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Mechanical deconstruction of post-consumer carpet results in plastic fibers as well as a finepowder, comprised mostly of calcium carbonate (CaCO3), ready for reuse. This powder isreferred to as post-consumer carpet calcium carbonate (PC4) and contains low levels ofmicroplastic fibers along with a wide range of trace components such as sand, antimony,perfluorinated compounds, and brominated flame retardants. While plastic fibers are relativelyeasy to reuse, the trace components of PC4 present recycling challenges. Clean-up of this powderis crucial for developing appropriate uses in recycled-content product manufacturing. Thermaltreatment, ashing/combustion with oxygen present or charring/pyrolysis if oxygen is excluded, isproposed as a relatively low-cost method to break down microplastics and other hazardouscomponents that accumulate in carpet. Fourier transform infrared (FTIR) spectroscopy was usedto quantify the mass loss of polyethylene terephthalate (PET) as well as nylon 6 (N6) in PC4samples when heated for 1 hour at 500 and 600 °C with and without oxygen. Single-bounceattenuated total reflectance, ATR-FTIR was used in addition to synchrotron-based FTIRmicrospectroscopy (SR-μFTIR) and a modified microscopic ATR-FTIR imaging technique usinga large germanium hemisphere and focal plane array (FPA) detector. The data demonstrate thatheat treatment at 600 °C successfully reduced both PET and N6 content below detection limits.Maps obtained via FTIR imaging reveal the size and spatial distribution of microplastics in PC4.This work is novel and significant as it addresses the long-term environmental challenges ofwaste and pollution from consumer goods and assesses the effectiveness of post-consumer carpetrecycling.

Organic–inorganic hybrid materials were synthesized by a sol–gel route, using silicon alkoxide together with low molecular weight polycaprolactone and caffetannic acid. The synthesized hybrids were characterized by scanning Fourier-transform infrared (FTIR) spectroscopy, and their surface morphology was acquired by scanning electron microscopy (SEM) analysis. The hybrids were investigated for their antiradical capacity using the DPPH and ABTS tests, while the Kirby–Bauer test was used to evaluate their effects on the growth of Escherichiacoli and Enterococcus faecalis. Furthermore, a biologically active hydroxyapatite layer has been observed to form on the surface of intelligently synthesized materials. The MTT direct test showed that the hybrid materials are biocompatible with NIH-3T3 fibroblast cells, while they were cytotoxic towards colon, prostate, and brain tumor cell lines. These results shed new light on the suitability of the synthesized hybrids in the medical field, thus affording knowledge on the features of the bioactive silica–polycaprolactone–chlorogenic acid hybrids.

Qualitative Fourier transform infrared (FTIR) spectroscopy has long been established and implemented in a wide variety of fields including pharmaceutical, biomedical, and clinical fields. While the quantitative applications are yet to reach their full potential, this technique is flourishing. It is tempting to shed light on modern engaging and the applicability of analytical quantitative FTIR spectroscopy in the aforementioned fields. More importantly, the credibility, validity, and generality of the application will be thoroughly demonstrated by reviewing the latest published work in the scientific literature. Utilizing FTIR spectroscopy in a quantitative approach in pharmaceutical, biomedical, and interdisciplinary fields has many undeniable advantages over traditional procedures. An insightful account will be undertaken in this regard. The technique will be introduced as an appealing alternative to common methods such as high performance liquid chromatography. It is anticipated that the review will offer researchers an update of the current status and prospect on the subject among the pharmacy and biomedical sciences both in academic and industrial fields.

The advantages of IR spectroscopy include relatively fast analysis and sensitivity, which facilitate its wide application in the pharmaceutical, chemical and polymer sectors. Thus, IR spectroscopy provides an excellent opportunity to monitor the degradation and concomitant evolution of the molecular structure within a perovskite layer. As is well-known, one of the main limitations preventing the industrialization of perovskite solar cells is the relatively low resistance to various degradation factors. The aim of this work was to study the degradation of the surface of a perovskite thin film CH3NH3PbI3-xClx caused by atmosphere and light. To study the surface of CH3NH3PbI3-xClx, a scanning electron microscope, infrared (IR) spectroscopy and optical absorption were used. It is shown that the degradation of the functional layer of perovskite proceeds differently depending on the acting factor present in the surrounding atmosphere, whilst the chemical bonds are maintained within the perovskite crystal structure under nitrogen. However, when exposed to an ambient atmosphere, an expansion of the NH3+ band is observed, which is accompanied by a shift in the N–H stretching mode toward higher frequencies; this can be explained by the degradation of the perovskite surface due to hydration. This paper shows that the dissociation of H2O molecules under the influence of sunlight can adversely affect the efficiency and stability of the absorbing layer. This work presents an approach to the study of perovskite structural stability with the aim of developing alternative concepts to the fabrication of stable and sustainable perovskite solar cells.

