TOF-SIMS

This dissertation demonstrates that a more accurate assessment of Quattrocento painting practice can be accomplished only if the original stratigraphy of the paint and ground layers is preserved during organic analysis. The evolution of oil painting in Renaissance Italy must now be re-examined due to advancements in the analysis of binding media and recent improvements in primary source research. Contemporary conceptions of Western European painting techniques stem from a complex history associated with conservation science, treatment methodologies, and connoisseurship. New findings suggest that Italian painters working in and around the Veneto were likely introduced to the oil technique well before 1400 while analysis and visual examination of fifteenth-century works from southern Italy also demonstrate an acute familiarity with the northern medium and aesthetic. The decision to use an egg vs. an oil binder is inextricably tied to an artist’s technique and arguably as important as the conscious selection of certain pigments. Such considerations will help to further elucidate the dissemination of oil painting south of the Alps during the fifteenth century.
In this dissertation I demonstrate that problematic and even incorrect assumptions have been made regarding the characterization of binding media in early Italian paintings. This is shown through the creation of historically representative paint reconstructions that can help in determining the visual qualities and chemical components of traditional egg tempera and oil paint as well as the analysis of actual works of art. In addition, Contamination from restoration materials, the migration of fatty acids, the presence of reactive pigments, and the formation of degradation products are now known to affect the detection of certain chemical markers that are key in helping scientists to identify the binders present in a work of art. Newly recognized inaccuracies relating to early analytical protocols have prompted scientists to develop more sophisticated methods for distinguishing egg tempera from oil paints, and earlier technical studies of Quattrocento paintings must now be re-evaluated. A new discourse is needed to develop a more accurate understanding of Quattrocento painting techniques, workshop practices, attribution, and the diffusion of artistic processes throughout Europe.

The effectiveness of latent fingerprint development techniques is heavily influenced by the physical and chemical properties of the deposition surface. The use of powder suspensions is increasing for development of prints on a range of surfaces. We demonstrate that carbon powder suspension development on polymers is detrimentally affected by the presence of common white pigment, titanium dioxide. Scanning electron microscopy demonstrates that patches of the compound are clearly associated with increased levels of powder adhesion. Substrates with nonlocalized titanium dioxide content also exhibit increased levels of carbon powder staining on a surface-wide basis. Secondary ion mass spectrometry and complementary techniques demonstrate the importance of levels of the pigment within the top 30 nm. The association is independent of fingermark deposition and may be related to surface energy variation. The detrimental effect of the pigment is not observed with small-particle reagent (MoS2 SPR) or cyanoacrylate (superglue) fuming techniques that exploit different development mechanisms.

Bacon, S. R., Ojeda, J. J., Downham, R., Sears, V. G. and Jones, B. J. (2013) Journal of Forensic Sciences (2013) 1486
http://dx.doi.org/10.1111/1556-4029.12206

Long afterglow CaAl2O4:0.03Eu2þ, 0.03Nd3þ phosphor was prepared by solution-combustion synthesis. The active role of boric acid (H3BO3)asa flux in enhancing the Eu2þ photoluminescence and the effect of a varied amount of urea (CO (NH2)2) as a fuel on the morphological, structural and photoluminescent (PL) properties of the CaAl2O4:0.03Eu2þ, 0.03Nd3þ systems were investigated. The results of X-ray diffraction, scanning electron microscopy, and PL spectra revealed the influence of the dosage of urea and hence the heated process on the crystallinity, morphology, and luminescence of the phosphor. The addition of H3BO3 favoured the formation of a monoclinic CaAl2O4 phase while the variation of the amount of CO (NH2)2 showed mixed phases although still predominantly monoclinic. Both H3BO3 and CO(NH2)2 to some extent influence the luminescence intensity of the obtained phosphor but unlike the case of CO (NH2)2, the presence of H3BO3 did not evidently shift the emission peak due to no obvious change in the energy level difference of the 4f–5d levels. The broad blue emissions consisting mainly of symmetrical bands having maxima between 440 and 445 nm originate from the energy transitions between the ground state (4f7) and the excited state (4f65d1) of the Eu2þ ions while the narrow emissions in the red region (600–630 nm) arise from the 5D0-7F2 transitions of the remnant unreduced Eu3þions. Higher concentrations of H3BO3 (0.228 mol and 0.285 mol) reduce both intensity and lifetime of the phosphor. The optimized content of H3BO3 was 0.171 mol for the obtained phosphor with the best optical properties.

