The physicochemical modifications of ammonia-treated polypropylene (PP) films have been studied and characterized in terms of acid-base properties using the contact angle titration method and X-ray photoelectron spectroscopy in conjunction with a molecular probe technique using chloroform as a reference Lewis acid. These techniques have shown that PP surfaces that have been treated for between 0.7-1 s are basic in character. For longer treatment times, the basic character of the surfaces decreases, as shown by the above techniques and confirmed by time of flight-secondary ion mass spectroscopy (ToF-SIMS). On the other hand, for such treatment times, a degradation of the adhesion and mechanical properties was observed.The ageing of an ammonia-plasma-treated PP was limited by a helium (Ne) plasma pretreatment known to crosslink the surface, stabilizing in this way the wettability, adhesion and mechanical properties. ToF-SIMS was performed on helium treated High Density Polyethylene (HDPE) in order to point out the structural modifications.

The fundamental state of poly(ethylene terephthalate) (PET) is investigated using the density functional theory (DFT). The nature of the molecular orbitals from which the valence electrons originate is first deduced from a 'band-by-band' analysis. Intermixing of the metal and the polymer orbitals together with the flow of electronic charge from the metal to the polymer is then examined. Our theoretical results are found to be in good agreement with previously published SSIMS data.

This feature article is focused on the application of secondary ion mass spectrometry (time-of-flight SIMS) to the chemical and structural study of plasma-treated organic surfaces and plasma polymer films. After a brief historical perspective and a presentation of the recent developments of SIMS, illustrative case studies involving plasma-treated polymer surfaces and plasma polymers are presented. Beyond surface analysis by static SIMS, we show the potential of molecular depth-profiling by low-energy Cs+ ions and large Ar-n(+) clusters for the in-depth chemical characterization of plasma-modified samples. Together with SIMS data processing by multivariate analysis, molecular depth-profiling could provide a step change for the analysis of films treated or polymerized with plasmas.

A major challenge regarding the characterization of multilayer films is to perform high-resolution molecular depth profiling of, in particular, organic materials. This experimental work compares the performance of C60 + and Ar1700 + for the depth profiling of model multilayer organic films. In particular, the conditions under which the original interface widths (depth resolution) were preserved were investigated as a function of the sputtering energy. The multilayer samples consisted of three thin δ-layers (~8 nm) of the amino acid tyrosine embedded between four thicker layers (~93 nm) of the amino acid phenylalanine, all evaporated on to a silicon substrate under high vacuum. When C60 + was used for sputtering, the interface quality degraded with depth through an increase of the apparent width and a decay of the signal intensity. Due to the continuous sputtering yield decline with increasing the C60 + dose, the second and third δ-layers were shifted with respect to the first one; this deterioration was more pronounced at 10 keV, when the third δ-layer, and a fortiori the silicon substrate, could not be reached even after prolonged sputtering. When large argon clusters, Ar1700 +, were used for sputtering, a stable molecular signal and constant sputtering yield were achieved throughout the erosion process. The depth resolution parameters calculated for all δ-layers were very similar irrespective of the impact energy. The experimental interface widths of approximately 10 nm were barely larger than the theoretical thickness of 8 nm for the evaporated δ-layers.

Surface preparation with gas cluster ion beam (GCIB) sputtering was performed on paint cross‐sections, which belong to the collection of the Royal Institute for Cultural Heritage (KIKIRPA), Brussels, Belgium. Superficial cleaning of cross sections with residual embedding resin surface contamination was studied with different sputtering times in order to obtain a gain in the spectral and imaging mode. Sputtering was made directly through the Time‐of‐Flight‐SIMS apparatus. It was thus demonstrated that GCIB sputtering for a short period was very efficient for the superficial decontamination of cultural heritage cross‐sections without visible damage on the valuable samples. The GCIB sputtering time and dose can be highly decreased when combined with a monoatomic argon ion beam preparation techniques such as the ion milling systems. Copyright © 2014 John Wiley & Sons, Ltd.

La spectroscopie de Resonance Paramagnetique Electronique (RPE), c’est-a-dire l’etude de la structure electronique des centres paramagnetiques, est de plus en plus utilisee pour des applications qui vont bien au-dela de celles imaginees initialement par les physiciens. La RPE permet d’obtenir des informations sur l’evolution de proprietes dans le temps (datation) et dans l’espace (tracage). Avec plus d’investissement, elle rend possible l’identification d’une molecule et la determination de niveaux d’energie. Cela concerne la physique, la chimie mais aussi les sciences de la Terre et de l’univers, celles de l’environnement, de la vie et de la sante. Cet ouvrage collectif presente une grande variete d’applications. Certaines ne necessitent pas un bagage theorique important pour etre comprises. Pour d’autres, il est possible de se referer a l’ouvrage La spectroscopie de RPE - Fondements dans la meme collection ou a certains complements de fin de chapitre. Des annexes sur des methodes ou techniques sont proposees de facon independante en fin d’ouvrage. Enfin, pour chaque application, des references sont proposees a ceux qui veulent approfondir. L’ouvrage est accessible a des etudiants de master 1 de physique, de chimie, de chimie physique, de biophysique et de biochimie. Il sera utile aux professionnels qui utilisent la technique de spectroscopie RPE, aux chercheurs mais aussi aux enseignants du superieur et des classes preparatoires qui pourront ainsi elargir leurs connaissances de facon tres concrete et illustree.