Hispano-Muslim culture flourished during the Middle Ages in the Iberian Peninsula and Balearic Islands. During the restoration of a Balearic nobiliary building (casal), several panels with polychrome decoration on the back side were found. They were part of an old Muslim wooden ceiling (alfarje). A multi-technique strategy including optical microscopy, infrared and Raman spectroscopies, field emission scanning electron microscopy-X-ray microanalysis (FESEM-EDX), focused ion beam (FIB-FESEM-EDX), atomic force microscopy nanoindentation (AFM-NI), and gas chromatography-mass spectrometry (GC-MS) has been applied in the analysis of these panel paintings and has provided morphological and compositional data that have led to the identification of the materials and artistic technique as well as the alteration mechanisms due to the natural aging and the adverse conditions of conservation. As a novelty, this study has confirmed the use of indigo as a blue pigment, an unusual material in Hispano-Muslim panel painting. Apart from the notable change in the visual appearance observed in the paintings, the study has also confirmed a change in the mechanical resistance in the paint layers. These changes have been induced by the combination of the chemical and microbiological alteration mechanisms identified., MCIN/AEI/10.13039/501100011033 PID2020- 113022GB-I00 and PID2019-105706GB-I00, Ministry of Universities European Union-NextGenerationEU

For the first time, the process of birch ethanol lignin sulfation with a sulfamic acid-urea mixture in a 1,4-dioxane medium was optimized experimentally and numerically. The high yield of the sulfated ethanol lignin (more than 96%) and containing 7.1 and 7.9 wt % of sulfur was produced at process temperatures of 80 and 90 °C for 3 h. The sample with the highest sulfur content (8.1 wt %) was obtained at a temperature of 100 °C for 2 h. The structure and molecular weight distribution of the sulfated birch ethanol lignin was established by FTIR, 2D 1H and 13C NMR spectroscopy, and gel permeation chromatography. The introduction of sulfate groups into the lignin structure was confirmed by FTIR by the appearance of absorption bands characteristic of the vibrations of sulfate group bonds. According to 2D NMR spectroscopy data, both the alcohol and phenolic hydroxyl groups of the ethanol lignin were subjected to sulfation. The sulfated birch ethanol lignin with a weight average molecular weight of 7.6 kDa and a polydispersity index of 1.81 was obtained under the optimum process conditions. Differences in the structure of the phenylpropane units of birch ethanol lignin (syringyl-type predominates) and abies ethanol lignin (guaiacyl-type predominates) was manifested in the fact that the sulfation of the former proceeds more completely at moderate temperatures than the latter. In contrast to sulfated abies ethanol lignin, the sulfated birch ethanol lignin had a bimodal and wider molecular weight distribution, as well as less thermal stability. The introduction of sulfate groups into ethanol lignin reduced its thermal stability.

FTIR spectroscopy has become a major tool to determine protein secondary structure. One of the identified obstacle forreaching better predictions is the strong overlap of bands assigned to different secondary structures. Yet, while for instancedisordered structures and α-helical structures absorb almost at the same wavenumber, the absorbance bands are differentiallyshifted upon deuteration, in part because exchange is much faster for disordered structures. We recorded the FTIR spectra of85 proteins at different stages of hydrogen/deuterium exchange process using protein microarrays and infrared imaging forhigh throughput measurements. Several methods were used to relate spectral shape to secondary structure content. Whilein absolute terms, β-sheet is always better predicted than α-helix content, results consistently indicate an improvement ofsecondary structure predictions essentially for the α-helix and the category called “Others” (grouping random, turns, bends,etc.) after 15 min of exchange. On the contrary, the β-sheet fraction is better predicted in non-deuterated conditions. Usingpartial least square regression, the error of prediction for the α-helix content is reduced after 15-min deuteration. Furtherdeuteration degrades the prediction. Error on the prediction for the “Others” structures also decreases after 15-min deuteration.Cross-validation or a single 25-protein test set result in the same overall conclusions.

