Malvern Instruments Introduces Dynamic Light Scattering (DLS) Microrheological Measurement Technology

Malvern Instruments recently introduced a new top class product in the Zetasizer Nano ZSP system family and has applied dynamic light scattering (DLS) micro-rheology technology to its material characterization technology portfolio. To introduce this powerful technology, the company published the article “Introduction of DLS Dynamic Light Scattering Microrheology Technology”. This paper fully explained the background knowledge of microrheology technology and how to use this technology to study very few sample volumes (micro The rheological properties of the upgraded weak structure system also include the microrheological measurements of (Bovine Serum Albumin (BSA)) and Polyethylene Oxide (PEO) solutions, which illustrate the significance and practical value of this method.

Malvern’s new Zetasizer Nano ZSP allows more laboratories to use DLS microfluidics.

Microrheology is a relatively new method of analysis. It has been a hot topic of academic research for the past 15 years. Researchers at the forefront of rheological characterization have become increasingly interested in this technology. This method mainly uses the tracking of the movement of colloidal tracer particles in a dispersed and complex fluid to obtain the viscoelasticity of the system. DLS microrheology is characterized by its ability to characterize very viscous samples (such as polymer solutions or protein solutions) with a viscoelasticity that far exceeds the reach of modern and most sophisticated mechanical rheometers. One of the most important advantages of the micro-rheological technique is that it can measure the viscoelasticity in the high frequency range or short time scale of weak structural fluids. In addition, the amount of sample required is very small, so this technique is very suitable for analyzing the viscoelasticity of expensive protein solutions.

Before discussing the DLS microrheological technology and its theory, the "Introduction of DLS Dynamic Light Scattering Microrheological Technology" first outlined the microfluidic technology. The development of experimental methods and the preparation of samples are all particularly important factors for reliable measurements. Therefore, this paper also discusses some practical features of microrheology in detail, providing guidance for method development and sample preparation. The paper also provides some experimental data to illustrate the applicability of microfluidic technology.

These data demonstrate the significant expansion of the viscoelastic frequency spectrum of polymer solutions in combination with conventional rotary rheometer technology and dynamic light scattering (DLS) microrheology, and illustrate the value of characterizing protein solutions. The results of the BSA solution indicate that changes in the viscoelasticity of the solution can be used to investigate when aggregation begins during protein denaturation, and to assess when the solution will show non-Newtonian flow with changes in protein concentration.