scholarly journals Self-assembled anchor layers/polysaccharide coatings on titanium surfaces: a study of functionalization and stability

2015 ◽  
Vol 6 ◽  
pp. 617-631 ◽  
Author(s):  
Ognen Pop-Georgievski ◽  
Dana Kubies ◽  
Josef Zemek ◽  
Neda Neykova ◽  
Roman Demianchuk ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Covalent Immobilization ◽  
Biologically Active ◽  
Force Microscopy ◽  
Atomic Force ◽  
Infrared Reflection ◽  
Alginate Immobilization ◽  
Titanium Surfaces ◽  
Self Assembled ◽  
The Stability

Composite materials based on a titanium support and a thin, alginate hydrogel could be used in bone tissue engineering as a scaffold material that provides biologically active molecules. The main objective of this contribution is to characterize the activation and the functionalization of titanium surfaces by the covalent immobilization of anchoring layers of self-assembled bisphosphonate neridronate monolayers and polymer films of 3-aminopropyltriethoxysilane and biomimetic poly(dopamine). These were further used to bind a bio-functional alginate coating. The success of the titanium surface activation, anchoring layer formation and alginate immobilization, as well as the stability upon immersion under physiological-like conditions, are demonstrated by different surface sensitive techniques such as spectroscopic ellipsometry, infrared reflection–absorption spectroscopy and X-ray photoelectron spectroscopy. The changes in morphology and the established continuity of the layers are examined by scanning electron microscopy, surface profilometry and atomic force microscopy. The changes in hydrophilicity after each modification step are further examined by contact angle goniometry.

scholarly journals Silane-Coating Strategy for Titanium Functionalization Does Not Impair Osteogenesis In Vivo

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1814
Author(s):  
Plinio Mendes Senna ◽  
Carlos Fernando de Almeida Barros Mourão ◽  
Rafael Coutinho Mello-Machado ◽  
Kayvon Javid ◽  
Pietro Montemezzi ◽  
...  
Keyword(s):  
Bone Formation ◽  
Photoelectron Spectroscopy ◽  
Titanium Surface ◽  
Rabbit Model ◽  
Biologically Active ◽  
Force Microscopy ◽  
Atomic Force ◽  
Silane Coating ◽  
Titanium Screws

Silane-coating strategy has been used to bind biological compounds to the titanium surface, thereby making implant devices biologically active. However, it has not been determined if the presence of the silane coating itself is biocompatible to osseointegration. The aim of the present study was to evaluate if silane-coating affects bone formation on titanium using a rabbit model. For this, titanium screw implants (3.75 by 6 mm) were hydroxylated in a solution of H2SO4/30% H2O2 for 4 h before silane-coating with 3-aminopropyltriethoxysilane (APTES). A parallel set of titanium screws underwent only the hydroxylation process to present similar acid-etched topography as a control. The presence of the silane on the surface was checked by x-ray photoelectron spectroscopy (XPS), with scanning electron microscopy (SEM) and atomic force microscopy (AFM). A total of 40 titanium screws were implanted in the tibia of ten New Zealand rabbits in order to evaluate bone-to-implant contact (BIC) after 3 weeks and 6 weeks of healing. Silane-coated surface presented higher nitrogen content in the XPS analysis, while micro- and nano-topography of the surface remained unaffected. No difference between the groups was observed after 3 and 6 weeks of healing (p > 0.05, independent t-test), although an increase in BIC occurred over time. These results indicate that silanization of a titanium surface with APTES did not impair the bone formation, indicating that this can be a reliable tool to anchor osteogenic molecules on the surface of implant devices.

Ta2O5-Incorporated WO3 Nanocomposite Film for Improved Electrochromic Performance in an Acidic Condition

2006 ◽  
Vol 6 (11) ◽  
pp. 3572-3576 ◽  
Author(s):  
Hee-Sang Shim ◽  
Hyo-Jin Ahn ◽  
Youn-Su Kim ◽  
Yung-Eun Sung ◽  
Won Bae Kim
Keyword(s):  
Surface Roughness ◽  
Photoelectron Spectroscopy ◽  
Potential Cycling ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Continuous Potential ◽  
Chemical States ◽  
The Stability