Prediction of protein secondary structure from FTIR spectra usually relies on the absorbance in the amide I–amide II regionof the spectrum. It assumes that the absorbance in this spectral region, i.e., roughly 1700–1500 cm−1 is solely arising fromamide contributions. Yet, it is accepted that, on the average, about 20% of the absorbance is due to amino acid side chains.The present paper evaluates the contribution of amino acid side chains in this spectral region and the potential to improvesecondary structure prediction after correcting for their contribution. We show that the β-sheet content prediction is improvedupon subtraction of amino acid side chain contributions in the amide I–amide II spectral range. Improvement is relativelyimportant, for instance, the error of prediction of β-sheet content decreases from 5.42 to 4.97% when evaluated by ascendingstepwise regression. Other methods tested such as partial least square regression and support vector machine have alsoimproved accuracy for β-sheet content evaluation. The other structures such as α-helix do not significantly benefit from sidechain contribution subtraction, in some cases prediction is even degraded. We show that co-linearity between secondarystructure content and amino acid composition is not a main limitation for improving secondary structure prediction. Wealso show that, even though based on different criteria, secondary structures defined by DSSP and XTLSSTR both arrive atthe same conclusion: only the β-sheet structure clearly benefits from side chain subtraction. It must be concluded that sidechain contribution subtraction benefit for the evaluation of other secondary structure contents is limited by the very roughdescription of side chain absorbance which does not take into account the variations related to their environment. The studywas performed on a large protein set. To deal with the large number of proteins present, we worked on protein microarraysdeposited on BaF2slides and FTIR spectra were acquired with an imaging system.

Enamel, dentin and cementum apatite has a complex composition. The lack of complete reports on the chemical composition of all tooth tissues together and the need to create a modern biomaterial that reproduces the correct ratio of individual tooth mineral components prompted the authors to undertake the research. A detailed evaluation of the micro- and macro-elements of tooth powder, using various methods of chemical analysis was conducted. All four groups of human sound teeth were crushed using the grinder. A fine powder was implemented for the FTIR (Fourier Transform Infrared Spectroscopy), ICP (Inductively Coupled Plasma Optical Emission Spectometry) and for the potentiometric titration, SEM and mercury porosimetry analyses. The obtained studies indicate that there is no significant correlation in chemical composition between the different teeth types. This proves that every removed, crushed tooth free of microorganisms can be a suitable material for alveolar augmentation. It is essential to know the chemical profiles of different elements in teeth to develop a new class of biomaterials for clinical applications.

Fourier transform infrared spectroscopy (FTIR) in connection with chemometric analysis were used as a fast and direct approach to classify spray dried honey powder compositions in terms of honey content, the type of diluent (water or skim milk), and carrier (maltodextrin or skim milk powder) used for the preparation of feed solutions before spray drying. Eleven variants of honey powders containing different amounts of honey, the type of carrier, and the diluent were investigated and compared to pure honey and carrier materials. Chemometric discrimination of samples was achieved by principal component analysis (PCA), hierarchical clustering analysis (HCA), linear discriminant analysis (LDA), and partial least squares-discriminant analysis (PLS-DA) modelling procedures performed on the FTIR preprocessed spectral data for the fingerprint region (1800–750 cm−1) and the extended region (3600–750 cm−1). As a result, it was noticed that the type of carrier is a significant factor during the classification of different samples of powdered multifloral honey. PCA divided the samples based on the type of carrier, and additionally among maltodextrin-honey powders it was possible to distinguish the type of diluent. The result obtained by PCA-LDA and PLS-DA scores yielded a clear separation between four classes of samples and showed a very good discrimination between the different honey powder with a 100.0% correct overall classification rate of the samples.

γ-Al2O3 nanoparticles (NPs) with a mean diameter of 60 nm were prepared through the sol–gel technique and characterized by X-ray diffraction, field emission scanning electron microscopy (FESEM), and ultraviolet–visible (UV-Vis) spectroscopy. The formation of cubic structures with the γ phase for Al2O3 NPs confirms. The average particle size obtained is about 60 nm by the FESEM image. The nonlinear optical properties were examined by a single-beam Z-scan method using a Gaussian visible continuous wave Nd:YAG laser (532 nm). The Z-scan findings indicated a self-focusing nonlinearity and saturable absorption process in order of 10−8 (cm2/W) and 10−4 (cm/W) in the synthesized γ-Al2O3 NPs, respectively. Moreover, Kramers–Kronig relations were applied to determine the complex refractive index and dielectric coefficient of the specimens by Fourier-transform infrared spectroscopy. The transversal and longitudinal optical (TO and LO) modes are the two intersection points in the real and imaginary parts of the complex refractive index. Also, the maximum position of the Im(−1/ ε) plot is related to LO frequency.