Eu2+ doped and Nd3+ co-doped calcium aluminate (CaAl2O4:Eu2+,Nd3+) phosphor was prepared by a urea-nitrate
solution combustion method at furnace temperatures as low as
500°C. The produced CaAl2O4:Eu2+,Nd3+ powder was investigated in terms of phase composition, morphology and luminescence by X-Ray diffraction (XRD), Scanning Electron Microscope (SEM),
Fourier Transform Infra Red spectroscopy (FTIR) and
Photoluminescence (PL) techniques respectively. XRD analysis depicts a dominant monoclinic phase that indicates no change in the crystalline structure of the phosphor with varying concentration of Eu2+ and Nd3+. SEM results show agglomerates with non-uniform shapes and sizes with a number of irregular network structures having lots of voids and pores. The Energy Dispersive X-ray Spectroscopy (EDS) and (FTIR) spectra confirm the expected chemical components of the phosphor. PL measurements indicated one broadband excitation spectra from 200 to 300 nm centred around 240 nm corresponding to the crystal field splitting of the Eu2+ d-orbital and an emission spectrum in the blue region with a maximum on 440 nm. This is a strong indication that there was dominantly one luminescence luminescence centre, Eu2+ which represents emission from transitions between the 4f7 ground state and the 4f6-5d1 excited state configuration. High concentrations of Eu2+ and Nd3+ generally reduce both intensity and lifetime of the phosphor powders. The optimized content of Eu2+ is 1mol% and for Nd3+ is 1mol% for the obtained phosphors with excellent optical properties. The phosphor also emits visible light at around 587 and 616 nm. Such emissions can be ascribed to the 5D0–7F1 and 5D0–7F2 intrinsic transition of Eu3+ respectively. The decay characteristics exhibit a significant rise in initial intensity with increasing Eu2+ doping concentration while the decay time increased with Nd3+ co-doping. The observed afterglow can be ascribed to the generation of suitable traps due to the presence of the Nd3+ ions.

Secondary ion mass spectrometry (SIMS) has joined the ranks
of commonplace analytical tools for nanostructures in ways
that would have been difficult to foresee even a decade ago. In
particular, improvements in numerical data processing have
permitted the use of SIMS in one dimension with uneven
surfaces and in reconstructing compositional profiles in two
and even three dimensions. These developments offer perhaps
the brightest prospects for making SIMS a leading member
within the select family of first-line characterization tools for
nanoelectronics, nanoparticles, and polycrystalline and
composite materials — as well as expanding the science base
for tailoring such structures.

The surface of six different archaeological obsidian tools are analyzed systematically with Time of Flight Secondary Ion Mass Spectrometry (ToF-SIMS) and Quad-SIMS for both the evaluation of the surface topography , as well as, the detection of remaining organic compounds via various amino acids, that may have been trapped in the surfaces. This initiates a new way to wear analysis and dating of prehistoric glass tools. The three basic criteria in surface topography and diffusion dating that has been investigated here for first time is the detection of organics, the elemental concentration mapping and 3D versus depth, and the simultaneous recording of several cations (C, F, Al, Mg). In any H + depth profile in the obsidian hydration rim, C and Mg must also be included in the measurement. A non-conformity of cation profiles between H + and these cations point to an area with inclusions and the measurement has to be repeated in different spots.

Overcoming the natural recalcitrance of lignocellulosic biomass is necessary in
order to efficiently convert biomass into biofuels or biomaterials and many
times this requires some type of chemical pretreatment and/or biological treatment.
While bulk chemical analysis is the traditional method of determining
the impact a treatment has on biomass, the chemistry on the surface of the
sample can differ from the bulk chemistry. Specifically, enzymes and microorganisms
bind to the surface of the biomass and their efficiency could be greatly
impacted by the chemistry of the surface. Therefore, it is important to study
and understand the chemistry of the biomass at the surface. Time-of-
flight
secondary ion mass spectrometry (ToF-SIMS)
is a powerful tool that can spectrally
and spatially analyze the surface chemistry of a sample. This review discusses
the advances in understanding lignocellulosic biomass surface chemistry
using the ToF-SIMS
by addressing the instrument parameters, biomass sample
preparation, and characteristic lignocellulosic ion fragmentation peaks along with their typical location in the plant cell wall. The use of the ToF-SIMS in detecting chemical changes due to chemical pretreatments, microbial treatments, and physical or genetic modifications is discussed along with possible future applications of the instrument in lignocellulosic biomass studies.