We report electrochromic and electrochemical properties of a WO3-Ta2O5 nanocomposite electrode that was fabricated from co-sputtering. Transmission electron microscopy (TEM)images of the WO3-Ta2O5 nanocomposite electrode revealed that morphology of the WO3 film was changed by incorporation of Ta2O5 nanoparticles, and their chemical states were confirmed to be W6+ and Ta5+ oxides from X-ray photoelectron spectroscopy (XPS). The introduction of Ta2O5 to the WO3 film played a role in alleviating surface roughness increase during continuous potential cycling; whereas the surface roughness of the WO3 film was increased from ca. 3.0 nm to ca. 13.4 nm after 400 cycles, the roughness increase on the WO3-Ta2O5 was significantly reduced to 4.2 nm after 400 cycles, as investigated by atomic force microscopy (AFM). This improvement of the stability by adding Ta2O5 may be responsible for the enhanced electrochemical and optical properties over long-term cycling with the WO3-Ta2O5 nanocomposite electrode.

Electroless Synthesis of 1.4 nm Pd and Pt Nanoparticles on Self-Assembled Rosette Nanotubes

2011 ◽  
Vol 1301 ◽  
Author(s):  
Rahul Chhabra ◽  
Hicham Fenniri
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Pt Nanoparticles ◽  
Hierarchical Organization ◽  
X Ray ◽  
Force Microscopy ◽  
Rosette Nanotubes ◽  
Atomic Force ◽  
Transmission Electron ◽  
Self Assembled

ABSTRACTElectroless synthesis and hierarchical organization of 1.4 nm Pd and Pt nanoparticles (NPs) on self-assembled Rosette Nanotubes (RNTs) is described. The nucleated NPs are nearly monodisperse and reveal supramolecular organizations guided by RNT templates. Interestingly, the narrow size distribution is attributable to unique templating behavior of RNTs. The resulting metal NP-RNT composites were characterized by Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). X-ray Photoelectron Spectroscopy (XPS) was also performed to confirm the nature and composition of RNT-templated NPs.

Synergistic effect of polyvinylpyrrolidone noncovalently modified graphene and epoxy resin in anticorrosion application

2020 ◽  
pp. 095400832094229
Author(s):  
Shifeng Wen ◽  
Jiacheng Ma
Keyword(s):  
Epoxy Resin ◽  
Photoelectron Spectroscopy ◽  
Electrochemical Impedance ◽  
Covalent Modification ◽  
Original Structure ◽  
Graphene Layers ◽  
Force Microscopy ◽  
Atomic Force ◽  
The Stability ◽  
Modified Graphene

In this article, polyvinylpyrrolidone (PVP) was used for the noncovalent modification on the surface of graphene. Compared with covalent modification, this method maintained the original structure of graphene layers, thereby maximizing the original properties of graphene. The π–π noncovalent bond was formed between PVP and graphene by X-ray photoelectron spectroscopy analysis, indicating that PVP successfully modified graphene. The thickness of graphene layer was measured by atomic force microscopy, which showed that the distance between graphene layers was increased by 5–6 nm, and the stability of the modified graphene in N, N-dimethylformamide was remarkably improved. The obtained composite coating by combination of the modified graphene and the epoxy resin was subjected to electrochemical impedance test to obtain the best anticorrosive effect of the coating with the graphene content of 0.3 wt%. The results showed that the addition of graphene to the epoxy resin could effectively improve the anticorrosive effect. Meanwhile, the good electrical conductivity allowed the electrons which lost from the substrate to led to air or saline rapidly, thereby reducing the combination of iron ions with oxygen and the generation of corrosion products (iron oxides).

scholarly journals Enzymatic Conversion of Oleuropein to Hydroxytyrosol Using Immobilized β-Glucosidase on Porous Carbon Cuboids

Nanomaterials ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 1166 ◽  
Author(s):  
Chatzikonstantinou ◽  
Gkantzou ◽  
Thomou ◽  
Chalmpes ◽  
Lyra ◽  
...  
Keyword(s):  
Porous Carbon ◽  
Photoelectron Spectroscopy ◽  
Thermotoga Maritima ◽  
Covalent Immobilization ◽  
Force Microscopy ◽  
Atomic Force ◽  
Repeated Use ◽  
First Time ◽  
Hydrolysis Of

