SPEcIAL particle the sample ISSN 949-625 Special Issue Size and shape of particles in suspensions, emulsions, colloidal systems, powders, granules and bulk materials Particle Measurement Analysis methods in a size range from.3 nm to 3 mm 3 µm - 3 mm Dynamic Image Analysis 1 µm - 3 mm Dynamic Image Analysis CAMSIZER NEW CAMSIZER XT.3 nm - 8 µm Dynamic Laser Light Scattering NEW.1 µm - 6 µm Static Laser Light Scattering HORIBA LA-3 nm - 3 mm Static Laser Light Scattering HORIBA SZ- HORIBA LA-95 Dynamic Image Analysis Static Laser Light Scattering Dynamic Laser Light Scattering
EDITORIAL Dear Readers, Customers and Business Partners Each particle analysis method has its typical application areas, but also advantages and disadvantages when compared to other techniques. In this special issue Particle Measurement of our customer magazine the sample we would like to introduce the product portfolio of Retsch Technology and, at the same time, give you an overview of the most important analysis methods for particle size and shape. In addition to the established analyzers HORIBA LA-95 and camsizer, we are happy to present you two new instruments: The camsizer XT is based on the same principle as the well-known camsizer, but allows for wet or dry of fine powders with particle sizes as low as 1 micron. The new Horiba SZ- analyzes size, zeta potential and molecular weight of nano particles with great flexibility, in low or high concentrations. We hope that our comparison of methods as well as the presentation of our analyzers will give you some ideas of how to analyze your samples more efficiently and reliably. Maybe you will even find your own application among the many examples presented in this issue? We hope you enjoy reading this special edition of the sample! Yours Dr. Jürgen Pankratz Managing Director Retsch Technology GmbH Our range of instruments for particle characterization covers a measuring range from.3 nm to 3 mm. Based on different techniques, they are used for the analysis of particle size and shape of suspensions, emulsions, colloidal systems, powders, granules and bulk materials. Particle analysis methods in a measuring range from.3 nm to 3 mm Optimum solutions for a great variety of applications Users can choose between various methods of particle size analysis which go beyond traditional, purely mechanical sieving. In this segment, Retsch Technology offers a wide product selection based on image processing techniques and laser diffraction methods. When looking for the method best suited for a particular application, a variety of criteria has to be taken into consideration. Technical parameters, such as measuring range, resolution, reproducibility and detection efficiency, as well as investment and operating costs play an important role in this context. Newly developed instruments offer alternatives to established techniques and challenge well-proven methods. SELECTION CRIterIA Particle Size The most important criterion for the selection of a suitable technique is the particle size to be measured. Static laser light scattering covers the widest measuring range from nm to 3 mm. Dynamic laser light scattering, in contrast, is only suitable for measuring particles in the nanometer range. Optical image processing methods, just like sieve analysis, are typically used in a range from microns to centimeters. A SUITABLE ANALYZER FOR each measuring RANGE Particle size: 1 nm 1 µm 1 mm 1 m Dynamic Image Analysis CAMSIZER 3 µm 3 mm CAMSIZER XT 1 µm 3 mm Static Laser Light Scattering LA-3.1 µm 6 µm LA-95 nm 3 mm Dynamic Laser Light Scattering SZ-.3 nm 8 µm Sieve Analysis Vibratory Sieve Shaker AS 2 Air Jet Sieving Machine AS 2 jet 2 µm 125 mm µm 4 mm Dry Wet
Sample Volume Another crucial factor is the sample volume. To obtain significant and reliable results, it is essential to measure a representative sample amount. It usually takes at least a few thousand up to a few million particles, depending on the width of the particle size distribution, to obtain statistically accurate results. Depending on the mean particle size, this can be from a few micrograms of nano particles to a few kilograms of gravel, coarsely broken ores or coal. The sampling and sample splitting processes are as important as the analysis itself, and should therefore be carried out with the same care. When using a microscope for automatic and evaluation, only a small number of particles is analyzed; whereas dynamic image analysis or laser diffraction allow to measure, to a few million particles. Laser diffraction instruments record the light scattering pattern that is generated by the entire particle collective, calculating the size distribution on that basis (indirect ). Image processing techniques record the