42 results match your criteria Applied Surface Science[Journal]

Oxygen intercalation in PVD graphene grown on copper substrates: A decoupling approach.

Appl Surf Sci 2020 Nov 11;529:147100. Epub 2020 Jul 11.

Materials Science Factory, Instituto de Ciencia de Materiales de Madrid, Consejo Superior de Investigaciones Científicas, Cantoblanco ES-28049, Madrid, Spain.

We investigate the intercalation process of oxygen in-between a PVD-grown graphene layer and different copper substrates as a methodology for reducing the substrate-layer interaction. This growth method leads to an extended defect-free graphene layer that strongly couples with the substrate. We have found, by means of X-ray photoelectron spectroscopy, that after oxygen exposure at different temperatures, ranging from 280 °C to 550 °C, oxygen intercalates at the interface of graphene grown on Cu foil at an optimal temperature of 500 °C. Read More

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November 2020

Reaction of BCl with H- and Cl-terminated Si(1 0 0) as a pathway for selective, monolayer doping through wet chemistry.

Appl Surf Sci 2020 Dec 4;533. Epub 2020 Jun 4.

Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware, 19716, United States.

The reaction of boron trichloride with the H and Cl-terminated Si(100) surfaces was investigated to understand the interaction of this molecule with the surface for designing wet-chemistry based silicon surface doping processes using a carbon- and oxygen-free precursor. The process was followed with X-ray photoelectron spectroscopy (XPS). Within the reaction conditions investigated, the reaction is highly effective on Cl-Si(100) for temperatures below 70°C, at which point both surfaces react with BCl. Read More

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December 2020

In-situ synthesis of CuO on cotton fibers with antibacterial properties and reusable photocatalytic degradation of dyes.

Appl Surf Sci 2021 Jan 26;536:147945. Epub 2020 Sep 26.

College of Textile Science and Engineering, Zhejiang Sci-Tech University, Hangzhou 310018, China.

In this study, the cotton fabrics/cuprous oxide-nanocellulose (CuO-NC) flexible and recyclable composite material (COCO) with highly efficient photocatalytic degradation of dyes and antibacterial properties was fabricated. Using flexible cotton fabrics as substrates, CuO were in-situ synthesized to make CuO uniformly grew on cotton fibers and were wrapped with NC. The photocatalytic degradation ability of COCO-5 was verified by use methylene blue (MB), the degradation rate was as high as 98. Read More

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January 2021

Indocyanine green modified silica shells for colon tumor marking.

Appl Surf Sci 2020 Jan 5;499. Epub 2019 Sep 5.

Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093, United States.

Marking colon tumors for surgery is normally done with the use of India ink. However, non-fluorescent dyes such as India ink cannot be imaged below the tissue surface and there is evidence for physiological complications such as abscess, intestinal perforation and inconsistency of dye injection. A novel infrared marker was developed using FDA approved indocyanine green (ICG) dye and ultrathin hollow silica nanoshells (ICG/HSS). Read More

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January 2020

Electrospun antibacterial poly(vinyl alcohol)/Ag nanoparticles membrane grafted with 3,3',4,4'-benzophenone tetracarboxylic acid for efficient air filtration.

Appl Surf Sci 2020 Dec 13;533:147516. Epub 2020 Aug 13.

College of Food Science, Sichuan Agricultural University, Yaan 625014, China.

In this study, poly(vinyl alcohol) (PVA) membranes containing Ag nanoparticles (AgNPs) were prepared by electrospinning and grafted copolymerization with 3,3',4,4'-benzophenone tetracarboxylic acid (BPTA) to provide better mechanical properties, lower water vapor transmittance, and higher antibacterial activity (against and ) than the PVA/AgNPs membrane. The PVA/AgNPs/BPTA membrane showed higher antibacterial activity than the other membranes, and it produced inhibition zones with diameters of 18.12 ± 0. Read More

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December 2020

Chemical synthesis and optical, structural, and surface characterization of InP-InO quantum dots.

Appl Surf Sci 2020 Nov 22;530:147294. Epub 2020 Jul 22.

Departamento de Física, Cinvestav-IPN, Av. Instituto Politécnico Nacional 2508, Col. San Pedro Zacatenco, C.P. 07360 Ciudad de México, Mexico.