In the present study, we developed novel β-glucosidase-based nano-biocatalysts for the bioconversion of oleuropein to hydroxytyrosol. Using non-covalent or covalent immobilization approaches, β-glucosidases from almonds and Thermotoga maritima were attached for the first time on oxidized and non-oxidized porous carbon cuboids (PCC). Various methods were used for the characterization of the bio-nanoconjugates, such as Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and fluorescence spectroscopy. The oxidation state of the nanο-support and the immobilization procedure play a key role for the immobilization efficiency or the catalytic activity of the immobilized β-glucosidases. The nano-biocatalysts were successfully used for the hydrolysis of oleuropein, which leads to the formation of its bioactive derivative, hydroxytyrosol (up to 2.4 g L−1), which is a phenolic compound with numerous health benefits. The bio-nanoconjugates exhibited high thermal and operational stability (up to 240 hours of repeated use), which indicated that they are efficient tools for various bio-transformations.

DISPERSITY AND STABILITY MEASUREMENT OF FUNCTIONALIZED MULTIWALLED CARBON NANOTUBES IN ALCOHOLS

2008 ◽  
Vol 22 (25) ◽  
pp. 2493-2501 ◽  
Author(s):  
HUN-SIK KIM ◽  
MINSUNG KANG ◽  
WON-IL PARK ◽  
DON-YOUNG KIM ◽  
HYOUNG-JOON JIN
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Multiwalled Carbon Nanotubes ◽  
Photoelectron Spectroscopy ◽  
Multiwalled Carbon ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Stability Measurement ◽  
The Stability

Multiwalled carbon nanotubes (MWCNTs) were dispersed in various alcohols such as methanol, ethanol and isopropanol using ultrasonication. In order to disperse the MWCNTs in the alcohols, they were treated using a mixture of H 2 SO 4 and HNO 3 (3 : 1, vol/vol). The concentration of MWCNTs was approximately 0.03 wt.% and they formed a homogeneous dispersion in the alcohol solutions. The functional groups introduced on the surface of the MWCNTs during the acid treatment were characterized by Fourier transform-infrared spectroscopy and X-ray photoelectron spectroscopy. The dispersibility of the MWCNTs in the alcohols was characterized using atomic force microscopy, scanning electron microscopy and transmission electron microscopy. The stability of the MWCNT dispersions was also measured using a recently developed optical analyzer (Turbiscan).

Study of Wear Self-Repair of Steel 100Cr6 Rubbed With Lubricants Modified With Schiff Base Copper Complex

2010 ◽  
Vol 132 (3) ◽  
Author(s):  
Xinlei Gao ◽  
Li Wu ◽  
Jian Li ◽  
Wanzhen Gao
Keyword(s):  
Organic Substance ◽  
Photoelectron Spectroscopy ◽  
Selective Transfer ◽  
Self Assembled Monolayer ◽  
Force Microscopy ◽  
Atomic Force ◽  
Self Repair ◽  
Self Assembled ◽  
Rape Oil

Preparation of a Cu (II) chelate of bis(salicylaldehyde)ethylenediamine was carried out directly in epoxidized rape oil via a water/oil microemulsion reactor. Detailed characterization of the friction of boundary lubrication produced by epoxidized rape oil with and without the Cu (II) chelate of bis(salicylaldehyde)ethylenediamine was performed in reciprocating sliding tests with a microtribometer. In the presence of a modification of the epoxidized rape oil with 2 wt % of the Cu (II) chelate of bis(salicylaldehyde)ethylenediamine, the friction coefficient decreased by 15%. The Cu (II) chelate of bis(salicylaldehyde)ethylenediamine served as the additive in the epoxidized rape oil and self-assembled on the surface of 100Cr6 steel. The self-assembled monolayer was detected with atomic force microscopy and scanning electron microscopy, and characterized with cyclic voltammetry. It was verified by energy dispersive spectroscopy and X-ray photoelectron spectroscopy analyses that steel/steel rubbing pairs underwent a selective transfer of organic substance and copper, as a result of lubrication with the modified lubricant. It indicated that the modification of epoxidized rape oil with Cu (II) chelate of bis(salicylaldehyde)ethylenediamine led to wear self-repair on the steel surface, with selective transfer of a film of organic substance and copper metal.