Thin films of insulating polymers are sometimes analyzed by secondary ion mass spectrometry (SIMS) or by X-ray photoelectron spectroscopy (XPS) without the use of an electron gun. In this work, both SIMS and XPS have been used to study the chemical and structural modifications due to the charge effect during Cs+ sputtering of a thin film of polyvinyl chloride (PVC). The kinetic energy distribution study shows that at a small primary fluence similar to 10(15)Cs(+) ions/cm(2), the dielectric breakdown voltage of the PVC film is reached, i.e. the minimum voltage that causes a portion of an insulator to become electrically conductive. XPS study indicates that the conducting phase created in the PVC film after energetic Cs+ bombardment consists of graphitized carbon and metallic cesium clusters. After the dielectric breakdown of the film, the positive charge, previously accumulated on the surface, is neutralized through the conductive regions, which are created in the insulating film. During Cs+ sputtering of a PVC film, the chemical structure of the analyzed surface is completely modified and some ionic bonds such as Cs-C and Cs-Cl are also created. (C) 2013 Elsevier B.V. All rights reserved.

Although nowadays the use of cluster ion sources seems to enhance the secondary ion emission for nearly all materials, the technique of metal-assisted SIMS can still give further insights in the secondary ion emission process. In this study, the metallization for static SIMS analysis was performed in situ. The combination of a detailed morphology study by SEM, TEM and the secondary yield enhancements in time-of-flight SIMS allows to develop a model explaining the secondary yield enhancement in metal-assisted SIMS. Copyright (C) 2012 John Wiley & Sons, Ltd.

Cluster secondary ion mass spectrometry is now widely used for the characterization of nanostructures. In order to gain a better understanding of the physics of keV cluster bombardment of surfaces and nanoparticles (NPs), the effects of the atomic masses of the projectile and of the target on the energy deposition and induced sputtering have been studied by means of molecular dynamics simulations. 10 keV C-60 was used as a model projectile and impacts on both a flat polymer surface and a metal NP were analyzed. In the first case, the mass of the impinging carbon atoms was artificially varied and, in the second case, the mass of the NP atoms was varied. The results can be rationalized on the basis of the different atomic mass ratios of the projectile and target. In general, the emission is at its maximum, when the projectile and target have the same atomic masses. In the case of the supported NP, the emission of the underlying organic material increases as the atomic mass of the NP decreases. However, it is always less than that calculated for the bare organic surface, irrespective of the mass ratio. The results obtained with C-60 impacts on the flat polymer are also compared to simulations of C-60 and monoatomic Ga impacts on the NP.

Molecular semiconductor devices, such as light‐emitting diodes and photovoltaic cells, have recently received considerable attention because of their compatibility with flexible substrates and large‐area applications. Because of the importance of the interfacial properties for the performance of the devices, these organic (multi)layers constitute an important field of application for molecular depth profiling by SIMS. In this contribution, we investigate the use of C60n+ and Ar1000–2000+ cluster projectiles at different energies (ranging from 2.5 to 20 keV) as sputter ions for the organic depth profiling of fullerene‐based films and heterojunctions. The bilayers consist of C60 fullerenes on tin phthalocyanine (SnPc), deposited on silicon substrates. Our preliminary results showed that C60 films could not be successfully profiled using C60n+ ions in regular analysis conditions (room temperature). In contrast, with Ar clusters, the depth profiling is successful (except for 20 keV Ar1000) and the sputtered volume shows a linear relationship with the Ar cluster energy. Surprisingly, for a given total energy of the projectiles, Ar2000 sputters approximately two times more than Ar1000. The observations are tentatively explained as being the result of a balance between the sputtering and the cross‐linking efficiency for the different bombardment conditions, larger clusters being expected to naturally induce less cross‐linking than smaller clusters with the same total energy. Copyright © 2012 John Wiley & Sons, Ltd.

In the present study, the feasibility of synthesizing chlorinated films by a dielectric barrier discharge at atmospheric pressure is assessed. Two different liquid monomers (hexachlorobuta-1,3-diene C4Cl6 and 1,1,1,2-tetrachloroethane C2H2Cl4) are tested and results show that organic coatings rich in chlorine can be deposited. The correlation and complementarity of water contact angle, X-ray photoelectron spectroscopy, secondary ion mass spectrometry and ellipsometry techniques have provided information to compare the properties of the perchlorinated layers built up from monomers with different Cl/C ratios and hydrogen concentrations. The bond dissociation energies of C-Cl-2, C-Cl and C-C/C=C/C-H are used to provide an explanation for the differences in films structure recorded by X-ray photoelectron spectroscopy and secondary ion mass spectrometry. Finally, dynamic-secondary ion mass spectrometry complemented by ellipsometry is used to calculate a deposition rate ranging from 40 to 70 nm/min depending on the plasma conditions. These measurements also show a good homogeneity of the film throughout its thickness. (C) 2013 Elsevier Ltd. All rights reserved.