scholarly journals Evaluation of New, Sputtered Carbon SPME Fibers with a Multi-Functional Group Test Mixture

Separations ◽  
2021 ◽  
Vol 8 (12) ◽  
pp. 228
Author(s):  
Dhananjay I. Patel ◽  
Tuhin Roychowdhury ◽  
Collin Jacobsen ◽  
Colton Myers ◽  
Jason S. Herrington ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Functional Group ◽  
Solid Phase ◽  
Chemical Properties ◽  
Analytical Techniques ◽  
Fused Silica ◽  
Water Contact ◽  
Fiber Fabrication ◽  
Wide Range ◽  
Throw Distance

We report the first fabrication of sputtered carbon, solid-phase microextraction (SPME) fibers. These fibers have competitive extraction capabilities compared with the commercial carbon wide range (CWR) SPME fiber. This report also includes a demonstration of a newly developed SPME test mix that includes 15 different compounds with a wide range of functional groups and chemical properties. The fiber fabrication process involves sputtering carbon onto fused silica fibers, and the effects of throw distance on the morphology of the carbon coatings were studied. Four different carbon coating thicknesses were evaluated, with PDMS added as a stationary phase. These fibers were characterized with multiple analytical techniques, including scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), water contact angle (WCA) goniometry, as well as headspace (HS) and direct immersion (DI)–SPME–GC–MS. The best (11.5 µm) sputtered carbon SPME fibers, with and without PDMS, were evaluated using the new evaluation mix and compared with the commercial CWR fiber and a previously sputtered/developed silicon fiber. The new probe mix helped elucidate differences among the fibers, which would have been missed by current commercial test mixes. The sputtered carbon SPME fibers showed similar functional group selectivity as commercial CWR fibers. However, the sputtered carbon fibers showed higher responses per volume compared with the commercial CWR fiber, indicating the porous morphology of the sputtered carbon has the ability to overcome large phase thickness/volume discrepancies and increase the relative recovery for various compounds.

Alternative technique for analyzing instrumented indentation data

2001 ◽  
Vol 16 (11) ◽  
pp. 3202-3206 ◽  
Author(s):  
W. C. Oliver
Keyword(s):  
Analytical Techniques ◽  
Fused Silica ◽  
New Technique ◽  
Alternative Technique ◽  
Berkovich Indenter ◽  
Instrumented Indentation ◽  
Materials Properties ◽  
Analysis Technique ◽  
Wide Range ◽  
Pile Up

A new analysis technique for calculating the hardness, modulus, and contact area from indentation data obtained using pyramidal or conical indenters was formulated and compared with another commonly used technique. Experimental data using a Berkovich indenter to indent fused silica and tungsten were examined. In addition, finite element modeling results were used to examine the effectiveness of the analytical techniques when a wide range of materials properties was considered. The new technique relies on the slope of the loading curve rather than the indenter displacement as an input. It is shown that the new technique is far less affected by the deviation of the geometry of the indenter from its intended shape. This effect removes the necessity to have detailed descriptions of the precise tip geometry in some cases. The new technique does not reduce errors associated with pile up of material near the indenter.

Preparation of BiOI Photocatalysts with Controllable Wettability and Their Enhanced Catalytic Degradation of 17α-ethinylestradiol

NANO ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. 2050150
Author(s):  
Sifeng Zhang ◽  
Lulu Wang ◽  
Ziguang Zheng ◽  
Yunrui Hei ◽  
Luting Zhou ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Contact Angle ◽  
Water Contact Angle ◽  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance Spectroscopy ◽  
Removal Rate ◽  
Chemical Properties ◽  
Water Contact ◽  
X Ray ◽  
Photocatalytic Performances

