This study aims at exploring the way paper samples may impact the performance of Single-Metal Deposition (SMD II), a fingermark detection technique known for its versatility of application as well as its sensitivity regarding porous substrates. To get a broader view on how porous substrates may impact the SMD II performances, 74 North American and European papers types were collected, characterized (UV–visible and infrared spectroscopy, roughness, porosity, and surface pH), and processed as substrates bearing fingermarks. This part of the study represented a first valuable outcome by the number of samples considered. After processing with SMD II, the samples were characterized again with the techniques mentioned above, background staining and fingermark quality were assessed and associated with a quality score. Overall, no positive nor negative trend was observed between the paper characteristics and the SMD II performance. As a consequence, it is currently still not possible to predict if a paper sample will behave well or bad with SMD II. Of all the monitored parameters, the chemical composition of the surface coating (i.e., silica or calcium carbonate) may be worth exploring further, as it has been observed that some coatings undergo partial degradation during the SMD II process. As a result, secretion residue may be damaged by the chemical solubilization of the support layer if they failed to penetrate deeper into the substrate.

For many forensic traces (inks, fibres, paints, ...) the chemical characterization of dyes or pigments is currently performed with reliable techniques that nonetheless show a few drawbacks (extraction, interfering signals, fluorescence). The forensic community could benefit from a less labor intensive method that provides high sensitivity to detect trace amounts of dyes ( < 5% weight) without matrix interference. Surface-Enhanced Raman Spectroscopy (SERS) is rapidly gaining interest in the forensic community for these particular reasons and is often cited as a technique of choice for dyes analysis. It remains however a specialized technique limited to well equipped laboratories for which substrates synthesis represent the largest constraint. In order to popularize its use, we present a simple synthesis of SERS substrates (less than 2 min heating time) using a conventional microwave furnace. The technique is fast, inexpensive and yields plasmonic silver nanoparticles suitable for many SERS applications. We optimize the heating time and microwave power (watts), and verify the plasmonic resonance using UV-Visible spectroscopy. The produced colloids possess a mean diameter of 35-40 nm, ideal for SERS experiments with a laser excitation in the blue-green, and are stable for months. We demonstrate the suitability of these colloids with the analysis of 11 dyes from different chemical categories, analyzed by both standard Raman and SERS. We infer the interaction mechanism between the dyes and the substrate as well as the contribution from molecular, surface plasmon, and charge transfer resonances. These results open up new possibilities for trace analysis of dyes and might contribute to promote its use in forensic and chemistry laboratories.

In this paper, we studied the hydrophobization of TEMPO-oxidized cellulose gel (TOCgel) by covalent coupling of long carbon chains via esterification and amidation processes. In this context, amidation process was achieved by covalent coupling of stearylamine (SA) on the carboxyl moieties of TOCgel using carbodiimide and hydroxysuccimide as catalyst and amidation agent. In parallel, esterification process was realized by grafting of alkyl ketene dimer (AKD) on the hydroxyl groups of TOCgel in the presence of 1-methylimidazole as a promoter. The grafting state of the final products obtained under heterogeneous conditions was confirmed by fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), transmission and scanning electron microscopy, and contact angle measurement (CAM). The hydrophobic behavior of the obtained products was discussed based on the results of CAM and absorption rate of water drop in their film surface. FTIR and XPS results indicated the formation of amide bonding for the SA-g-TOCgel (amidation), and β-keto ester linkages for the AKD-g-TOCgel (esterification). As confirmed by CAM, the both chemical treatments enhanced the transition hydrophilic/hydrophobic behavior of the TOCgel fibers. It appeared also that CA values of grafted samples showed a slightly greater hydrophobicity of AKD-g-TOCgel (115° ± 2°) relatively to SA-g-TOCgel (102° ± 2°). However, the absorption rate of water drop seems to be relatively faster for AKD-g-TOCgel than for SA-g-TOCgel. Indeed, the water resistance of amidation product could be due to the high graft efficiency obtained (46.3 %) in comparison with that of the esterification product (30 %). In parallel, this result was confirmed by the dispersion test of modified TOCgels in hexane solvent which indicated clearly the high stable dispersion of SA-g-TOCgel obtained through the amidation process. Moreover, TGA result demonstrated that the thermal stability was found to be slightly higher for SA-g-TOCgel than for AKD-g-TOCgel. Finally, the excellent hydrophobic properties of modified TOCgel material could be suitable to be used as reinforcement for nonpolar polymer matrices in industrial applications.

