[go: up one dir, main page]

WO2000006993A1 - Procede pour determiner la taille de particules dans une solution - Google Patents

Procede pour determiner la taille de particules dans une solution Download PDF

Info

Publication number
WO2000006993A1
WO2000006993A1 PCT/EP1999/003128 EP9903128W WO0006993A1 WO 2000006993 A1 WO2000006993 A1 WO 2000006993A1 EP 9903128 W EP9903128 W EP 9903128W WO 0006993 A1 WO0006993 A1 WO 0006993A1
Authority
WO
WIPO (PCT)
Prior art keywords
particles
size
laser
plasma emissions
particle size
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/EP1999/003128
Other languages
German (de)
English (en)
Inventor
Wolfgang Hauser
Tobias Bundschuh
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Karlsruher Institut fuer Technologie KIT
Original Assignee
Forschungszentrum Karlsruhe GmbH
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Forschungszentrum Karlsruhe GmbH filed Critical Forschungszentrum Karlsruhe GmbH
Publication of WO2000006993A1 publication Critical patent/WO2000006993A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Classifications

    • 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
    • G01N21/62—Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light
    • G01N21/71—Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light thermally excited
    • G01N21/718—Laser microanalysis, i.e. with formation of sample plasma
    • 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

Definitions

  • the invention relates to a method for determining the size of particles in a solution.
  • the laser-induced breakdown detection (LIBD) was dissolved in Younger ⁇ possible time as a method for highly sensitive quantification of colloids in solutions established [1, 2, 3]. Compared to kon ⁇ tional methods such as static / dynamic Streulichtde- tetation (z. B. photon correlation spectroscopy), this ⁇ Me Thode in particular for particles of ⁇ 100 s the advantage of a lower by several orders of magnitude detection limit.
  • the commercial use was so far against the relatively high appa ⁇ rative effort.
  • pulsed laser light sources such as excimer lasers / dye lasers or flash lamp-pumped Nd: YAG lasers with resonator lengths in the 1 m range and thus high pulse energy were used to generate the breakdown.
  • the principle of laser-induced breakdown detection is based on the generation of a dielectric breakdown in the focus of a high-energy pulsed laser beam. Since the energy threshold for triggering breakdown is lower in fe ⁇ art matter as in liquids or gases, breakdown events can be triggered by present in the focal volume particle selectively at a suitable pulse energy. This is shown in Fig. 1.
  • the pulsed laser beam is focused into the measuring medium (here: colloidal solution) with a converging lens.
  • the breakdown ie a plasma
  • Plasma formation is associated with a short-term volume expansion and thus the triggering of a pressure wave in the measuring medium.
  • a piezoelectric transducer pressure wave sensor pressed against the medium converts this wave into an electrical signal.
  • a comparison of these events with the number of laser pulses delivered reveals a breakdown frequency.
  • the concentration of the particles in the measuring medium (colloids in the solution) can be determined.
  • the object of the invention is to provide a method based on the principle of laser-induced breakdown detection, with which the particle size can also be determined.
  • the previously missing information about the particle size is the subject of the method according to the invention.
  • An online procedure for the direct determination of an average particle diameter using the LIBD is shown here. It is based on the optical detection and measurement of breakdown events with an externally triggered, personal computer-based image processing system. The systems suitable for this have only recently become available (e.g. externally triggerable video camera). The invention is explained in more detail below on the basis of an exemplary embodiment with the aid of the figures.
  • Fig. 1 shows the principle of laser-induced breakdown detection
  • Fig. 2 shows the schematic structure of an apparatus for performing the method according to the invention.
  • 3 and 4 show the distributions for breakdown events related to the direction of the laser beam.
  • the plasma on the solid particles is excited with a pulsed laser 11.
  • a converging lens of short focal length 7 focuses the parallel laser beam into a measuring cell 5.
  • the energy of the laser pulses is thereby via a variable attenuator (gray wedge) 10 adjusted and measured with an energy detector 9 in a reflection arrangement.
  • a beam splitter 8 positioned in the primary beam hides part of the laser intensity.
  • the simplifywei ⁇ preparing laser beam terminates in a beam stopper 4.
  • a to the sample cell 5 perpendicular to the incident laser beam angepress- ter pressure wave sensor 6 detects the pressure wave generated by a plasma formation (photoacoustic breakdown detection).
  • the components which are likewise arranged perpendicular to the incident laser beam for the optical measurement of the breakdown events are a macro microscope 2 with variable magnification and a video camera 1.
  • a bandpass filter fixed between the macro microscope 2 and measuring cell 5 Filter 3 almost completely suppresses the scattered, primary laser radiation. It has been shown that the best contrast ratio for mapping the breakdown events is achieved.