While several Raman, CD or FTIR spectral libraries are available for well-characterized proteins of known structure, proteins themselves are usually very difficult to acquire, preventing a convenient calibration of new instruments and new recording methods. The problem is particularly critical in the field of FTIR spectroscopy where numerous new methods are becoming available on the market. The present papers reports the construction of a protein library (cSP92) including commercially available products, that are well characterized experimentally for their purity and solubility in conditions compatible with the recording of FTIR spectra and whose high-resolution structure is available. Overall, 92 proteins were selected. These proteins cover well the CATH space at the level of classes and architectures. In terms of secondary structure content, an analysis of their high-resolution structure by DSSP shows that the mean content in the different secondary structures present in cSP92 is very similar to the mean content found in the PDB. The 92-protein set is analyzed in details for the distribution of helix length, number of strands in β- sheets, length of β-strands and amino acid content, all features that may be important for the interpretation of FTIR spectra., SCOPUS: ar.j, info:eu-repo/semantics/published

It was established that isopropyl salicylate can be used similarly to 1,3-diketones as a key component for a new efficient extraction system for selective separation of alkali metal cations. According to DFT modeling of complexes of isopropyl salicylate and 1,3-diketone with alkali metal cations (Li+, Na+, K+), six-membered metallacycles are formed whose stability decreases along the series Li > Na > K, which results in the observed enhanced affinity to lithium. The extraction ability of isopropyl salicylate is manifested in the presence of trioctylphosphine oxide (TOPO). The newly obtained complexes of isopropyl salicylate with alkali metal cations as well as their extracts in a mixture with TOPO are characterized by means of FT-IR, Raman, and NMR spectroscopy. The probable structure of the extracted lithium complex is presumed and the role of TOPO in the extraction process is investigated in detail. Extraction experiments showed extremely high separation coefficients for Li/Na and Li/K pairs in the extraction from a model multi-component solution.

Pullulan is a linear exopolysaccharide, produced in the fermentation media of Aureobasidium pullulans, with a variety of applications in the food and pharmaceutical industries. Pullulan derivatives have growing potential for biomedical applications, but the high cost of pullulan biofabrication currently restricts its commercial use. Better control over pullulan yield, molecular weight and melanin production by altering fermentation conditions could improve the economics. In this study, the effects of sugar and mineral salt stresses on the pullulan production of A. pullulans ATCC 42023 were examined in batch processes. The chemical structure of the recovered pullulan was characterized by FTIR and NMR spectroscopy, and the molecular weight distribution was obtained via SEC. Pullulan yield and melanin production varied when the conditions were adjusted, and pullulans with different molar masses were obtained. Higher-yield pullulan production and a lower polydispersity index were observed when CuSO4 was added to the fermentation in comparison with the control and with the addition of sugars and other salts. Biofabrication of pullulan under stress conditions is a promising strategy to enhance biopolymer yield and to obtain pullulan with a targeted molecular weight. ispartof: MOLECULES vol:28 issue:6 ispartof: location:Switzerland status: published

Introduction: Medulloblastoma (MB) is the most common malignant tumor of the central nervous system in childhood. FTIR spectroscopy provides a holistic view of the chemical composition of biological samples, including the detection of molecules such as nucleic acids, proteins, and lipids. This study evaluated the applicability of FTIR spectroscopy as a potential diagnostic tool for MB. Materials and methods: FTIR spectra of MB samples from 40 children (boys/girls: 31/9; age: median 7.8 years, range 1.5–21.5 years) treated in the Oncology Department of the Children’s Memorial Health Institute in Warsaw between 2010 and 2019 were analyzed. The control group consisted of normal brain tissue taken from four children diagnosed with causes other than cancer. Formalin-fixed and paraffin-embedded tissues were sectioned and used for FTIR spectroscopic analysis. The sections were examined in the mid-infrared range (800–3500 cm−1) by ATR-FTIR. Spectra were analysed using a combination of principal component analysis, hierarchical cluster analysis, and absorbance dynamics. Results: FTIR spectra in MB were significantly different from those of normal brain tissue. The most significant differences related to the range of nucleic acids and proteins in the region 800–1800 cm−1. Some major differences were also revealed in the quantification of protein conformations (α-helices, β-sheets, and others) in the amide I band, as well as in the absorbance dynamics in the 1714–1716 cm−1 range (nucleic acids). It was not, however, possible to clearly distinguish between the various histological subtypes of MB using FTIR spectroscopy. Conclusions: MB and normal brain tissue can be distinguished from one another to some extent using FTIR spectroscopy. As a result, it may be used as a further tool to hasten and enhance histological diagnosis.

