Analysis And Design Of QCM Viscosity Measurement In Liquid Phase

Viscosity is an important physical quantity that characterizes the properties of fluids,and is an index that measures the resistance to flow within a fluid.Viscosity measurement is widely used in chemical,biomedical,materials,petroleum,food,cosmetics and other fields.In industrial production,viscosity is the same as pressure and temperature,which are important parameters in engineering production.By controlling and monitoring these parameters,you can achieve the goals of improving product quality,improving operation technology,improving production conditions,and ensuring production safety.Commonly used viscosity measurement methods are capillary method,falling ball method,rotation method and vibration method.However,the viscometers produced by these methods have long measurement time,high cost,and strict measurement conditions.This article attempts to use a new type of viscosity measurement device,Quartz Crystal Microbalance(QCM),for viscosity measurement.The study found that there is a good correlation between the frequency response of the quartz crystal microbalance and the viscosity characteristics,as a sensor that can convert small changes in the system shape(density,viscosity,mass,concentration,conductivity,etc.)into frequency changes in the system Compared with traditional viscosity measurement methods,quartz crystal microbalances have the advantages of high sensitivity,low cost,sensitive response,real-time output,simple system structure,stable physical and chemical properties,etc.,and are widely used as chemical and biosensors.This article first introduces the principle of quartz crystal microbalance,deduces its piezoelectric constitutive equation,and analyzes the vibration of quartz crystal microbalance in different regions.Then it introduces the classic Saurebrey detection model of QCM in the gas phase detection environment.Compared with the gas-phase environment,the fluid characteristics under liquid load make the QCM response characteristics in the liquid-phase environment more complicated.After deducing and indepth analysis of the classic Kanazawa liquid phase detection model and Martin modified BVD model,the traditional liquid phase Insufficient detection methods,using small droplets to inject QCM to increase the resonance quality factor(Q value)to improve the output frequency signal quality.The subject uses a calibrated rotary viscometer to measure the sample viscosity,obtain the true viscosity of three samples of peanut oil,lubricating oil,and glucose oral solution,and then use the QCM viscosity measurement method to measure the frequency shift,droplet radius,density and other parameters.Then the viscosity value under QCM viscosity measurement is calculated according to the liquid load response model.After comparing with the real value,it is found that the errors of the above three samples are 3.5%,2.9%,and 1.7%,respectively.It can be seen that the results of the QCM viscosity measurement are basically consistent with the results of the rotary viscometer.With feasibility,it provides some new ideas for solving some common problems of traditional viscosity measuring instruments.