Modification of Wetting Property of Polycarbonate by Means of Ion Beam Implantation and Storage in Different Gas Environments

1997 ◽  
Vol 504 ◽  
Author(s):  
A. Poirier ◽  
G. G. Ross ◽  
P. Bertrand ◽  
V. Wiertz
Keyword(s):  
Contact Angle ◽  
Ion Irradiation ◽  
Ion Beam ◽  
New Technology ◽  
Fluid Management ◽  
Harmful Effect ◽  
Chemical Species ◽  
Thin Film Adhesion ◽  
Wetting Property ◽  
And Storage

AbstracrThe wetting property of polymers is very important in different applications such as biomaterials, textiles, aerospace (fluid management and materials processing in microgravity), and thin film adhesion. Therefore, there is a strong interest in the development of a new technology for the modification at will of this property. The use of low energy ion beams allows the modification of the first surface atomic layers. Nitrogen ions of 500 eV/at. were used to bombard the surface of polycarbonate (PC) samples to a fluence of 5×1016 at/cm2. Five different environments (oxygen, nitrogen, argon, dry air and vacuum) were used to store the samples for some hours (1 to 24 hours) after the implantation. Aging studies of the contact angle (advancing and receding) have shown that the environment gas influences the long term value of the contact angle and helps to maintain the stability of the treated surfaces with the passage of time. XPS and ToF-SIMS have been used to study the chemical effects of both N2+ ion irradiation and storage gas surrounding the samples. The results show faster aging in the case of the samples stored in vacuum, a harmful effect of nitrogen gas on the treatment and the formation of new chemical species for all treatments.

Identification of Hydrophilic Group Formation on Polymer Surface During Ar+ Ion Irradiation in O2 Environment

1996 ◽  
Vol 438 ◽  
Author(s):  
Jun-Sik Cho ◽  
Won-Kook Choi ◽  
Sung-Ryong Kim ◽  
Hyung-Jin Jung ◽  
Seok-Keun Koh
Keyword(s):  
Contact Angle ◽  
Photoelectron Spectroscopy ◽  
Ion Irradiation ◽  
Ion Beam ◽  
Group Formation ◽  
Polymer Surface ◽  
Sample Surface ◽  
Spectroscopy Analysis ◽  
Hydrophilic Group ◽  
Oxygen Gas

AbstractAr+ ion irradiation on low density polyethylene (LDPE), and polystyrene (PS) was performed in an O2 environment in order to improve wettability of polymers to water and to identify the formation of hydrophilic groups originated from chemical reactions on the surface of polymers. Doses of a broad Ar+ ion beam of 1 keV energy were changed from 5 × 1015 to 1 × 1017 /cm2 and the rate of the oxygen gas flowing near the sample surface was varied from 0 to 7 mi/min. The contact angle of polymers was not reduced much by Ar+ ion irradiation without oxygen gas. However, it dropped largely to a minimum of 35 ° and 26 ° for At+ ion irradiation in the presence of flowing oxygen gas on LDPE and PS, respectively. From x-ray photoelectron spectroscopy analysis, it was observed that hydrophilic groups were formed on the surface of polymers through an ion-assisted chemical reaction between the ion-induced unstable chains and oxygen. The newly formed hydrophilic group was identified as -(C=O)- bond and -(C=O)-O- bond. The contact angle of polymer was greatly dependent on the hydrophilic group formed on the surface.

SHI induced evolution of surface and wettability of BaF2 thin films

MRS Advances ◽  
2019 ◽  
Vol 4 (28-29) ◽  
pp. 1667-1672 ◽  
Author(s):  
Ratnesh K Pandey ◽  
Tanuj Kumar ◽  
Udai B Singh ◽  
Shikha Awasthi ◽  
Avinash C Pandey
Keyword(s):  
Thin Films ◽  
Contact Angle ◽  
Water Droplet ◽  
Ion Irradiation ◽  
Ion Beam ◽  
Normal Incidence ◽  
Heavy Ion ◽  
Ion Beam Irradiation ◽  
Major Factors ◽  
Shi Irradiation

AbstractWe report evolution of the surface and wetting behavior of Barium fluoride (BaF2) thin films under the effect of swift heavy ion (SHI) irradiation at different fluences. The analogy of this study may be used may be used for the development of dust resistant fabric technology for rural area. The ion irradiation has been performed at normal incidence on the films with Au ions having 100 MeV energy. Further, the wettability of irradiated surfaces is studied through contact angle of water droplet. The value of contact angle of droplet changes with irradiation, it increases from 111° to 123° with the increase in fluence from 5×1011 to 1×1013 ions/cm2. The mechanism of wettability of BaF2 is explained on the basis of increase in contact area of water droplet with surface. SHI irradiation deposits a huge amount of energy in materials due to extreme electronic excitation and it causes a large increase in the temperature of material around the ion track. Ion beam irradiation leads to the large ejection of atoms from the surface which is one of the major factors in increasing the roughness of the surface and thus for the change in contact angle.

