References of "Denayer, Jessica"
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See detailInnovative materials improving energy efficiency of buildings
Dewalque, Jennifer ULiege; Denayer, Jessica ULiege; Schrijnemakers, Audrey ULiege et al

Conference (2014, July 01)

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See detailMesoporous amorphous tungsten oxide electrochromic films: a Raman analysis of their good switching behavior
Chatzikyriakou, Dafni ULiege; Krins, Natacha ULiege; Gilbert, Bernard ULiege et al

in Electrochimica Acta (2014), 137

The intercalation and de-intercalation of lithium cations in electrochromic tungsten oxide thin films are significantly influenced by their structural and surface characteristics. In this study, we ... [more ▼]

The intercalation and de-intercalation of lithium cations in electrochromic tungsten oxide thin films are significantly influenced by their structural and surface characteristics. In this study, we prepared two types of amorphous films via the sol-gel technique: one dense and one mesoporous in order to compare their response upon lithium intercalation and de-intercalation. According to chronoamperometric measurements, Li+ intercalates/de-intercalates faster in the mesoporous film (24s/6s) than in the dense film (48s/10s). The electrochemical measurements (cyclic voltammetry and chronoamperometry) also showed worse reversibility for the dense film compared to the mesoporous film, giving rise to important Li+ trapping and remaining coloration of the film. Raman analysis showed that the mesoporous film provides more accessible and various W-O surface bonds for Li+ intercalation. On the contrary, in the first electrochemical insertion and de-insertion in the dense film, Li+ selectively reacts with a few surface W-O bonds and preferentially intercalates into pre-existing crystallites to form stable irreversible LixWO3 bronze. [less ▲]

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See detailSurfactant-assisted ultrasonic spray pyrolysis of nickel oxide and lithium-doped nickel oxide thin films, towards electrochromic applications
Denayer, Jessica ULiege; Bister, Geoffroy; Simonis, Priscilla et al

in Applied Surface Science (2014), 321

Lithium-doped nickel oxide and undoped nickel oxide thin films have been deposited on FTO/glass substrates by a surfactant-assisted ultrasonic spray pyrolysis. The addition of polyethylene glycol in the ... [more ▼]

Lithium-doped nickel oxide and undoped nickel oxide thin films have been deposited on FTO/glass substrates by a surfactant-assisted ultrasonic spray pyrolysis. The addition of polyethylene glycol in the sprayed solution has led to improved uniformity and reduced light scattering compared to films made without surfactant. Furthermore, the presence of lithium ions in NiO films has resulted in improved electrochromic performances (coloration contrast and efficiency), but with a slight decrease of the electrochromic switching kinetics. [less ▲]

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See detailImproved coloration contrast and electrochromic efficiency of tungsten oxide films thanks to a surfactant-assisted ultrasonic spray pyrolysis process
Denayer, Jessica ULiege; Aubry, Philippe; Bister, Geoffroy et al

in Solar Energy Materials & Solar Cells (2014), 130

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See detailElectrochemical and spectroscopic study of the self-assembling mechanism of normal and chelating alkanethiols on copper
Dilimon, V. S.; Denayer, Jessica ULiege; Delhalle, J. et al

in Langmuir (2012), 28(17), 6857-6865

The self-assembly of aliphatic thiol (RSH), dithiol (R(SH) 2), and dithiocarboxylic acid (RS 2H) onto mildly oxidized and highly oxidized copper was studied in real time by in situ electrochemical ... [more ▼]

