Fabrication of Novel Nanoporous Films in Moisture-in-Oil Sensors via Chemical Dealloying of Cu-Cr using Combinatorial Search of Cu–Cr Alloy Compositions

MRS Advances ◽  
2018 ◽  
Vol 3 (4) ◽  
pp. 225-232 ◽  
Author(s):  
Yusuke Yoshii ◽  
Junpei Sakurai ◽  
Mizue Mizoshiri ◽  
Seiichi Hata
Keyword(s):  
Pore Size ◽  
The Novel ◽  
Combinatorial Search ◽  
Initial Composition ◽  
Compositional Gradient ◽  
Nanoporous Film ◽  
Cr Content ◽  
Nanoporous Films ◽  
Deposited Film

ABSTRACTAn as-deposited film with a Cr compositional gradient (22–15 at.% Cr) was immersed in 22.5% HNO3 for 15 hours. In the part of the film with initial Cr content in the range of 22–18 at.%, Cu dealloying resulted in sufficient Cu dealloying (final Cr content = 33–80 at.%) without film dissolution. Using the film with optimal initial composition Cu82Cr18, we successfully fabricated a nanoporous film with a pore size in the range of 20–40 nm. As a result of the formation of Cr2O3 during dealloying, this film was transparent and exhibited an insulation state. The novel nanoporous film is expected to be applied as a nanofilter in moisture-in-oil sensors.

Gaia spectroscopic view of the asteroid main belt and beyond

2021 ◽  
Author(s):  
Marco Delbo ◽  
Laurent Galluccio ◽  
Francesca De Angeli ◽  
Paolo Tanga ◽  
Alberto Cellino ◽  
...  
Keyword(s):  
Solar System ◽  
Preliminary Investigation ◽  
Planetary Science ◽  
Reflectance Spectra ◽  
Physical Parameters ◽  
The Novel ◽  
Main Belt ◽  
Compositional Gradient ◽  
Solar System Object ◽  
Science Community

<div class="">Asteroids reflectance spectra in the visible light will be one of the novel products of the Gaia Data Release 3 (DR3). These spectra are produced from Gaia observations obtained by means of the blue and red photometers — the so-called BP and RP, respectively. We will review the strategy adopted to produce asteroid reflectance spectra from BP-RP data, focusing on the choice of spectro-photometric calibrations computed taking into account solar system object astrometry and suitable lists of solar-analog stars.</div> <div class=""> </div> <div class="">Our preliminary investigation shows that we will be able to obtain reflectance spectra for asteroids as small as some km in the main belt, by exploiting the fact that each object has been observed multiple times by Gaia. We will show the capability of Gaia to probe the detailed compositional gradient of the main belt down to small sizes and to study correlations between spectral classes and other asteroid physical parameters, such as albedo and size.</div> <div class=""> </div> <div class="">Concerning the brightest asteroids, we expect to have substantial signal at wavelengths shorter than 450 nm, allowing Gaia to examine this region of the spectrum that has been poorly investigated by ground-based asteroid spectroscopic surveys. This region is characterised by the presence of a reflectance downturn that is diagnostic for the composition of classes of primitive asteroids, for instance those including the parent bodies of carbonaceous chondrites. These asteroids may have played an important role for the delivery of prebiotic compounds to Earth during the early phases of solar system' s history and, as such, are at the center of attention of the planetary science community. </div>

AES Studies on the Ti/N Compositionally Gradient Film Deposited onto Ti-6Al-4V Alloy by Reactive DC Sputtering

2006 ◽  
Vol 12 (4) ◽  
pp. 356-361
Author(s):  
Tsutomu Sonoda ◽  
Akira Watazu ◽  
Kiyotaka Katou ◽  
Tadashi Asahina
Keyword(s):  
Fine Particles ◽  
Blood Compatibility ◽  
X Ray Diffraction ◽  
Compositional Gradient ◽  
Alloy Substrate ◽  
Peak Overlap ◽  
Dc Sputtering ◽  
Depth Direction ◽  
Auger Spectra ◽  
Deposited Film