In this study, BiOI was successfully synthesized using a hydrothermal method and then modified using hexamethyldisiloxane (HMDS) and polydimethylsiloxane (PDMS), respectively, to achieve a controllable water contact angle (WCA) for these materials. The physical and chemical properties of the modified BiOI were characterized using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer–Emmett–Teller (BET) method, UV–Vis diffuse reflectance spectroscopy (DRS), Fourier transform infrared (FTIR) spectroscopy and water contact angle (WCA) techniques. Compared with the unmodified BiOI, HMDS- and PDMS-modified BiOI had higher photocatalytic activities for 17[Formula: see text]-ethinylestradiol (EE2) under visible light irradiation for 28 min after reacting in dark for 30 min. When BiOI was modified using HMDS and PDMS, the WCA increased. When the WCA of HMDS- and PDMS-modified BiOI was controlled in the range of 25.3–32.7[Formula: see text] and 38.1–78.5[Formula: see text], respectively, better photocatalytic performances were achieved. When the WCA of modified BiOI was 29.7[Formula: see text] (1.00[Formula: see text]mL HMDS) and 47.8[Formula: see text] (0.20[Formula: see text]mL PDMS), the best photocatalytic performances were achieved with EE2 removal rate of 98.85% and 98.72%, respectively, however, the removal rate of the unmodified BiOI was 85.01%. The reaction rate constants of BiOI (1.00[Formula: see text]mL HMDS) and BiOI (0.20[Formula: see text]mL PDMS) were 2.33 and 2.15 times higher than the unmodified BiOI, respectively. The improved catalytic performances of modified BiOI could be attributed to the synergistic effect of the controlled wettability of BiOI and functional groups on the surface of photocatalysts.

Determination of Ten N-Nitrosoamino Acids in Cured Meat Products

1990 ◽  
Vol 73 (2) ◽  
pp. 226-230
Author(s):  
John W Pensabene ◽  
Walter Fiddler
Keyword(s):  
Solid Phase ◽  
Methyl Esters ◽  
Meat Products ◽  
Sulfamic Acid ◽  
Fused Silica ◽  
Wide Range ◽  
Cured Meat ◽  
Glass Column ◽  
Fused Silica Capillary ◽  
Chemiluminescence Detector

Abstract A rapid, sensitive, and accurate solid-phase extraction method was developed for the measurement of 10 N-nitrosoamino acids (NAAs) in cured meat products. In the procedure, the comminuted meat was mixed with sulfamic acid and Celite, and then added to a glass column containing anhydrous sodium sulfate. The column was washed with pentane, and the NAAs were eluted with ethyl acetate. The eluate was concentrated, then derivatized with diazomethane followed by acetic anhydride-pyridine reagent. The NAA methyl esters and their acylated hydroxy derivatives were separated by gas chromatography on a DB-5 fused silica capillary column and quantitated with a thermal energy analyzer, a chemiluminescence detector specific for nitric oxide derived from the thermal denitrosation of nitrosamines. Recovery of 10 of the NAAs exceeded 75% at the 10 ppb level. The method is applicable to a wide range of cured meat products.

Wettability Control of Gold Surfaces Modified with Benzenethiol Derivatives: Water Contact Angle and Thermal Stability

2016 ◽  
Vol 16 (4) ◽  
pp. 3295-3300 ◽  
Author(s):  
Shingo Tatara ◽  
Yasutaka Kuzumoto ◽  
Masatoshi Kitamura
Keyword(s):  
Thermal Stability ◽  
Contact Angle ◽  
Water Contact Angle ◽  
Photoelectron Spectroscopy ◽  
Water Contact ◽  
Wide Range ◽  
Water Wettability ◽  
Modified Surface ◽  
Surface Modified ◽  
Activation Energy Of Desorption

The water wettability of Au surfaces has been controlled using various benzenethiol derivatives including 4-methylbenzenethiol, pentafluorobenzenethiol, 4-fluorobenzenethiol, 4-methoxybenzenethiol, 4-nitrobenzenethiol, and 4-hydroxybenzenethiol. The water contact angle of the Au surface modified with the benzenethiol derivative was found to vary in the wide range of 30.9° to 88.3°. The contact angle of the modified Au films annealed was also measured in order to investigate their thermal stability. The change in the contact angle indicated that the modified surface is stable at temperatures below about 400 K. Meanwhile, the activation energy of desorption from the modified surface was estimated from the change in the contact angle. The modified Au surface was also examined using X-ray photoelectron spectroscopy.

scholarly journals Investigations on Aging Behavior and Mechanism of Polyurea Coating in Marine Atmosphere

Materials ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 3636 ◽  
Author(s):  
Kaiyuan Che ◽  
Ping Lyu ◽  
Fei Wan ◽  
Mingliang Ma
Keyword(s):  
Photoelectron Spectroscopy ◽  
Functional Group ◽  
Chemical Properties ◽  
Chain Scission ◽  
Attenuated Total Reflectance ◽  
Marine Atmosphere ◽  
Stability Behavior ◽  
X Ray ◽  
Hard Segments ◽  
Group Change