InP-InO colloidal quantum dots (QDs) synthesized by a single-step chemical method without injection of hot precursors (one-pot) were investigated. Specifically, the effect of the tris(trimethylsilyl)phosphine, P(TMS), precursor concentration on the QDs properties was studied to effectively control the size and shape of the samples with a minimum size dispersion. The effect of the P(TMS) precursor concentration on the optical, structural, chemical surface, and electronic properties of InP-InO QDs is discussed. Read More

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November 2020

Photosensitizing potential of tailored magnetite hybrid nanoparticles functionalized with levan and zinc (II) phthalocyanine.

Appl Surf Sci 2020 Sep 7;524:146602. Epub 2020 May 7.

Faculty of Chemistry, Nicolaus Copernicus University in Torun, Gagarina 7, 87-100 Torun, Poland.

Phototherapies, including photodynamic therapy (PDT), have been widely used in the treatment of various diseases, especially for cancer. However, there is still a lack of effective, safe photosensitizers that would be well tolerated by patients. The combination of several methods (like phototherapy and hyperthermia) constitutes a modern therapeutic approach, which demands new materials based on components that are non-toxic without irradiation. Read More

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September 2020

Creating superhydrophobic and antibacterial surfaces on gold by femtosecond laser pulses.

Appl Surf Sci 2020 Mar;506:144952

The Institute of Optics, University of Rochester, Rochester, NY 14627, USA.

Femtosecond laser-induced surface structuring is a promising technique for the large-scale formation of nano- and microscale structures that can effectively modify materials' optical, electrical, mechanical, and tribological properties. Here we perform a systematic study on femtosecond laser-induced surface structuring on gold (Au) surface and their effect on both hydrophobicity and bacterial-adhesion properties. We created various structures including subwavelength femtosecond laser-induced periodic surface structures (fs-LIPSSs), fs-LIPSSs covered with nano/microstructures, conic and 1D-rod-like structures ( 6 μm), and spherical nanostructures with a diameter 10 nm, by raster scanning the laser beam, at different laser fluences. Read More

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Zinc Oxide nanoparticles induce oxidative and proteotoxic stress in ovarian cancer cells and trigger apoptosis Independent of p53-mutation status.

Appl Surf Sci 2019 Sep;487:807-818

Department of Nanotechnology, SRM Institute of Science and Technology, Tamil Nadu. 603203. India.

Ovarian cancer continues to be the most lethal among gynecological malignancies and the major cause for cancer-associated mortality among women. Limitations of current ovarian cancer therapeutics is highlighted by the high frequency of drug-resistant recurrent tumors and the extremely poor 5-year survival rates. Zinc oxide nanoparticles (ZnO-NPs) have shown promise in various biomedical applications including utility as anti-cancer agents. Read More

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September 2019

Operational and environmental conditions regulate the frictional behavior of two-dimensional materials.

Appl Surf Sci 2019 ;483

School of Mechanical Engineering, University of Ulsan, Ulsan 44610, Republic of Korea.

The friction characteristics of single-layer h-BN, MoS, and graphene were systematically investigated via friction force microscopy measurements at various operational (e.g., normal force and sliding speed) and environmental (e. Read More

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January 2019

Ultra-precise surface processing of LYSO scintillator crystals for Positron Emission Tomography.

Appl Surf Sci 2019 Mar 9;469:573-581. Epub 2018 Nov 9.

The State Key Lab of Digital Manufacturing Equipment and Technology, School of Mechanical Science and Engineering, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China.

The Lutetium-Yttrium Oxyorthosilicate (LYSO) is one of the most widely used scintillation crystal in the high-performance Positron Emission Tomography (PET) systems. The quality of the surface finish of the LYSO has an important impact on the light output, the decoding performance, the energy resolution and timing resolution of the PET detectors and systems. In this paper, we present an ultra-precise method for processing the surface of LYSO crystals. Read More

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Evaluation of the colloidal stability and adsorption performance of reduced graphene oxide-elemental silver/magnetite nanohybrids for selected toxic heavy metals in aqueous solutions.

Appl Surf Sci 2019 ;471:8-17

Groundwater, Watershed, and Ecosystem Restoration Division, National Risk Management Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, 919 Kerr Research Drive, Ada, OK 74820, USA.

Reduced graphene oxide (rGO) hybridized with magnetite and/or elemental silver (rGO/magnetite, rGO/silver, and rGO/magnetite/silver) nanoparticles were evaluated as potential adsorbents for toxic heavy metal ions (Cd (II), Ni(II), Zn(II), Co(II), Pb(II), and Cu(II)). Although the deposition of iron oxide and silver nanoparticles on the rGO nanosheets played an inhibitory role in metal ion adsorption, the metal adsorption efficiency by the nanohybrids (NHs) was still higher than that reported for many other sorbents (e.g. Read More

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January 2019

Formation of aggregated nanoparticle spheres through femtosecond laser surface processing.