In this study, we investigate the hydration of three different functional groups present on cellulose nanocrystal (CNC) surfaces: hydroxyls, carboxylates and sulphates by means of quantum chemical calculation. The performance of several density functional theory (DFT) functionals in reproducing, against higher level MP2 benchmark calculations, relevant non-covalent CNC interactions is also assessed. The effect of a sodium ion on the hydration of the surface functional groups was also investigated. Major restructuring of the hydrogen-bonding network within cellulose was found in the presence of a sodium ion. The calculated binding energy of water with a surface group ion pair was also greater, which indicates a greater hydrophilicity of CNC surfaces in the presence of adsorbed sodium. Cellulose hydrophilic surfaces (1 1 0) and (1 −1 0) were also calculated using DFT methods. The results indicate that the surfaces possess different electrostatic potential maps. Hydrogen bond restructuring is found on the chemically modified surfaces. The adsorption energy of water and electrolyte is also found to be different on each surface.

Cellulose chains are linear and aggregation occurs via both intra- and intermolecular hydrogen bonds. Cellulose has a strong affinity to itself and toward materials containing hydroxyls groups. Based on the preponderance of hydroxyl functional groups, cellulose is very reactive with water. At room temperature, cellulose chains will have at least a monomolecular layer of water associated to it. Theformation of hydrogen bonds at the cellulose/water interface is shown to depend essentially on the adsorption site, for example, the equatorial hydroxyls or OH moieties pointing outward from the cellulose chains. The vdWforces also contribute significantly to the adsorption energy. They are a considerable cohesive energy into the cellulose network. At the surface of the cellulose chains, many intermolecular hydrogen bonds of the cellulose chains are lost. However, they are compensated by hydrogen bonds with water molecules. Electronic clouds can be distorted and create electrostatic dipoles. The large antibonding electron cloud that exists around the glucosidic bonds produces an induced polarization at the approach of water molecules. The electron cloud can be distorted and create an electrostatic dipole. It applies to the total displacement of the atoms within the material. Orbitals play a special role in reaction mechanism. Hydrophilic/hydrophobic nature of cellulose is based on its structural anisotropy. Cellulosewater interactions are exothermic reactions. These interactions may occur spontaneously and result in higher randomness of the system. They are denoted by a negative heat flow (heat is lost to the surroundings). Energy does not need to be inputted in order for cellulose-water interactions to occur.

The hydrophilic/hydrophobic nature of cellulose is based on its structural anisotropy. Cellulose chains are arranged in a parallel manner and are organized in sheets stabilized by interchain OH-O hydrogen bonds, whereas the stacking of sheets is stabilized by both van der Waals (vdW) dispersion forces and weak CH-O hydrogen bonds. Cellulose has a strong affinity to itself and materials containing hydroxyls, especially water. Based on the preponderance of hydroxyl functional groups, cellulose polymer is very reactive with water. Water molecular smallness promotes the reaction with the cellulose chains and immediately formed hydrogen bonds. Besides that, vdW dispersion forces play an important role between these two reactive entities. They stabilize the cellulose structure according to the considerable cohesive energy in the cellulose network. Hydrogen bonding, electrostatic interactions, and vdW dispersion forces play an important role in determining the cellulose crystal structure during the cellulose-water interactions. As a result of these interactions, the volume of cellulose undergoes a meaningful change expressed not only by an exponential growth in amorphous regions, but also by an expansion in nanocrystalline regions. In addition, the volume change is associated with the swelling material expressed as a weight gain of the cellulose polymer. Molecular modeling using Accelrys Materials Studio allowed us to open a new horizon and is helpful for understanding cellulose-water interactions.

Esterification and click-chemistry were evaluated as surface modification treatments for TEMPO-oxidized nanocelluloses (TONC) using Polycaprolactone-diol (PCL) as modifying compound in order to improve the dispersion of nanofibers in organic media. These two grafting strategies were analyzed and compared. The first consists of grafting directly the PCL onto TONC, and was carried out by esterification between hydroxyl groups of PCL and carboxyl groups of TONC. The second strategy known as click-chemistry is based on the 1,3-dipolar cycloaddition reaction between azides and alkyne terminated moieties to form the triazole ring between PCL and TONC. The grafted samples were characterized by transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and Thermogravimetry analysis (TGA). Further, the effects of the two treatments on the surface hydrophobization of TONC were investigated by contact angle measurements. The results show that both methods confirm the success of such a modification and the click reaction was significantly more effective than esterification.