Hydrogen fuel cells have long been regarded as a more environmentally friendly alternative to traditional fossil fuels. Ethanol steam reforming (ESR) is a promising long-term, safe method of producing carbon-neutral hydrogen. ESR products are (CeCO2) support generate hydrogen (H2) with byproducts such as carbon dioxide (CO2) and carbon monoxide (CO). The researchers are interested in the quantification and estimation of syngas components. The current article introduces the Johnsen index-based measure in partial least squares (PLS) for predicting ESR products with cube, polyhydra, and rod morphologies, based on FTIR. The proposed method makes use of existing filter measures such as loading weights, variable importance on projection, and significant correlation. The proposed PLS measures based on the Johnsen index outperform the existing methods for predicting ESR products based on FTIR spectroscopic data. For (H2) conversion percent prediction with cube and polyhedra morphologies, the functional compounds (C-O), (C=O), (CH), and (C-H,=CH2) are common. Similarly, the functional compound (s-RCH=CHR) is frequently used for (H2) conversion percent prediction with polyhedra and rod morphologies. Moreover, on simulated data, the proposed Johnsen measure in PLS demonstrates higher sensitivity and accuracy. Furthermore, the proposed Johnsen measure in PLS identifies influential wavenumbers that map over the functional compounds.

The extraction of lithium from aqueous solutions of LiNTf2 and LiCl salts using benzo-15-crown-5 ether (B15C5) as an extractant in [C8mim][NTf2] ionic liquid was studied. The transition of the extractant into the aqueous phase and the distribution of Cl− ions during lithium extraction from LiCl solutions were determined. LiNTf2 complexes with B15C5 with different LiNTf2:B15C5 ratios were isolated for the first time and characterized via X-ray diffraction and IR spectroscopy. Differences in the extraction process of LiCl and LiNTf2 were determined via an infrared spectroscopic study of the extraction systems.

In the present paper, we investigate how the optical and structural properties, in particular the observed photoluminescence (PL) of photocurable and organic-inorganic TiO2-SiO2 sol-gel films doped with Rhodamine 6G (R6G) are affected by γ-rays. For this, four luminescent films, firstly polymerized with UV photons (365 nm), were submitted to different accumulated doses of 50 kGy, 200 kGy, 500 kGy and 1 MGy while one sample was kept as a reference and unirradiated. The PL, recorded under excitations at 365 nm, 442 nm and 488 nm clearly evidences that a strong signal peaking at 564 nm is still largely present in the γ-irradiated samples. In addition, M-lines and Fourier-transform infrared (FTIR) spectroscopies are used to quantify the radiation induced refractive index variation and the chemical changes, respectively. Results show that a refractive index decrease of 7 × 10−3 at 633 nm is achieved at a 1 MGy accumulated dose while a photo-induced polymerization occurs, related to the consumption of CH=C, Si-OH and Si-O-CH3 groups to form Ti-O and Si-O bonds. All these results confirm that the host matrix (TiO2-SiO2) and R6G fluorophores successfully withstand the hard γ-ray exposure, opening the way to the use of this material for sensing applications in radiation-rich environments.

In this study, Fourier transform infrared spectroscopy (FTIR) and luminescence imaging were used to identify the coatings of seven Persian lacquer papier mache penboxes, of which two were contemporary, one was from the Pahlavi era, and four belonged to the Qajar era. First, FTIR was used to identify the nature of the coating. Then, UV-induced visible luminescence imaging at the spectral ranges of 420–680 nm (UVL), 425–495 nm (UVIBL), and 615–645 nm (UVIRL) was performed for further examination. The FTIR results showed that the coatings were made of alkyd resin, oil-resin varnish (Kaman oil), and shellac. In UV-induced visible luminescence images, synthetic alkyd resin showed no fluorescence, which made it distinguishable from the natural organic coatings. While it is slightly challenging to differentiate Kaman oil from shellac based on FTIR results, these two coatings can be easily distinguished by their fluorescence in UVL and UVIBL images. The results suggest that the combined use of spectroscopy and spectral imaging methods can provide substantial information about the organic coatings of historical objects.

Thermal and structural properties of historical woods from apparatuses of the Historical Collection of the Physics Instruments of the University of Palermo have been investigated by FTIR spectroscopy coupled with thermogravimetric analysis. Specifically, the wooden portions of apparatuses from XIX century have been studied. The investigated woods belong to different taxa (Swietenia mahagoni, Picea abies and Juglans regia). The thermal behavior of the wooden materials has been successfully interpreted on the basis of specific indexes determined by the quantitative analysis of the FTIR spectra. The kinetics of the wood pyrolysis have been investigated by using a non-isothermal approach based on model-free isoconversional procedures, such as Kissinger–Akahira–Sunose (KAS) and Friedman methods. Interestingly, the activation energy of the pyrolysis process reflects both the peculiar composition (related to the specific wooden taxon) and the conservation state of the historical woods. In this regards, we estimated that the average activation energies obtained from KAS analysis are 203, 156 and 43 kJ mol−1 for Swietenia mahagoni, Picea abies and Juglans regia woods, respectively. The thermogravimetric parameters have been correlated to the lignin index of the woods by proper experimental equations, which can be considered as a novel protocol to estimate the preservation conditions of historical woods from different taxon.