The self-assembly of aliphatic thiol (RSH), dithiol (R(SH) 2), and dithiocarboxylic acid (RS 2H) onto mildly oxidized and highly oxidized copper was studied in real time by in situ electrochemical impedance spectroscopy (EIS). Ex situ characterization of the films was carried out using linear sweep voltammetry (LSV), polarization modulation infrared reflection absorption spectroscopy (PM-IRRAS), and X-ray photoelectron spectroscopy (XPS). In situ EIS studies found a very fast adsorption of RSH, R(SH) 2, and RS 2H (within 10-15 s). This fast adsorption step is followed by the long-term additional adsorption and consolidation of SAM. However, the self-assembly of RS 2H passes through an intermediate step of molecule rearrangement for around 10 to 30 min after around 2 to 7 min of self-assembly. The binding of both sulfur moieties of R(SH) 2 with Cu happens simultaneous. The oxide reduction capacity of RSH, R(SH) 2, and RS 2H was good. However, the XPS studies showed the decomposition of RS 2H-based SAMs to Cu 2S. Monolayers prepared on both mildly oxidized and heavily oxidized Cu with R(SH) 2 had the highest stability. Monolayers of RS 2H showed the least stability on both mildly oxidized and heavily oxidized Cu. Although RSH-based SAMs had good organization on both mildly oxidized and highly oxidized Cu, R(SH) 2-based SAMs did not show good organization in either case. The RS 2H monolayer had good organization only on mildly oxidized Cu. © 2012 American Chemical Society. [less ▲]

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See detailFormation on copper of perfluoroetheralkyl-thiol and dithiol self-assembled monolayers with a perfluoropolyether overlayer
Denayer, Jessica ULiege; Volcke, C.; Delhalle, J. et al

in Electrochimica Acta (2012), 63

Copper based electrical contacts are widely used thanks to the high electric conductivity and low cost of this metal. However, the efficiency and durability of the devices can be affected by several ... [more ▼]

Copper based electrical contacts are widely used thanks to the high electric conductivity and low cost of this metal. However, the efficiency and durability of the devices can be affected by several factors including metal oxidation and corrosion. In this paper, a bilayer mixed lubricant has been developed to attenuate those hindrances. It is composed of an immobile layer (perfluoroetheralkyl-thiol and dithiol SAMs) to reduce copper corrosion, and by a mobile layer (PFPE lubricant) to reduce the friction. The perfluorinated SAMs have been successfully achieved on copper and the resulting monolayers exhibit high blocking and insulating behaviors. The spreading of PFPE lubricant on those self-assemblies has then been performed. The resulting bilayer systems are homogeneous and completely wetted by the lubricant. Furthermore, the bilayer systems show higher retention of the thin lubricant film than the bare copper. © 2011 Elsevier Ltd. All rights reserved. [less ▲]

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See detailStability of self-assembled monolayers of organothiol mono and bipode on copper in presence of another organothiol solution
Denayer, Jessica ULiege; Delhalle, J.; Mekhalif, Z.

in Thin Solid Films (2012), 520(6), 2017-2021

The stability of alkanethiol self-assembled monolayers (SAMs) on metallic substrates is an important aspect for further application. Some studies point out the poor stability of this coating and the ... [more ▼]

The stability of alkanethiol self-assembled monolayers (SAMs) on metallic substrates is an important aspect for further application. Some studies point out the poor stability of this coating and the displacement of alkanethiol from the monolayer by immersion in another alkanethiol solution. The aim of this work consists in a comparative investigation of self-exchange of three organothiols: 11-perfluorobutyl-1-thiol-undecane (or R fSH), 2-dodecylpropane-1,3- dithiol (or R(SH) 2) and n-decanedithiocarboxylic (or RS 2H). The immersion of RS 2H monolayer into R fSH solution (first approach) leads to the incorporation of thiol molecules into the defects of the initial SAMs followed by the displacement of RS 2H molecules by R fSH. While for R fSH SAM in presence of R(SH) 2 solution (second approach), longer time of immersion is required to observe the incorporation of dithiol molecules into the coating as well as the displacement of thiol molecules. © 2011 Elsevier B.V. All rights reserved. [less ▲]

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See detailSelf-assembly of amine terminated alkylthiol and alkyldithiol films on a polycrystalline copper substrate
Denayer, Jessica ULiege; Delhalle, J.; Mekhalif, Z.

in Journal of the Electrochemical Society (2011), 158(8), 100-108

Amine terminated self-assembled monolayers on gold are widely used as adhesion promoter agent to immobilize nanostructure such as fullerene, proteins and biological cells. The reactivity of the amine ... [more ▼]