measured values of every single particle (direct size and shape analysis), calculating the size distribution on the basis of the individual values. The difference between direct and indirect methods and the number of detected particles determine the detection limits of the instruments: small amounts of oversized or undersized particles (<.1 %) can be reliably detected with sieve analysis and dynamic image analysis but neither with laser diffraction nor with static microscopy. A COMPARISON OF measurement techniques Retsch Technology offers individual application consultation which comprises an unbiased consideration of the pros and cons of the different techniques. For more details on the techniques as well as information on the different particle analyzers, please refer to the following pages. CAMSIZER page 4-5 camsizer XT page 6-9 HORIBA LA-95 page -13 HORIBA LA-3 page 13 HORIBA SZ- page 14-15 Sieve Shakers www.retsch.com Performance Feature Dynamic Image Analysis Static Light Scattering Dynamic Light Scattering Sieve Analysis Analysis of nano particles x x Reproducibility and repeatability High resolution for narrow distributions - - Particle shape analysis x x x Determination of molecular weight x x x Determination of zeta potential x x x Reliable detection of oversized grains - - Wet Measurement Dry Measurement x High speed, short times - Investment costs high high high low Operating costs (work load) low low low high highly suitable suitable suitable to a limited extent not possible www.retsch-technology.com 3
Dynamic Image Analysis Dry of powders and granules Dynamic Image Analysis CAMSIZER : more than 5 installations 3 µm measuring range 3 mm BENEFITS Dynamic Image Analysis with patented Two-Camera-System (acc. to ISO 13322-2) Wide measuring range from 3 μm to 3 mm Detailed particle size analysis results are stored in at least 1, size classes Particle shape analysis (e. g. for the detection of agglomerates, broken particles or contaminations) Very short time of 2 to 3 minutes Realtime results Highest precision and reproducibility Results are % compatible to sieve analysis and laser diffraction Simple and comfortable operation Non-contact, non-destructive Calibration in seconds Options: AutoSampler, Online version Quality control of bulk materials with the CAMSIZER The CAMSIZER has been used for the quality control of freely pourable bulk materials for more than 12 years. Over 5 installations around the globe document the success and the universal suitability of this measuring method. The main fields of application include: food (e. g. granulated chocolate, nuts, rice, or sugar), pharmaceutical products (e. g. pain tablets or cough medicine), fertilizer products (e. g. uncoated or coated fertilizer granulates, such as urea beads, nitrogen, potassium or phosphate based products), catalysts products (e. g. round beads or extrudates), and, finally, mass bulk goods (e. g. ceramic proppants, sand, salt, coal, ores, glass beads, and plastics). Compared to other methods, the camsizer offers crucial advantages in the measuring range from 3 µm to 3 mm. On the one hand, the instrument is easy to operate, robust and almost maintenance-free. On the other hand, the user obtains results with high reproducibility and resolution in a very short time of typically 2 to 3 minutes. The high resolution and short measuring time are achieved by the patented two-camera principle: one camera analyzes the finer particles with high resolution, whereas the other camera with its large field of view records simultaneously many and also larger particles at high detection efficiency. www.retsch.com/camsizer 4 www.retsch-technology.com
Dynamic Image AnalySIS APPLICATION EXampleS Abrasives, carbon products, catalysts, coffee, fertilizer, food, glass/ceramics, metal powders, pelletized carbon black, pharmaceutical products, plastics, polystyrene, refractories, salt, sand, sugar, etc. TECHNICAL Data Determination of the coating thickness of pharmaceutical pellets and granules Many pharmaceutical agents are produced in the form of pellets or granules with a controlled release formulation. The size and shape of the mostly spherical particles are important parameters in the production process and are therefore carefully monitored to detect undersized and oversized grains, broken particles or agglomerates. The parameters for the time release profile of the active pharmaceutical ingredient (API) inside the human body are controlled via the size of the granules and the layer coating thickness. The release rate of the api is affected by the particle surface. The larger the particle surface the faster the APIs are released. The release time increases with the thickness of the coating. The granules are often coated