  • the pulsed laser 11 triggers an analog / digital converter multifunctional cat 13 implemented in a personal computer 12. With this, the signal amplitudes of the pressure wave sensor 6 and energy detector 9 are read out and the video camera 1 is triggered in a time-delayed and synchronous manner with the laser shot.
  • the breakdown image recorded for each laser pulse is digitized via a frame grabber card 14 and fed to the personal computer 12.
  • Nd YAG laser, frequency doubled (532 nm), pulse repetition rate max. 20 Hz, pulse energy reduced to approx. 5 mJ at 532 nm
  • Video camera 1 Video camera 1
  • Plano-convex lens focal length 8 mm (Minilite I) or 40 mm
  • the control of the measuring process, the data recording and the evaluation take place with an image processing software installed on the personal computer.
  • a specially developed macro can be used to control the measurement parameters required to control the recording process, such as trigger signal pulse widths and delay times for the video camera or the two inputs of the A / D converter card (energy signal, pressure wave sensor signal ) freely set.
  • the system allows all individual images including data from the pressure wave sensor and energy detector to be stored either in the RAM memory of the computer or on the hard disk.
  • an optical trigger is set to reduce the memory requirement through the stored images of a series of measurements. This is done by defining a horizontal trigger line on the axis of the breakdown events (laser beam axis) and by specifying a threshold value for the light intensity to be detected (gray level) on this line. With the appropriate preselection, the image processing system automatically recognizes breakdown events and stores only the usable images even with breakdown frequencies ⁇ 1.
  • the "Region of Interest” window (ROI window) is also used for data reduction. This means that the parts of the image that do not contain any information are hidden (upper and lower image areas).
  • the system described is thus capable of several thousand such individual images with associated voltage values of the pressure wave sensor and energy detector for the subsequent Filing evaluation or alternatively evaluating the data directly from ⁇ .
  • the individual images of a series of measurements are measured directly with the image processing software for evaluation.
  • an intensity threshold gray level
  • the system automatically recognizes the breakdown events on each image and can separate single and multiple events.
  • the software is able to take every single picture
  • the derivation of the effective focal length from the XY coordinates of the plasma centroids and the determination of an average particle diameter knife described in the measurement sample are the basis for determining the particle size or size distribution.
  • the derivation of the effective focal length from the XY coordinates of the plasma centroids and the determination of an average particle diameter knife described in the measurement sample are the basis for determining the particle size or size distribution.
  • measurement samples that contain solutions with particles of a defined size or diameter (monodisperse particles).
  • the samples are produced using spherical polystyrene particle standards with particle diameters from 19 nm to 1072 nm, being ultra-pure
  • the X coordinates of the centroid of each of 8,000 breakdown events of measurement samples with - 73 nm and 1072 nm - particle standards are plotted.
  • the coordinates have been transformed so that the coordinate zero point is identical to the focal point of the converging lens.
  • the breakdown events scatter much more in the direction of the laser beam axis (X direction) than perpendicular to the beam direction (Y direction).
  • the measured effective focus length L x is plotted against the diameter d of the polystyrene particle standards.
  • the values measured in the range of 19 nm to 1072 nm can do well in a double logarithmic representation using a straight line be approximated.
  • the parameter is determined using the Me ⁇ Thode least squares.
  • the calibration function, FIG. 5, is calculated from this by reshaping
  • the course of the calibration curve or the calculated fit parameters depend on the spatial distribution of the laser pulse power density in the focus volume. This is determined on the one hand by properties of the laser used (e.g. wavelength, beam diameter, beam profile, beam divergence) and on the other hand by properties of the optical components used (e.g. focal length of the converging lens).
  • properties of the laser used e.g. wavelength, beam diameter, beam profile, beam divergence
  • optical components used e.g. focal length of the converging lens.
  • an Nd: YAG laser Continuum Surelite I at 532 nm is used and a plano-convex lens with a 40 mm focal length is used. The following parameters are calculated for the calibration curve recorded with this configuration
  • the mean particle diameter in colloidal solutions can thus be determined directly by determining the effective focus length L x with an image processing system.
  • the statistically based particle size information is available after about 3 minutes of measurement time (breakdown frequency 100%).
  • the mean size of the colloids (spherical particles) determined with this method thus makes it possible to directly derive the particle concentration from the measurement of the breakdown frequency.
  • Another possibility for determining the size is to measure a measured local distribution by a quantity of Distribution-adapted distribution functions of solutions with