Appl Surf Sci 2017 Oct 12;419:778-787. Epub 2017 May 12.

Department of Electrical and Computer Engineering, University of Nebraska-Lincoln, 844 N 16th St, Lincoln, NE 68588, USA.

A detailed structural and chemical analysis of a class of self-organized surface structures, termed aggregated nanoparticle spheres (AN-spheres), created using femtosecond laser surface processing (FLSP) on silicon, silicon carbide, and aluminum is reported in this paper. AN-spheres are spherical microstructures that are 20-100 μm in diameter and are composed entirely of nanoparticles produced during femtosecond laser ablation of material. AN-spheres have an onion-like layered morphology resulting from the build-up of nanoparticle layers over multiple passes of the laser beam. Read More

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October 2017

Indirect photopatterning of functionalized organic monolayers via copper-catalyzed "click chemistry".

Appl Surf Sci 2018 Jul 3;447:535-541. Epub 2018 Apr 3.

Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716, United States.

Solution-based lithographic surface modification of an organic monolayer on a solid substrate is attained based on selective area photo-reduction of copper (II) to copper (I) to catalyze the azide-alkyne dipolar cycloaddition "click" reaction. X-ray photoelectron spectroscopy is used to confirm patterning, and spectroscopic results are analyzed and supplemented with computational models to confirm the surface chemistry. It is determined that this surface modification approach requires irradiation of the solid substrate with all necessary components present in solution. Read More

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Surface Chemistry of Thermal Dry Etching of Cobalt Thin Films Using Hexafluoroacetylacetone (hfacH).

Appl Surf Sci 2018 Oct 24;455:438-445. Epub 2018 May 24.

University of Delaware, Department of Chemistry and Biochemistry, Newark, DE, USA.

Amechanism of thermal dry etching process of cobalt thin films by using 1,1,1,5,5,5-hexafluoro-2,4-pentanedione (hexafluoroacetylacetone, hfacH) was investigated. This process, relevant to atomic layer etching (ALE) technology directed towards oxidized cobalt films, requires adsorption of molecular organic precursor, such as hfacH, at moderate temperatures and is often thought of as releasing water and Co(hfac) at elevated temperatures. The reaction was analyzed in situ by temperature-programmed desorption (TPD) and the resulting surface was investigated ex situ by X-ray photoelectron spectroscopy (XPS). Read More

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October 2018

Effect of substrate storage conditions on the stability of "Smart" films used for mammalian cell applications.

Appl Surf Sci 2017 Jan 1;392:950-959. Epub 2016 Sep 1.

Center for Biomedical Engineering, Department of Chemical and Biological Engineering, University of New Mexico, United States.

When poly(-isopropyl acrylamide) (pNIPAM) is tethered to a surface, it can induce the spontaneous release of a sheet of mammalian cells. The release of cells is a result of the reversible phase transition the polymer undergoes at its lower critical solution temperature (LCST). Many techniques are used for the deposition of pNIPAM onto cell culture substrates. Read More

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January 2017

Micro/nanostructures formation by femtosecond laser surface processing on amorphous and polycrystalline NiNb.

Appl Surf Sci 2017 Feb 15;396:1170-1176. Epub 2016 Nov 15.

Department of Mechanical and Materials Engineering, University of Nebraska-Lincoln, Lincoln, NE 68588, USA.

Femtosecond laser surface processing is a technology that can be used to functionalize many surfaces, imparting specialized properties such as increased broadband optical absorption or superhydrophilicity/superhydrophobicity. In this study, two unique classes of surface structures, below surface growth (BSG) and above surface growth (ASG) mounds, were formed by femtosecond laser surface processing on amorphous and polycrystalline NiNb with two different grain sizes. Cross sectional imaging of these mounds revealed thermal evidence of the unique formation processes for each class of surface structure. Read More

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February 2017

Enhanced photocatalytic, electrochemical and photoelectrochemical properties of TiO nanotubes arrays modified with Cu, AgCu and Bi nanoparticles obtained via radiolytic reduction.

Appl Surf Sci 2016 Nov;387:89-102

Department of Environmental Technology, Faculty of Chemistry, University of Gdansk, 63 Wita Stwosza St., 80-308 Gdansk, Poland.