with several layers, not only with the actual apis but also with coatings resistant to gastric acid or with membranes which allow for a controlled release of the APIs. The camsizer analyzes the coating thickness for a representative number of particles with an accuracy of 2 microns quickly and reproducibly. This makes the camsizer superior to methods such as sieving or microscopy which either analyze many particles with a poor resolution or only a few particles very accurately with a great expenditure of time. Moreover, the camsizer provides additional information about the particle shape, e.g. the sphericity of the particles. Measuring principle Dynamic Image Analysis (ISO 13322-2) Type of analysis dry analysis of powders and granules Measuring range 3 µm to 3 mm Measured properties particle size, shape, density, transparency, and number Measuring time approx. 2 to 3 mins (depends on required statistics) Sample volume mg - 25 kg Measuring speed 6 images/s each with more than 78, pixels Width of analysis area 1 mm (FoV) Resolution typ. 15 µm/pixel The camsizer is CE-tested and fulfills all relevant directives and standards. Option 21 CFR Part 11 compliant software IQ/OQ documentation acc. to GLP/GMP 13% coating 15% coating The image shows pellets with different coating thickness. In cases where the difference in the coating thickness is extremely small, only the precise of many particles allows a statistically accurate result. Q 3 [%] 9 8 7 6 5 4 3 2 1.6 1.8 2. 2.2 2.4 2.6 particle size percent by volume q 3 [%/µm] 5 45 4 35 3 25 2 15 5 x [mm] The graphic shows the original material (red) and 2 batches of coated granules with a medium difference in the coating thickness of 4.5 microns (green and blue). The width of the distribution not only gives information about the mean diameter but also about the homogeneity of the coating. relative frequency The CAMSIZER is also available with an Autosampler for automatic sample feeding (see picture) or as online version for process-integrated s. www.retsch-technology.com 5
Dynamic Image Analysis NEW Measurement of fine powders, granules and suspensions Dynamic Image Analysis CAMSIZER XT: proven method new measuring range 1 µm measuring range 3 mm BENEFITS Dynamic Image Analysis with patented Two-Camera-System (acc. to ISO 13322-2) Wide dynamic measuring range from 1 μm to 3 mm Newly developed optical system with ultra-strong LEDs for highest resolution and excellent depth of sharpness Reliable detection of smallest amounts of undersize and oversize Particle shape analysis (e.g. for the detection of broken particles, twinnings or aggregations) Very short time of 1 to 3 minutes Excellent reproducibility Modular system X-Change for dry and wet dispersion Measurement results are % compatible to sieve analysis and laser diffraction analysis www.retsch.com/camsizerxt The quality control of fine powders can be improved substantially with the CAMSIZER XT: More precise and faster analysis of particle size and particle shape helps to improve product quality, reduce rejects and save costs. The camsizer XT is an advancement of the well-proven optical system camsizer for finer samples. In addition to the newly developed optics with a higher resolution it also features enhanced options for sample feeding. Fine particles tend to agglomerate which makes it difficult to detect the geometric dimensions of each individual particle. It is therefore beneficial to have various possibilities of feeding the sample to the area, finding for each material the best way to separate the agglomerates without destroying the primary particles. The camsizer XT provides flexible solutions: The free fall cartridge, which provides the mildest dispersion method for the material; the air pressure dispersion cartridge with adjustable pressure and variable nozzle geometry; and, additionally, a wet module in which particles are dispersed in liquids, optionally by an ultrasonic probe. Thanks to the modular design of the camsizer XT (X-Change-Technology), changing between dispersion methods is easy and comfortable. Watch the video on www.retschtechnology.com/camsizerxt to see how easy the X-Change system works. 6 www.retsch-technology.com
