Patent ID: 8520206

Claim:
Method for determination of the viscoelastic properties of a complex medium starting from the movement of particles in suspension, in which a sample of the medium is placed in a device for measuring the light that is scattered by the particles in suspension, able to project a coherent light on said sample, and to detect and analyze the scattered light for calculating the inter-image distance d 2 , characterized in that it comprises the stages that essentially consist in: a) Characterizing the opacity of the medium by measuring the transport length l* of said medium, b) Introducing a sample of said medium into a flask of given dimensions, c) Placing the flask in a thermostatically-controlled measuring chamber ( 1 ) of said measuring device, d) Projecting a coherent light beam on the sample and detecting the light that is scattered by the particles in the form of a series of sequenced images, e) Analyzing the movement of the particles based on time by calculating the inter-image distance d 2 and the ratio d 2 /d 2max , d 2max denoting a maximum value towards which d 2 converges asymptotically, f) Establishing an analytical expression E putting into direct relationship, for the value of l* that is determined in stage a), the ratio d 2 /d 2max and the mean square displacement MSD for the purpose of calculating the viscous and elastic moduli of the medium.