Secondary ion mass spectrometry (SIMS) is a widespread analytical technique for the study of surfaces in materials science. Mostly used for elemental analyses and depth profiling, it is particularly relevant for many different fields of research including cultural heritage studies. Reviews of its use for the study of ancient glasses or metal artefacts already exist in the literature, but as only elemental information is obtained, these studies are limited to inorganic materials.
Nevertheless, the introduction of time-of-flight (ToF) analysers for SIMS analyses at the beginning of the 1980’s, as well as the recent development of liquid ion sources delivering cluster projectiles now permit the analysis of organic materials with high sensitivity and selectivity. Moreover, thanks to its excellent lateral resolution (in the order of micrometers), and its minimal sample preparation, ToF-SIMS has become the reference technique for chemical imaging by mass spectrometry.
Beside numerous applications for biological samples, studies of organic materials from cultural heritage artefacts have been developing since the beginning of the twenty-first century. In this review we show, through some selected examples, the different aspects and possibilities of ToF-SIMS analyses.
First, because ToF-SIMS is not yet a classical technique for cultural heritage studies, we will begin with a brief overview of the physical principle, the instrumentation and sample preparation. The aim is not to present a complete description of the technique, since this can be found elsewhere, but to give the reader an idea of the specificity and applicability of ToF-SIMS analyses.

The goal of this study is to investigate the effect of carbon incorporation upon thermal oxidation of Si1−x Ge x alloys and its role on strain compensation in Si1−x Ge x alloys. Si1−x Ge x and Si1−x−y Ge x C y alloys on Si(100) are grown by combined ion and molecular beam deposition and are then oxidized at 1000 °C in a dry oxygen ambient for two h. The thickness and the composition of all samples before and after oxidation are measured by Rutherford backscattering spectrometry (RBS) combined with ion channeling at 2.0 MeV and carbon nuclear resonance analysis at 4.3 MeV using 4He++ ions. In agreement with previously reported results of dry oxidation on Si1−x Ge x thin films, 2.0 MeV RBS analysis shows that a layer of SiO2 is formed on the top surface of both Si1−x Ge x and Si1−x−y Ge x C y thin films, while Ge segregates towards the top surface and at the SiO2/Si1−x Ge x and SiO2/Si1−x−y Ge x C y interfaces. However, it is observed for the first time that dry oxidation rates of Si1−x Ge x thin films decrease with increasing Ge fraction x for x≳0.20 and with increasing minimum yield. Ion channeling analysis and strain measurements indicate that the incorporation of C rather than the amount of C itself affects the dry oxidation mechanism because of its strong influence on film strain and crystalline quality. These results are discussed in conjunction with observations by secondary ion mass spectrometry, high resolution transmission electron microscopy, Fourier transform infrared spectrometry, and tapping mode atomic force microscopy.

The relative ability of the small laccase (sLac) and dye-decoloring peroxidase (DyP2) from Amycolatopsis sp. 75iv2 to transform a variety of lignins was investigated using Time of Flight Secondary Ion Mass Spectrometry (ToF-SIMS). The enzymes modified organosolv hardwood lignin to different extents even in the absence of an added mediator. More particularly, sLac decreased the lignin modification metric S (S-lignin)/Ar (total aromatics) by 58% over 16 hours while DyP2 lowered this ratio by 31% in the absence of exogenous H2O2. When used on their own, both sLac and DyP2 also modified native lignin present in aspen wood powder, albeit to lesser extents than in the organosolv lignin. The addition of ABTS for sLac, and Mn2+ as well as H2O2 for DyP2 led to increased lignin modification in aspen wood powder as reflected by a decrease in the G/Ar metric by up to a further 13%. This highlights the importance of exogenous mediators for transforming lignin within its native matrix. Furthermore, the addition of ABTS reduced the selectivity of sLac for S-lignin over G-lignin, indicating that the mediator also altered the product profiles. Finally, when sLac was included in reactions containing DyP2, in part to generate H2O2 in situ, the relative abundance of lignin products differed from individual enzymatic treatments. Overall, these results identify possible routes to tuning lignin modification or delignification through choice of enzyme and mediator. Moreover, the current study expands the application of ToF-SIMS to evaluating enzyme action on technical lignins, which can accelerate the discovery and engineering of industrially relevant enzymes for lignin valorization.

Parmi les matériaux archéologiques, les restes humains, comme la peau de momie, constituent un héritage précieux et particulier des pratiques funéraires et des modes de vie anciens. Ils donnent également accès à des informations sur la dégradation des tissus biologiques sur des échelles de temps particulièrement longues.

L’imagerie chimique, notamment par spectrométrie de masse TOF-SIMS a été appliquée à l’analyse de ces matériaux hybrides, particulièrement complexes. Complétée par d’autres méthodes d’analyse (MEB-EDX, FT-IR, DRX), cette étude a permis de préciser la structure et la composition de micro-échantillons de peau de momies naturelles ou artificielles. Pour cela, l’étape cruciale de préparation des échantillons a été optimisée.