Dynamic Image AnalySIS Modular design for optimum conditions The CAMSIZER XT s X-Change system offers three alternative dispersion methods, allowing the selection of the optimum method for each sample type. Dry Wet Air pressure dispersion Gravity dispersion Basic instrument Module X-Flow Plug-in cartridge X-Jet Module X-Dry Plug-in cartridge X-Fall Air Pressure Dispersion with X-Jet Measuring range from 1 µm to 1.5 mm The dispersion, i. e. the separation of the particles when passing through the area, is a crucial precondition for a correct of the particles. Thanks to the flexible pressure adjustment of the X-Jet plug-in cartridge materials can be measured under optimum conditions. With the dynamic image analysis method it is possible to detect broken particles and agglomerates by analyzing the particle shape, and then adjust the pressure as required. The sample is collected in a vacuum cleaner after the. If the sample material needs to be recovered for further analysis, an optional cyclone is available. Although the air pressure dispersion accelerates the particles to up to 5 m/sec, the patented two-camera system ensures that wide particle size distributions as well as narrow, mono-modal samples below microns are analyzed accurately. Gravity Dispersion with X-Fall Measuring range from µm to 3 mm Pourable, not agglomerated samples can be analyzed by using the X-Fall plug-in cartridge. In this mode the particles fall from the chute through the field of view of the two cameras accelerated by gravity. Thanks to the low speed of the particles, the large field of view and the high frame rate, the detection efficiency is very high, even for large particles of e. g. 3 mm. Only a few coarser particles in the sample are sufficient for the reliable, reproducible detection. After the the sample material falls into a collector box and is available for further analyses without loss or contamination. Wet Dispersion with X-Flow Measuring range from 1 µm to 6 µm The wet module X-Flow analyzes samples in a range from 1 to 6 microns in suspensions or emulsions. An advantage of this module is the small required sample volume. A low particle concentration in the dispersion medium of, for example, 2 mg/l is already sufficient to detect enough particles for a reproducible result in only 1 minute. The range of the X-Flow module starts at 1 micron. The CAMSIZER XT also analyzes particles larger than 1 mm without difficulty, provided they are kept suspended in the dispersion medium. Depending on the maximum particle size of the sample, cells of up to 4 mm can be used. Agglomerates can be further separated by an integrated ultrasonic probe. www.retsch-technology.com 7
Dynamic Image Analysis CAMSIZER XT: more precise size mea Multimodal distributions Optical microscope q 3 [%/µm] 45 4 relative frequency 35 3 25 2 15 5 1 2 3 4 5 6 7 8 particle size x [µm] APPLICATION EXampleS Abrasives (medium-sized and small grit), detergent powder and raw materials, fine sands and cement, fine wood fibers, fine plastic fibers, metal and ore powders, pharmaceutical powders, granules and fine pellets, plastic powders (also with electrostatic charge), pulverized and granulated food, etc. The direct method which analyzes every single particle on each picture in real time allows for the reliable detection even of very small amounts of oversized grains. The CAMSIZER XT detects oversized particles even if the fraction is considerably less than.1%, whereas the laser diffraction method needs at least 1% to 2%. Thanks to the high resolution of the optics, Dynamic Image Analysis with the CAMSIZER XT allows for the separate resolution of narrow multimodal distributions. In contrast to laser diffraction analyzers, the CAMSIZER XT is able to separate, for example, the size fractions in a particle mixture of 2.5 and 5 microns and to determine the respective volumes. Dynamic Image Processing analyzes each particle with a resolution of approx. 1 micron, thus allowing for a much better resolution of narrow multimodal distributions than is achievable with laser diffraction. The application example shows a mixture of polymer beads of 2.5 and 5 microns. The result of a laser diffraction would show a wide distribution with only one peak. The patented principle The patented principle is fairly simple: Dispersed particles pass in front of two bright, pulsed LED light sources. The shadows of the particles are captured with two digital cameras. One camera is optimized to analyze the small particles with high resolution; the other camera detects the larger particles with good statistics, due to a large field of view. Each camera is illuminated by one LED with optimized brightness, pulse length and field of illumination. To cover a small measuring window of limited space with two light sources, optics and cameras, the X-Technology was developed: the optical paths of both cameras intersect in the area. Particle size and particle shape are analyzed with a userfriendly software which calculates the respective distribution curves in real-time. light source 1 light source 2 sample flow basic camera zoom camera 8 www.retsch-technology.com
