scholarly journals Protection of LiFePO4 against Moisture

Materials ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 942 ◽  
Author(s):  
Nicolas Delaporte ◽  
Michel L. Trudeau ◽  
Daniel Bélanger ◽  
Karim Zaghib
Keyword(s):  
Photoelectron Spectroscopy ◽  
Inductively Coupled Plasma ◽  
Atomic Emission ◽  
Carbon Surface ◽  
Water Contact ◽  
Inductively Coupled ◽  
Spontaneous Reduction ◽  
Angle Measurements ◽  
Contact Angle Measurements ◽  
Carbon Coated

In this study, a carbon-coated LiFePO4 (LFP/C) powder was chemically grafted with trifluoromethylphenyl groups in order to increase its hydrophobicity and to protect it from moisture. The modification was carried out by the spontaneous reduction of in situ generated 4-trifluoromethylphenyl ions produced by the diazotization of 4-trifluoromethylaniline. X-ray photoelectron spectroscopy was used to analyze the surface organic species of the modified powder. The hydrophobic properties of the modified powder were investigated by carrying out its water contact angle measurements. The presence of the trifluoromethylphenyl groups on the carbon-coated LiFePO4 powder increased its stability in deionized water and reduced its iron dissolution in the electrolyte used for assembling the battery. The thermogravimetric and inductively coupled plasma atomic emission spectroscopy analyses revealed that 0.2–0.3 wt.% Li was deinserted during grafting and that the loading of the grafted molecules varied from 0.5 to 0.8 wt.% depending on the reaction conditions. Interestingly, the electrochemical performance of the modified LFP/C was not adversely affected by the presence of the trifluoromethylphenyl groups on the carbon surface. The chemical relithiation of the grafted samples was carried out using LiI as the reducing agent and the lithium source in order to obtain fully lithiated grafted powders.

Photocatalytic Oxidation of Alcohols Over Magnetically Recoverable Gold Supported Iron Oxide Nanoparticles

2019 ◽  
Vol 11 (12) ◽  
pp. 1731-1738 ◽  
Author(s):  
Ma Hui ◽  
Wu Juzhen ◽  
Zhao Li ◽  
Zhou Zheng ◽  
Guo Jiahu
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Inductively Coupled Plasma ◽  
Photocatalytic Oxidation ◽  
Organic Dyes ◽  
Atomic Emission ◽  
One Pot ◽  
X Ray ◽  
Inductively Coupled ◽  
Oxidation Of Alcohols

A one-pot simple and efficient synthetic route for the synthesis of Au-loaded Fe2O3 nanoparticles was developed, and this material's photocatalytic activity for visible light assisted oxidation of alcohols and degradation of organic dye were studied. As-synthesized nanostructured catalyst was characterised by powder X-ray diffraction (XRD), transmission electron microscopy (HRTEM), scanning electron microscopy (SEM), SEM-mapping, X-ray photoelectron spectroscopy (XPS), N2 adsorption–desorption isotherm (BET), and inductively coupled plasma-atomic emission spectroscopy (ICP-AES). It was observed that 5–10 nm Au-nanoparticles supported on 10–80 nm Fe2O3 shows boomerang-shaped nanoparticle. Gold loading of 1 wt% shows high conversion and selectivity towards the target product aldehyde. The synthesized nanomaterial also proved to be an excellent photocatalyst for degradation of organic dyes such as methylene blue (MB) and rhodamine B (RhB). The catalyst proved to be noteworthy as it does not loss in its catalytic activity even after five cycles of reuse.

Comparison of Molecular Monolayer Interface Treatments in Organic-inorganic Photovoltaic Devices

2009 ◽  
Vol 1154 ◽  
Author(s):  
Jamie M. Albin ◽  
Darick J. Baker ◽  
Cary G. Allen ◽  
Thomas E. Furtak ◽  
Reuben T. Collins ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Molecular Layer ◽  
Sol Gel ◽  
Photovoltaic Devices ◽  
Water Contact ◽  
Angle Measurements ◽  
Contact Angle Measurements ◽  
Ir Transmission ◽  
Transmission Measurements ◽  
Molecular Layers

AbstractIn this study, we explore the effects of alkyl surface terminations on ZnO for inverted, planar ZnO/poly(3-hexylthiophene) (P3HT) solar cells using two different attachment chemistries. Octadecylthiol (ODT) and octadecyltriethoxysilane (OTES) molecules were used to create 18-carbon alkyl surface molecular layers on sol gel-derived ZnO surfaces. Molecular layer formation was confirmed and characterized using water contact angle measurements, infrared (IR) transmission measurements, and X-ray photoelectron spectroscopy (XPS). The performances of the ZnO/P3HT photovoltaic cells made from ODT- and OTES-functionalized ZnO were compared. The ODT-modified devices had higher efficiencies than OTES-modified devices, suggesting that differences in the attachment scheme affect the efficiency of charge transfer through the molecular layers at the treated ZnO surface.