In this investigation, the aging behaviors of polyurea coating exposed to marine atmosphere for 150 days were studied and the mechanism was analyzed. The influences on surface and mechanical properties, surface morphology, thermal stability behavior, as well as chemical changes evolution of the coating were investigated. By attenuated total reflectance fourier transform infrared spectroscopy (ATR–FTIR) and X-ray photoelectron spectroscopy (XPS), changes in the chemical properties of polyurea coatings before (PCB) and after 150 d (PCA) of aging were analyzed, and emphasis was given to the effect of aging on functional group change, the hydrogen bonding behavior, and phase separated morphology. The results displayed prominent chain scission during aging, such as N–H, C=O, and C–O–C and the hydrogen bonded urea carbonyl content showed a decrease trend. The relative content of soft and hard segments showed a significant change, which increased the degree of phase separation.

Surface Wettability of Polypropylene Non-Woven Using Atmospheric Pressure N2 Dielectric Barrier Discharge Plasma

2010 ◽  
Vol 455 ◽  
pp. 472-475
Author(s):  
Yan Zhang ◽  
Bo Zhao ◽  
Jing Lin Tong
Keyword(s):  
Dielectric Barrier Discharge ◽  
Photoelectron Spectroscopy ◽  
Atmospheric Pressure ◽  
Barrier Discharge ◽  
Chemical Properties ◽  
Angle Measurement ◽  
Surface Wettability ◽  
Dbd Plasma ◽  
Water Contact ◽  
Dielectric Barrier

In this thesis, the atmospheric pressure nitrogen dielectric barrier discharge (DBD) plasma modified polyproylene (PP) melt blown non-woven surface wettability are investigated. The change of surfaces physical and chemical properties are studied by water contact angle measurement and X-ray photoelectron spectroscopy (XPS) before and after plasma treatment. The experimental results indicate the surface hydrophilic can be greatly improved when the PP simples is treated by atmospheric pressure nitrogen DBD plasma for a short time. And a large number of oxygen-containing and nitrogen-containing functional groups are inplanted on the PP non-woven sample surface.

scholarly journals Silicalite-1 Layers as a Biocompatible Nano- and Micro-Structured Coating: An In Vitro Study on MG-63 Cells

Materials ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 3583 ◽  
Author(s):  
Martina Doubkova ◽  
Ivana Nemcakova ◽  
Ivan Jirka ◽  
Vitezslav Brezina ◽  
Lucie Bacakova
Keyword(s):  
Photoelectron Spectroscopy ◽  
Chemical Properties ◽  
In Vitro Study ◽  
Ammonium Hydroxide ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Orthopaedic Implants ◽  
Water Contact ◽  
Physico Chemical

Silicalite-1 is a purely siliceous form of zeolite, which does not contain potentially harmful aluminum in its structure as opposed to ZSM-5 aluminosilicate types of zeolite. This paper reports on a study of a silicalite-1 film, deposited on a silicon Si(100) substrate, as a potential anti-corrosive and biocompatible coating for orthopaedic implants. Silicalite-1 film was prepared in situ on the surface of Si(100) wafers using a reaction mixture of tetrapropyl-ammonium hydroxide (TPAOH), tetraethyl-orthosilicate (TEOS), and diH2O. The physico-chemical properties of the obtained surface were characterized by means of X-ray photoelectron spectroscopy, water contact angle measurement, atomic force microscopy, and scanning electron microscopy. The biocompatibility was assessed by interaction with the MG-63 cell line (human osteosarcoma) in terms of cell adhesion, morphology, proliferation, and viability. The synthesized silicalite-1 film consisted of two layers (b- and a, b-oriented crystals) creating a combination of micro- and nano-scale surface morphology suitable for cell growth. Despite its hydrophobicity, the silicalite-1 film increased the number of initially adhered human osteoblast-like MG-63 cells and the proliferation rate of these cells. The silicalite-1 film also improved the cell viability in comparison with the reference Si(100) substrate. It is therefore a promising candidate for coating of orthopaedic implants.

scholarly journals Friction Behavior of Silver Perrhenate in Oil as Lubricating Additive for Use at Elevated Temperatures