Deposition of Ti/N compositionally gradient film onto Ti-6Al-4V alloy substrates was carried out by reactive DC sputtering, not only to improve the blood compatibility of the alloy but also to relax the stress concentrated at the interface between the film and the alloy substrate. The compositional gradient was realized by varying continuously the nitrogen content in Ar-N2 sputter gas during deposition. In Auger electron spectroscopy (AES) analysis, Auger spectra were acquired in the N(E) mode using the beam brightness modulation (BBM) method to overcome the problem of the peak overlap of the principal Auger nitrogen transition peak (N-KLL) with one of titanium peaks (Ti-LMM). The deposited film appeared to be uniform and adhesive. TiN formation at the surface of the film was assumed, because of its yellow gold color and the X-ray diffraction (XRD) pattern for it. Under scanning electron microscopy, it was found that the surface had fine particles dispersed on a smooth accumulated deposit and that this depositing method improved the structural property of the film at the surface. According to AES in-depth profiles, the nitrogen (N) concentration in the film gradually decreased in the depth direction from the surface toward the alloy, confirming that a Ti/N compositionally gradient film had formed on the alloy substrate.

Nanoporous Films with Sub-10 nm in Pore Size from Acid-Cleavable Block Copolymers

2017 ◽  
Vol 38 (5) ◽  
pp. 1600662 ◽  
Author(s):  
Yayuan Li ◽  
Yawei Xu ◽  
Shubo Cao ◽  
Yongbin Zhao ◽  
Ting Qu ◽  
...  
Keyword(s):  
Block Copolymers ◽  
Pore Size ◽  
Nanoporous Films

Electrical, Mechanical, and Structural Properties of Fluoro-Containing Poly(silsesquioxanes) Based Porous Low k Thin Films

2003 ◽  
Vol 766 ◽  
Author(s):  
Jingyu Hyeon-Lee ◽  
Jihoon Rhee ◽  
Jungbae Kim ◽  
Jin-Heong Yim ◽  
Seok Chang
Keyword(s):  
Thin Films ◽  
Pore Size ◽  
Dielectric Constants ◽  
Commercial Application ◽  
Porous Films ◽  
Low Dielectric ◽  
Nanoporous Films ◽  
Positronium Annihilation ◽  
Positronium Annihilation Lifetime Spectroscopy ◽  
Low K

AbstractLow dielectric fluoro-containing poly(silsesquioxanes) (PSSQs) have been synthesized using trifluoropropyl trimethoxysilane (TFPTMS), methyl trimethoxysilane (MTMS), and 2, 4, 6, 8-tetramethyl-2, 4, 6, 8-tetra(trimethoxysilylethyl) cyclotetrasiloxane. The properties of fluorocontaining PSSQs based thin films were studied by electrical, mechanical, and structural characterization. Film was spun on a silicon substrate, baked at 150°C and 250°C for 1 minute, respectively, and cured in the furnace at 420°C for 1 hour under vacuum condition. Thermally decomposable trifluoropropyl groups of the fluoro-containing PSSQ were served as a pore generator and partially contributed to lower a dielectric constant. â-cyclodextrin (CD) was also employed as a pore generator. The concentration of the pore generator in the film was varied from 0 to 30 %. The dielectric constants of the porous PSSQ films were found to be in the range of 2.7 – 1.9 (at 100 kHz). Hardness and Young's modulus of the films were measured by nano-indentation. The elastic modulus and hardness of the porous films were well correlated with the concentration of the pore generators. Positronium Annihilation Lifetime Spectroscopy (PALS) was employed to characterize a pore size of the porous fluoro-containing PSSQ film. The pore size of the film was less than 2.2 nm. The nanoporous films showed quite promising properties for commercial application.

scholarly journals Nanoporous Polymer Films from Immiscible Polymer Blends: Pore Size and Composition Dependence

2004 ◽  
Vol 856 ◽  
Author(s):  
Tong Liu ◽  
Rahmi Ozisik ◽  
Richard W. Siegel
Keyword(s):  
Pore Size ◽  
Polymer Films ◽  
Spin Coating ◽  
Composition Dependence ◽  
Processing Parameters ◽  
Immiscible Polymer Blends ◽  
Immiscible Blends ◽  
Nanoporous Films ◽  
Phase Separation Process ◽  
Poly Caprolactone

