Reómetro interfacial de cizalla por aguja magnética y sistema y método de accionamiento del mismo

摘要

The invention relates to a magnetic needle interfacial shear rheometer, and to a system and method for actuating same. The system for actuating the needle of the magnetic needle interfacial shear rheometer comprises: two permanent magnets (13) with axes of magnetisation perpendicular to the plane of the interface on which the magnetic needle (3) of the rheometer (30) is situated. The magnets (13) are located at the same distance (h) from the plane and with the polarities of each inverted with respect to the other. The actuating system also comprises actuating means (15) to displace the magnets (13) in an oscillatory manner at a frequency ω in a longitudinal direction parallel to the plane of the interface, keeping the distance (d) between the magnets constant. Among other advantages, the present invention allows very precise initial positioning of the needle (3), as well as perfect characterisation of the rheological properties of thin films at low frequencies.