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1. MALVERN ZETASIZER NANO ZSP LASER DIRECTION SOFTWARE
2. MALVERN ZETASIZER NANO ZSP LASER DIRECTION SERIES

Einstein and Smoluchowski proposed that liquid should be considered as a continuous medium where thermal fluctuations create inhomogeneities, which result in density and concentration fluctuations (Fluctuation theory of light scattering, Einstein ( 1910) v.

MALVERN ZETASIZER NANO ZSP LASER DIRECTION SERIES

The usefulness of light scattering as a method to characterize the diffusion behaviour of particles in solution resulted from a series of seminal discoveries. Peter Debye suggested that scattering for particles can be studied independently of assumptions on mass, size, or shape as a function of angle (Debye 1915), which is often referred as Rayleigh–Debye scattering. In contrast to Rayleigh theory, Gustav Mie ( 1908) described a theory (Mie theory) to study the scattering of light from absorbing and non-absorbing particles that are large compared to the wavelength of light by taking into account particle shape and the difference in refractive index between particles and the medium the particles are present in. Soon after, Lord Rayleigh described light scattering from particles that are smaller than the wavelength of light (Rayleigh scattering), which explained both that the sky’s blue colour is a result of scattering of light due to atmospheric particles and that the refractive index of the scattering medium plays a crucial role in light scattering (Strutt 1871a, b). One of the earliest light-scattering experiments was described by John Tyndall, which characterized light scattering from colloidal suspensions (Tyndall effect), where particles are larger than the wavelength of the incident light (Tyndall 1868).

In a typical light-scattering experiment, sample is exposed to a monochromatic wave of light and an appropriate detector detects the signal. Standard Operating Procedures (SOP) simplify routine measurements, a quality factor gives a single place for confirmation of data quality, and an expert advice system is provided to assist with data interpretation.Detection of light scattering from matter is a useful technique with applications in numerous scientific disciplines where, depending on the light source and detector, specific properties of molecules can be studied.

MALVERN ZETASIZER NANO ZSP LASER DIRECTION SOFTWARE

The software is designed to be versatile and rich in features without compromising ease of use. This technique is very demanding on the sensitivity and stability of the whole system, and requires that every element of the design is optimized to ensure accuracy and repeatability. From this the weight average molecular weight and second virial coefficient can be calculated, which provides a measure of protein solubility. The scattering intensity of a number of concentrations of the sample is measured, and used to construct a Debye plot. Static Light Scattering is used to determine the molecular weight of proteins and polymers. This enables the calculation of electrophoretic mobility and from this the zeta potential and zeta potential distribution. This velocity is measured using a patented laser interferometric technique called M3-PALS (Phase analysis Light Scattering). An electric field is applied to a solution of molecules or a dispersion of particles, which then move with a velocity related to their zeta potential. Laser Doppler Micro-electrophoresis is used to measure zeta potential. The Microrheology option uses the DLS measurement of tracer particles to probe the structure of dilute polymer and protein solutions. Measurement of size as a function of concentration enables the calculation of kD, the DLS interaction parameter. DLS measures the diffusion of particles moving under Brownian motion, and converts this to size and a size distribution using the Stokes-Einstein relationship. The Zetasizer Nano ZSP incorporates three techniques in a single compact unit, and has a range of options and accessories to optimize and simplify the measurement of different sample types.ĭynamic Light Scattering is used to measure particle and molecule size.