Dynamic Image AnalySIS surement with particle shape analysis Particle size: exact length and width or just an effective scattering cross section? CAMSIZER XT basic camera Particle size analysis with the camsizer XT comprises recording the various dimensions of a particle. The example of cellulose fibers shows that the distributions of the diameter, the mean diameter and the length of the fibers are analyzed separately. The user obtains more detailed infor- Q 3 [%] 9 8 7 6 5 4 width diameter of the coextensive circle length laser diffraction 3 result 2 5 15 2 25 3 35 4 x [µm] particle size percent by volume mation, thus getting a broader knowledge of the size of the cellulose fibers. This is not possible with other methods such as, for example, laser diffraction, which only provide the effective scattering cross section. TECHNICAL Data Measuring Dynamic Image principle Analysis (ISO 13322-2) Type of analysis analysis of fine powders, granules and suspensions Measuring range X-Dry with X-Fall : µm to 3 mm X-Dry with X-Jet : 1 µm to 1.5 mm X-Flow : 1 µm to 6 µm Measured properties particle size and particle shape Measuring time approx. 1 to 3 mins (depends on required statistics) Sample volume <2 mg g (depends on sample and dispersion method) Measuring speed >275 images/sec. each with approx. 1.3 MPixel Width of analysis area 2 mm (FoV) Resolution 1 µm/pixel The camsizer XT is CE-tested and fulfills all relevant directives and standards. Particle shape analysis Optional 21 CFR Part 11 - compliant software IQ/OQ documentation acc. to GLP/GMP CAMSIZER XT basic camera Q 3 [%] 9 Measurement 1 8 Measurement 2 7 Measurement 3 percent by volume 6 5 Measurement 4 Measurement 5 broken 4 3 2.4.5.6.7.8.9 breadth/length ratio spherical b/l Non-round, broken particles are detected via the breadth/length ratio (b/l) or the symmetry. The series of s shows how an increasing amount of broken particles leads to an increase of the broken fraction in the b/l diagram. The original material is almost spherical, with a b/l ratio of.95 (red curve). The increasing proportion of broken particles can be read directly from the amount at the threshold value of.95. www.retsch-technology.com 9
STATIC LASER LIGHT SCATTERING Wet and dry Static Laser Light Scattering Laser Granulometer HORIBA LA-95: extremely wide measuring range nm measuring range 3 mm BENEFITS Single measuring range nm 3 mm (no change of measuring range required) Complete analysis process only takes 1 minute Wet and dry Modular design Intuitive software, including optimization of and evaluation parameters Effective dispersion inside the instrument 21 CFR Part 11 compliant software (option) www.retsch.com/la95 Static laser light scattering (also known as laser diffraction) excels by a combination of extremely wide measuring range, simple operation and high s accuracy. An analysis with the laser granulometer HORIBA LA-95, including sample preparation, and cleaning, only takes 1 minute. Every step of the process is carried out fully automatically thanks to easily programmable Standard Operating Procedures (SOPs). With the LA-95 particle size distributions from nm to 3 mm can be measured without the need to switch the measuring range or change lenses. The software allows comprehensive analyses and evaluations as required in science, research and development. All process steps can be automated in such a way that the LA-95 is also suitable for quality control routine s. Due to these benefits, the LA-95 is used in many different industries such as, for example, automotive, pigment and food, but application areas also include aircraft construction, pharmaceutics and desulfurization of flue gas in coal-fired power plants, to name but a few. www.retsch-technology.com
STATIC LASER LIGHT SCATTERING The unique optical system of the LA-95 The interaction of laser light and particles generates characteristic scattered light distributions. These are influenced by the size of the particles, their optical properties and the wavelength of the light. Larger particles scatter the light in small angles. The HORIBA LA-95 is equipped with a 64-element detector for highest angular accuracy as well as with 23 detectors for light which is scattered sideways and backwards. This technology in combination with two light sources with different wavelengths allows for the unique measuring range from nm to 3 mm. Blue LED Laser diode Detectors for back scattering Fourier lens Fourier lens Detectors for back scattering 4-channel detectors for side scattering Measuring cell Segmented multielement-detector for forward scattering Mirror with automatic adjustment 4-channel detectors for side scattering TECHNICAL Data Measuring principle Mie Scattering Theory according to ISO 1332 Type of analysis dry and wet Measuring range nm to 3 mm Measuring time ~1 minute (from filling in the dispersion liquid to the following with result display and subsequent flushing of the system) Measuring methods manual flow cell manual fraction cell (fraction cell and cell holder required) dry (PowderJet dry feeder required) Sample volume approx. mg 5 g Dispersion flow cell: media approx. 