Afin de comprendre les processus de dégradations, protéiques en particulier, des tissus biologiques, anciens et modernes, de composition proches ont également été analysés (os, cornes, laine, soie, cheveux et poils animaux).

Notre étude a ainsi pu mettre en évidence l’apport de l’imagerie TOF-SIMS pour comprendre les processus de préparation des corps et de dégradation des tissus au cours des siècles.

Time-of-flight secondary ion mass spectrometry (ToF-SIMS) is quickly becoming a critical tool in the field of art conservation. This technique provides high-resolution spatial maps of both inorganic and organic components located within cross-sectional samples collected from works of art. With recent advances in surface analysis, ToF-SIMS can now be used to identify specific amino acids present in protein-containing materials as well as fatty acids in drying oils. For example, the detection of the ion fragment associated with the amino acid hydroxyproline can be used to confirm the use of animal glue in a paint sample. As an analytical technique, ToF-SIMS avoids the need for derivatization/silylation reagents, with no interference by the presence of pigments. Furthermore, the layered systems that are often encountered in historical paint samples remain intact throughout the analytical procedure. This allows for the colocalization of organic and inorganic species in specific layers (...

Graphene, as well as other two-dimensional materials, is a promising candidate for use in bioimaging, therapeutic drug delivery, and bio-sensing applications. Here, we developed a protocol to functionalize graphene with recombinant proteins using genetically encoded SpyTag-SpyCatcher chemistry. SpyTag forms a covalent isopeptide bond with its genetically encoded partner SpyCatcher through spontaneous amidation under physiological conditions. The functionalization protocol developed is based on the use of short proteins as a linker, where two graphene-binding-peptides (GBPs) are attached to both ends of SpyTag (referred to as GStG), followed by the covalent conjugation with SpyCatcher-fusion proteins. The proposed method enables the decoration of crystalline graphene with various proteins, such as fluorescent proteins and affibody molecules that bind to cancerous cells. This scheme, which takes advantage of the cleanness of single-crystal graphene and the robustness of SpyTag-SpyCatcher chemistry, provides a versatile platform on which to study the biomolecule-surface and cell-substrate interactions and, indeed, may lead to a new way of designing biomedical devices. The interaction between peptides and graphene was clearly shown using molecular dynamics simulation and proven using specially designed experiments.

We studied the time-of-flight secondary ion mass spectrometry fragmentation mechanisms of polystyrenes-phenyl-fluorinated polystyrene (5FPS), phenyl-deuterated polystyrene (5DPS), and hydrogenated polystyrene (PS). From the positive ion spectra of 5FPS, we identified some characteristic molecular ion structures with isomeric geometries such as benzylic, benzocyclobutene, benzocyclopentene, cyclopentane, and tropylium systems. These structures were evaluated by the B3LYP-D/jun-cc-pVDZ computation method. The intensities of the C 7 H 2 F 5 + (m/z = 181), CyPent-C 9 H 3 F 4 + (m/z = 187), CyPent-C 9 H 4 F 5 + (m/z = 207), and CyPent-C 9 H 2 F 5 + (m/z = 205) ions were enhanced by resonance stabilization. The positive fluorinated ions from 5FPS tended to rearrange and produce fewer fluorine-containing molecular ions through the loss of F (m/z = 19), CF (m/z = 31), and CF 2 (m/z = 50) ion fragments. Consequently, the fluorine-containing polycyclic aromatic ions had much lower intensities than their hydrocarbon counterparts. We propose the fragmentation mechanisms for the formation of C 5 H 5 + , C 6 H 5 + , and C 7 H 7 + ion fragments, substantiated with detailed analyses of the negative ion spectra. These ions were created through elimination of a pentafluoro-phenyl anion (C 6 F 5 −) and H + , followed by a 1-electron-transfer process and then cyclization of the newly generated polyene with carbon-carbon bond formation. The pendant groups with elements of different electronegativities exerted strong influences on the intensities and fragmentation processes of their corresponding ions.