Materials ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2199
Author(s):  
Junhai Wang ◽  
Ting Li ◽  
Tingting Yan ◽  
Xiaoyi Wei ◽  
Xin Qu ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Elevated Temperatures ◽  
Synthesis Method ◽  
Chemical Properties ◽  
Solution Synthesis ◽  
Friction Behavior ◽  
Base Oil ◽  
X Ray ◽  
Wide Range ◽  
Alpha Olefin

In this study, we use an aqueous solution synthesis method to prepare silver perrhenate powders and suspend them into a poly alpha olefin (PAO) base oil with polyoxyethylene octylphenyl ether. Four ball tests and ball-on-disk reciprocating mode are performed to determine how silver perrhenate performs tribologically as a lubricating additive over a wide range of temperatures. The physical and chemical properties, as well as the lubricating mechanisms of the silver perrhenate additive, are characterized via X-ray diffraction, scanning electron microscope, Fourier transformation infrared spectroscopy, Raman spectrum, and X-ray photoelectron spectroscopy. The four-ball test results demonstrate that the oil added with silver perrhenate additive is more effective than the base oil in reducing friction and improving wear resistance, and provides the best lubricating performance when at a concentration of 0.5 wt%. The reciprocating mode findings indicate that the hybrid lubricant exhibits distinctively better tribological properties than the base oil at high temperatures, and its low shear strength and chemical inertness allow for low friction at elevated temperatures. The resulting silver perrhenate layer that incorporates native superalloy oxides on the worn surface can provide lubrication by serving as a barrier that prevents direct contact between the rubbing surfaces at elevated temperatures.

scholarly journals Osteoinduction Evaluation of Fluorinated Hydroxyapatite and Tantalum Composite Coatings on Magnesium Alloys

2021 ◽  
Vol 9 ◽  
Author(s):  
Zheng Cao ◽  
Li Li ◽  
Linjun Yang ◽  
LiLi Yao ◽  
Haiyan Wang ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Composite Coatings ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Implant Design ◽  
Water Contact ◽  
Thermal Synthesis ◽  
X Ray ◽  
Wide Range ◽  
Novel Strategy

Magnesium (Mg) alloys have a wide range of biomaterial applications, but their lack of biocompatibility and osteoinduction property impedes osteointegration. In order to enhance the bioactivity of Mg alloy, a composite coating of fluorinated hydroxyapatite (FHA) and tantalum (Ta) was first developed on the surface of the alloy through thermal synthesis and magnetron sputtering technologies in this study. The samples were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), energy dispersive spectroscopy (EDS) mapping, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and water contact angle measurement (WCA), which characterized the surface alternation and confirmed the deposition of the target FHA/Ta coating. The results of cell morphology showed that the MC3T3-E1 cells on the surface of Mg/FHA/Ta samples had the largest spreading area and lamellipodia. Moreover, the FHA coating endowed the surface with superior cell viability and osteogenic properties, while Ta coating played a more important role in osteogenic differentiation. Therefore, the combination of FHA and Ta coatings could synergistically promote biological functions, thus providing a novel strategy for implant design.

Recent Applications of High Resolution Electron Microscopy to Crystalline Arrays of Virus Particles

1978 ◽  
Vol 36 (3) ◽  
pp. 470-482 ◽  
Author(s):  
R.W. Horne
Keyword(s):  
Electron Microscopy ◽  
Image Processing ◽  
Analytical Techniques ◽  
Staining Technique ◽  
High Resolution Electron Microscopy ◽  
Optical Diffraction ◽  
Full Potential ◽  
Virus Particles ◽  
Resolution Electron ◽  
Wide Range

The technique of surrounding virus particles with a neutralised electron dense stain was described at the Fourth International Congress on Electron Microscopy, Berlin 1958 (see Home & Brenner, 1960, p. 625). For many years the negative staining technique in one form or another, has been applied to a wide range of biological materials. However, the full potential of the method has only recently been explored following the development and applications of optical diffraction and computer image analytical techniques to electron micrographs (cf. De Hosier & Klug, 1968; Markham 1968; Crowther et al., 1970; Home & Markham, 1973; Klug & Berger, 1974; Crowther & Klug, 1975). These image processing procedures have allowed a more precise and quantitative approach to be made concerning the interpretation, measurement and reconstruction of repeating features in certain biological systems.

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