[EN] A multi-technique strategy, including microscopy, spectroscopic and electrochemical techniques, is proposed to study thin corrosion layers that form on the surface of historic copper-based coins. An accurate characterisation of this external corrosion layer is important for selecting a suitable conservation and/or restoration treatment. For this purpose, a series of copper-based coins from different historical periods and provenances, which mainly exhibited atmospheric corrosion, was analysed. The morphology of the corrosion layer and the upper core of coins was studied in trenches done on coin surfaces with a focused ion beam gun, coupled to a field emission scanning electron microscope-X-ray microanalysis (FIB-FESEM-EDX). The X-ray microanalysis performed with FESEM-EDX on trenches allowed elemental composition profiles on the corrosion layer to be obtained. These results were complemented with the compositional data of the corrosion products provided by the voltammetry of immobilised microparticles (VIMP) and Fourier transform infrared spectroscopy (FTIR), and by studying visual appearance by optical microscopy and colorimetry. Cuprite and tenorite (the latter increased with coin age) were the main identified corrosion products, which were accompanied, to a lesser extent, by copper trihydroxychloride polymorphs. Interestingly, metal oxalates and metal-carboxylate complexes were identified on the corrosion layer of most coins. These unusual alteration products of copper-based coins were formed from the organic matter deposited on coin surfaces given their use when placed in circulation or by further manipulations of collectors., Financial support is gratefully acknowledged from the Spanish "R + D + I" project CTQ2017-85317-C2-1-P, CTQ2014-53736-C3-1-P and CTQ2014-53736-C3-2-P, which are supported by the Ministerio de Ciencia, Innovation y Universidades, Fondo Europeo de Desarrollo Regional (ERDF) funds and Agencia Estatal de Investigation (AEI). The authors wish to thank Mr. Manuel Planes, Dr. Jose Luis Moya and Mrs. Alicia Nuez Inbernon, technical supervisors of the Electron Microscopy Service of the Universitat Politecnica de Valencia.

One of the major problems in book conservation is the long-term deconstructive effect of acidity introduced into the paper by several additives, which, in the presence of humidity, generates a hydrogen cation with a strong catalytic role in cellulose depolymerization. Many types of treatment have been used in the past, but up to now, research for less-invasive, fast and cheap methods is still vividly ongoing. In this study, an approach to book deacidification is presented, where alkaline water solutions are administered to bound books in the form of micrometer-sized aerosol droplets, without using vacuum apparatus accessories. Alkaline clouds treatments were alternated with gentle air fluxes of drying steps. Few cycles are required to achieve uniform deacidification of books. The treatment could be conducted with proper apparatus on large volumes, resulting in rapid treatment time and low cost. The titration curve reporting the variation of book pH, with respect to the amount of absorbed alkaline aerosol, was built and interpreted in terms of a chemical model for the neutralization process. FTIR, PXRD and XRF spectroscopies were used to characterize the book chemistry. The effects of the treatment on the book were evaluated by measuring the degree of polymerization (DP) of the paper and the colorimetric coordinates of the paper and ink. Artificial aging tests revealed a general increase in the aging stability of the deacidified paper samples with respect to the untreated samples. Finally, the alkaline reserve data are discussed.

Multidrug resistance of bacteria is a worrying concern in the therapeutic field and an alternative method to combat it is designing new efflux pump inhibitors (EPIs). This article presents a molecular study of two quinazoline derivatives, labelled BG1189 and BG1190, proposed as EPIs. In silico approach investigates the pharmacodynamic and pharmacokinetic profile of BG1189 and BG1190 quinazolines. Molecular docking and predicted ADMET features suggest that BG1189 and BG1190 may represent attractive candidates as antimicrobial drugs. UV-Vis absorption spectroscopy was employed to study the time stability of quinazoline solutions in water or in dimethyl sulfoxide (DMSO), in constant environmental conditions, and to determine the influence of usual storage temperature, normal room lighting and laser radiation (photostability) on samples stability. The effects of irradiation on BG1189 and BG1190 molecules were also assessed through Fourier-transform infrared (FTIR) spectroscopy. FTIR spectra showed that laser radiation breaks some chemical bonds affecting the substituents and the quinazoline radical of the compounds.