scholarly journals Fabricating Antibacterial and Antioxidant Electrospun Hydrophilic Polyacrylonitrile Nanofibers Loaded with AgNPs by Lignin-Induced In-Situ Method

Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 748
Author(s):  
Md. Kaiser Haider ◽  
Azeem Ullah ◽  
Muhammad Nauman Sarwar ◽  
Takumi Yamaguchi ◽  
Qianyu Wang ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Inductively Coupled Plasma ◽  
Atomic Emission ◽  
Emission Spectrometry ◽  
Burst Release ◽  
Bacterial Strains ◽  
Plasma Atomic Emission Spectrometry ◽  
Water Contact ◽  
X Ray ◽  
E Coli

Concerning the environmental hazards owing to the chemical-based synthesis of silver nanoparticles (AgNPs), this study aimed to investigate the possibility of synthesizing AgNPs on the surface of polyacrylonitrile (PAN) nanofibers utilizing biomacromolecule lignin. SEM observations revealed that the average diameters of the produced nanofibers were slightly increased from ~512 nm to ~673 nm due to several factors like-swellings that happened during the salt treatment process, surface-bound lignin, and the presence of AgNPs. The presence of AgNPs was validated by transmission electron microscope (TEM) and X-ray photoelectron spectroscopy (XPS) analysis. The amount of synthesized AgNPs on PAN nanofibers was found to be dependent on both precursor silver salt and reductant lignin concentration. Fourier transform infrared-attenuated total reflectance (FTIR-ATR) spectra confirm the presence of lignin on PAN nanofibers. Although the X-ray diffraction pattern did not show any AgNPs band, the reduced intensity of the stabilized PAN characteristics bands at 2θ = 17.28° and 29.38° demonstrated some misalignment of PAN polymeric chains. The water contact angle (WCA) of hydrophobic PAN nanofibers was reduced from 112.6 ± 4.16° to 21.4 ± 5.03° for the maximum AgNPs coated specimen. The prepared membranes exhibited low thermal stability and good swelling capacity up to 20.1 ± 0.92 g/g and 18.05 ± 0.68 g/g in distilled water and 0.9 wt% NaCl solution, respectively. Coated lignin imparts antioxidant activity up to 78.37 ± 0.12% at 12 h of incubation. The resultant nanofibrous membranes showed a proportional increase in antibacterial efficacy with the rise in AgNPs loading against both Gram-positive S. aureus and Gram-negative E. coli bacterial strains by disc diffusion test (AATCC 147-1998). Halos for maximum AgNPs loading was calculated to 18.89 ± 0.15 mm for S. aureus and 21.38 ± 0.17 mm for E. coli. An initial burst release of silver elements within 24 h was observed in the inductively coupled plasma-atomic emission spectrometry (ICP-AES) test, and the release amounts were proportionally expansive with the increase in Ag contents. Our results demonstrated that such types of composite nanofibers have a strong potential to be used in biomedicine.

scholarly journals Interface Characteristics and Anticorrosion Performances of Cold Galvanizing Coatings Incorporated with γ-chloropropyl Triethoxysilane on Hot-Dip Galvanized Steel

Coatings ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 402
Author(s):  
Jiwen Li ◽  
Qiumeng Wang ◽  
Ningjie Gao ◽  
Izuchukwu Kenneth Nwokolo ◽  
Wanyu Zhang ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Large Scale ◽  
Galvanized Steel ◽  
Water Contact ◽  
Electrochemical Tests ◽  
Angle Measurements ◽  
Dry Adhesion ◽  
Interface Characteristics ◽  
Contact Angle Measurements ◽  
Poor Adhesion

The cold galvanizing coatings (CGCs) are used to repair old hot-dip galvanized steel (HDG) in numerous anticorrosion engineering, but poor adhesion of the CGC restricts its large-scale applications in the industries. For the purpose of overcoming the weak adhesion problems of the CGC on HDG, γ-chloropropyl triethoxysilane (CPTES) was added directly into cold galvanizing coatings (CPTES/CGC). Interface characteristics and related corrosion protection behaviors were investigated by the pull-off adhesion test, water contact angle measurements, Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), and electrochemical tests. The experimental results revealed that, there is an increase by 19.1% of the CPTES/CGC surface free energy when compared with that of CGC. In addition, Si–O–Si and Si–O–Zn bonds were found in the CPTES/CGC, which indicate new network structures formed inside the CPTES/CGC, between the interface of the CPTES/CGC and HDG substrate, resulting in dry adhesion, wet adhesion, and the cathodic protection time of CPTES/CGC increased by 50% and 200% and 300% respectively compared with the CGC.