The main objective of this work is the grafting of polycaprolactone diol (PCL) on the surface of oxidized nanocelluloses (ONC) in order to enhance the compatibility between the hydrophilic cellulose nanofibres and the hydrophobic polymer matrix. This grafting was successfully realized with a new strategy known as click chemistry. In this context, the oxidized nanocelluloses bearing alkyl groups (ONC-PR) were prepared by reacting amino groups of propargylamine (PR) with carboxyl groups of ONC. In parallel, PCL was converted into azido-polycaprolactone (PCL-N3) in two steps: (i) tosylation of polycaprolactone (PCL-OTs) and (ii) conversion of PCL-OTs into PCL-N3 by nucleophilic displacement using sodium azide. Finally, ONC-PR was reacted with PCL-N3 in heterogeneous conditions through click chemistry in order to prepare polycaprolactone grafted oxidized nanocellulose (ONC-g-PCL), which could be suitable for improving the interfacial adhesion in the composite materials. The grafted samples were characterized by transmission electron microscopy and by Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and Carbon-13 nuclear magnetic resonance spectroscopy (13C-NMR) spectroscopic techniques.

This paper describes the application of computer modelling techniques to study reductive bleaching of mechanical pulps by amineboranes. Amineboranes have been studied as reductive bleaching chemicals for mechanical pulps. The general understanding of the structure-reactivity relationship found in the literature cannot explain either their bleaching efficiencies or their reaction mechanisms. We studied a wide range of both synthesised and commercially available primary, secondary and tertiary amineboranes of the H3B:NR3 type (where R=H, methyl, ethyl, i-propyl, t-butyl) and compared our experimental results with those predicted by the use of molecular simulation. The simulations were done at various levels of theory from semi-empirical to at) initio calculations. While computer simulations of reactions in vacuum gave us erratic results, simulations of reactions in an aqueous media, either with a continuum or explicit solvent, correctly predicted the experimentally observed reactivity order cif our amineboranes. The aqueous media induces a charge delocalization on the boron hydrides; modulated by the steric hindrance of the amine part.

The first part of our study is about the kinetic of a lignin model compound, acetovanillone, in TAED/H2O2 and peroxide-alone systems (TAED stands for tetraacetylethylenediamine). Our results show that the oxidation of acetovanillone follows a first-order kinetic in both systems studied. TAED/H2O2 system is about one hundred times more reactive than peroxide-alone system in term of the oxidation of acetovanillone. The results of this study explain why, while using TAED/H2O2 system to bleach TMP softwood pulp, the initial pH should be around 11 for increased production of peroxyacetic acid, and the final pH should be around 7 to minimize decomposition and increase bleaching efficiency and reactivity.The second part focuses on the TAED/H2O2 bleaching system at low consistency on spruce-balsam thermomechanical pulp. Our experiments show that the TAED/H2O2 system improves significantly (6% ISO) the brightness of softwood TMP pulp, compared with the peroxide-alone system. For each fixed molar ratio of TAED/H2O2, there is an optimum range for addition of alkali to achieve a maximum brightness gain of TMP pulp, a well-defined linear correlation was found between the molar ratio of TAED/H2O2 and the optimal alkali charge. An optimal TAED/H2O2 ratio is obtained at 0.7, slightly higher that the theoretical value of 0.5, due to the saponification reaction of TAED. TAED/H2O2 results in pulps slightly more susceptible to light-induced yellowing in the UV and visible region of the spectrum at very long irradiation times. The short term light-induced yellowing is about the same for both kinds of pulps.

This work focuses on a new TAED/H2O2 bleaching system on spruce-balsam thermomechanical pulp, at low consistency. The experiments show that the TAED/H2O2 system improves the brightness of the softwood thermo-mechanical pulp significantly (6% ISO), compared to the peroxide system alone. For each fixed molar ratio of TAED/H2O2, there is an optimum range for alkali addition, for achieving a maximum brightness gain of the thermomechanical pulp, a well-defined linear correlation being found between the TAED/H2O2 molar ratio and the optimal alkali charge. An optimal TAED/H2O2 ratio is obtained at 0.7, slightly higher than the theoretical value of 0.5, as due to the saponification reaction of TAED. TAED/H2O2 results in pulps being slightly more susceptible to light-induced yellowing in the UV and visible regions of the spectrum, at very long irradiation times. Short term light-induced yellowing is approximately the same for both kinds of pulps.