Overcoming the natural recalcitrance of lignocellulosic biomass is necessary in order to efficiently convert biomass into biofuels or biomaterials and many times this requires some type of chemical pretreatment and/or biological treatment. While bulk chemical analysis is the traditional method of determining the impact a treatment has on biomass, the chemistry on the surface of the sample can differ from the bulk chemistry. Specifically, enzymes and microorganisms
bind to the surface of the biomass and their efficiency could be greatly
impacted by the chemistry of the surface. Therefore, it is important to study and understand the chemistry of the biomass at the surface. Time-of-flight secondary ion mass spectrometry (ToF-SIMS) is a powerful tool that can spectrally and spatially analyze the surface chemistry of a sample. This review discusses the advances in understanding lignocellulosic biomass surface chemistry using the ToF-SIMS by addressing the instrument parameters, biomass sample preparation, and characteristic lignocellulosic ion fragmentation peaks along with their typical location in the plant cell wall. The use of the ToF-SIMS in detecting chemical changes due to chemical pretreatments, microbial treatments, and physical or genetic modifications is discussed along with possible future applications of the instrument in lignocellulosic biomass studies.

To properly process and reconstruct 3D ToF-SIMS data from systems such as multi-component polymers,
drug delivery scaffolds, cells and tissues, it is important to understand the sputtering behavior of the
sample. Modern cluster sources enable efficient and stable sputtering of many organics materials.
However, not all materials sputter at the same rate and few studies have explored how different sputter
rates may distort reconstructed depth profiles of multicomponent materials. In this study spun-cast
bilayer polymer films of polystyrene and PMMA are used as model systems to optimize methods for the
reconstruction of depth profiles in systems exhibiting different sputter rates between components. Transforming
the bilayer depth profile from sputter time to depth using a single sputter rate fails to account for
sputter rate variations during the profile. This leads to inaccurate apparent layer thicknesses and interfacial
positions, as well as the appearance of continued sputtering into the substrate. Applying measured single
component sputter rates to the bilayer films with a step change in sputter rate at the interfaces yields
more accurate film thickness and interface positions. The transformation can be further improved by
applying a linear sputter rate transition across the interface, thus modeling the sputter rate changes seen
in polymer blends. This more closely reflects the expected sputtering behavior. This study highlights the
need for both accurate evaluation of component sputter rates and the careful conversion of sputter time
to depth, if accurate 3D reconstructions of complex multi-component organic and biological samples are
to be achieved. The effects of errors in sputter rate determination are also explored.

Eu2+ doped and Dy3+ co-doped strontium aluminate (SrAl2O4:Eu2+,Dy3+) phosphors were synthesized by the solution - combustion technique at 500 oC using urea as a reducer, a widely known method for preparing nano sized phosphors. Sr(NO3)2, Al(NO3)3.9H2O, CH4N2O, Eu(NO3)3.5H2O and Dy(NO3)3 were used as raw materials for the preparation of the SrAl2O4 (RE: Eu, Dy) precursor. The thermoluminescence (TL) properties of beta (β) irradiated SrAl2O4:Eu2+,Dy3+ have been studied. The electron-trapping properties in terms of TL glow curves are discussed in detail. The TL intensity was recorded for different beta doses at different heating rates. The influence of repeated measurements on the same sample on peak temperature and TL intensity was also investigated. Different kinetic parameters like activation energy and frequency factor are calculated for different TL glow curves. We have also calculated the trap depth with the variable heating method.

"Numerous African art objects collected in the course of colonial or ethnological expeditions during the 20th century are partially or completely covered with a so-called “patina”. These patinas have been formed during religious and ritual ceremonies, where different substances have been spread out at the surface of the objects. The anthropomorphic statuettes from the Dogon culture are well-known examples of this kind of practice. A better understanding of the chemical composition of these patinas could explain details of the ceremonial practices realized throughout the centuries. An important challenge is to extract unequivocal information about the original constituents of these patinas, and the techniques used for their application on ritual objects.
The Dogon statuary can be divided into three periods. The oldest one, before 1350 A.D., is called the Tellem period, according to the name of the people who lived in this area before the arrival of the Dogon. The most recent, after 1650 A.D., is the Dogon period. These two periods are separated by an intermediary period, where the attribution to the Tellem or to the Dogon cultures is difficult. During our study, we have worked on the patina of 12 Dogon artefacts from these three different periods. In this paper, we present the results obtained for two representative objects, one of the Tellem period and one of the Dogon period. The aim is to access the chemical composition of the patinas and to see if they can be compared to ethnological reports, as is often done in the literature on ethnological studies.