TiO nanotubes arrays (NTs), obtained via electrochemical anodization of Ti foil, were modified with monometallic (Cu, Bi) and bimetallic (AgCu) nanoparticles. Different amounts of metals' precursors were deposited on the surface of NTs by the spin-coating technique, and the reduction of metals was performed via gamma radiolysis. Surface modification of titania was studied by EDS and XPS analysis. Read More

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November 2016

Building High-Coverage Monolayers of Covalently Bound Magnetic Nanoparticles.

Appl Surf Sci 2016 Dec 25;388(A):461-467. Epub 2015 Nov 25.

Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716, USA.

This work presents an approach for producing a high-coverage single monolayer of magnetic nanoparticles using "click chemistry" between complementarily-functionalized nanoparticles and a flat substrate. This method highlights essential aspects of the functionalization scheme for substrate surface and nanoparticles to produce exceptionally high surface coverage without sacrificing selectivity or control over the layer produced. The deposition of one single layer of magnetic particles without agglomeration, over a large area, with a nearly 100% coverage is confirmed by electron microscopy. Read More

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December 2016

Silicon epitaxy on H-terminated Si (100) surfaces at 250 °C.

Appl Surf Sci 2016 Aug 31;378:301-307. Epub 2016 Mar 31.

National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States.

Low temperature Si epitaxy has become increasingly important due to its critical role in the encapsulation and performance of buried nanoscale dopant devices. We demonstrate epitaxial growth up to nominally 25 nm, at 250°C, with analysis at successive growth steps using STM and cross section TEM to reveal the nature and quality of the epitaxial growth. STM images indicate that growth morphology of both Si on Si and Si on H-terminated Si (H: Si) is epitaxial in nature at temperatures as low as 250 °C. Read More

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Different methods to alter surface morphology of high aspect ratio structures.

Appl Surf Sci 2016 Mar;365:180-190

Department of Electrical and Computer Engineering, University of Utah, Salt Lake City, UT, USA; Blackrock Microsystems, Salt Lake City, UT, USA.

In various applications such as neural prostheses or solar cells, there is a need to alter the surface morphology of high aspect ratio structures so that the real surface area is greater than geometrical area. The change in surface morphology enhances the devices functionality. One of the applications of altering the surface morphology is of neural implants such as the Utah electrode array (UEA) that communicate with single neurons by charge injection induced stimulation or by recording electrical neural signals. Read More

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Substituent Effects in the Surface-Initiated ATRP of Substituted Styrenes.

Appl Surf Sci 2015 Dec;359:911-916

Department of Chemistry, Michigan State University, East Lansing, MI 48840.

Surface initiated atom transfer radical polymerization (ATRP) of substituted styrenes leads to rapid synthesis of uniform and thick substituted polystyrene brushes (>100 nm in 1 hour) from gold surface. High growth rates were observed for styrenes substituted with electron withdrawing groups in meta/para positions. The effects seen in surface and solution polymerizations are similar for styrenes with electron withdrawing groups, and for electron donors in ortho and para positions. Read More

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December 2015

Microstructures and superconducting properties of high performance MgB thin films deposited from a high-purity, dense Mg-B target.

Appl Surf Sci 2015 Dec 8;357 Pt A:452-458. Epub 2015 Sep 8.

Center for Superconducting and Magnetic Materials, Department of Materials Science and Engineering, The Ohio State University, Columbus, OH USA 43210.

High quality, -axis oriented, MgB thin films were successfully grown on 6H-SiC substrates using pulsed laser deposition (PLD) with subsequent annealing. To obtain high purity films free from oxygen contamination, a dense Mg-B target was specially made from a high temperature, high pressure reaction of Mg and B to form large-grained (10~50 µm) MgB. Microstructural analysis via electron microscopy found that the resulting grains of the film were composed of ultrafine columnar grains of 19-30 nm. Read More

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December 2015

Ionization of covalent immobilized poly(4-vinylphenol) monolayers measured by ellipsometry, QCM and SPR.

Appl Surf Sci 2015 Jul;343:166-171

Department of Chemistry, University of Massachusetts Lowell, 1 University Ave., Lowell, MA 01854, United States ; KTH-Royal Institute of Technology, Department of Chemistry, Teknikringen 30, S-10044 Stockholm, Sweden.