18 29 ml Miniflow: approx. 3 55 ml fraction cell: approx. 15 ml Dispersion water, alcohol and liquid other organic solvents Effective dispersion and of nano materials Thanks to the integrated ultrasonic probe and the powerful circulation system, sample preparation can be carried out with the instrument for most materials. The wide measuring range allows for the reliable characterization of nano materials. The application example shows the particle size distribution of a zinc oxide suspension. If the sample is analyzed without sample preparation, the result is a bimodal distribution with 2 peaks. The coarser peak represents agglomerates, the finer one the primary particles. The use of ultrasound effectively dissolves the agglomerates within 2 minutes, ensuring that only the primary particles are measured with a size of 7 nm. The accuracy in the nanometer range can also be demonstrated with certified standard materials (see below). APPLICATION EXampleS Ceramics, cosmetics, emulsions, food, metal powders, pharmaceutical agents, pigments Q 3 [%] q 3 * percent by volume 9 8 7 6 5 4 3 2 28 25 2 15 5 3 1, x [nm] particle size relative frequency q 3 * 7 6 relative frequency 5 4 3 2 1,, particle size x [nm] Example: zinc oxide suspension Blue: no ultrasound, with agglomerates Green: 1 min. ultrasound Red: 2 min. ultrasound, no agglomerates Example: Duke Scientific Standards Blue: 3 nm Red: 6 nm Green: nm www.retsch-technology.com 11
STATIC LASER LIGHT SCATTERING HORIBA LA-95: precise and flexible Application example: Desulfurization of flue gas in coal-fired power plants Legal requirements and regulations are often the reason for routine particle size analyses in the context of process and product monitoring. A typical example is the removal of polluting sulfur compounds (SO 2 and SO 3 ) from the flue gas of power plants. During the desulfurization of flue gas in coal-fired power plants it is important to continuously monitor the particle size distribution of the resulting calcium sulfate to ensure a smooth and effective process. This example shows the suitability of the LA-95 analyzer for optimum process monitoring. It not only helps to Q 3 [%] q 3 * 12 percent by volum 9 8 7 6 5 4 3 2.1 1 1, particle size comply with the regulations for the prevention of air pollution but also guarantees trouble-free and cost-efficient operation. 8 6 4 2 relative frequency x [µm] NEW Software and Method Expert The software of the LA-95 helps the user with the method development and the selection of suitable evaluation parameters for unfamiliar sample materials. The module Method Expert guides the users in several, easily comprehensible steps through the different settings required for the. Automatic test s are carried out with varying settings for circulation speed, particle concentration and ultrasound. The light scattering patterns of fine particles are not only described by the diffraction but also by the optical characteristics of the particles. These characteristics are refraction index and absorbance. If the relevant literature does not provide any references, it is possible to obtain a suitable value by reverse calculation (R parameter). This involves a comparison of the light scattering pattern which was actually measured with a theoretical pattern which was calculated using defined optical constants. The quality of the evaluation can be judged by the match between these patterns (see graphic). The congruence can be quantified with the R parameter. The Method Expert helps the user to determine the refraction index with the best R parameter. With this procedure it is possible to obtain optimum results even with unknown materials or mixtures. R parameter.179.168 1.6 1.63 1.66 1.69 1.72 refraction index The better the match between the measured light scattering and the result of the reverse calculation, the more accurate is the evaluation. A low R parameter (here at a refraction index of 1.66) indicates the optimum evaluation parameters. intensity 1.1 intensity 1.1.1 1 2 3 4 5 6 7 8 87.1 1 2 3 4 5 6 7 8 87 channels channels Poor evaluation: Actual light scattering pattern (blue) and reverse calculated (theoretical) light scattering pattern show great differences. Good evaluation: Actual and theoretical light scattering pattern are mostly congruent. 12 www.retsch-technology.com
