Browsing by Author "Liao, Guo-Chun"

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A Cold Planar Nitrogen-Based Atmospheric-Pressure Dielectric Barrier Discharge Jet With Enhanced UV Emission and Radical Generation Using Short Electrodes
(2016-12)
Cheng, Kuang-Yao
;
Yang, Yi-Wei
;
Lin, Zhi-Hua
;
Liao, Guo-Chun
;
Liu, Chih-Tung
In this paper, a planar nitrogen-based atmospheric-pressure dielectric barrier discharge (DBD) jet with enhanced UV emission and radical generation, and much lower power consumption and gas temperature using shorter electrodes as compared with a previously developed DBD jet is presented. The highest UV intensity (five times larger) and radical generation (two times larger) in the DBD jet region are found to occur when the electrode length is 1 cm. Corresponding jet gas temperature and power consumption are 31 degrees C and 39 W, respectively. The 1-cm DBD jet was used to treat polylactide film for enhancing its hydrophilic properties. The results show that a contact angle of 28.4 degrees could be obtained with a residence time of 4 s. The resulting 1-cm DBD jet may provide an efficient surface treatment tool for delicate industrial and biomedical devices/materials.
A Cold Planar Nitrogen-Based Atmospheric-Pressure Dielectric Barrier Discharge Jet With Enhanced UV Emission and Radical Generation Using Short Electrodes
(2016-12-01)
Cheng, Kuang-Yao
;
Yang, Yi-Wei
;
Lin, Zhi-Hua
;
Liao, Guo-Chun
;
Liu, Chih-Tung
In this paper, a planar nitrogen-based atmospheric-pressure dielectric barrier discharge (DBD) jet with enhanced UV emission and radical generation, and much lower power consumption and gas temperature using shorter electrodes as compared with a previously developed DBD jet is presented. The highest UV intensity (five times larger) and radical generation (two times larger) in the DBD jet region are found to occur when the electrode length is 1 cm. Corresponding jet gas temperature and power consumption are 31 degrees C and 39 W, respectively. The 1-cm DBD jet was used to treat polylactide film for enhancing its hydrophilic properties. The results show that a contact angle of 28.4 degrees could be obtained with a residence time of 4 s. The resulting 1-cm DBD jet may provide an efficient surface treatment tool for delicate industrial and biomedical devices/materials.
An Optimized Two-Step Nitrogen-Based Plasma Treatment Procedure under Atmospheric-Pressure Condition and its Surface Amination Mechanism
(2015-07-01)
Yang, Yi-Wei
;
Wu, Jane-Yii
;
Liu, Chih-Tung
;
Liao, Guo-Chun
;
Cheng, Kuang-Yao
Atmospheric pressure nitrogen-based dielectric barrier discharge (DBD) jet with two-step plasma treatment procedure has been verified to be very effective in facilitating nitrogen-containing group incorporation on Polylactide (PLA) surface. It includes: 1) pretreatment plasma treatment by a nitrogen discharge with a trace amount of oxygen, and 2) ammonia plasma treatment by a nitrogen discharge with a small amount of ammonia. In this study, the optimized operation condition of two-step plasma procedure is investigated under different concentrations of added gases (0-1% oxygen; 0-10% ammonia). XPS analysis shows that approximate to 0.19 of N/C ratio can be achieved by means of the optimized two-step plasma procedures. Furthermore, a surface amination mechanism is proposed based on the observations of Optical Emission Spectra (OES), Atomic Force Microscope (AFM), and X-ray Photoelectron Spectra (XPS) analyses.
Enhancement of cell growth on honeycomb-structured polylactide surface using atmospheric-pressure plasma jet modification
(2017-02-01)
Cheng, Kuang-Yao
;
Chang, Chia-Hsing
;
Yang, Yi-Wei
;
Liao, Guo-Chun
;
Liu, Chih-Tung
In this paper, we compare the cell growth results of NIH-3T3 and Neuro-2A cells over 72 h on flat and honeycomb structured PLA films without and with a two-step atmospheric-pressure nitrogen-based plasma jet treatment. We developed a fabrication system used for forming of a uniform honeycomb structure on PLA surface, which can produce two different pore sizes, 3-4 mu m and 7-8 mu m, of honeycomb pattern. We applied a previously developed nitrogen-based atmospheric-pressure dielectric barrier discharge (DBD) jet system to treat the PLA film without and with honeycomb structure. NIH-3T3 and a much smaller Neuro-2A cells were cultivated on the films under various surface conditions. The results show that the two-step plasma treatment in combination with a honeycomb structure can enhance cell growth on PLA film, should the cell size be not too smaller than the pore size of honeycomb structure, e.g., NIH-3T3. Otherwise, cell growth would be better on flat PLA film, e.g., Neuro-2A. (C) 2016 Elsevier B.V. All rights reserved.
Fast incorporation of primary amine group into polylactide surface for improving C2C12 cell proliferation using nitrogen-based atmospheric-pressure plasma jets
(2014-01-01)
Yang, Yi-Wei
;
Wu, Jane-Yii
;
Liu, Chih-Tung
;
Liao, Guo-Chun
;
Huang, Hsuan-Yu
In this article, we report the development of the fast incorporation of primary amine functional groups into a polylactide (PLA) surface using the post-discharge jet region of an atmospheric-pressure nitrogen-based dielectric barrier discharge (DBD). Plasma treatments were carried out in two sequential steps: (1) nitrogen with 0.1% oxygen addition, and (2) nitrogen with 5% ammonia addition. The analyses show that the concentration of N/C ratio, surface energy, contact angle, and surface roughness of the treated PLA surface can reach 19.1%, 70.5 mJ/m(2), 38 degrees and 73.22 nm, respectively. In addition, the proposed two-step plasma treatment procedure can produce a PLA surface exhibiting almost the same C2C12 cell attachment and proliferation performance as that of the conventional gelatin coating method. Most importantly, the processing/preparation time is reduced from 13-15 h (gelatin coating method) to 5-15 min (two-step plasma treatment), which is very useful in practical applications. (c) 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 160-169, 2014.