Micro Texturing of Polycarbonate Plate with Ion Beam Irradiation and its Friction Properties in Water

2010 ◽  
Vol 447-448 ◽  
pp. 676-680
Author(s):  
Noritsugu Umehara ◽  
Yasuhito Demizu ◽  
Junichi Nishio ◽  
Takayuki Tokoroyama
Keyword(s):  
Contact Angle ◽  
Polymer Brushes ◽  
Sliding Friction ◽  
Electron Cyclotron Resonance ◽  
Ion Irradiation ◽  
Ion Beam ◽  
Optical Microscope ◽  
Oxygen Ions ◽  
Oxygen Ion ◽  
Lubrication Condition

In order to fabricate micro textured polymer plate, some kinds of ions were irradiated to the substrate by using an Electron Cyclotron Resonance (ECR) ion shower apparatus. Surface morphology of specimens was observed by SEM, and measured by AFM. We observed a lot of micro polymer brushes on the substrate. The surface roughness of untreated specimen increased and reached to 248 nm by N2 ion irradiation. We have used Argon, Nitrogen and Oxygen ions. Oxygen ion shows more effective to etch than the other two ions. Also we measured the contact angle of water on the surface of specimens with optical microscope. The contact angle of untreated specimen decreased and reached to 8 degree by N and O ion irradiation. After the irradiation, we conducted sliding friction test between ion irradiated polycarbonate slider and flat polycarbonate specimen. It was observed that friction coefficient of ion irradiated polycarbonate slider showed lower friction than flat polycarbonate specimen under mixed lubrication condition in water.

Modification of the Wettability of Plexiglas and Carbon by Means of Ion Beam Implantation: Application to Fluid Management and Materials Processing in Microgravity.

1995 ◽  
Vol 396 ◽  
Author(s):  
J.F. Pageau ◽  
G.G. Ross ◽  
É. Couture ◽  
A. Poirier ◽  
F. Quirion
Keyword(s):  
Surface Composition ◽  
Ion Beam ◽  
New Technology ◽  
Fluid Management ◽  
Contact Angles ◽  
Low Energy ◽  
Materials Processing ◽  
Partial Recovery ◽  
Wetting Properties ◽  
At Will

AbstractIn the absence of gravity, the behaviour of a liquid within a container will depend on its ability to wet the container. For instance, we evidenced that wetting property is involved in the propagation of perturbation, at the liquid-air interface. Because of perturbation in space, there is a strong interest in the modification of wetting properties for fluid management and materials processing in microgravity. The use of low energy (-500 eV) ion beams is attractive. Combining their low mean range (a few nm) and erosion rate, they are well suited for the modification at will of surface composition. Nitrogen, oxygen and neon ions of low energy were used to bombard the surface of plexiglas (polymethylmethacrylate or PMMA) and carbon samples at different fluences. Advancing and receding contact angles were measured before and after the implantation. A decrease of the contact angle as a function of the fluence of implanted ions was measured. A partial recovery of the contact angles as a function of time after the implantation was also observed. There was evidence that the long term value of the contact angles was influenced by the composition of the gas surrounding the samples. These results are discussed in terms of the development of a new technology for the modification at will of wetting properties of materials.

Electron and ion irradiation-induced dissolution of mechanical twins in the intermetalic U3Si: An in situ HVEM study

1989 ◽  
Vol 47 ◽  
pp. 652-653
Author(s):  
Charles W. Allen ◽  
Robert C. Birtcher
Keyword(s):  
Elevated Temperatures ◽  
Ion Irradiation ◽  
Ion Beam ◽  
National Laboratory ◽  
Argonne National Laboratory ◽  
Heavy Ion ◽  
High Energy ◽  
Mechanical Twinning ◽  
In Situ Experiments

The uranium silicides, including U3Si, are under study as candidate low enrichment nuclear fuels. Ion beam simulations of the in-reactor behavior of such materials are performed because a similar damage structure can be produced in hours by energetic heavy ions which requires years in actual reactor tests. This contribution treats one aspect of the microstructural behavior of U3Si under high energy electron irradiation and low dose energetic heavy ion irradiation and is based on in situ experiments, performed at the HVEM-Tandem User Facility at Argonne National Laboratory. This Facility interfaces a 2 MV Tandem ion accelerator and a 0.6 MV ion implanter to a 1.2 MeV AEI high voltage electron microscope, which allows a wide variety of in situ ion beam experiments to be performed with simultaneous irradiation and electron microscopy or diffraction.At elevated temperatures, U3Si exhibits the ordered AuCu3 structure. On cooling below 1058 K, the intermetallic transforms, evidently martensitically, to a body-centered tetragonal structure (alternatively, the structure may be described as face-centered tetragonal, which would be fcc except for a 1 pet tetragonal distortion). Mechanical twinning accompanies the transformation; however, diferences between electron diffraction patterns from twinned and non-twinned martensite plates could not be distinguished.