It is critical to develop new methods to assess genotoxic effects in human biomonitoring since the conventional methods are usually laborious, time-consuming, and expensive. It is aimed to evaluate if the analysis of a drop of serum by Fourier Transform Infrared spectroscopy, allow to assess genotoxic effects in occupational exposure to cytostatic drugs in hospital professionals, as obtained by the lymphocyte cytokinesis-block micronucleus assay. It was considered peripheral blood from hospital professionals exposed to cytostatic drugs (n = 22) and from a non-exposed group (n = 36). It was observed that workers occupationally exposed presented a higher number of micronuclei (p 0.05) in lymphocytes, in relation to the non-exposed group. The serum Fourier Transform Infrared spectra from exposed workers presented diverse different peaks (p 0.01) in relation to the non-exposed group. The hierarchical cluster analysis of serum spectra separated serum samples of the exposed group from the non-exposed group with 61% sensitivity and 88% specificity. A support vector machine model of serum spectra enables to predict exposure with high accuracy (0.91), precision (0.89), sensitivity (0.86), F1 score (0.87) and AUC (0.96). Therefore, Fourier Transform Infrared spectroscopic analysis of a drop of serum enabled to predict in a rapid and simple mode the genotoxic effects of cytostatic drugs. The method presents therefore potential for high-dimension screening of exposure of genotoxic substances, due to its simplicity and rapid setup mode.

Fourier transform infrared (FTIR) absorption spectroscopy of cold molecules and clusters in supersonic slit jet expansions complements and extends more sensitive action spectroscopy techniques and provides important reference data for the latter. We describe how its major drawback, large substance and carrier gas consumption, can be alleviated by one to two orders of magnitude via direct and continuous recycling of the gas mixture. This is achieved by a combination of dry rotary lobe and screw pump compression. The signal-to-noise ratio is boosted by the established buffered giant gas pulse technique with full interferogram synchronization. The buildup of water impurities typically limits the recycling gain, but is turned into a feature for the study of hydrate complexes of volatile molecules. Continuous operation with a single gas filling over several days becomes practical and useful. Decadic absorbances in the low ppm range are detectable and the mid infrared range can be recorded simultaneously with the near infrared. The less straightforward hydration number assignment of spectral features in direct absorption spectroscopy is supported by a gradual water buildup at a rate of less than 0.5 mg/h. A recent reassignment proposal for the water dimer OH stretching spectrum is refuted and vibrational spectra of vacuum-isolated 18O-water clusters are presented for the first time. Methanol docking on asymmetric ketones is used to illustrate the advantages and limitations of the recycling concept. Previous assignments of the hydrate complex of 1-phenylethanol are confirmed. Additional features of the setup await testing and refinement, but the recycling technique already substantially widens the applicability of direct absorption spectroscopy of neutral molecular clusters. It may be attractive for other high-throughput jet spectrometers.

To demonstrate the importance of sample preparation used in Fourier transform infrared (FTIR) spectroscopy of microbiological materials, bacterial biomass samples with and without grinding and after different drying periods (1.5–23 h at 45 °C), as well as biogenic selenium nanoparticles (SeNPs, without washing and after one to three washing steps) were comparatively studied by transmission FTIR spectroscopy. For preparing bacterial biomass samples, Azospirillum brasilense Sp7 and A. baldaniorum Sp245 (earlier known as A. brasilense Sp245) were used. The SeNPs were obtained using A. brasilense Sp7 incubated with selenite. Grinding of the biomass samples was shown to result in slight downshifting of the bands related to cellular poly-3-hydroxybutyrate (PHB) present in the samples in small amounts (under ~10%), reflecting its partial crystallisation. Drying for 23 h was shown to give more reproducible FTIR spectra of bacterial samples. SeNPs were shown to contain capping layers of proteins, polysaccharides and lipids. The as-prepared SeNPs contained significant amounts of carboxylated components in their bioorganic capping, which appeared to be weakly bound and were largely removed after washing. Spectroscopic characteristics and changes induced by various sample preparation steps are discussed with regard to optimising sample treatment procedures for FTIR spectroscopic analyses of microbiological specimens.

