scholarly journals Copper-Coated Polypropylene Filter Face Mask with SARS-CoV-2 Antiviral Ability

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1367
Author(s):  
Sunghoon Jung ◽  
Jun-Yeoung Yang ◽  
Eun-Yeon Byeon ◽  
Do-Geun Kim ◽  
Da-Gyum Lee ◽  
...  

Face masks will be used to prevent pandemic recurrence and outbreaks of mutant SARS-CoV-2 strains until mass immunity is confirmed. The polypropylene (PP) filter is a representative disposable mask material that traps virus-containing bioaerosols, preventing secondary transmission. In this study, a copper thin film (20 nm) was deposited via vacuum coating on a spunbond PP filter surrounding a KF94 face mask to provide additional protection and lower the risk of secondary transmission. Film adhesion was improved using oxygen ion beam pretreatment, resulting in cuprous oxide formation on the PP fiber without structural deformation. The copper-coated mask exhibited filtration efficiencies of 95.1 ± 1.32% and 91.6 ± 0.83% for NaCl and paraffin oil particles, respectively. SARS-CoV-2 inactivation was evaluated by transferring virus-containing media onto the copper-coated PP filters and subsequently adding Vero cells. Infection was verified using real-time polymerase chain reaction and immunochemical staining. Vero cells added after contact with the copper-coated mask did not express the RNA-dependent RNA polymerase and envelope genes of SARS-CoV-2. The SARS-CoV-2 nucleocapsid immunofluorescence results indicated a reduction in the amount of virus of more than 75%. Therefore, copper-coated antiviral PP filters could be key materials in personal protective equipment, as well as in air-conditioning systems.

2018 ◽  
Author(s):  
C.S. Bonifacio ◽  
P. Nowakowski ◽  
M.J. Campin ◽  
M.L. Ray ◽  
P.E. Fischione

Abstract Transmission electron microscopy (TEM) specimens are typically prepared using the focused ion beam (FIB) due to its site specificity, and fast and accurate thinning capabilities. However, TEM and high-resolution TEM (HRTEM) analysis may be limited due to the resulting FIB-induced artifacts. This work identifies FIB artifacts and presents the use of argon ion milling for the removal of FIB-induced damage for reproducible TEM specimen preparation of current and future fin field effect transistor (FinFET) technologies. Subsequently, high-quality and electron-transparent TEM specimens of less than 20 nm are obtained.


2021 ◽  
Author(s):  
Gyo Wun Kim ◽  
Won Jun Chang ◽  
Ji Eun Kang ◽  
Hee Ju Kim ◽  
Geun Young Yeom

Abstract Even though EUV lithography has the advantage of implenting a finer pattern compared to ArF immersion lithography due to the use of 13.5 nm instead of 193 nm as the wavelengh of the light source, due to the low energy of EUV light source, EUV resist has a thinner thickness than conventional ArF resist. EUV resist having such a thin thickness is more vulnerable to radiation damage received during the etching because of its low etch resistance and also tends to have a problem of low etch selectivity. In this study, the radiation damage to EUV resist during etching of hardmask materials such as Si3N4, SiO2, etc. using CF4 gas was compared between neutral beam etching (NBE) and ion beam etching (IBE). When NBE was used, after the etching of 20 nm thick EUV resist, the line edge roughness (LER) increase and the critical dimension (CD) change of EUV resist were reduced by ~ 1/3 and ~ 1/2, respectively, compared to those by IBE. Also, at that EUV etch depth, the RMS(root mean square) surface roughness value of EUV resist etched by NBE was ~2/3 compared to that by IBE on the average. It was also confirmed that the etching selectivity between SiO2, Si3N4, etc. and EUV resist was higher for NBE compared to IBE. The less damage to the EUV resist and the higher etch selectivity of materials such as Si3N4 and SiO2 over EUV resist for NBE compared to IBE are believed to be related to the no potential energy released by the neutralization of the ions during the etching for NBE.


2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
A. Goncharov ◽  
A. Guglya ◽  
A. Kalchenko ◽  
E. Solopikhina ◽  
V. Vlasov ◽  
...  

This review summarizes results of our study of the application of ion-beam assisted deposition (IBAD) technology for creation of nanoporous thin-film structures that can absorb more than 6 wt.% of hydrogen. Data of mathematical modeling are presented highlighting the structure formation and component creation of the films during their deposition at the time of simultaneous bombardment by mixed beam of nitrogen and helium ions with energy of 30 keV. Results of high-resolution transmission electron microscopy revealed that VNxfilms consist of 150–200 nm particles, boundaries of which contain nanopores of 10–15 nm diameters. Particles themselves consist of randomly oriented 10–20 nm nanograins. Grain boundaries also contain nanopores (3–8 nm). Examination of the absorption characteristics of VNx, TiNx, and(V,Ti)Nxfilms showed that the amount of absorbed hydrogen depends very little on the chemical composition of films, but it is determined by the structure pore. The amount of absorbed hydrogen at 0.3 MPa and 20°C is 6-7 wt.%, whereas the bulk of hydrogen is accumulated in the grain boundaries and pores. Films begin to release hydrogen even at 50°C, and it is desorbed completely at the temperature range of 50–250°C. It was found that the electrical resistance of films during the hydrogen desorption increases 104times.