STATIC LASER LIGHT SCATTERING Suitable sample feeding for every application Powder Jet The dry powder feeder Powder Jet allows for particle size distribution analysis of dry powders and granules in a size range from nm to 3 mm. Agglomerates are gently dispersed via a Venturi nozzle, ensuring that the results are comparable to those of wet s. The laminar stream of particles effectively prevents depositions and contaminations. De-agglomeration is achieved by a dispersion pressure varying between and 4 bar without particles being destroyed. Fraction Cell The fraction cells of the LA-95 are suitable for the particle size distribution analysis even of very small amounts of valuable sample materials. They are also ideal to analyze dispersions in expensive or harmful media. The required liquid volume lies between 7 and 2 ml. In the fraction cell, the sample is homogenized with a small magnetic stirrer. Miniflow Module The Miniflow unit also reduces the required sample amount and liquid volume. Compared to 2 35 ml dispersion liquid required for the standard version, Miniflow only needs 35 55 ml. Nonetheless, it provides all the options of the standard circulation system, such as automatic filling, variable stirring speed, ultrasonic probe and automatic flushing. Paste Cell The paste cell is suitable for measuring particle size distributions in highly viscous media which cannot be recirculated in a circulation system such as, for example, resins, oils or phthalates. The sample is placed as a thin film between two glass plates and inserted into the analyzer. Autosampler The Autosampler automatically feeds 24 samples one after the other to the analyzer. It is suitable for dry samples which are measured in wet dispersion. The Slurry Sampler accommodates up to 6 previously dispersed samples (suspensions or emulsions) which are allocated for successive s. HORIBA LA-3 the compact alternative The LA-3 is the compact alternative to the LA-95. With a measuring range from nm to 6 microns for wet s, it is suitable for many different applications. The small footprint allows for variable sites of operation. Effective dispersion in the LA-3 is provided by a powerful circulation system with integrated ultrasonic bath. The LA-3 is optionally available in an organic version which is suitable for s in most dispersion liquids (water, alcohol, organic solvents). Laser Granulometer LA-3 www.retsch.com/la3 www.retsch-technology.com 13
DYNAMIC LASER LIGHT SCATTERING NEW Particle Size, Zeta Potential and Molecular Weight Dynamic Laser Light Scattering PCS Particle Analyzer HORIBA SZ-: the new 3-in-1 system.3 nm measuring range 8 µm BENEFITS Extremely wide range from.3 nm 8 μm Samples ranging from low ppmorder concentrations to 4 Vol% Flexible optics with s at 9 or 173 scattering angle Temperature-controlled chamber Easy operation, no cleaning or maintenance required Measurement of zeta potential Determination of molecular weight and 2. virial coefficient Rapid analysis (2 min) Simple, intuitive software, 21CFR Part11 conformity (option) Highest resolution and precision Compact design allows for installation in any laboratory environment www.retsch.com/sz The new compact nano particle analyzer HORIBA SZ- was designed for particle size down to the nano range as well as for the determination of zeta potential and molecular weight. The SZ- measures particles down to the nanometer range, both with extremely high and extremely low sample concentrations. This newly developed analyzer is used in the fields of bio- and nanotechnology (e.g. nanoceramics, nanometals) and for protein analyses. The HORIBA SZ- provides excellent results and features a wide measuring range from.3 nm to 8 microns. The instrument not only meets the requirements of modern laboratories but is also perfect for quality control at production facilities. In the nanomaterial and biomaterial fields, raw-material particle size and zeta potential have a significant influence on product performance and properties. The key to ensure high product performance is to control the quality of nano particle raw materials. The instruments conventionally used in laboratories to analyze ultrafine particles require operator expertise and involve complex operations. With the SZ- an advanced analyzer has been introduced which is easy to employ for routine s, and yet can analyze low-concentration ultrafine particles with highest accuracy. With these functions, the SZ- is a modern, high-performance analyzer suitable for R&D applications. Thanks to the comfortable operation, it is not only ideal for use in laboratories but also for quality control in the production process. 14 www.retsch-technology.com
