Effect of Negative High-Voltage Corona Field on Hydrophilicity and Vigor of Astragalus mongolicus Seeds

Abstract

This work aims to study the effect of dc negative high-voltage corona electric field on the vigor and hydrophilicity of Astragalus membranceus (Fisch.) Bge. var. mongolicus (Bge.) Hsiao seeds. The ion wind generated by the multipin pole generator at −3, −4, −5, −6, and −7 kV and the electrostatic field acted together. <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${A}$ </tex-math></inline-formula> . mongholicus seeds were exposed to the electric field for 30, 60, and 90 min. Results show that the ion wind velocity increases significantly with the increase of applied voltage. Malonaldehyde (MDA), electrical conductivity (EC), and apparent contact angle (APCA) in all treatment groups decreased to different degrees compared with the control samples. MDA, EC, and APCA decreased by 56.28%, 20.89%, and 31%, respectively. The hydrophilicity of seeds treated by negative corona field was improved, and the water absorption of seeds was increased by 1.34 times. Fourier infrared spectroscopy, scanning electron microscopy, and energy dispersive X-ray (EDX) spectroscopy were used to examine the spectra, apparent morphology, and surface elements of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${A}$ </tex-math></inline-formula> . mongholicus seed coats from different treatment groups. Results showed that the ionic wind generated by the negative high-voltage corona electric field had a significant etching effect on the seed coat and enhanced the water absorption and fiber strength of hydrophilic functional groups of the seed coat.