This paper reports the generation of cold plasma jet working under atmospheric pressure condition, for surface treatment of polymeric films. The discharge has been characterized by electrical and optical methods. The electrical property of the discharge has been studied by taking current-voltage wave forms using voltage and current probes. The production of argon plasma jet is done in atmospheric conditions which are relatively much cheaper, convenient, and safer to use. The atmospheric pressure plasma jet sustained in pure argon has been used to improve wettability of polypropylene (PP). Cold atmospheric pressure plasma jet (CAPPJ) has been generated by a high-voltage power supply (5.5 kV, 0-20 kV) at an operating frequency of 20 kHz. The surface properties of the controls and plasma-treated PP samples were characterized by contact angle measurement, surface free energy measurement, scanning electron microscopy, and the Fourier transform-infrared spectroscopy analysis.

The effect on the germination and seedling growth of radish (Raphanus sativus) seeds were examined employing a dielectric barrier discharge (DBD) at atmospheric pressure and room temperature for various treatment time. DBD plasma using argon gas of flow rate 2 l m−1 was employed in this study. Radish seeds were treated with DBD plasma for 1–5 min, respectively. Germination characteristics, seedling growth parameters, the contact angle of the seed coat, water uptake capacity, mass loss, the temperature of the seeds, chlorophyll, and carotenoid contents of the seedlings were measured before and after the DBD plasma treatments. Plasma treatment of radish seeds significantly increased germination-related characters, including germination percentage, fresh and dry weight, vigor index, and total carotenoids contents. However, the cumulative production rate was found to be decreased. Results from the experiment indicate an acceleration in the water uptake of the radish seeds and make the seed surface hydrophilic by plasma treatment. Scanning electron microscopy analysis showed that etching effects on the seed coat occurred after the argon plasma treatments, which affected the wettability of the radish seed. The experimental findings showed that seeds being treated by DBD plasma for 2 and 3 min had a positive effect on the germination and seedling growth of radish.

An atmospheric-pressure plasma jet (APPJ) has a lot of applications in recent years such as in material processing, surface modification, biomedical material processing, and thin film deposition. APPJ has been generated by a high-voltage power supply (0-20 kV) at an operating frequency of 27 kHz. This paper reports the generation and characterization of APPJ in argon environment and its application in the surface modification of polyethylene terephthalate (PET). The plasma jet has been characterized by electrical and optical methods. In order to characterize the plasma jet, electron density and electron temperature have been determined. The surface roughness of the untreated and plasma-treated PET samples was characterized by contact angle measurement, surface energy analysis, Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and atomic force microscopy (AFM).

Seed germination is a complicated physiological process that starts with the seed absorbing water and concludes with the radicle emerging. The kinetics and amount of water uptake by seeds are known to be influenced by both seed surface properties and the surrounding environment. As a result, altering seed surface features are linked to seed medium and is a valuable strategy for controlling seed germination. In the agricultural field, non-thermal plasma surface activation of seeds is currently being investigated as an efficient pre-sowing treatment for modifying seed germination. The impact of non-thermal plasma (NTP) on the germination and seedling growth of carrot seeds at room temperature and atmospheric pressure for varied treatment times was investigated in this study. Seed's germination properties and growth parameters were examined for both control and NTP treated seeds. Germination-related parameters such as germination percentage, vigor index, and chlorophyll content were all improved by NTP treatment. However, no significant changes were seen in the carotenoid content. Similarly, the in-vitro radical scavenging activities, total phenol, and total flavonoid contents in the seedlings were altered by NTP treatment. Our results indicate that NTP treatment has a favorable effect on carrots germination and seedling development.

The present work is focused on investigating the effect of plasma-activated water (PAW) on the seed germination and seedling growth of radish, fenugreek, and pea seeds. A home-made gliding arc discharge (GAD) reactor generated in air under atmospheric pressure and operating at 50 Hz line frequency is used for water activation. PAW was prepared by exposing deionized water to GAD for 5, 10, 15, and 20 min. As a result of plasma treatment, deionized water showed substantial changes in physical characteristics such as pH and electrical conductivity along with chemical parameters such as nitrites, nitrates, and ammonia. The effect on germination was evaluated based on the fraction of germinated seeds and their length at 7 and 12 days after treatment. Seeds irrigated with PAW resulted in a higher imbibition rate than those irrigated by deionized water. When the seeds were irrigated with PAW, the germination parameters such as final germination rate, mean germination rate, coefficient of velocity of germination, germination index, and growth parameters such as shoot/seedling length and vigor index increased. In conclusion, PAW may be utilized to increase the germination rate of seeds.