Covalently immobilized poly(4-vinylphenol) (PVP) monolayer films were fabricated by spin coating PVP on perfluorophenyl azide (PFPA)-functionalized surface followed by UV irradiation. The pH-responsive behavior of these PVP ultrathin films was evaluated by ellipsometry, quartz crystal microbalance (QCM) and surface plasmon resonance (SPR). By monitoring the responses of these films to pH , the ionization constant of the monolayer thin films was obtained. Read More

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Silane surface modification for improved bioadhesion of esophageal stents.

Appl Surf Sci 2014 Aug;311:684-689

Department of Chemical and Biomolecular Engineering, The Johns Hopkins University, Baltimore, MD, USA.

Stent migration occurs in 10-40% of patients who undergo placement of esophageal stents, with higher migration rates seen in those treated for benign esophageal disorders. This remains a major drawback of esophageal stent therapy. In this paper, we propose a new surface modification method to increase the adhesion between self-expandable metallic stents (SEMS) and tissue while preserving their removability. Read More

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Imaging, Spectroscopic, Mechanical and Biocompatibility Studies of Electrospun Tecoflex EG 80A Nanofibers and Composites Thereof Containing Multiwalled Carbon Nanotubes.

Appl Surf Sci 2014 Dec;321:205-213

Department of Biomedical Engineering, The University of Memphis, Memphis, TN 38152, USA USA.

The present study discusses the design, development and characterization of electrospun Tecoflex EG 80A class of polyurethane nanofibers and the incorporation of multiwalled carbon nanotubes (MWCNTs) to these materials. Scanning electron microscopy results confirmed the presence of polymer nanofibers, which showed a decrease in fiber diameter at 0.5% wt. Read More

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December 2014

A novel ToF-SIMS operation mode for sub 100 nm lateral resolution: Application and performance.

Appl Surf Sci 2014 Jan;289(100):407-416

Institute of Chemical Technologies and Analytics, Vienna University of Technology, Getreidemarkt 9, A-1060 Vienna, Austria.

A novel operation mode for time of flight-secondary ion mass spectrometry (ToF-SIMS) is described for a TOF.SIMS 5 instrument with a Bi-ion gun. It features sub 100 nm lateral resolution, adjustable primary ion currents and the possibility to measure with high lateral resolution as well as high mass resolution. Read More

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January 2014

Solid-State Densification of Spun-Cast Self-Assembled Monolayers for Use in Ultra-Thin Hybrid Dielectrics.

Appl Surf Sci 2012 Nov;261

Department of Materials Science and Engineering, University of Washington, Seattle, Washington 98195.

Ultra-thin self-assembled monolayer (SAM)-oxide hybrid dielectrics have gained significant interest for their application in low-voltage organic thin film transistors (OTFTs). A [8-(11-phenoxy-undecyloxy)-octyl]phosphonic acid (PhO-19-PA) SAM on ultrathin AlO (2.5 nm) has been developed to significantly enhance the dielectric performance of inorganic oxides through reduction of leakage current while maintaining similar capacitance to the underlying oxide structure. Read More

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November 2012

Synthesis, characterization, and mercury adsorption properties of hybrid mesoporous aluminosilicate sieve prepared with fly ash.

Appl Surf Sci 2013 May;273(100):706-716

School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, PR China.

A novel hybrid mesoporous aluminosilicate sieve (HMAS) was prepared with fly ash and impregnated with zeolite A precursors. This improved the mercury adsorption of HMAS compared to original MCM-41. The HMAS was characterized by X-ray diffraction (XRD), nitrogen adsorption-desorption, Fourier transform infrared (FTIR) analysis, transmission electron microscopy (TEM) images and Si and Al magic angle spinning nuclear magnetic resonance (MAS NMR) spectra. Read More

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Monitoring preparation and phase transitions of carburized W(1 1 0) by reflectance difference spectroscopy.

Appl Surf Sci 2012 Oct;258(24):10123-10127

Institute of Physical Chemistry, University of Innsbruck, Innrain 52a, A-6020 Innsbruck, Austria.

Reflectance difference spectroscopy (RDS) is applied to follow in situ the preparation of clean and carburized W(1 1 0) surfaces and to study the temperature-induced transition between the R(15 × 3) and R(15 × 12) carbon/tungsten surface phases. RDS data for this transition are compared to data obtained from Auger-electron spectroscopy and low-energy electron diffraction. All techniques reveal that this transition, occurring around 1870 K, is reversible with a small hysteresis, indicating a first-order-like behaviour. Read More

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October 2012