Amine terminated self-assembled monolayers on gold are widely used as adhesion promoter agent to immobilize nanostructure such as fullerene, proteins and biological cells. The reactivity of the amine function makes difficult the formation of high quality SAMs. Most studies report disordered structure with the presence of oxidized sulphur on the surface. In this work, SAMs of 11-aminoundecyl-1-thiol (NH 2-(CH 2) 11-SH) and 2-aminoundecylpropane-1,3-dithiol (NH 2-(CH 2) 11-CH-(CH 2SH) 2) have been elaborated on copper substrates, following different protocols (alkalinization during or after the self-assembly). The modification of copper by amine terminated SAMs of thiol and dithiol has been successfully achieved. The best quality of SAMs are obtained when the alkalinization to free amine is carried on after the self-assembly process. Characterizaton of the SAMs are carried out using contact angle goniometry, PM-IRRAS, XPS and CV. © 2011 The Electrochemical Society. [less ▲]

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See detailAminealkylthiol and dithiol self-assembly as adhesion promoter between copper substrate and epoxy resin
Denayer, Jessica ULiege; Delhalle, J.; Mekhalif, Z.

in Applied Surface Science (2011), 257(24), 10686-10691

To improve adhesion between copper and epoxy resin in printed circuit board, a roughness treatment of copper has been widely used. Nevertheless, new adhesion promoters have to be developed to face the ... [more ▼]

To improve adhesion between copper and epoxy resin in printed circuit board, a roughness treatment of copper has been widely used. Nevertheless, new adhesion promoters have to be developed to face the miniaturization and sophistication of the electronic device. Self-assembled monolayers have met increasing interest in this field by using them as coupling agent between copper and the epoxy resin. This paper presents the deposition of an epoxy resin on copper modified by amine alkylthiol and dithiol monolayers and highlights the benefit brought by the monolayer in terms of adhesion. The chemical linkage between the amine SAMs and the epoxy function has been proved by the deposition on a short epoxy fragment, the 2-(4-fluorophenoxy-methyl)oxirane. The deposition of an epoxy resin mixed with amine curing agent has then been successfully achieved on amine terminated SAMs. The resulting polymer is homogeneous and well adherent on their surface, while the adhesion is lower on bare copper and not existing on methyl terminated SAMs. The formation of chemical bond Cu-S and N-epoxy is thus essential to increase the adhesion strength between copper and the polymer. © 2011 Elsevier B.V. All rights reserved. [less ▲]

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See detailElectro-assisted assembly of aliphatic thiol, dithiol and dithiocarboxylic acid monolayers on copper
Maho, Anthony ULiege; Denayer, Jessica ULiege; Delhalle, J. et al

in Electrochimica Acta (2011), 56(11), 3954-3962

Molecular assemblies of organothiol molecules on polycrystalline copper surfaces are a well known process to confer them specific organizational and protective properties. In this paper, an original and ... [more ▼]

Molecular assemblies of organothiol molecules on polycrystalline copper surfaces are a well known process to confer them specific organizational and protective properties. In this paper, an original and promising approach is considered through an electro-assisted adsorption process via a cathodic polarization of the copper substrate. Spectroscopic characterizations (PM-IRRAS, XPS) and electrochemical studies (CV, LSV, cathodic desorption, SECM) highlight and confirm the benefits brought by this methodology in terms of resulting SAMs features and considerable savings of preparation time. In addition to normal alkylthiols with a monopod anchoring group, alkyldithiocarboxylic acid and alkyldithiol monolayers - both bipodal - are characterized with the prospect of forming either easier to remove or more adherent films, respectively. © 2011 Elsevier Ltd. All rights reserved. [less ▲]

