A variety of microstructures can occur during the solidification of melts depending on the conditions during cooling. The optical and physical properties of materials can be influenced by the generation of these microstructures and may decrease the quality of the resulting product or deteriorate the material. Typical examples for such unwanted properties would be fat blooming in chocolate products or „sweating“ lipsticks. The application of Diffusing Wave Spectroscopy allows for the prediction and consequently the prevention of such effects.
Diffusion wave spectroscopy (DWS) allows observing microstructural changes of thinly applied dispersions, such as glues or paint. Drying mechanisms and characteristical drying times on different substrates and carrier materials can be determined.
The electric conductivity of a liquid remains an important parameter for the determination of ionic composition and purity in oils and other unpolar solvents. In dispersions, this parameter is an indicator for colloidal properties of particles dispersed within a given media. We are offering probes for both aqueous as well as organic based media with very low conductivity.
The relative permittivity (also known as dielectric constant) is an indicator for the ability of a material to permit electric fields through it and also attributes towards weakening of such fields, when passing through the material. It is also a measure for the ability of a liquid to dissolve ionic compounds. Furthermore, the dielectric constant is required for the determination of colloidal properties such as zeta potential. For measuring permittivities we recommend using the probe 871.
An essential parameter for the characterization of droplets in emulsions or particles in suspensions is the particle size distribution. We offer a variety of different instruments and methods to tackle the different challenges in application, no matter if in quality control or in research and development.
Particle size 0.02 – 2600 µm
Dynamic light scattering (DLS) is applied in measuring particle sizes on a nano- and submicrometer scale.
Particle size 1 – 9500 nm
Characterization of the particle size distribution in concentrated suspensions or emulsions commonly found in ceramics and construction industry as well as food and cosmetic applications, requires a method to analyze samples in their original concentrations and on a macroscopic scale. This can be achieved by employing acoustic spectrometry, which determines particle sizes in proportion to their respective masses by measuring the damping of ultrasonic waves in concentrated dispersion with particle sizes on the nanometer to micrometer scale.
Particle size 5 nm – 1000 µm; measuring in original concentration up to 50 Vol.-%
Particle size 5 nm – 1000 µm; measuring in original concentration up to 50 Vol.-%; measuring zeta potential
In a number of applications it is not only required to determine particle size distributions for further processing of a powder, but to analyze particle shape as well. Color, procession and dispersion characteristics as well as mechanic properties are influenced by particle shape significantly. Furthermore, anisotropic shapes such as rods may exhibit problems when using standard particle size analysis without imaging processes.
Particle size and particle shape 2 – 10000 µm
Particle size and particle shape 0.01 – 3500 µm
The rheological properties of emulsions and suspensions are crucial for both manufacturing and processing them. Depending on the application, we offer different methods and instruments in order to address challenges as best as possible.
Viscosity is the essential parameter when characterizing a flowing liquid. The Fluidicam RHEO measures flow curves of products with a broad variety of viscosities (liquids, gels, half-solid emulsions, etc.) with regards to temperature and shear rate.
The stability of emulsions or suspensions with regards towards particle migration of agglomeration is a key paramter for storing or processing of such materials. For this we offer an application with multi light scattering (MLS), which can determine these characteristics in real-time and on the original system.
The classic instrument for characterization of global dispersion stability.
High throughput for 54 samples simultaneously
Quantification of stability with full temperature control.
The new reference, a 6-Station instrument with active cooling.
A detailed description of the Turbiscan method – multi light scattering (MLS) can be found HERE.
The zeta potential is an indicator for the stability of a dispersion and the mobility of its particles in external fields. A characteristic value is the isoelectrical point (IEP, zeto potential = 0), at which the particles agglomerate and the system precipitates. With electroacoustics we offer a method, by which these parameters can be determined in original concentration.