orthogonal polarization states and are preferably operable to take simultaneously the measurements to be combined.
- control means is operable to time average measurements.
- measurements are time averaged over a period sufficient long for substantially all possible particle orientations to have been expected to be present in the sample during the measurement period.
- control means combines measurements by forming a correlation coefficient, preferably a normalised correlation coefficient.
- the control means may be operable in accordance with one of the following formulae:
- I ⁇ is the data value for the scattering angle ⁇
- I ( and I 2 are the intensity measurements for respective polarization states at the measurement angle ⁇ .
- control means comprises a computer programmed to receive intensity measurements from the measurement means and to combine measurements as aforesaid.
- Fig. 1 is a schematic diagram of apparatus for taking measurements in accordance with the present invention.
- Fig. 2 is a plot of results obtained in accordance with the invention.
- the apparatus 10 shown in Fig. 1 is used to obtain information relating to the shape of particles in a sample 12.
- the sample is illuminated, as will be described, with polarized radiation from a source 14.
- Scattered radiation 16 leaves the sample 12 and is measured at 18 by sensors 18a, 18b which measure intensity at different polarization states.
- Measurements from the sensors 16a, 16b are provided to a control arrangement 20, which may be in the form of a computer, which combines data to produce a data value for the corresponding scattering angle.
- the set of data so produced is characteristic of the particle shape, as will be described.
- the sample 12 is shown in a closed cell 22 and will consist of the particles to be measured, suspended in a generally transparent fluid.
- the cell 22 could be a section of pipe through which fluid and suspended particles are flowing.
- the volume of the sample 12 should be sufficiently large for random particular orientation to be expected to give rise to an even distribution of particles in all possible orientations.
- the source 14 is a polarized laser producing polarized, coherent illuminating radiation 24 through a lens 26 focusing the radiation 24 into the sample 12. Radiation entering the sample 12 is scattered by the particles. A pin hole 28 selects light scattered to a particular angle relative to the illuminating radiation 24, according to the position of the pin hole 28. The radiation passing through the pin hole 28 enters a polarizing beam splitter (a device which is well known in itself) which simultaneously divides the radiation into two beams 32 which pass respectively to the sensors 18a, 18b. Both beams 32 are polarized, the polarization states being orthogonal to each other and at 45° to the polarization state of the illuminating radiation 24.
- a polarizing beam splitter a device which is well known in itself
- the sensors 18a, 18b are photo-multiplier tubes which measure light intensity by counting photons arriving over a period of time.
- the computer 20 is able to control the period of time over which measurements are taken, and then to receive the measurements so produced.
- the arrangement is also such that measurements from both sensors 18a, 18b are taken simultaneously, over the same period of time.
- the computer 20 can instruct the sensors 18a, 18b to begin measuring. Measurement continues during a period of time sufficiently long for substantially all possible particle orientations to have been expected to be present in the sample 12, for instance by virtue of Brownian motion in a static sample, or as a result of the random orientation of particles flowing through a pipe. It is important to the analysis of the results that all possible particle orientations are equally likely to be encountered by the radiation.
- Measurements are passed from the sensors 18a, 18b to the computer 20 for further analysis as will be described below. These measurements allow the computer to produce a data value corresponding to the scattering angle selected by the pin hole 28.
- the process will then be repeated to acquire data corresponding to a different scattering angle. This can be done either by moving the illuminating arrangements relative to the sample, or by moving the detecting arrangements relative to the sample, or both.
- Fig. 1 the first of these options is illustrated in broken lines, indicating that the source 14 and lens 26 have moved to illuminate from a different angle, so that the radiation passing through the pin hole 28 has been scattered at a different angle.
- the two intensity measurements obtained by the sensors 18a, 18b for a particular scattering angle are combined to produce a single data value for that scattering angle, as follows.
- the value I ⁇ which may be termed the correlation coefficient, is given as follows:
- I ⁇ is the data value for the scattering angle ⁇
- I ; and I 2 are the intensity measurements for respective polarization states at the measurement angle ⁇ .
- the use of the bar superscript in this formula (e.g. I) is to indicate that the value is time averaged.
- the left formula set out above (in which measurements are squared in the denominator) is used to account for pin hole averaging when using a relatively large pin hole.
- the other formula (without denominator measurements being squared) is used when a relatively small pin hole is being used.
- I e can be plotted against scattering angle to produce a plot similar to those shown in Fig. 2. If every particle in the sample 12 is perfectly spherical, I ⁇ will be unity for all scattering angles, giving the flat profile 34. If the particles are distorted from a pure spherical shape, to a spheroidal shape, profiles like those shown at 36a,b,c,d are produced. Initially, for low scattering angles, these have a value close to unity, but the value drops away for higher scattering angles.
