scholarly journals Effect of Low Molecular Weight Oxidized Materials and Nitrogen Groups on Adhesive Joints of Polypropylene Treated by a Cold Atmospheric Plasma Jet

Polymers ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 4396
Author(s):  
Kateřina Polášková ◽  
Miloš Klíma ◽  
Zdeňka Jeníková ◽  
Lucie Blahová ◽  
Lenka Zajíčková

Polypropylene is a typical representative of synthetic polymers that, for many applications including adhesive joints, requires an increase in wettability and chemical surface reactivity. Plasma processing offers efficient methods for such surface modifications. A particular disadvantage of the plasma jets can be the small plasma area. Here, we present a cold atmospheric plasma radio-frequency slit jet developed with a width of 150 mm applied to polypropylene plasma treatment in Ar, Ar/O2 and Ar/N2 We identified two main parameters influencing the tensile strength of adhesive joints mediated by epoxy adhesive DP 190, nitrogen content, and the amount of low molecular weight oxidized materials (LMWOMs). Nitrogen functional groups promoted adhesion between epoxy adhesive DP 190 and the PP by taking part in the curing process. LMWOMs formed a weak boundary layer, inhibiting adhesion by inducing a cohesive failure of the joint. A trade off between these two parameters determined the optimized conditions at which the strength of the adhesive joint increased 4.5 times. Higher adhesion strength was previously observed when using a translational plasma gliding arc plasma jet with higher plasma gas temperatures, resulting in better cross linking of polymer chains caused by local PP melting.

Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 249
Author(s):  
Zhitong Chen ◽  
Richard Obenchain ◽  
Richard E. Wirz

Conventional plasma jets for biomedical applications tend to have several drawbacks, such as high voltages, high gas delivery, large plasma probe volume, and the formation of discharge within the organ. Therefore, it is challenging to employ these jets inside a living organism’s body. Thus, we developed a single-electrode tiny plasma jet and evaluated its use for clinical biomedical applications. We investigated the effect of voltage input and flow rate on the jet length and studied the physical parameters of the plasma jet, including discharge voltage, average gas and subject temperature, and optical emissions via spectroscopy (OES). The interactions between the tiny plasma jet and five subjects (de-ionized (DI) water, metal, cardboard, pork belly, and pork muscle) were studied at distances of 10 mm and 15 mm from the jet nozzle. The results showed that the tiny plasma jet caused no damage or burning of tissues, and the ROS/RNS (reactive oxygen/nitrogen species) intensity increased when the distance was lowered from 15 mm to 10 mm. These initial observations establish the tiny plasma jet device as a potentially useful tool in clinical biomedical applications.


2013 ◽  
Vol 10 (8) ◽  
pp. 706-713 ◽  
Author(s):  
Sander Bekeschus ◽  
Kai Masur ◽  
Julia Kolata ◽  
Kristian Wende ◽  
Anke Schmidt ◽  
...  

2019 ◽  
Vol 47 (11) ◽  
pp. 4848-4860 ◽  
Author(s):  
Donghai Li ◽  
Guiling Li ◽  
Jing Li ◽  
Zhi-Qiang Liu ◽  
Xuman Zhang ◽  
...  

2020 ◽  
Vol 24 (4) ◽  
pp. 1465-1477 ◽  
Author(s):  
Yang Yang ◽  
Miao Zheng ◽  
Yang Yang ◽  
Jing Li ◽  
Yong-Fei Su ◽  
...  

2019 ◽  
Vol 8 (11) ◽  
pp. 1930 ◽  
Author(s):  
Bih-Show Lou ◽  
Chih-Ho Lai ◽  
Teng-Ping Chu ◽  
Jang-Hsing Hsieh ◽  
Chun-Ming Chen ◽  
...  

Using the Taguchi method to narrow experimental parameters, the antimicrobial efficiency of a cold atmospheric plasma jet (CAPJ) treatment was investigated. An L9 array with four parameters of CAPJ treatments, including the application voltage, CAPJ-sample distance, argon (Ar) gas flow rate, and CAPJ treatment time, were applied to examine the antimicrobial activity against Escherichia coli (E. coli). CAPJ treatment time was found to be the most influential parameter in its antimicrobial ability by evaluation of signal to noise ratios and analysis of variance. 100% bactericidal activity was achieved under the optimal bactericidal activity parameters including the application voltage of 8.5 kV, CAPJ-sample distance of 10 mm, Ar gas flow rate of 500 sccm, and CAPJ treatment time of 300 s, which confirms the efficacy of the Taguchi method in this design. In terms of the mechanism of CAPJ’s antimicrobial ability, the intensity of hydroxyl radical produced by CAPJ positively correlated to its antimicrobial efficiency. The CAPJ antimicrobial efficiency was further evaluated by both DNA double-strand breaks analysis and scanning electron microscopy examination of CAPJ treated bacteria. CAPJ destroyed the cell wall of E. coli and further damaged its DNA structure, thus leading to successful killing of bacteria. This study suggests that optimal conditions of CPAJ can provide effective antimicrobial activity and may be grounds for a novel approach for eradicating bacterial infections.


2020 ◽  
Vol 17-18 ◽  
pp. 100098 ◽  
Author(s):  
Mohamed Fofana ◽  
Julio Buñay ◽  
Florian Judée ◽  
Silvère Baron ◽  
Sébastien Menecier ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document