Chemical imaging techniques, based on the combination of microscopy and spectroscopy, are well suited to study both the composition and the spatial organization of heterogeneous complex mixtures of organic and inorganic matter. Time-of-flight secondary ion mass spectrometry (ToF-SIMS), followed by scanning electron microscopy with energy dispersive X-ray analysis (SEM-EDS), and Synchrotron radiation-based Fourier transform infrared microscopy (SR-µFTIR) have been applied to non-destructive analyses of micro-samples of the patinas of several Dogon statuettes. A very careful preparation, using ultramicrotomy on embedded samples, allowed us to perform successively all these measurements on a single fragment. Comparison and superposition of the different chemical images lead us to identify minerals (clays, quartz and calcium carbonate), and different organic products (proteins, starch, lipids), as well as to map their spatial distribution.
The patina of the most recent statuettes presents a stratigraphy which can be related to successive uses of the objects for ritual purposes, and the results are in agreement with the ethnological reports. For the Tellem objects, the significant quantity of minerals and the lack of stratigraphy suggest that the patina was deposited according to a different recipe. This difference suggests the existence of a diversity of rituals that are more extensive than that described by the ethnologists.

Keywords: African Art / Dogon / Tellem / ritual patina / Time-of-flight secondary ions Mass spectrometry (ToF-SIMS) /Imaging mass spectrometry / Fourier transform Infrared Microscopy (µFTIR) / Synchrotron radiation / Scanning Electron Microscopy with energy dispersive X-ray analysis (SEM-EDX)"

Life-history parameters such as pregnancies, skeletal trauma, and renal disease have previously been identified from hypomineralised growth layers (incremental lines) of acellular extrinsic fibre cementum (AEFC) using optical microscopy. We show that the precise periodicity of these growth layers remains poorly understood, so life history parameters for putative cementum deposition periodicity cannot be rigorously calculated. In an attempt to better understand the underlying formation processes, our study investigates whether or not mineralisation of AEFC incremental lines clearly indicate life history parameters in an ideal sample, using light microscopy, electron microscopy, and Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS). Based on our results we reject the possibility of accurate estimation of the distribution of mineralisation of tooth cementum using light and scanning electron microscopy alone. On the other hand, we detect an apparent drop in calcium in the AEFC of a patient
with six documented full-term pregnancies, using ToF SIMS. We conclude that although ToF-SIMS analysis holds great promise for increasing our knowledge of cementum composition, far more caution is required by researchers linking observed lines in this tissue to underlying causal life history mechanisms and explanations.

Time-of-flight secondary ion mass spectrometry (TOF-SIMS) spectra of polystyrene (PS) films supported on silicon wafers were obtained at temperatures ranging from room temperature to 100 °C. Principal component analysis (PCA) of the TOF-SIMS data revealed a transition temperature (TT) at which the surface structure of PS was rearranged. The TT of a 120-nm thick PS (weight-average molecular weight of 3 000 g/mol) thin film was determined to be about 36 °C, which is approximately 30 °C lower than the bulk glass transition temperature (Tg) of that PS. Similar TTs were observed on PSs with different molecular weights. As the TT is strongly related to the Tg and dependent on the molecular weight, it is believed that the TT determined by TOF-SIMS is related to the surface glass transition temperature (TgS) measured by other techniques. This suggests that TOF-SIMS combined with PCA can be used to determine the TgS of polymer films. Furthermore, the detailed PCA analyses indicate that the phenyl groups of PS tended to move away from the surface at temperatures above TT. This conclusion was further confirmed by contact angle and XPS measurements.

Obsidian surface roughness and rind structure both play a major influence on the Obsidian Hydration Dating (OHD). AFM (Atomic Force Microscopy) investigation coupled with quadrupole SIMS hydrogen data profiles establish a validation criterion of quantitative evaluation of roughness for OHD dating purposes. More evidence of the importance of the surface morphology at the nanoscale is given for five obsidian tools of different origin. The latter relates to the dynamic ion influx diffusion kinetics between surface and surrounded sediment media, and the obsidian structure, thus, 2D and 3D surface mapping, as well as, cation profiling (H, C, Mg, Al, F, S, Cl, CN, O isotopes) were made by TOF-SIMS and quad-SIMS. It was found that the C and Mg are considered as imposed criteria for accepting suitability of H + profiles for further processing by SIMS-Surface Saturation dating method. The effect of roughness to dating is discussed.

Films of a series of polymers with variable CF2 segments were studied by angle-dependent X-ray photoelectron spectroscopy (ADXPS) and time-of-flight secondary ion mass spectroscopy (ToF-SIMS). The effects of the length of the CF2 segment on the surface composition of the polymers were investigated. ADXPS results indicated that the CF2 segment segregated on the surface of the polymers after thermal annealing at temperatures above their bulk glass transition temperatures when the number of CF2 units was increased to 8. Because of the higher surface sensitivity, ToF-SIMS results showed more CF2 segments at the topmost surface than shown by ADXPS. Copyright © 2006 John Wiley & Sons, Ltd.

