Interface rheology

　　Interface rheologyUsed for measuring the rheology and viscoelasticity of gas-liquid and liquid-liquid interfaceszhuan liSystem.

　　Rheometers are typically used to measure volume or three-dimensional material properties. However, many materials, such as pharmaceuticals, food, personal care products, and coatings, are typically composed of liquid-liquid or gas-liquid interfaces with different rheological properties. In these cases, studying the characteristics of these two-dimensional interfaces can reveal key information about the contribution of interface dynamics and structure to the properties of bulk materials.ARES-G2ofzhuan liThe Double Wall Ring (DWR) system provides a specialized geometric shape for quantitatively characterizing interfacial viscosity and viscoelasticity over a wide measurement range.

　　Technology:

ARES-G2 interface attachment obtained byThe platinum iridium measuring ring of Zhong Li is composed of a specially designed Delrin groove. These materials were chosen because they have inert chemical compositions and are easy to clean. The groove adopts the double wall geometry of DuTe, providing clear interface shear planes on both sides of the geometric surface to enhance sensitivity to the single-layer viscoelastic response of the liquid air or liquid gas interface.

Double walled rings can perform true quantitative viscoelastic measurements because the interface is "fixed" on the diamond cross-section of the geometric ring. thisThe diameter of the Zhong Li ring is 60 millimeters, designed specifically for ease of use and sensitivity. The use of double walled ring geometry facilitates the measurement of surface viscosity -5Pa. s · m at interface viscosities as low as 10 without the need for complex sub phase corrections. Due to the independent motor and sensor (SMT) design of ARES-G2 du Te, which eliminates artifacts caused by instrument inertia, it can be used in any interface systemzuiPerform oscillation measurements over a wide frequency range.

　　Application:

Interface characteristics of SPAN 65 at the water dodecane interface

SPAN 65 is a complex surfactant with a nonlinear structure that can selectively separate into the interface between water and dodecane, forming a viscoelastic monolayer. These figures show the interface characteristics of the monolayer characterized using ARES-G2 double walled rings. The left image reports the evolution of interface formation within 70 minutes, highlighted by the steady increase in storage modulus during this period. The viscoelastic properties of the interface components have been quantified in the frequency scan data on the right. There is a clear modulus intersection at 0.2 rad/s, and the main elastic properties exist at higher frequencies, demonstrating a strong interface structure. The data quality clearly indicates that the high sensitivity and inertia free measurement of ARES-G2 has the ability to characterize the viscoelasticity of weak structural interfaces at frequencies up to 100 rad/swu yu lun biThe advantage.