DYNAMIC LASER LIGHT SCATTERING Measuring Principle Dynamic Laser Light Scattering The SZ- detects light scattered by particles at 9 or 173 angle, depending on the concentration. Ultrafine particles suspended in a liquid medium are constantly in motion (Brownian motion). Hence, the intensity of the scattered light is not constant. If the particles are small, they move with higher speed so that the measured signal varies rapidly. Larger particles move more slowly so that Laser light source Particle diameter (high-concentration samples) Rear detector (PMT) Reference beam Size analysis of liposomes Liposomes are natural or artificially produced two-layer vesicles with walls of phospholipids. They are mainly used in pharmaceutics and cancer therapy as agent carriers. The typical particle size is smaller than 1 micron and has a Particle the measured signal remains stable for a longer period of time. The time dependent fluctuations of the light scattering signal can be evaluated via a so-called autocorrelation function from which the particle size is calculated. The SZ- is ideally suited for the characterization of, for example, proteins, liposomes, colloidal metals and metal oxides. Cell Particle diameter (low-concentration samples) Side detector (PMT) Modulator Molecular weight Transmitted light monitor (PD) Zeta potential Forward detector (PMT) decisive influence on the agent s transport and release. Dynamic light scattering is the ideal method to measure the size of liposomes. TECHNICAL Data Particle size: Measuring principle Photon Correlation Spectroscopy (PCS) acc. to ISO 13321 Measuring range.3 nm 8 µm Molecular weight: Measuring principle Debye plot method (static light scattering) Measuring range 1 x 3-2 x 7 g/mol Particle size / molecular weight: Measuring time approx. 2 min under standard conditions Measuring cells various measuring cells Sample volume 12 µl 1.2 ml minimum, depending on type of measuring cell Dispersion liquid water, alcohol, organic solvents Zeta potential: Measring Laser Doppler electroprinciple phoresis Measuring range -2 mv - 2 mv Measuring time approx. 2 min under standard conditions Measuring cells disposable cells with electrodes Sample volume µl Dispersion liquid water, alcohol, organic solvents APPLICATION EXampleS autocorrelation function 1.2 1..8.6.4.2. 1 1,, delay time x [µs] Q 3 [%] q 3 * percent by volume 9 8 7 6 5 4 3 2 1, particle size 7 6 5 4 3 2 relative frequency 1 x [nm] Colloidal metals and metal oxides, liposomes, proteins The autocorrelation function (left) provides the basis for the determination of the intensity-based particle size and the polydispersity index. With the Mie-Theory-based evaluation, the data are converted into a volume-related distribution (right) Zeta potential of a nano SiO 2 dispersion For the zeta potential the sample is filled into special cells with electrodes. An electric field is set up inside the cells in which the particles move according to their surface charge. A strong surface charge leads to a movement of the particles which can be quantified and measured via fluctuations of the scattered light. The of the zeta potential allows for an estimation of the stability of the dispersion, as strong surface charges lead to the repulsion of the particles thus preventing agglomerations. The example shows the zeta potential of a nano SiO 2 dispersion with different ph values. With a ph value of 4, the zeta potential is (isoelectric point). With a zeta potential >3 mv / <-3 mv, a dispersion is generally called stable. [mv] 6 5 4 3 2 2 3 4 5 6 7 8 9 - -2-3 -4-5 -6 zeta potential ph value www.retsch-technology.com 15
RETSCH TECHNOLOGY Retsch Technology The Specialists in Particle Measurement Technology Visit our website for brochures, videos and application reports www.retsch-technology.com Retsch Technology s core competence is the combination of innovative particle characterization technologies with a maximum of operating convenience. The line of products for optical particle analysis covers a size range from.3 nm to 3 mm. Significant analyses of particle size and particle shape in suspensions, emulsions, colloidal systems, powders, granules and bulk materials can be carried out on the basis of different measuring techniques Together with our sister company Retsch GmbH, we offer a complete selection of products for sample preparation (grinding, sample division, analytical sieving). n Personal Consultation Retsch Technology works with a global network of distributors who provide expertise and application support. n Product Demonstrations We demonstrate our equipment in our own application laboratory or at your premises. Please contact our sales team for further information. 99.997.Partikel/E Editor: Retsch Technology GmbH, Germany Subject to technical modifications and errors Retsch Technology GmbH Rheinische Straße 43 42781 Haan, Germany Phone 49 ( )2129 / 5561 - Fax 49 ( )2129 / 5561-87 E-Mail technology@retsch.com Internet www.retsch-technology.com