Low Thermal Budget NiSi Films on SiGe Alloys

2002 ◽  
Vol 745 ◽  
Author(s):  
S. K. Ray ◽  
T. N. Adam ◽  
G. S. Kar ◽  
C. P. Swann ◽  
J. Kolodzey
Keyword(s):  
Photoelectron Spectroscopy ◽  
Thermal Budget ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Higher Temperature ◽  
Ultra Shallow Junctions ◽  
The Stability ◽  
Xps Study ◽  
Low Thermal Budget

ABSTRACTNickel silicides were formed on Si (100) substrates and CVD grown Si0.9Ge0.1/Si layers by low thermal budget annealing of evaporated Ni films to evaluate their utility for ultra shallow junctions. The phase formation and microstructure of silicides formed using conventional furnace and rapid thermal annealing were studied by x-ray diffraction, Rutherford backscattering (RBS), x-ray photoelectron spectroscopy (XPS) and atomic force microscopy. RBS simulations and XPS study revealed the formation of a ternary nickel germanosilicide phase for the SiGe alloy. The incorporation of Ge resulted in a higher temperature window for the stability of low-resistive monosilicide phase. Electrical properties of the grown silicides were characterized by four-probe resistivity and contact resistance measurements.

scholarly journals Novel N-chloramine precursors for antimicrobial application: synthesis and facile covalent immobilization on polyurethane surface based on perfluorophenyl azide (PFPA) chemistry

2018 ◽  
Vol 96 (10) ◽  
pp. 939-948 ◽  
Author(s):  
Lingdong Li ◽  
Fengxiang Zhang ◽  
Fangyuan Gai ◽  
Hao Zhou ◽  
Xiaofang Chi ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Uv Light ◽  
Covalent Immobilization ◽  
Material Surface ◽  
Biocidal Activity ◽  
Force Microscopy ◽  
Atomic Force ◽  
Antimicrobial Materials ◽  
Surface Modified ◽  
Perfluorophenyl Azide

To control the pathogen cross contaminations on medical material surface, there is a pressing need to develop antimicrobial materials with highly efficacious surface biocidal activity. In this work, N-chloramine precursors containing a quaternary ammonium unit and perfluorophenyl azide unit were synthesized and covalently immobilized on inert polyurethane (PU) film upon UV light irradiation. The surface modification was confirmed by contact angle, Fourier transform infrared (ATR FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM) analyses. After bleaching treatment, satisfactory biocidal activity was achieved for the surface-modified PU films. It was found that the introduced surface QA center contributed an even faster surface contact killing behavior and that precursors with a longer structural linker caused higher surface chlorine content and higher antimicrobial efficacy. This approach provides a novel and facile method that enables the covalent immobilization of N-chloramine precursors on inert polymeric surface to produce durable antimicrobial materials.

scholarly journals P3HT Processing Study for In-Liquid EGOFET Biosensors: Effects of the Solvent and the Surface

Sensors ◽  
2019 ◽  
Vol 19 (20) ◽  
pp. 4497 ◽  
Author(s):  
Matteo Parmeggiani ◽  
Alessio Verna ◽  
Alberto Ballesio ◽  
Matteo Cocuzza ◽  
Erik Piatti ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Gate Dielectric ◽  
Morphological Structure ◽  
Cost Effective ◽  
Electrical Measurements ◽  
Adhesion Promoter ◽  
Force Microscopy ◽  
Atomic Force ◽  
New Frontier ◽  
The Stability

In-liquid biosensing is the new frontier of health and environment monitoring. A growing number of analytes and biomarkers of interest correlated to different diseases have been found, and the miniaturized devices belonging to the class of biosensors represent an accurate and cost-effective solution to obtaining their recognition. In this study, we investigate the effect of the solvent and of the substrate modification on thin films of organic semiconductor Poly(3-hexylthiophene) (P3HT) in order to improve the stability and electrical properties of an Electrolyte Gated Organic Field Effect Transistor (EGOFET) biosensor. The studied surface is the relevant interface between the P3HT and the electrolyte acting as gate dielectric for in-liquid detection of an analyte. Atomic Force Microscopy (AFM) and X-ray Photoelectron Spectroscopy (XPS) characterizations were employed to study the effect of two solvents (toluene and 1,2-dichlorobenzene) and of a commercial adhesion promoter (Ti Prime) on the morphological structure and electronic properties of P3HT film. Combining the results from these surface characterizations with electrical measurements, we investigate the changes on the EGOFET performances and stability in deionized (DI) water with an Ag/AgCl gate electrode.

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