TURBISCAN LAB
![TURBISCAN LAB]( "TURBISCAN LAB")
- Measured size range: 10 nm - 1 mm
- Number of Samples: 1
- Подробное описание
Static Multiple Light Scattering (SMLS) is an optical method that allows for the direct characterization of native concentrated liquid dispersions. Microtrac’s TURBISCAN range uses this technology to provide accurate and rapid results. TURBISCAN was the first patented technology to provide tools that allow accelerated aging tests on unstressed products, thus becoming a reference for direct stability characterization technology.
Static Multiple Light Scattering (SMLS) is the most suited method to characterize liquid dispersions, directly, in their native state.
Most emulsions, suspensions, and formulations are too concentrated to be analyzed “as is” and their characterization requires dilution or mechanical stress, which alters their state and structure. Static Multiple Light Scattering (SMLS) offers the ability to investigate the dispersion state and its evolution over time, without any dilution, even on highly concentrated samples. The SMLS principle is based on a patented optical setup and measurement principle.
Static Multiple Light Scattering (SMLS) offers an extraordinary resolution to detect size and concentration variation occurring in complex formulations and in a very wide range of applications and industries. SMLS is in perfect agreement with ISO TR13097's recommendation regarding shelf-life and stability measurement as a direct optical method that does not require sample preparation (such as dilution).
With Static Multiple Light Scattering (SMLS), photons (NIR light source, 880 nm) are sent into the sample. After these photons have been scattered several times by the particles (or droplets) in the dispersion, they emerge from the sample and are detected by two synchronous detectors. For opaque samples the backscattering is measured at 135°, for transparent samples the transmission is measured at 0° from the light source.
Backscattering is directly related to the photon transport mean free path (I*). I* (µm) is the distance above which the photon loses the initial direction of the incident beam. The transmission is directly related to the photon mean free path (I), which is the average distance between scatterers. Thus, the transmission and backscattering light intensities both depend on particle size and concentration.
The TURBISCAN technology, employing Static Multiple Light Scattering (SMLS), measures transmission or backscattering intensities versus the sample’s height and aging time. Particle diameter evolution (aggregation, flocculation, coalescence) and concentration change (sedimentation, creaming) can easily be detected and monitored. The particles’ mean diameter can be calculated from backscattering or transmission intensities thanks to the Mie theory using the following equations.
The TSI is a Turbiscan-specific parameter designed for formulators to compare and characterize the physical stability of various formulations with a single click and a single, comparable and reproducible number. It enables the quantification of any type of destabilization, thanks to a one-click calculation that is a robust and completely user-independent tool.
Considered one of the key benefits of the TURBISCAN, this index provides users with a robust and easy method for stability comparison and a global approach. The TURBISCAN Stability Index was developed for R&D research and quality control and is also widely used in scientific publications by the academic community. All these applications make this index the reference parameter for stability comparisons and durability measurements.
Dispersions are thermodynamically unstable, and over time complex formulations evolve to reduce their energy and reach the lowest state, usually leading to complete phase separation. The mechanisms for achieving this low-energy configuration are numerous and complex, but can be divided into two categories:
Each phenomenon can be detected and quantified based on the backscatter (BS) and / or transmission (T) signal intensities measured with TURBISCAN technology, as both signals depend on particle concentration and particle size, utilizing Static Multiple Light Scattering (SMLS). The transmission and backscattering intensities are recorded over the entire sample height and over time to gain full insight into the stability / instability of the sample.
For objective stability comparisons, the global destabilization must be taken into account. This means that the amplitude of the destabilization in the entire sample must be compared quantitatively. This is the reason for the TSI calculation: to provide a robust, objective and global parameter with a single click that takes into account the whole destabilization and reflects the overall stability of a given sample.
The TSI calculation is based on an integrated algorithm that sums up the evolution of the T or BS light at each measured position (h), based on a scan-to-scan difference over the entire sample height (H):
From any data generated with a TURBISCAN, TURBISIZE software allows the determination of the particle size distribution and migration velocity in a few seconds (ISO 13317- Determination of particle size distribution by gravitational liquid sedimentation methods) and still with no dilution and on native samples.
From the migration profiles, TURBISZE can determine:
