scholarly journals Towards Understanding the Role of Surface Gas Nanostructures: Effect of Temperature Difference Pretreatment on Wetting and Flotation of Sulfide Minerals and Pb-Zn Ore

Nanomaterials ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1362
Author(s):  
Yuri Mikhlin ◽  
Anton Karacharov ◽  
Sergey Vorobyev ◽  
Alexander Romanchenko ◽  
Maxim Likhatski ◽  
...  
Keyword(s):  
Temperature Difference ◽  
Photoelectron Spectroscopy ◽  
Sessile Drop ◽  
Surface Composition ◽  
Cold Water ◽  
Contact Angles ◽  
Effect Of Temperature ◽  
Force Microscopy ◽  
Atomic Force ◽  
Composition Of Minerals

Surface nanobubbles at hydrophobic interfaces now attract much attention in various fields but their role in wetting-related phenomena is still unclear. Herein, we report the effect of a preliminary contact of “hot” solids with cold water previously proposed for generation of surface nanobubbles, on wettability of compact materials and flotation of particulate galena (PbS), sphalerite (ZnS), and Pb-Zn sulfide ore. Atomic force microscopy was applied to visualize the nanobubbles at galena crystals heated in air and contacted with cold water; X-ray photoelectron spectroscopy was used to characterize the surface composition of minerals. Contact angles measured with the sessile drop of cold water were found to increase when enhancing the support temperature from 0 to 80 °C for sphalerite and silica, and to pass a maximum at 40–60 °C for galena and pyrite (FeS2) probably due to oxidation of sulfides. The temperature pretreatment depressed the recovery of sulfides in collectorless schemes and improved the potassium butyl xanthate-assisted flotation both for single minerals and Gorevskoye Pb-Zn ore. The results suggest that the surface nanobubbles prepared using the temperature difference promote flotation if minerals are rather hydrophobic and insignificantly oxidized, so the addition of collector and activator (for sphalerite) is necessary.

scholarly journals Synthesis of amphiphilic ABA triblock oligomer via ATRP and its surface properties

2017 ◽  
Vol 95 (5) ◽  
pp. 605-611 ◽  
Author(s):  
Lei Wang ◽  
Shaoqing Wen ◽  
Zhanxiong Li
Keyword(s):  
Photoelectron Spectroscopy ◽  
Microphase Separation ◽  
Gel Permeation Chromatography ◽  
Contact Angles ◽  
Chemical Compositions ◽  
Water Contact ◽  
Force Microscopy ◽  
Atomic Force ◽  
Poly Ethylene ◽  
Magnetic Resonances

A series of novel amphiphilic ABA-type poly(tridecafluorooctylacrylate)-poly(ethylene glycol)-poly(tridecafluorooctylacrylate) (henceforth referred to as p-TDFA-PEG-p-TDFA) triblock oligomers were successfully synthesized via atom transfer radical polymerization (ATRP) using well-defined Br-PEG-Br as macroinitiator and copper as catalyst. The block oligomers were characterized by Fourier transform infrared (FTIR) spectroscopy and 1H and 19F nuclear magnetic resonances (NMR). Gel permeation chromatography (GPC) showed that the block oligomers have been obtained with narrow molecular weight distributions of 1.22–1.33. X-ray photoelectron spectroscopy (XPS) was carried out to confirm the attachment of p-TDFA-PEG-p-TDFA onto the silicon substrate, together with the chemical compositions of p-TDFA-PEG-p-TDFA. The wetabilities of the oligomer films were measured by water contact angles (CAs). Water CAs of p-TDFA-PEG-p-TDFA film were measured and their morphologies were tested by atomic force microscopy (AFM). The result showed that the CAs of the oligomer films, which possess fluoroalkyl groups assembled on the outer surface, increase after heating due to the migration of fluoroalkyl groups and the resulted microphase separation of the p-TDFA-PEG-p-TDFA.

Thermal Stability and Analysis of Laser Deposited Platinum Films

2000 ◽  
Vol 624 ◽  
Author(s):  
G.J. Berry ◽  
J.A. Cairns ◽  
M.R. Davidson ◽  
Y.C. Fan ◽  
A.G. Fitzgerald ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Photoelectron Spectroscopy ◽  
Elevated Temperatures ◽  
Surface Composition ◽  
Direct Write ◽  
Force Microscopy ◽  
Annealing Conditions ◽  
Atomic Force ◽  
Transmission Electron ◽  
Induced Decomposition

ABSTRACTAs the trend towards device miniaturisation continues, surface effects and the thermal stability of metal deposits becomes increasingly important. We present here a study of the morphology and composition of platinum films, produced by the UV-induced decomposition of organometallic materials, under various annealing conditions. The surface composition of the metal deposits was studied by X-ray photoelectron spectroscopy, both as-deposited and following thermal treatment. In addition, the morphology of the surface was studied by atomic force microscopy which enabled the investigation of film restructuring. These studies were performed over a range of temperatures up to 1000°C in air and up to 600°C in reducing environments. Complementary information regarding the film morphology has been obtained from transmission electron microscopy. The data has been used to provide an insight into the effects of elevated temperatures on metal films deposited by a direct write method

Surface Modification of Polyetheretherketone by Helium/nitrogen and Nitrous Oxide Plasma Enhanced Chemical Vapour Deposition

2014 ◽  
Vol 33 (2) ◽  
pp. 147-153
Author(s):  
Stanisława Kluska ◽  
Elżbieta Pamuła ◽  
Stanisława Jonas ◽  
Zbigniew Grzesik
Keyword(s):  
Free Energy ◽  
Surface Free Energy ◽  
Photoelectron Spectroscopy ◽  
Sessile Drop ◽  
Chemical Vapour ◽  
Chemical Vapor ◽  
Morphological Characterization ◽  
Polar Component ◽  
Force Microscopy ◽  
Atomic Force

AbstractThe surface of the polyetheretherketone (PEEK) samples was modified by the plasma enhanced chemical vapor deposition (PECVD) in the mixture of He and N2 as well as in the N2O atmosphere. Morphological characterization of the PEEK as well as its surface roughness, chemical structure, and surface free energy were investigated by atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and sessile drop technique, respectively. The highest increase in the polar component of the total surface energy was observed for PEEK modified by He+N2 plasma, which correlated with significant increase in the concentration of oxygen and nitrogen-containing chemical functionalities as revealed by XPS. For PEEK submitted to N2O plasma treatment significant changes in surface topography and increase in roughness were observed, but changes in surface chemistry and surface free energy were mild.

scholarly journals The Oleofobization of Paper via Plasma Treatment

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2148
Author(s):  
Matic Resnik ◽  
Eva Levičnik ◽  
Žiga Gosar ◽  
Rok Zaplotnik ◽  
Janez Kovač ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Secondary Ion Mass Spectrometry ◽  
Surface Characteristics ◽  
High Volume ◽  
Barrier Properties ◽  
Contact Angles ◽  
Plasma Reactors ◽  
Force Microscopy ◽  
Atomic Force ◽  
Secondary Ion

Cellulose is a promising biomass material suitable for high volume applications. Its potential lies in sustainability, which is becoming one of the leading trends in industry. However, there are certain drawbacks of cellulose materials which limit their use, especially their high wettability and low barrier properties, which can be overcome by applying thin coatings. Plasma technologies present a high potential for deposition of thin environmentally friendly and recyclable coatings. In this paper, two different plasma reactors were used for coating two types of cellulose-based substrates with hexamethyldisiloxane (HMDSO). The changes in surface characteristics were measured by atomic force microscopy (AFM), scanning electron microscopy (SEM), surface free energy and contact angles measurements, X-ray photoelectron spectroscopy (XPS), and secondary ion mass spectrometry (SIMS). Successful oleofobization was observed for an industrial scale reactor where pure HMDSO was used in the absence of oxygen.

scholarly journals Modification of FA0.85MA0.15Pb(I0.85Br0.15)3 Films by NH2-POSS

Crystals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1544
Author(s):  
Yangyang Zhang ◽  
Na Liu ◽  
Haipeng Xie ◽  
Jia Liu ◽  
Pan Yuan ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Photoelectron Spectroscopy ◽  
Spin Coating ◽  
Surface Composition ◽  
Morphological Changes ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Coating Method