Our previous studies have shown that Fluorescent Whitening Agents (FWA) and Optical Brighteners (OB) can be efficiently used to reduce photo-induced yellowing of papers with high lignin content like those from thermomechanical pulps (TMP). However, the complete understanding of the efficiency of these FWAS and OB, as well as their exact mechanism, is by far incomplete. Our previous works lead-us to believe that there is a relationship between the energy of the HOMO-LUMO, and there variants, transition involved in the FWA spectra and the energy levels of the "components" of the lignin molecule. In this study, we try to establish a relationship between the FWA and OB spectra obtained in solution, those obtained when the FWA and OB are deposited over high lignin (TMP) and low lignin (Kraft) papers, and those obtained by molecular simulation in ab initio, DFT and semiempirical methods. The experimental spectra were taken according to the Kubelka-Munk theory. The molecular simulations were done using Gaussian 09W. This study aims at the understanding of the exact mechanism involved, paving the way to the synthesis of even more efficient FWA and OB.

Off-the-shelves general purpose modeling languages cannot obviously cover the whole range of needs that can be encountered in current systems design. Therefore, putting efficiently Model-Driven Engineering into practice involves designing specific modeling languages. The goal is to cover in a more suitable manner a particular application domain (e.g. automotive) or specific concerns (e.g. hardware modeling) or even to focus on a given class of practitioners. In this respect, two design approaches are generally opposed which respectively propose to define domain-specific modeling languages from scratch or to customize an existing general-purpose language. This paper focuses on the latter approach and claims that UML profiles do provide handy and powerful mechanisms to design domain-specific modeling languages but are penalized by lacks of methodological guidelines and tool support. To cope with these lacks, a profile design approach is introduced, which includes a methodological framework to structure profiles design process and tool support to partly automate this process.

Deinked pulps are not currently used in value-added paper manufacturing. To implement their use, both strength and optical properties must be improved. TEMPO oxidation has been shown to improve strength properties of thermomechanical and deinked pulps. However, a significant reduction of the pulp brightness results due to yellowing of mechanical fibers. Spectroscopic techniques were used to investigate the effect of TEMPO oxidation on deinked fiber properties. Fourier transform infra-red (FTIR) spectroscopy and UV/VIS spectrum showed that oxidation conditions are driving important chemical reactions that affect optical properties. Results indicated that ortho-quinone compounds as well as carboxylic groups are generated depending on oxidation conditions resulting in pulp brightness decrease. Spectroscopic studies also revealed that residual ink detachment from fiber surfaces is occurring during oxidation contributing to improve pulp brightness.

This paper considers some specific issues relating to model-driven system management applied to complex systems. Exami ning dynamically coupled systems-of-systems on the one hand and high ly distributed devices for service access on the other, we define a common met aodel of (semi-) automated management applicable in both domains. Ta king monitoring by way of illustration, we then show how this meta-model i s put into practice along two complementary aspects: management modelling and run time event processing support.

One of the two existing methods to solubilize chemical pulp fibres for the measurement of the degree (of polymerization distribution (DPD) of cellulose and hemicelluloses by size exclusion chromatography (SEC) consists of the derivatization of the pulp polysoccharides into carbanilates using phenylisocyanate, followed by SEC using tetrahydrqfuran as the solvent. This method can provide good results, but we have observed that many Canadian kraft and sulphite carbanilated pulps exhibit an SEC profile distortion leading to a significant overestimation of the DPD and calculated average degrees of polymerization. Th is paper presents our results on procedure modifications that have allowed us to obtain representative DPDs for these problematic pulps.

The kinetics of reaction of a lignin model compound, acetovanillone (4'-hydroxy-3'-methoxyacetophenone), in tetraacetylethylenediamine (TAED)/H2O2 and peroxide-alone systems were investigated. The oxidation of acetovanillone followed first-order kinetics in both systems. In the TAED-peroxide system, the first-order rate constant, k , was 0.34 min(-1) with a half-life, t(1/2) , of 2 min, compared to k of 0.0035 min(-1) and t 1/2 of 220 min in the peroxide-alone system. Thus, TAED/H2O2 oxidized acetovanillone about one hundred times faster than peroxide alone. The results of the study explain why, when using TAED/H2O2 to bleach TMP softwood pulp, the initial pH should be about 11 for increased production of peroxyacetic acid, and the final pH should be about 7 to minimize decomposition and increase bleaching efficiency and reactivity.