scholarly journals Surface Energy of Filtration Media Influencing the Filtration Performance against Solid Particles, Oily Aerosol, and Bacterial Aerosol

Polymers ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 935 ◽  
Author(s):  
Seojin Jung ◽  
Jaejin An ◽  
Hyungjin Na ◽  
Jooyoun Kim
Keyword(s):  
Surface Energy ◽  
Plasma Treatment ◽  
Chemical Vapor ◽  
Filtration Efficiency ◽  
Dioctyl Phthalate ◽  
Solid Particles ◽  
Filtration Performance ◽  
Bacterial Aerosol ◽  
O2 Plasma Treatment ◽  
O2 Plasma

Particulate airborne pollutants are a big concern to public health, and it brings growing attention about effective filtration devices. Especially, particulate matters smaller than 2.5 µm can reach the thoracic region and the blood stream, and the associated health risk can be exacerbated when pathogenic microbials are present in the air. This study aims at understanding the surface characteristics of nonwoven media that influence filtration performance against solid particles (sodium chloride, NaCl), oily aerosol (dioctyl phthalate, DOP), and Staphylococcus aureus (S. aureus) bacteria. Nonwoven media of polystyrene (PS) fibers were fabricated by electrospinning and its pristine surface energy (38.5 mN/m) was modified to decrease (12.3 mN/m) by the plasma enhanced chemical vapor deposition (PECVD) of octafluorocyclobutane (C4F8) or to increase (68.5 mN/m) by the oxygen (O2) plasma treatment. For NaCl particles and S. aureus aerosol, PS electrospun web showed higher quality factor than polypropylene (PP) meltblown electret that is readily available for commercial products. The O2 plasma treatment of PS media significantly deteriorated the filtration efficiency, presumably due to the quick dissipation of static charges by the O2 plasma treatment. The C4F8 treated, fluorinated PS media resisted quick wetting of DOP, and its filtration efficiency for DOP and S. aureus remained similar while its efficiency for NaCl decreased. The findings of this study will impact on determining relevant surface treatments for effective particulate filtration. As this study examined the instantaneous performance within 1–2 min of particulate exposure, and the further study with the extended exposure is suggested.

scholarly journals Erratum: Surface Energy of Filtration Media Influencing the Filtration Performance against Solid Particles, Oily Aerosol, and Bacterial Aerosol. Polymers 2019, 11, 935

Polymers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1189
Author(s):  
Seojin Jung ◽  
Jaejin An ◽  
Hyungjin Na ◽  
Jooyoun Kim
Keyword(s):  
Surface Energy ◽  
Solid Particles ◽  
Filtration Performance ◽  
Bacterial Aerosol ◽  
Published Paper

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scholarly journals Comparison of Argon and Oxygen Plasma Treatments for Ambient Room-Temperature Wafer-Scale Au–Au Bonding Using Ultrathin Au Films

Micromachines ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 119 ◽  
Author(s):  
Michitaka Yamamoto ◽  
Takashi Matsumae ◽  
Yuichi Kurashima ◽  
Hideki Takagi ◽  
Tadatomo Suga ◽  
...  
Keyword(s):  
Surface Energy ◽  
Plasma Treatment ◽  
Bonding Strength ◽  
Room Temperature ◽  
Activation Mechanism ◽  
Spectroscopy Analysis ◽  
Wafer Scale ◽  
O2 Plasma Treatment ◽  
Ar Plasma ◽  
O2 Plasma

Au–Au surface activated bonding is promising for room-temperature bonding. The use of Ar plasma vs. O2 plasma for pretreatment was investigated for room-temperature wafer-scale Au–Au bonding using ultrathin Au films (<50 nm) in ambient air. The main difference between Ar plasma and O2 plasma is their surface activation mechanism: physical etching and chemical reaction, respectively. Destructive razor blade testing revealed that the bonding strength of samples obtained using Ar plasma treatment was higher than the strength of bulk Si (surface energy of bulk Si: 2.5 J/m2), while that of samples obtained using O2 plasma treatment was low (surface energy: 0.1–0.2 J/m2). X-ray photoelectron spectroscopy analysis revealed that a gold oxide (Au2O3) layer readily formed with O2 plasma treatment, and this layer impeded Au–Au bonding. Thermal desorption spectroscopy analysis revealed that Au2O3 thermally desorbed around 110 °C. Annealing of O2 plasma-treated samples up to 150 °C before bonding increased the bonding strength from 0.1 to 2.5 J/m2 due to Au2O3 decomposition.

Influence of O2 plasma treatment on NiO x layer in perovskite solar cells

2018 ◽  
Vol 57 (4S) ◽  
pp. 04FS07 ◽  
Author(s):  
Yoshihiko Nishihara ◽  
Masayuki Chikamatsu ◽  
Said Kazaoui ◽  
Tetsuhiko Miyadera ◽  
Yuji Yoshida
Keyword(s):  
Solar Cells ◽  
Plasma Treatment ◽  
Perovskite Solar Cells ◽  
O2 Plasma Treatment ◽  
O2 Plasma

scholarly journals Facile Functionalization via Plasma-Enhanced Chemical Vapor Deposition for the Effective Filtration of Oily Aerosol

Polymers ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1490 ◽  
Author(s):  
Sanghyun Roh ◽  
Sungmin Kim ◽  
Jooyoun Kim
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Filter Design ◽  
Chemical Vapor ◽  
Surface Modifications ◽  
Solid Particles ◽  
Oxygen Species ◽  
Plasma Process ◽  
Filter Performance ◽  
Filtration Performance

With the growing concern about the health impacts associated with airborne particles, there is a pressing need to design an effective filter device. The objective of this study is to investigate the effect of plasma-based surface modifications on static charges of electrospun filter media and their resulting filtration performance. Polystyrene (PS) electrospun web (ES) had inherent static charges of ~3.7 kV due to its electric field-driven process, displaying effective filtration performance. When oxygen species were created on the surface by the oxygen plasma process, static charges of electret media decreased, deteriorating the filter performance. When the web surface was fluorinated by the plasma-enhanced chemical vapor deposition (PECVD), the filtration efficiency against oily aerosol significantly increased due to the combined effect of decreased wettability and strong static charges (~−3.9 kV). Solid particles on the charged media formed dendrites as particles were attracted to other layers of particles, building up a pressure drop. The PECVD process is suggested as a facile functionalization method for effective filter design, particularly for capturing oily aerosol.

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