1995 ◽  
Vol 384 ◽  
Author(s):  
Michael B. Hintz

ABSTRACTThe magneto-optical (MO) layer in current rare earth-transition metal (RE-TM) based MO recording media is typically 20 nm to 60 nm thick. It has been suggested, however, that media structures employing a multiplicity of thinner MO layers may be advantageous, e.g., for multilevel recording applications [1] or media noise reduction [2]. As magnetic layer thickness is reduced, interactions among magnetic layers and adjacent materials can have an increasingly large influence on magnetic properties; in many instances, these interactions can dominate the observed magnetic behavior.As a means of studying MO layer - adjacent layer interactions, we have used thin (≈3 nm) films of several materials to separate single 24 nm thick ion-beam-deposited FeTbCo layers into N thinner layers of 24/N nm thickness (N × 24/N). As N increases, the FeThCo magnetic properties generally change; however, the relative magnitude of the changes is strongly dependent upon the adjacent layer composition. Magnetization (Ms), energy product (MsHc) at 30 C and Curie temperature data for 1 × 24 nm structures and 6 × 4 nm structures are compared and discussed for specimens employing SiCx, Six, YOx, HfOx, Si and SiOx adjacent layer materials.


2004 ◽  
Vol 22 (3) ◽  
pp. 279-284 ◽  
Author(s):  
ANNE-SOPHIE MORLENS ◽  
PHILIPPE ZEITOUN ◽  
LAURENT VANBOSTAL ◽  
PASCAL MERCERE ◽  
GRÉGORY FAIVRE ◽  
...  

A XUV Michelson interferometer has been developed by LIXAM/CEA/LCFIO and has been tested as a Fourier-transform spectrometer for measurement of X-ray laser line shape. The observed strong deformation of the interference fringes limited the interest of such an interferometer for plasma probing. Because the fringe deformation was coming from a distortion of the beam splitter (5 × 5 mm2open aperture, about 150 nm thick), several parameters of the multilayer deposition used for the beam splitter fabrication have been recently optimized. The flatness has been improved from 80 nm rms obtained by using the ion beam sputtering technique, to 20 nm rms by using the magnetron sputtering technique. Over 3 × 3 mm2, the beam splitter has a flatness better than 4 nm rms.


2001 ◽  
Vol 687 ◽  
Author(s):  
D.F. Bahr ◽  
K.R. Bruce ◽  
B.W. Olson ◽  
L.M. Eakins ◽  
C.D. Richards ◽  
...  

AbstractA piezoelectric thin film MEMS device for generating power from a novel heat engine which approaches a Carnot cycle has been developed. The structure of the underlying electrode and PZT thin film generator has been optimized for increased adhesion. Atomic force microscopy was used to track electrode grain size and roughness; generating grain sizes of approximately 100 and 200 nm in diameter and a roughness of about 14-20 nm provide substantial improvements in film adhesion over systems with smaller grains and smoother surfaces. This has led to the ability to operate the engine at frequencies between 10 and 1500 Hz. The system of interest (a fluid filled cavity sealed by a micromachined silicon membrane and the PZT film) shows increased deflections for a given pressure applied to the membrane at frequencies where the system resonates. By operating the system dynamically, it is possible to generate more than 2 V from a single generator structure.


1986 ◽  
Vol 5 (6) ◽  
pp. 659-661 ◽  
Author(s):  
K. R. Padmanabhan ◽  
J. Chevallier ◽  
G. Sørensen

2021 ◽  
Author(s):  
Oluwatosin Oginni

Abstract Disposable face mask has become a mandatory personal protective equipment in order to prevent contracting COVID-19. With the significant surge in its usage, its adverse environmental impact is becoming a source of concern. Disposable face masks are made from thermoplastic polymers and therefore they can be safely converted into valuable bioproducts. This paper discussed the possibility of converting waste/contaminated face masks into valuable bioproducts, which will essentially eliminate secondary transmission of the coronavirus and the concerns of environmental pollution.


Author(s):  
Yuanjing (Jane) Li ◽  
Steven Scott ◽  
Howard Lee Marks

Abstract This paper presents a backside chip-level physical analysis methodology using backside de-processing techniques in combination with optimized Scanning Electron Microscopic (SEM) imaging technique and Focused Ion Beam (FIB) cross sectioning to locate and analyze defects and faults in failing IC devices. The case studies illustrate the applications of the method for 28nm flip chip bulk Si CMOS devices and demonstrate how it is used in providing insight into the fab process and design for process and yield improvements. The methods are expected to play an even more important role during 20-nm process development and yield-ramping.


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