Landscapes

  • Health & Medical Sciences (AREA)
  • Chemical & Material Sciences (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Biochemistry (AREA)
  • General Health & Medical Sciences (AREA)
  • Immunology (AREA)
  • Pathology (AREA)
  • Dispersion Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Optics & Photonics (AREA)
  • Plasma & Fusion (AREA)
  • Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
  • Investigating, Analyzing Materials By Fluorescence Or Luminescence (AREA)

Abstract

L'invention vise à mettre au point un procédé fondé sur le principe de la détection de pannes, induite par laser, qui permette également de déterminer la taille des particules. A cet effet, il est prévu de produire des émissions de plasma, de détecter en mode à résolution locale les émissions de plasma individuelles pour un nombre d'impulsions laser significatives au plan statistique, de représenter les émissions de plasma sur un diagramme de position et de fréquence, qui est fonction de la taille des particules et de déterminer la taille des particules par comparaison du diagramme de position et de fréquence avec des diagrammes de positon et de fréquence de solutions comprenant des particules de taille connue.
PCT/EP1999/003128 1998-07-24 1999-05-06 Procede pour determiner la taille de particules dans une solution Ceased WO2000006993A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE19833339.0 1998-07-24
DE1998133339 DE19833339C1 (de) 1998-07-24 1998-07-24 Verfahren zur Bestimmung der Größe von Partikeln in einer Lösung

Publications (1)

Publication Number Publication Date
WO2000006993A1 true WO2000006993A1 (fr) 2000-02-10

Family

ID=7875171

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP1999/003128 Ceased WO2000006993A1 (fr) 1998-07-24 1999-05-06 Procede pour determiner la taille de particules dans une solution

Country Status (2)

Country Link
DE (1) DE19833339C1 (fr)
WO (1) WO2000006993A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2013091118A1 (fr) 2011-12-22 2013-06-27 Nanotion Ag Procédé et dispositif d'analyse d'échantillons contenant de petites particules

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2007129667A1 (fr) * 2006-05-10 2007-11-15 National University Corporation Kyoto Institute Of Technology Procédé et appareil de détection de particules, procédé et appareil de formation d'une différence de concentrations de particules dans un liquide de dispersion
DE102006051227B9 (de) * 2006-10-31 2008-06-19 Forschungszentrum Karlsruhe Gmbh Verfahren zum Nachweis der Veränderung einer Population von Partikeln in einer Lösung
DE102007055000B4 (de) 2007-11-17 2010-07-15 Iav Gmbh Ingenieurgesellschaft Auto Und Verkehr Verfahren zur Bestimmung des Phasenüberganges eines in einem Gasstrom befindlichen Multikomponententropfens, in dem kristalline Feststoffe gelöst sind, in einen festen Zustand
AT509883B1 (de) * 2010-05-04 2011-12-15 Kompetenzzentrum Das Virtuelle Fahrzeug Forschungsgmbh Verfahren und vorrichtung zur bestimmung des rotationsverhaltens und der grösse von partikel und tropfen in mehrphasenströmungen

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5316983A (en) * 1990-08-03 1994-05-31 Hitachi, Ltd. Apparatus for analysis of particulate material, analytical method for same, apparatus for production of ultrapure water, apparatus for manufacturing of semiconductor, and apparatus for production of pure gas

