CLASSIZER™ ONE is the cutting-edge particle analysis platform based on patented SPES methods for the multiparametric analysis, classification, and counting of particle mixtures for research, tailored particles, dispersions formulation, and quality control in life sciences, cosmetics, cosmeceuticals, pigments, inks, cements, abrasives, agrochemicals and environmental sciences.

The instrument based on patented Single-Particle Extinction and Scattering method was installed in 2024.

SPES is an optical interferometric technique based on the far-field self-reference interference between the zero-angle field scattered by a nano- or micro-particle passing through a focused laser beam and the more intense field transmitted through the sample. The effectiveness of this method lies in providing two independent parameters directly related to the real and imaginary part of the forward scattering amplitude from single particles. Even more importantly, the measurement of these two parameters is simultaneous, therefore with exactly the same illumination conditions and particle orientation, thus making it possible to derive quantitative information on its shape and internal structure and to distinguish compact particles from aggregates of smaller particles. Furthermore, the technique does not require any kind of prior calibration and allows rigorous measurement of the optical properties of nano- and micro-particles without any free parameter.

Detection range: 0.1 up to 20 μm

Sample numerical concentration range: 104-107 ptc/mL.

Compatible flow rates: 0.2, 0.5, 1, 2, 4 mL/min

Wetted surfaces: Quartz, BK7, PTFE, PCTFE, FEP, FFKM, PEEK, and Stainless Steel

Applicability of the SPES technique

  1. Calibration-free optical properties characterization of solid particles in liquid suspension (both water and other solvents, such as ethanol)
  2. Calibration-free optical properties characterization of solid particles in liquid suspension (both water and other solvents, such as ethanol)

  3. Measurements of liquid samples particle concentration (particles/mL)

  4. Statistical approaches as Oversize Measure and PCA for Hi-Quality Batch-2-Batch analysis and out-of-specifics identifications in product formulation and production.

  5. Hi-resolution Continuous Flow Analysis (CFA)

  6. Quality Control of particle porosity, wetting, aspect ratio, payload, impurities, scraps

  7. Monitoring sample evolution and stability over time, assessing the potential formation of particle aggregates

  8. Determination of sample Particle Size Distribution (PSD)

Referents:

Marco Potenza, marco.potenza@unimi.it

Llorenç Cremonesi, llorenc.cremonesi@unimi.it