- the angle at which this drop occurs is a characteristic of the aspect ratio of the spheroidal particles and in particular, the closer they are to a spherical shape, the higher the scattering angle at which the profile 36 begins to drop away. Consequently, the shape of the profile 36 produced from a real sample can be used to deduce the average shape of the particles in the sample.
- I ⁇ is independent of the strength of the incident radiation (and thus of any variation which may occur during the measurement period); is independent of the absolute transparency of any elements of the system; is independent of the sensitivity of the sensors and of any differences between them; and is independent of the size and shape of the illuminated volume containing the particles of interest.
Abstract
Description
Claims
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP99944720A EP1112481A1 (en) | 1998-09-09 | 1999-09-09 | Particle shape |
AU57536/99A AU5753699A (en) | 1998-09-09 | 1999-09-09 | Particle shape |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GBGB9819547.2A GB9819547D0 (en) | 1998-09-09 | 1998-09-09 | Particle shape |
GB9819547.2 | 1998-09-09 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2000014510A1 true WO2000014510A1 (en) | 2000-03-16 |
Family
ID=10838507
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/GB1999/002996 WO2000014510A1 (en) | 1998-09-09 | 1999-09-09 | Particle shape |
Country Status (4)
Country | Link |
---|---|
EP (1) | EP1112481A1 (en) |
AU (1) | AU5753699A (en) |
GB (1) | GB9819547D0 (en) |
WO (1) | WO2000014510A1 (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2017129547A (en) * | 2016-01-22 | 2017-07-27 | 株式会社堀場製作所 | Particle analyzing device, particle analyzing method and particle analyzing program |
FR3100333A1 (en) * | 2019-09-03 | 2021-03-05 | Cordouan Technologies SAS | Device and method for determining characteristic parameters of the dimensions of nanoparticles |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US10119910B2 (en) | 2015-10-09 | 2018-11-06 | Malvern Panalytical Limited | Particle characterisation instrument |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4710025A (en) * | 1982-06-22 | 1987-12-01 | Wyatt Technology Company | Process for characterizing suspensions of small particles |
GB2264556A (en) * | 1992-02-21 | 1993-09-01 | Hatfield Polytechnic Higher Ed | Diffraction analysis of particle size, shape and orientation |
WO1996042006A2 (en) * | 1995-06-13 | 1996-12-27 | University Of South Florida | Multi-angle, multiwavelength particle characterization system and method |
-
1998
- 1998-09-09 GB GBGB9819547.2A patent/GB9819547D0/en not_active Ceased
-
1999
- 1999-09-09 AU AU57536/99A patent/AU5753699A/en not_active Abandoned
- 1999-09-09 WO PCT/GB1999/002996 patent/WO2000014510A1/en not_active Application Discontinuation
- 1999-09-09 EP EP99944720A patent/EP1112481A1/en not_active Withdrawn
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4710025A (en) * | 1982-06-22 | 1987-12-01 | Wyatt Technology Company | Process for characterizing suspensions of small particles |
GB2264556A (en) * | 1992-02-21 | 1993-09-01 | Hatfield Polytechnic Higher Ed | Diffraction analysis of particle size, shape and orientation |
WO1996042006A2 (en) * | 1995-06-13 | 1996-12-27 | University Of South Florida | Multi-angle, multiwavelength particle characterization system and method |
Non-Patent Citations (3)
Title |
---|
BATES A P ET AL: "Particle shape determination from polarization fluctuations of scattered radiation", JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A (OPTICS, IMAGE SCIENCE AND VISION), DEC. 1997, OPT. SOC. AMERICA, USA, vol. 14, no. 12, pages 3372 - 3378, XP000861539, ISSN: 0740-3232 * |
CHANG P C Y ET AL: "Polarization properties of light multiply scattered by non-spherical Rayleigh particles", WAVES IN RANDOM MEDIA, JULY 1999, IOP PUBLISHING, UK, vol. 9, no. 3, pages 415 - 426, XP000863415, ISSN: 0959-7174 * |
PITTER M C ET AL: "Structure of polarization fluctuations and their relation to particle shape", LIGHT SCATTERING BY NONSPHERICAL PARTICLES'98, NEW YORK, NY, USA, 29 SEPT.-1 OCT. 1998, vol. 63, no. 2-6, Journal of Quantitative Spectroscopy and Radiative Transfer, Sept.-Dec. 1999, Elsevier, UK, pages 433 - 444, XP000863411, ISSN: 0022-4073 * |
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2017129547A (en) * | 2016-01-22 | 2017-07-27 | 株式会社堀場製作所 | Particle analyzing device, particle analyzing method and particle analyzing program |
CN106996906A (en) * | 2016-01-22 | 2017-08-01 | 株式会社堀场制作所 | Grading analysis device and grading analysis method |
GB2547327A (en) * | 2016-01-22 | 2017-08-16 | Horiba Ltd | Particle analyzer, particle analysis method, and particle analysis program |