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19602048C2 (de) * 1996-01-20 1999-07-01 Karlsruhe Forschzent Druckwellensensor

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5316983A (en) * 1990-08-03 1994-05-31 Hitachi, Ltd. Apparatus for analysis of particulate material, analytical method for same, apparatus for production of ultrapure water, apparatus for manufacturing of semiconductor, and apparatus for production of pure gas

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
HAHN DW: "laser-induced breakdown spectroscopy for sizing and elemental analysis of discrete aerosol particles", APPLIED PHYSICS LETTERS., vol. 72, no. 23, 8 June 1998 (1998-06-08), AMERICAN INSTITUTE OF PHYSICS. NEW YORK., US, pages 2960 - 2962, XP002110910, ISSN: 0003-6951 *

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2013091118A1 (fr) 2011-12-22 2013-06-27 Nanotion Ag Procédé et dispositif d'analyse d'échantillons contenant de petites particules

Also Published As

Publication number Publication date
DE19833339C1 (de) 2000-04-13

Similar Documents

Publication Publication Date Title
DE69314205T2 (de) Methode und Vorrichtung zur Messung der Grösse von Teilchen oder Fehlern
DE69115876T2 (de) Bildgebender Durchflusszytometer
DE69628542T2 (de) Verfahren und vorrichtung zur durchflusscytometrie
EP1982159B1 (fr) Dispositif de mesure destiné à déterminer la dimension, la répartition dimensionnelle et la quantité de particules à l'échelle nanoscopique
DE69535012T2 (de) Verfahren und Vorrichtung zur Messung der Konzentration von absorbierenden Bestandteilen in einem streuenden Medium
DE69126120T2 (de) Durchfluss-Abbildungszytometer
DE69202242T2 (de) Methode und apparat zur prüfung von mit flüssigkeit gefüllten behältern.
DE69828345T2 (de) Kreuzkorrelationsverfahren und Vorrichtung zur Unterdrückung der Effekte von Mehrfachstreuung
EP3612845B1 (fr) Procédé de détermination sans contact de paramètres d'écoulement
DE102020100020A1 (de) Verfahren und Vorrichtung für die Bestimmung von Merkmalen von Partikeln durch multiparametrische Erfassung von Streulicht- und Extinktionssignalen
DE69635790T2 (de) Vorrichtung und Verfahren zur Messung eines streuenden Mediums
DE2551026C3 (de) Verfahren zur Analysieren von Teilchen
DE2058124A1 (de) Verfahren und Vorrichtung zur Untersuchung der Verteilung schwebender Teilchen
WO2015136038A2 (fr) Trajet de faisceau commun pour obtenir une information concernant des particules par évaluation directe d'images et par analyse différentielle d'images
DE1296420B (de) Verfahren und Vorrichtung zur Untersuchung einer Fluessigkeit auf darin enthaltene Teilchen
DE69427067T2 (de) Streulichtintensitätsdetektor für von Filmen in kolloidalen Medien gestreutes Licht
DE19833339C1 (de) Verfahren zur Bestimmung der Größe von Partikeln in einer Lösung
DE102007004346A1 (de) Vorrichtung zur optischen Charakterisierung
DE112011101562T5 (de) Erfassen von Wärmekapazitätsänderungen aufgrund von Oberflächen-inkonsistenzen unter Verwendung von Spektralbereichen hoher Absorption im mittleren IR
WO2017101895A2 (fr) Sonde de mesure transparente pour balayage de rayonnement
CH711170A1 (de) Verfahren und Vorrichtung zur Detektion von Aerosolpartikeln.
DE3204295A1 (de) Verfahren und vorrichtung zur ermittlung von oberflaechenfehlern an mechanischen teilen, insbesondere an teilen mit gekruemmter oberflaeche
EP3543681A1 (fr) Système de détection destiné à la détection des petites particules organiques spécifiques sur verre non revêtu ou revêtu à haut débit
DE3319922C2 (fr)
DE69318632T2 (de) Einrichtung zur Messung von Teilchen

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): JP US

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LU MC NL PT SE

DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
121 Ep: the epo has been informed by wipo that ep was designated in this application
122 Ep: pct application non-entry in european phase