Plasma Modification of DLC Films and the Resulting Surface Biocompatibility

2014 ◽  
Vol 783-786 ◽  
pp. 1396-1401 ◽  
Author(s):  
Mei Wang ◽  
Ying Zhao ◽  
Rui Zhen Xu ◽  
Ming Zhang ◽  
Ricky K.Y. Fu ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Plasma Modification ◽  
Cell Viability Assay ◽  
Water Contact ◽  
Viability Assay ◽  
Angle Measurements ◽  
Contact Angle Measurements ◽  
Generate Surface ◽  
A Cell ◽  
P Type

Diamond-like carbon (DLC) films were synthesized on a p-type silicon wafer using radio-frequency plasma composed of a mixture of Ar and C2H2(ratio of 7 to 28). NH3plasma treatment of as-grown DLC substrate was carried out to generate surface-terminal amino groups while oxidation of as-grown DLC was performed in O2plasma. X-ray photoelectron spectroscopy (XPS) was used to characterize the different surface functions formed on DLC surfaces. Water contact angle measurements indicate different wetbility of modified surfaces. The cell (Mouse MC3T3-E1pre-osteoblasts) morphology and proliferation were monitored to evaluate the biocompatibility of the modified DLC surfaces. A cell count kit-8 (CCK-8 Beyotime) was employed to determine quantitatively the viable pre-osteoblasts. The cell viability assay shows that osteoblast proliferation are improved on NH3and O2plasma-treated DLC surface after culturing for 1day, 2days and 3 days. The cell-surface interactions are studied by fluorescence microscopy. There are more osteoblasts as well as better spreading on the aminated and oxidized surfaces after culturing for 3 days. In summary, compared to the as-grown sample, the modified DLC shows better biocompatibility.

Magnetic properties of ZnFe2O4 nanoparticles

Open Physics ◽  
2012 ◽  
Vol 10 (2) ◽  
Author(s):  
Niko Guskos ◽  
Spiros Glenis ◽  
Janusz Typek ◽  
Grzegorz Zolnierkiewicz ◽  
Pawel Berczynski ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Photoelectron Spectroscopy ◽  
Inductively Coupled Plasma ◽  
Fine Particles ◽  
Atomic Emission ◽  
Magnetic Interactions ◽  
Mixed System ◽  
X Ray ◽  
Inductively Coupled ◽  
Znfe2o4 Nanoparticles

AbstractFine particles of ZnFe2O4 were synthesized by a wet chemical method in the (80 wt.% Fe2O3 + 20 wt.% ZnO) system. The morphological and structural properties of the mixed system were investigated by scanning electron microscopy, X-ray diffraction, inductively coupled plasma atomic emission, and X-ray photoelectron spectroscopy. The major phase was determined to be the ZnFe2O4 spinel with particle size of 11 nm. The magnetic properties of the material were investigated by ferromagnetic resonance (FMR) in the temperature range from liquid helium to room temperature. A very intense, asymmetric FMR signal from ZnFe2O4 nanoparticles was recorded, which has been analyzed in terms of two Callen-lineshape lines. Temperature dependence of the FMR parameters was obtained from fitting the experimental lines with two component lines. Analysis of the FMR spectra in terms of two separate components indicates the presence of strongly anisotropic magnetic interactions.

scholarly journals Facile Preparation of Pd/UiO-66-v for the Conversion of Furfuryl Alcohol to Tetrahydrofurfuryl Alcohol under Mild Conditions in Water

Nanomaterials ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1698 ◽  
Author(s):  
Yanliang Yang ◽  
Dongsheng Deng ◽  
Dong Sui ◽  
Yanfu Xie ◽  
Dongmi Li ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Inductively Coupled Plasma ◽  
Furfuryl Alcohol ◽  
Furan Ring ◽  
Physical Adsorption ◽  
Energy Dispersive Spectrometer ◽  
Atomic Emission ◽  
X Ray ◽  
Inductively Coupled ◽  
Mild Conditions

The hydrogenation of furan ring in the biomass-derived furans is of great importance for the conversion of biomass to valuable chemicals. Fabrication of high activity and selectivity catalyst for this hydrogenation under mild conditions was one of the focuses of this research. In this manuscript, UiO-66-v, in which vinyl bonded to the benzene ring, was first prepared. Then, the uniformly distributed vinyl was used as the reductant for the preparation of Pd/UiO-66-v. The catalyst was characterized by X-ray diffraction, thermogravimetric, N2 physical adsorption/desorption, X-ray photoelectron spectroscopy, scanning electron microscope, transmission electron microscopy, energy dispersive spectrometer elemental mappings, and inductively coupled plasma atomic emission spectroscopy to find the Pd/UiO-66-v had a narrow palladium nanoparticles size of 3–5 nm and maintained the structure and thermal stability of UiO-66-v. The Pd/UiO-66-v was used for the hydrogenation of furfuryl alcohol to tetrahydrofurfuryl alcohol in water. 99% conversion of furfuryl alcohol was obtained with 90% selectivity to tetrahydrofurfuryl alcohol after reacted at 0.5 MPa H2, 303 K for 12 h. The Pd/UiO-66-v was proved to be effective for the hydrogenation of furan ring in furans and could be used for at least five times.