The prehistoric tools made by natural glass of obsidian can be
dated by the recent method of the secondary ion mass spectrometry
with the surface saturation using the surface saturation
approach (SIMS-SS). In its initial tests, the method inhered
some limitations mainly derived from surface roughness.
Indeed, the surface irregularities i.e. presence of wellscracks, pits, crystals and/or crests, induce uncertain errors in
the dating procedure. Here, we provide further images of the
Atomic Force Microscopy (AFM) of obsidian surfaces and
discuss the impact of AFM results on the SIMS-SS dating,
investigating the problematic non-smoothed surfaces.

"""Chemical imaging techniques, based on the combination of microscopy and spectroscopy, are well suited to study both the composition and the spatial organization of heterogeneous complex mixtures of organic and mineral matter. Time-of-flight secondary ion mass spectrometry (ToF-SIMS), followed by scanning electron microscopy with energy dispersive X-ray analysis (SEM-EDX) and Fourier transform infrared microscopy (FTIR microscopy) have been applied to non-destructive analysis of micro-samplings of ritual matters deposited on the surface of African wooden statuettes. With a very careful preparation, using ultramicrotomy on embedded samples, it was possible to perform successively all the measurements on a single fragment. Comparison and superposition of the different chemical images, obtained on a sample from a significant actual artefact, have allowed us to identify minerals (clays, quartz and calcium carbonate), proteins, starch, urate salts and lipids and to map their spatial distribution.

Keywords: Imaging techniques; Time-of-flight secondary ion mass spectrometry (ToF-SIMS); Scanning electron microscopy with energy dispersive X-ray analysis (SEM-EDX); Fourier transform infrared microscopy (FTIR microscopy); Cultural heritage; African art"""

This article reviews the recent applications of time-of-flight secondary ion mass spectrometry in the determination of surface structures of semicrystralline and amorphous polymer films. Examples given include the determination of end-group distributions on semicrystalline polymer surfaces, lamellar orientation on thin-film surfaces, the structures of the folds of lamellae, the morphologies of polymer blends, the relationship between film stability and the concentration of the end groups, and the structures of thin polymer films.

Small-angle X-ray scattering revealed that a semirigid oligomer of bisphenol-A-co-ether-octane with a monodisperse chain length is capable of forming ciliated-folded, once-folded, ciliated-extended and fully extended lamellar structures. Isothermal crystallization studies suggested a sequence of structures with increasing crystallization temperature, from a ciliated-folded to a once-folded form and then to a ciliated-extended form as the degree of supercooling is decreased. The crystal surface thus changed from octane cilia to bisphenol A segments and then back to octane cilia as the lamellar structure changed. The results of time-of-flight secondary ion mass spectrometry analyses strongly supported the fold structural models.

The effect of film thickness on the structural conformation of the surfaces of the amorphous state, edge-on lamellae and flat-on lamellae of a semiflexible polymer, poly(bisphenol-A-etheroctane), was investigated by time-of-flight secondary ion mass spectrometry (ToF-SIMS) with the aid of principal component analysis (PCA). PCA results empirically indicate that a structurally regular polymer surface was obtained with the formation of the flat-on lamellae from the amorphous state at a low degree of supercooling. A higher concentration of end group and cilium ion fragments, which are indicative of free chain ends, was observed on the edge-on lamellar surfaces than on the amorphous and the flat-on lamellar surfaces. This finding was attributed to the fact that the lateral surface of the edge-on lamellae contains many growth fronts, leaving behind a large number of uncrystallized chain remnants on the surfaces. Structural disorder was facilitated on both edge-on and flat-on lamellar surfaces as the film thickness decreased. Hence, this PCA study offers new insights into the nonequilibrium nature of polymer crystals and the mechanism of polymer crystallization in thin and ultrathin films. Copyright © 2010 John Wiley & Sons, Ltd.

Obsidian surface roughness and rind structure both play a major influence on the Obsidian Hydration Dating (OHD). AFM (Atomic Force Microscopy) investigation coupled with quadrupole SIMS hydrogendata profiles establish a validation criterion of quantitative evaluation of roughness for OHD dating purposes. More evidence of the importance of the surface morphology at the nanoscale is given for fiveobsidian tools of different origin. The latter relates to the dynamic ion influx diffusion kinetics betweensurface and surrounded sediment media, and the obsidian structure, thus, 2D and 3D surface mapping,as well as, cation profiling (H, C, Mg, Al, F, S, Cl, CN, O isotopes) were made by TOF-SIMS and quad-SIMS.It was found that the C and Mg are considered as imposed criteria for accepting suitability of H+profiles for further processing by SIMS-Surface Saturation dating method. The effect of roughness to dating is discussed.