US10520431B2 (en) | 2016-01-22 | 2019-12-31 | Horiba, Ltd. | Particle analyzer, particle analysis method, and particle analysis program |
GB2547327B (en) * | 2016-01-22 | 2020-02-19 | Horiba Ltd | Particle analyzer, particle analysis method, and particle analysis program |
FR3100333A1 (en) * | 2019-09-03 | 2021-03-05 | Cordouan Technologies SAS | Device and method for determining characteristic parameters of the dimensions of nanoparticles |
EP3789750A1 (en) * | 2019-09-03 | 2021-03-10 | Cordouan Technologies | Device and method for determining characteristic parameters of the dimensions of nanoparticles |
Also Published As
Publication number | Publication date |
---|---|
EP1112481A1 (en) | 2001-07-04 |
GB9819547D0 (en) | 1998-10-28 |
AU5753699A (en) | 2000-03-27 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
Silva et al. | Particle sizing measurements in pharmaceutical applications: Comparison of in-process methods versus off-line methods | |
EP3279636B1 (en) | Particle size measuring method and device | |
Zhang et al. | Two-dimensional array Debye ring diffraction protein recognition sensing | |
Pecora | Dynamic light scattering measurement of nanometer particles in liquids | |
CA1072362A (en) | Method for determining the volume and the volume distribution of suspended small particles | |
Sriram et al. | A rapid readout for many single plasmonic nanoparticles using dark-field microscopy and digital color analysis | |
Kratohvil | Light scattering | |
US11002655B2 (en) | Cuvette carrier | |
GB2520491A (en) | Improvements in or relating to calibration of instruments | |
US5063301A (en) | Noninvasive method and apparatus using coherent backscattering for process control | |
CN101122555A (en) | High concentration super fine granule measuring device and method based on backward photon related spectrum | |
CN107884368A (en) | A kind of optic testing system and method for testing | |
CN109883902A (en) | Haze device for detecting particles and its detection method based on solar blind UV circular polarization | |
US20070291265A1 (en) | Optical apparatus for simultaneously measuring the scattering and concentration of signals of macromolecules in a flow cell | |
CN209027957U (en) | Dual wavelength multi-angle transmission-type air particles measuring device | |
US7956998B2 (en) | Method and system for the polarmetric analysis of scattering media utilising polarization difference sensing (PDS) | |
EP1112481A1 (en) | Particle shape | |
Medebach et al. | Dynamic light scattering in turbid colloidal dispersions: A comparison between the modified flat-cell light-scattering instrument and 3D dynamic light-scattering instrument | |
CN107991233A (en) | Noble metal nano array extinction spectra measuring device and its sensing detection method | |
Bumiller et al. | A preliminary investigation concerning the effect of particle shape on a powder’s flow properties | |
US8531516B2 (en) | Imaging polar nephelometer | |
Liu et al. | Multi-camera single-plane PIV imaging in two-phase flow for improved dispersed-phase concentration | |
CN206505016U (en) | A kind of multi-angle based on transmission grating light splitting receives scattering optical measurement instrument | |
Niskanen et al. | Assessment of refractive index of pigments by Gaussian fitting of light backscattering data in context of the liquid immersion method | |
Wu et al. | A rheo‐light‐scattering instrument for the study of the phase behavior of polymer blends under simple‐shear flow |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AK | Designated states |
Kind code of ref document: A1 Designated state(s): AE AL AM AT AU AZ BA BB BG BR BY CA CH CN CR CU CZ DE DK DM EE ES FI GB GD GE GH GM HR HU ID IL IN IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MD MG MK MN MW MX NO NZ PL PT RO RU SD SE SG SI SK SL TJ TM TR TT UA UG US UZ VN YU ZA ZW |
|
AL | Designated countries for regional patents |
Kind code of ref document: A1 Designated state(s): GH GM KE LS MW SD SL SZ UG ZW AM AZ BY KG KZ MD RU TJ TM AT BE CH CY DE DK ES FI FR GB GR IE IT LU MC NL PT SE BF BJ CF CG CI CM GA GN GW ML MR NE SN TD TG |
|
121 | Ep: the epo has been informed by wipo that ep was designated in this application | ||
DFPE | Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101) | ||
WWE | Wipo information: entry into national phase |
Ref document number: 1999944720 Country of ref document: EP |
|
WWP | Wipo information: published in national office |
Ref document number: 1999944720 Country of ref document: EP |
|
REG | Reference to national code |
Ref country code: DE Ref legal event code: 8642 |
|
WWE | Wipo information: entry into national phase |
Ref document number: 09786784 Country of ref document: US |
|
WWW | Wipo information: withdrawn in national office |
Ref document number: 1999944720 Country of ref document: EP |