Scientific program of DERICA — prospective accelerator and storage ring facility for radioactive ion beam research

2018 ◽  
Vol 189 (07) ◽  
pp. 721-738
Author(s):  
Leonid V. Grigorenko ◽  
Boris Yu. Sharkov ◽  
Andrei S. Fomichev ◽  
Aleksei L. Barabanov ◽  
V. Bart ◽  
...  
Keyword(s):  
Storage Ring ◽  
Ion Beam ◽  
Scientific Program ◽  
Radioactive Ion Beam ◽  
And Storage

The FATE Landscape of Sign Language AI Datasets

2021 ◽  
Vol 14 (2) ◽  
pp. 1-45
Author(s):  
Danielle Bragg ◽  
Naomi Caselli ◽  
Julie A. Hochgesang ◽  
Matt Huenerfauth ◽  
Leah Katz-Hernandez ◽  
...  
Keyword(s):  
Sign Language ◽  
New Technology ◽  
Individual Data ◽  
Community Members ◽  
Sign Languages ◽  
Language Data ◽  
History Of ◽  
Language Technologies ◽  
And Storage ◽  
Access Mechanisms

Sign language datasets are essential to developing many sign language technologies. In particular, datasets are required for training artificial intelligence (AI) and machine learning (ML) systems. Though the idea of using AI/ML for sign languages is not new, technology has now advanced to a point where developing such sign language technologies is becoming increasingly tractable. This critical juncture provides an opportunity to be thoughtful about an array of Fairness, Accountability, Transparency, and Ethics (FATE) considerations. Sign language datasets typically contain recordings of people signing, which is highly personal. The rights and responsibilities of the parties involved in data collection and storage are also complex and involve individual data contributors, data collectors or owners, and data users who may interact through a variety of exchange and access mechanisms. Deaf community members (and signers, more generally) are also central stakeholders in any end applications of sign language data. The centrality of sign language to deaf culture identity, coupled with a history of oppression, makes usage by technologists particularly sensitive. This piece presents many of these issues that characterize working with sign language AI datasets, based on the authors’ experiences living, working, and studying in this space.

scholarly journals Comparison of short-range order in irradiated dysprosium titanates

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Roman Sherrod ◽  
Eric C. O’Quinn ◽  
Igor M. Gussev ◽  
Cale Overstreet ◽  
Joerg Neuefeind ◽  
...  
Keyword(s):  
Long Range ◽  
Short Range ◽  
Structural Model ◽  
Ion Irradiation ◽  
Function Analysis ◽  
Ion Beam ◽  
Structural Response ◽  
Heavy Ion ◽  
Range Order ◽  
Radiation Resistant

AbstractThe structural response of Dy2TiO5 oxide under swift heavy ion irradiation (2.2 GeV Au ions) was studied over a range of structural length scales utilizing neutron total scattering experiments. Refinement of diffraction data confirms that the long-range orthorhombic structure is susceptible to ion beam-induced amorphization with limited crystalline fraction remaining after irradiation to 8 × 1012 ions/cm2. In contrast, the local atomic arrangement, examined through pair distribution function analysis, shows only subtle changes after irradiation and is still described best by the original orthorhombic structural model. A comparison to Dy2Ti2O7 pyrochlore oxide under the same irradiation conditions reveals a different behavior: while the dysprosium titanate pyrochlore is more radiation resistant over the long-range with smaller degree of amorphization as compared to Dy2TiO5, the former involves more local atomic rearrangements, best described by a pyrochlore-to-weberite-type transformation. These results highlight the importance of short-range and medium-range order analysis for a comprehensive description of radiation behavior.

Increasing Storage Modulus, Contact Angle and Surface Tension of Airway Mucus Increases Clearance by Simulated Cough Through a Model Trachea

2010 ◽  
Author(s):  
Anpalaki J. Ragavan ◽  
Cahit A. Evrensel ◽  
Peter Krumpe
Keyword(s):  
Surface Tension ◽  
Contact Angle ◽  
Storage Modulus ◽  
Surface Properties ◽  
Respiratory Diseases ◽  
Interactive Effects ◽  
Altered Surface ◽  
Human Trachea ◽  
Tension Increase ◽  
And Storage

Altered surface and viscoelastic material properties of mucus during respiratory diseases have a strong influence on its clearance by cilia and cough. Combined effects of the surface properties (contact angle and surface tension) and storage modulus with relatively unchanged viscosity on displacement of the simulated mucus aliquot during simulated cough through a model adult human trachea is investigated. For the mucus simulants used in this study contact angle and surface tension increase significantly as storage modulus increase while viscosity remains practically unchanged. Displacement of mucus simulant aliquots increased significantly with increasing storage modulus (and contact angle) at a given cough velocity in the range between 5 meters/second (m/s) and 30 m/s with duration 0.3 s. Results suggest that the interactive effects of elasticity and surface properties may help facilitate mucus displacement at low cough velocities.

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