ABSTRACT Supersonic molecular beam deposition is a far-from-thermal-equilibrium kinetic activated growth technique, which allows the fine control of the kinetic energy of molecular species. We present a study of the growth of very thin layers of copper phthalocyanine on nanostructured surfaces of titanium dioxide nanograins; the study combines time-of-flight secondary ion mass spectrometry, Raman, X-ray photoelectron spectroscopy, and multivariate statistical analysis. Different kinetic energies and layer thicknesses were considered to investigate bond formation and surface interaction between the organic molecules and the inorganic nanograins. This study allowed the clarification of the key role of the energetic properties of the supersonic beam in the surface activation, enabling bond formation, not available with other processes at equilibrium. In particular, high kinetic energy regimes for copper phthalocyanine molecules in high-dilution seeded beams allow the formation of stronger bonds at the interface, which is useful for producing innovative nanohybrid materials having specific improved structural and chemical characteristics. The comparison among different surface characterization measurements orchestrated by multivariate statistical analysis proved to be a valuable approach for surface interaction study and interpretation.

Mazel, V. and Richardin, P.(2009) ToF-SIMS Study of Organic Materials in Cultural Heritage: Identification and Chemical Imaging, in Organic Mass Spectrometry in Art and Archaeology (eds MP Colombini and F. Modugno), John Wiley & Sons, Ltd, Chichester, UK. doi: ...

Poly (2, 3, 4, 5, 6-pentafluorostyrene) (5FPS) was prepared by bulk radical polymerization. The spin-cast films of this polymer were analyzed using time-of-flight secondary ion mass spectrometry (ToF-SIMS) at various temperatures ranging from room temperature to 120 °C. Principal component analysis (PCA) of the ToF-SIMS data revealed a transition temperature (T T) at which the surface structure of 5FPS was rearranged. A comparison between the results of the PCA of ToF-SIMS spectra obtained on 5FPS and polystyrene (PS) indicate that the pendant groups of 5FPS and PS moved in exactly opposite directions as the temperature increased. More pendant groups of 5FPS and PS migrated from the bulk to the surface and verse versa, respectively, as the temperature increased. These results clearly support the view that the abrupt changes in the normalized principal component 1 value was caused by the surface reorientation of the polymers and not by a change in the ion fragmentation mechanism at temperatures above the T T. Contact angle measurement, which is another extremely surface sensitive technique, was used to monitor the change in the surface tension as a function of temperature. A clear T T was determined by the contact angle measurements. The T T values determined by contact angle measurements and ToF-SIMS were very similar.

In this article, we addressed the applicability of time-of-flight secondary ion mass spectrometry (TOF-SIMS) to examine the effects of molecular weight and of flexible-segment length on the polymer chain arrangement at the folding surfaces of the lamellae. Poly(bisphenol A−etheralkane) (Cn) contains both rigid aromatic and flexible aliphatic CH2 segments. The number of CH2 units per flexible segment, n, varies from 8 to 12. Principal component analysis (PCA) of TOF-SIMS data revealed the chemical and structural variations of the folding surfaces of these polymers and identified the ion peaks contributing to these variations. We highlighted the discriminating power of PCA to distinguish the structural conformations of the amorphous and flat-on lamellar surfaces of these polymers. PCA loadings analyses showed that relatively more flexible structures were deposited on the folding surfaces when the flexible-segment length increased from 8 to 10 CH2 units. The concentration of short loops at folding surfaces and the disorder of folding surfaces increased when the molecular weight increased. All these results led us to conclude that TOF-SIMS has great potential for probing the chemical composition of the folding surfaces of polymers.

Poly(bisphenol-A-etheralkane), BA-Cn(n, which is the number of aliphatic CH2 units, = 8 and 10), composed of rigid and flexible segments, is a semicrystalline polymer. In 50-nm-thick films, the polymers tend to develop flat-on lamellae at the surfaces. Principal component analyses (PCAs) of the ion images were used to discriminate the conformation between the amorphous and flat-on lamellar surfaces of the polymers. The changes of the surface structure were directly detected by time-of-flight secondary ion mass spectrometry chemical imaging when flat-on lamellae were developed from the polymer melts. These structural changes were related to the lengths of the folded segments, which were strongly influenced by the crystallization temperature. The PCA loading analyses suggested that the length of the folded segments, which contained flexible and the rigid segments with an ether linkage, increased when the crystallization temperature decreased, suggesting the kinetic origin of polymer crystallization. Copyright © 2010 John Wiley & Sons, Ltd.