scholarly journals Strong Biomimetic Immobilization of Pt-Particle Catalyst on ABS Substrate Using Polydopamine and Its Application for Contact-Lens Cleaning with H2O2

Nanomaterials ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 114 ◽  
Author(s):  
Yuji Ohkubo ◽  
Tomonori Aoki ◽  
Daisuke Kaibara ◽  
Satoshi Seino ◽  
Osamu Mori ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Contact Lens ◽  
Photoelectron Spectroscopy ◽  
Inductively Coupled Plasma ◽  
Acrylonitrile Butadiene Styrene ◽  
Atomic Emission ◽  
H2o2 Concentration ◽  
H2o2 Decomposition ◽  
Inductively Coupled ◽  
Considerable Problem

Polydopamine (PDA)—a known adhesive coating material—was used herein to strongly immobilize a Pt-particle catalyst on an acrylonitrile–butadiene–styrene copolymer (ABS) substrate. Previous studies have shown that the poor adhesion between Pt particles and ABS surfaces is a considerable problem, leading to low catalytic durability for H2O2 decomposition during contact-lens cleaning. First, the ABS substrate was coated with PDA, and the PDA film was evaluated by X-ray photoelectron spectroscopy. Second, Pt particles were immobilized on the PDA-coated ABS substrate (ABS-PDA) using the electron-beam irradiation reduction method. The Pt particles immobilized on ABS-PDA (Pt/ABS-PDA) were observed using a scanning electron microscope. The Pt-loading weight was measured by inductively coupled plasma atomic emission spectroscopy. Third, the catalytic activity of the Pt/ABS-PDA was evaluated as the residual H2O2 concentration after immersing it in a 35,000-ppm H2O2 solution (the target value was less than 100 ppm). The catalytic durability was evaluated as the residual H2O2 concentration after repeated use. The PDA coating drastically improved both the catalytic activity and durability because of the high Pt-loading weight and strong adhesion among Pt particles, PDA, and the ABS substrate. Plasma treatment prior to PDA coating further improved the catalytic durability.

scholarly journals Polysaccharide-Based Bilayer Coatings for Biofilm-Inhibiting Surfaces of Medical Devices

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4720
Author(s):  
Urban Ajdnik ◽  
Thomas Luxbacher ◽  
Alenka Vesel ◽  
Alja Štern ◽  
Bojana Žegura ◽  
...  
Keyword(s):  
Hyaluronic Acid ◽  
Medical Devices ◽  
Photoelectron Spectroscopy ◽  
Water Contact ◽  
Polyelectrolyte Complexes ◽  
Pdms Surface ◽  
Additional Layer ◽  
Angle Measurements ◽  
Contact Angle Measurements ◽  
Bilayer Coatings

Chitosan (Chi) and 77KS, a lysine-derived surfactant, form polyelectrolyte complexes that reverse their charge from positive to negative at higher 77KS concentrations, forming aggregates that have been embedded with amoxicillin (AMOX). Dispersion of this complex was used to coat polydimethylsiloxane (PDMS) films, with an additional layer of anionic and hydrophilic hyaluronic acid (HA) as an outer adsorbate layer to enhance protein repulsion in addition to antimicrobial activity by forming a highly hydrated layer in combination with steric hindrance. The formed polysaccharide-based bilayer on PDMS was analyzed by water contact angle measurements, X-ray photoelectron spectroscopy (XPS), and surface zeta (ζ)-potential. All measurements show the existence and adhesion of the two layers on the PDMS surface. Part of this study was devoted to understanding the underlying protein adsorption phenomena and identifying the mechanisms associated with biofouling. Thus, the adsorption of a mixed-protein solution (bovine serum albumin, fibrinogen, γ-globulin) on PDMS surfaces was studied to test the antifouling properties. The adsorption experiments were performed using a quartz crystal microbalance with dissipation monitoring (QCM-D) and showed improved antifouling properties by these polysaccharide-based bilayer coatings compared to a reference or for only one layer, i.e., the complex. This proves the benefit of a second hyaluronic acid layer. Microbiological and biocompatibility tests were also performed on real samples, i.e., silicone discs, showing the perspective of the prepared bilayer coating for medical devices such as prostheses, catheters (balloon angioplasty, intravascular), delivery systems (sheaths, implants), and stents.

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