The surface composition and morphology of FA0.85MA0.15Pb(I0.85Br0.15)3 films fabricated by the spin-coating method with different concentrations of NH2-POSS were investigated with atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), angle-resolved X-ray photoelectron spectroscopy (AR-XPS), and Fourier transform infrared spectroscopy (FTIR). It was found that the surface composition of the FA0.85MA0.15Pb(I0.85Br0.15)3 films was changed regularly through the interaction between NH2-POSS and the perovskite film. The corresponding surface morphological changes were also observed. When the concentration of NH2-POSS exceeded 10 mg/mL, a lot of cracks on the surface of the perovskite film were observed and the surface morphology was damaged. The surface composition and its distribution can be adjusted by changing the concentration of NH2-POSS and the proper concentration of NH2-POSS can substantially improve the quality of perovskite film.

scholarly journals Structural and optical properties of HDPE implanted with medium fluences silver ions

2021 ◽  
Vol 53 (2) ◽  
pp. 187-198
Author(s):  
Milos Nenadovic ◽  
Danilo Kisic ◽  
Miljana Mirkovic ◽  
Snezana Nenadovic ◽  
Ljiljana Kljajevic
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Surface Composition ◽  
Silver Ions ◽  
Surface Region ◽  
Sample Surface ◽  
Phase Imaging ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron

The implantation of high-density polyethylene (HDPE) has been conducted using Ag+ ions with energy of 60 keV, achieved fluences 1.5 and 10?1015 ions/cm2. Transmission electron microscopy (STEM) and field emission gun - scanning electron microscopy (FEG-SEM) showed the existence of nanoparticle clusters. X ray photoelectron spectroscopy (XPS) revealed the presence of silver in the sample surface region. The surface topography was studied by atomic force microscopy (AFM), while the surface composition uniformity was analyzed using phase imaging AFM. Optical characterization obtained by spectroscopic ellipsometry (SE) showed changes in refractive index, extinction coefficient and the optical band gap with the fluence of implanted ions.

scholarly journals Surface Studies of UV Irradiated Polypropylene Films Modified with Mineral Fillers Designed as Piezoelectric Materials

Polymers ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 562
Author(s):  
Marta Chylińska ◽  
Halina Kaczmarek ◽  
Dariusz Moszyński ◽  
Bogusław Królikowski ◽  
Jolanta Kowalonek
Keyword(s):  
Photoelectron Spectroscopy ◽  
Piezoelectric Materials ◽  
Contact Angles ◽  
Polymeric Films ◽  
Accelerated Weathering ◽  
Force Microscopy ◽  
Atomic Force ◽  
Orientation Process ◽  
Potential Applications ◽  
Mineral Fillers

Isotactic-polypropylene (i-PP) films with inorganic minerals such as Sillikolloid, perlite, or glass beads were prepared. The obtained polymeric films were subjected to an orientation process. Moreover, this paper includes results how the artificial accelerated weathering influences surface properties of the unoriented and oriented i-PP films with the mineral fillers. Changes in the ultraviolet (UV) treated polymeric films were studied with attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and by measuring contact angles. The results revealed that photooxidation of i-PP was more effective in the presence of the fillers and depended on the type of the filler but not on its amount. Moreover, the oriented samples experienced more effective photooxidation compared with the unoriented ones. In all studied samples the same photoproducts were detected, suggesting the same route of polymer photooxidation with and without the filler. These polymeric films were produced for potential applications in the devices in which piezoelectric effect can be used.

scholarly journals Ashwagandha Extract as Green Sustainable Corrosion Inhibitor for Aluminum in Acidic Solutions

2020 ◽  
Vol 11 (2) ◽  
pp. 9719-9734
Keyword(s):  
Corrosion Inhibitor ◽  
Photoelectron Spectroscopy ◽  
Electrochemical Impedance ◽  
Effect Of Temperature ◽  
Aluminum Surface ◽  
Force Microscopy ◽  
Atomic Force ◽  
Hydrochloric Acid Solutions ◽  
Good Accord ◽  
Surface Examination

In this study, the employment of Ashwagandha extract (AE) as a green sustainable corrosion inhibitor for aluminum in one molar hydrochloric acid solutions was examined utilizing “mass loss (ML), electrochemical frequency modulation (EFM), electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PP) measurements”. The surface examination was analyzed utilizing atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS) analysis. The effect of temperature on corrosion demeanor with adding a different dose of AE was investigated within the temperature varieties of 25-45 ºC by ML strategy. The curves of polarization reveal that AE is considered as a mixed sort inhibitor. The performance of inhibition rises with raising the AE concentration and diminished with the temperature ascending. The adsorption of the inhibitor on aluminum surface complies with the Langmuir’s adsorption isotherm and is considered as physisorption. The outcomes attained from chemical and electrochemical methods are in good accord.