ABSTRACTNanoporous polymer films have been prepared using immiscible blends of polyetherimide (PEI) and poly(caprolactone diol) (PCLD). The films were prepared by spin-coating from a common solvent — dichloromethane (DCM). To create the nanoporous films, PCLD was removed by immersing the films in acetone, which dissolves PCLD only. Field emission scanning electron microscopy was used to study the porous structure. The pore structure of the films was affected by many factors such as composition of the blend, molecular weight, and various processing parameters. The formation of nanometer size pores was mainly due to the fast phase separation process during spin-coating. The pore size and pore size distribution was found to depend on the blend composition.

scholarly journals Fabrication of highly-specific SERS substrates by co-precipitation of functional nanomaterials during the self-sedimentation of silver nanowires into a nanoporous film

2015 ◽  
Vol 51 (7) ◽  
pp. 1309-1312 ◽  
Author(s):  
Rui Liu ◽  
Jie-fang Sun ◽  
Dong Cao ◽  
Li-qiang Zhang ◽  
Jing-fu Liu ◽  
...  
Keyword(s):  
Silver Nanowires ◽  
Functional Materials ◽  
The Self ◽  
Sers Substrate ◽  
Functional Nanomaterials ◽  
Nanoporous Film ◽  
Sers Substrates ◽  
Nanoporous Films ◽  
Co Precipitation

In this report, we propose and demonstrate the fabrication of a highly-specific SERS substrate by co-precipitating of functional materials, such as nanosorbents and nanocatalysts, into Ag nanoporous films.

Preparation of Porous Polymer Membrane with Controllable Pore Size via Spray Spinning

2017 ◽  
Vol 909 ◽  
pp. 157-162
Author(s):  
Wen Ting Sun ◽  
Shuang Xi Liu ◽  
Xiao Yu Hu ◽  
Qiu Ying Jia ◽  
Ya Qin Shen ◽  
...  
Keyword(s):  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Polymer Membranes ◽  
Processing Parameters ◽  
Polymer Membrane ◽  
Water Soluble ◽  
Porous Polymer ◽  
The Novel ◽  
Uniform Pore Size

Polymer membranes with fixed pore size or narrow pore size distribution can be used for special separation. However, polymer membranes prepared by conventional method usually have wide pore size distribution and the pore size is hard to control. Here we prepared a porous polymer membrane with uniform pore size via spraying a blend of polystyrene (PS) and polyethylene oxide (PEO) on a filtration paper. Dissolving the water-soluble component (PEO) forms the pore and varying the ratios of PEO in the blend controls the pore size. The pore size and size distribution are also affected by processing parameters, such as the flow rate of solution and carrier gas, and gap length. The morphologies of the membrane are observed using scanning electron microscopy (SEM). The novel polymer membrane with controllable and uniform pore size will be used for the separation of solutes with predictable sizes.

Promoting nitrogen photofixation over a periodic WS2@TiO2 nanoporous film

2020 ◽  
Vol 8 (3) ◽  
pp. 1059-1065 ◽  
Author(s):  
Li Shi ◽  
Zhao Li ◽  
Licheng Ju ◽  
Alejandro Carrasco-Pena ◽  
Nina Orlovskaya ◽  
...  
Keyword(s):  
Nanoporous Film ◽  
Nanoporous Films

WS2@TiO2 nanoporous films were fabricated by implanting WS2 nanosheets in TiO2 nanoporous films and show efficient photocatalytic N2 fixation.

Synthesis of Porous Noble Metal Films With Tunable Porosity by Timed Dealloying

2018 ◽  
Author(s):  
Stanislau Niauzorau ◽  
Placid Ferreira ◽  
Bruno Azeredo
Keyword(s):  
Thin Films ◽  
Pore Size ◽  
Pore Volume ◽  
Volume Fraction ◽  
Chemical Catalysis ◽  
Nanoporous Films ◽  
Simple Strategy ◽  
Pore Volume Fraction ◽  
Nanoporous Metal ◽  
High Degree

Nanoporous metal foams have an increasing importance in applications such as chemical catalysis, energy storage, and nanomedicine. This paper examines a simple strategy for controlling the pore volume fraction and pore size of nanoporous films synthesized by dealloying thin-films. By means of controlling the temperature and concentration of nitric acid in dealloying of AgAu thin-films, partially dealloyed AgAu nanoporous films are produced with a high degree of control over the pore size and pore volume fraction. Such capability enables the design of nanoporous metal catalysts materials with desired morphology.

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