The plasma-coupling agent synergistically modified the acoustic matching layer for the preparation of a gas ultrasonic flowmeter

Abstract

The plasma-silane coupling agent synergistically modified the hollow glass microsphere (HGM) process, blended with epoxy resin (EP), to prepare an acoustic matching layer suitable for the gas ultrasonic transducers. In comparison to the traditional NaOH solution stirring co-hydroxylation process, the plasma treatment method can rapidly activate the surface activity of HGM, leading to the generation of a large number of hydroxyl groups on the HGM surface. This process eliminates the need for mechanical stirring and cleaning steps, thus reducing the damage degree of HGM and the loss degree of surface hydroxyl groups. The results indicate that the amination modification effect of HGM treated with plasma is more pronounced, and the HGM/EP composite material exhibits better compatibility and density. The assembled ultrasonic transducer exhibits a sensitivity of up to 1.58 V, showing an improvement of nearly 61.2 % compared to the reference ultrasonic transducer with a sensitivity of 0.98 V. Furthermore, the calibrated testing of the gas ultrasonic flowmeter using the improved ultrasonic transducer demonstrates a percentage error absolute value below 0.7 % and a measurement result standard deviation below 0.15 %, demonstrating better measurement accuracy and consistency. This study aims to provide a new feasible process for improving the performance of gas ultrasonic transducers and ultrasonic flowmeters.