Effect of Different Acid Treatment on Surface Characteristics of Titanium Alloy

2011 ◽  
Vol 694 ◽  
pp. 490-496 ◽  
Author(s):  
De Gui Zhang ◽  
Hai Mei Cheng ◽  
Ying Jun Wang ◽  
Cheng Yun Ning
Keyword(s):  
Titanium Alloy ◽  
Photoelectron Spectroscopy ◽  
Acid Treatment ◽  
Sessile Drop ◽  
Surface Characteristics ◽  
Acid Etching ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Titanium Alloy Ti6al4v

This study was aimed to investigate the effects of acid treatment on the surfacee characteristics ofgrit-blasted titanium alloy (Ti6Al4V). These treatments included (a) Al2O3 blasting, (b) Al2O3 blasting + HF acid etching, (c) Al2O3 blasting + HCl/H2SO4 acid etching, and (d) Al2O3 blasting + HF acid etching + HCl/H2SO4 acid etching. The surface topography and chemical composition of the samples were identified by field-emission scanning electron microscopy and X-ray photoelectron spectroscopy, respectively. Roughness of the as-treated samples was obtained from atomic force microscopy (AFM) and profilometry. Wettability of the samples was measured using sessile drop method. The results showed that porous structure on the surface of titanium alloy was prepared by dual acid etching treatment and the surfaces treated with acid had higher roughness and better wettability than the surface treated only by grit-blasting.

scholarly journals STUDY OF THE MICROSTRUCTURE AND COMPOSITION OF TIN DIOXIDE LAYERS MODIFIED BY SILVER NANOPARTICLES

2021 ◽  
pp. 447-456
Author(s):  
Замир Валериевич Шомахов ◽  
Светлана Сергеевна Налимова ◽  
Рустам Мухамедович Калмыков ◽  
Кирилл Аубекеров ◽  
Вячеслав Алексеевич Мошников
Keyword(s):  
Silver Nanoparticles ◽  
Gas Sensors ◽  
Photoelectron Spectroscopy ◽  
Tin Dioxide ◽  
Surface Composition ◽  
Metallic Silver ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Before And After

Слои диоксида олова синтезированы гидротермальным методом из водного раствора SnF. Наночастицы серебра осаждены на поверхность полученных слоев методом фотовосстановления. Проведено исследование морфологии поверхности образцов методом атомно-силовой микроскопии. Размер наночастиц серебра зависит от концентрации раствора AgNO, используемого для проведения реакции фотовосстановления. При синтезе из раствора с концентрацией 0,02 М размер полученных наночастиц составляет варьируется от 10 до 100 нм, при увеличении концентрации раствора в два раза размер наночастиц составляет порядка 100 нм. С помощью рентгеновской фотоэлектронной спектроскопии изучен состав поверхности слоев до и после осаждения наночастиц серебра. При выбранных условиях синтеза формируется слой диоксида олова без посторонних включений, и происходит осаждение металлического серебра. Химический сдвиг пиков олова и кислорода после осаждения наночастиц серебра свидетельствует об обмене электронами между оловом и серебром. Полученные слои представляют интерес для применения в области полупроводниковых адсорбционных газовых сенсоров. Tin dioxide layers were synthesized by hydrothermal method from an aqueous solution of SnF. Silver nanoparticles were deposited on the surface of the obtained layers by the photoreduction method. The surface morphology of the samples was studied by atomic force microscopy. The size of the silver nanoparticles depends on the concentration of the AgNO solution used for the photoreduction reaction. When synthesized from 0,02 M solution with a concentration of, the size of the nanoparticles varies from 10 to 100 nm, when the concentration of the solution is doubled, the size of the nanoparticles is about 100 nm. The surface composition of the layers before and after the deposition of silver nanoparticles was studied using the X-ray photoelectron spectroscopy. It was shown that a layer of the tin dioxide is formed without external inclusions, and metallic silver is deposited. The chemical shift of the peaks of tin and oxygen after the deposition of silver nanoparticles indicates the exchange of electrons between tin and silver. The synthesized layers are of interest for application in the field of semiconductor adsorption gas sensors.

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