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See detailAssemblage-moléculaire électro-assisté d'organothiols sur cuivre polycristallin
Maho, Anthony ULiege; Denayer, Jessica ULiege; Delhalle, Joseph et al

in Chimie Nouvelle (2011), 5

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See detailBilayers coating on titanium surface: The impact on the hydroxyapatite initiation
Arnould, C.; Denayer, Jessica ULiege; Planckaert, M. et al

in Journal of Colloid & Interface Science (2010), 341(1), 75-82

Most of the actual orthopaedic devices, widely made of titanium and its alloys, present different weaknesses like ions release and risks of loosening over a long period. To solve such problems, new ... [more ▼]

Most of the actual orthopaedic devices, widely made of titanium and its alloys, present different weaknesses like ions release and risks of loosening over a long period. To solve such problems, new developments in surface modification are crucial. This work is an extension of our recent effort on the development and improvement of a multifunctional inorganic/organic bilayers coating. A thin tantalum oxide layer is formed by sol-gel synthesis followed by the modification with organophosphonic acids of the tantalum oxide layer. We focus in particular on the effect of the bilayers coating on corrosion resistance and hydroxyapatite growth rate by immersion in a simulated body fluid solution. It is also highlighted that the structure of the organophosphonic acid is of major importance on the osteoinduction character of the material. © 2009 Elsevier Inc. All rights reserved. [less ▲]

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See detailComparative study of copper surface treatment with self-assembled monolayers of aliphatic thiol, dithiol and dithiocarboxylic acid
Denayer, Jessica ULiege; Delhalle, J.; Mekhalif, Z.

in Journal of Electroanalytical Chemistry (2009), 637(1-2), 43-49

The stability of alkanethiol self-assembled monolayers (SAMs) on metallic substrates, in particular copper, is an important aspect for their application. Some technologies, such as lithographic patterning ... [more ▼]

The stability of alkanethiol self-assembled monolayers (SAMs) on metallic substrates, in particular copper, is an important aspect for their application. Some technologies, such as lithographic patterning, can potentially benefit from the use of a transient easily removal protective coatings. Other applications like corrosion resistance, and thin-film lubrication request rather robust and stable films. The aim of this work consists in a comparative investigation of three organothiols (n-tetradecanethiol or RSH, 2-dodecylpropane-1,3-dithiol or R(SH)2 and n-tetradecanedithiocarboxylic or RS2H) on their ability to form SAMs on electrochemically reduced polycrystalline copper substrates and their respective stability. Characterizations of the SAMs are carried out using contact angle goniometry, XPS, PM-IRRAS and electrochemical studies (CV, LSV and cathodic desorption). R(SH)2 leads to monolayers with lower molecular organization than in the case of RSH and RS2H molecules. R(SH)2 monolayers are found the more stable when subjected to both anodic and cathodic desorption tests. © 2009 Elsevier B.V. All rights reserved. [less ▲]

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See detailSurface modification of copper with 2-dodecylpropane-1,3-dithiol: The key effect of the solvent
Denayer, Jessica ULiege; Delhalle, J.; Mekhalif, Z.

in Applied Surface Science (2009), 256(5), 1426-1430

Self-assembly of alkanethiol on gold in various solvents (alkane, alcohol, etc) leads to monolayers with similar properties. However when the self-assembly is performed on copper substrates, the nature of ... [more ▼]

Self-assembly of alkanethiol on gold in various solvents (alkane, alcohol, etc) leads to monolayers with similar properties. However when the self-assembly is performed on copper substrates, the nature of the solvent has an effect on the properties of the monolayer. This phenomenon arises from the chemical interaction of copper with the solvent, which is not the case of gold. Ethanol is a solvent widely used for self-assembly, however some studies pointed out its negative effect due to its significant chemical reactivity towards copper and its ability to chemisorb on the surface. The aim of this work consists in a comparative investigation of 2-dodecylpropane-1,3-dithiol (or R(SH)2) in various solvents and its ability to form stable SAMs, densely packed and well ordered. Characterizations of the SAMs are carried out using X-ray photoelectron spectroscopy (XPS), polarization modulation infrared reflection-absorption spectroscopy (PM-IRRAS) and cyclic voltammetry (CV). © 2009 Elsevier B.V. All rights reserved. [less ▲]

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