Attention deficit and hyperactivity disorder (ADHD) is one of the most common neurodevelopmental disorders of childhood. It affects similar to 10% of the world's population of children, and about 30-50% of those diagnosed in childhood continue to show ADHD symptoms later, with 2-5% of adults having the condition. Current diagnosis of ADHD is based on the clinical evaluation of the patient, and on interviews performed by clinicians with parents and teachers of the children, which, together with the fact that it shares common symptoms and frequent comorbidities with other neurodevelopmental disorders, makes the accurate and timely diagnosis of the disorder a difficult task. Despite the large effort to identify reliable biomarkers that can be used in a clinical environment to support clinical diagnosis, this goal has never been achieved hitherto. In the present study, infrared spectroscopy was used together with multivariate statistical methods (hierarchical clustering and partial least-squares discriminant analysis) to develop a model based on the spectra of blood serum samples that is able to distinguish ADHD patients from healthy individuals. The developed model used an approach where the whole infrared spectrum (in the 3700-900 cm(-1) range) was taken as a holistic imprint of the biochemical blood serum environment (spectroscopic biomarker), overcoming the need for the search of any particular chemical substance associated with the disorder (molecular biomarker). The developed model is based on a sensitive and reliable technique, which is cheap and fast, thus appearing promising to use as a complementary diagnostic tool in the clinical environment. Scientific and Technological Research Council of Turkey-TUBITAK 1001 ProjectTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [116Z294]; Portuguese Science Foundation (Fundacao para a Ciencia e a Tecnologia; FCT-Lisbon) [UIDB/EQU/00102/2020, UIDP/EQU/00102/2020]; COMPETE-EU This research was funded by the Scientific and Technological Research Council of Turkey-TUBITAK 1001 Project, grant number 116Z294. R.F. thanks the Portuguese Science Foundation (Fundacao para a Ciencia e a Tecnologia; FCT-Lisbon) for financial support to the Coimbra Chemistry Centre (CQC) through the projects UIDB/EQU/00102/2020 and UIDP/EQU/00102/2020 (national funds), also funded by COMPETE-EU.

In heritage sciences, the ability to obtain information about the origin and dating of cultural heritage objects is fundamental for placing an object into its historical context. Radiocarbon (¹⁴C) dating can help to identify the period during which a work of art was created by dating its constitutive materials. Such information can, however, only be obtained by removing a sample from the object, which is critical since art is irreplaceable and demands that the sampling be kept to a minimum. In this context, we propose a novel dating approach, which targets the natural organic binder of the pictorial layer as a new ¹⁴C candidate. In combination with spectroscopic techniques to ensure suitable sample selection, both canvas and paint samples were dated from three oil paintings. While not authenticating the paintings for belonging to a given artist, the ¹⁴C results from the baroque and neoclassical objects tend to align themselves with the purported attribution. The third object, attributed to the beginning of the 20th century’s modern expressionism movements, showcases the challenges in dating the natural organic binder owing to the presence of paraffin wax. The presented case studies showcase, how ¹⁴C dating of the natural organic binder may complement or offer alternate routes of study in assessing an object’s historical context. Moreover, the importance of material studies in the sampling step is enlightened as a prerequisite to access reliable ¹⁴C ages., Technè, 52, ISSN:2534-5168, ISSN:1254-7867

The changes upon water addition in the nanostructure of a deep eutectic solvent (DES) formed by choline chloride (ChCl) and sesamol in 1:3 ratio have been studied by means of small- and wide-angle X-ray scattering (SWAXS), ATR-FTIR spectroscopy and molecular dynamics (MD) simulations. SWAXS data show that small inhomogeneities in the sub-nanometer scale are formed for water/DES molar ratios (W) up to 6, while after this threshold segregation to higher scale occurs up to the formation of nanoscale structures with size of about 70 A. This behavior is different from that obtained for 1:2 ChCl:urea (reline) mixtures with water. 2D-correlation spectroscopy plots between SWAXS and FTIR spectra evidence that this pseudo-phase separation can be ascribed to the formation of nanometric water aggregates inside the DES for high W values. MD simulations show that, for high water concentration, water segregation from sesamol occurs by confining most of ChCl in the aqueous region.

Zeolite Y is one of the earliest known and most widely used synthetic zeolites. Many experimental investigations verify the valuable ion exchange capability of this zeolite. In this study, we assessed the effects of ion exchange on its vibrational spectra. We applied classical lattice dynamics methods for IR and Raman intensity calculations. Computed spectra of optimized zeolite Y structures with different cations were compared with experimental data. The spectra obtained in this study are in agreement with previous experimental and computational studies on zeolites from the faujasite group.

The influence of polluting gases on the stability of polymeric films has not been studied extensively. In fact, the chemical interactions of such materials in contact with the ambient atmosphere depend on different factors such as the environmental conditions, the manufacturing process of the product, the presence of additives or various pigments. In this study, accelerated artificial gas ageing was carried out. The experiments were performed in a gas chamber exposing the samples to sulphur dioxide (SO2) and nitrogen oxide (NOx) with a concentration of 15 ppm. The relative humidity (RH) content chosen was 50% and 80% for a total of 168 h of gas exposure. The paint samples under investigation were composed of three different binding media (acrylic, alkyd, and styrene-acrylic) with various inorganic pigments. The morphological changes on the sample surface due to the different impact of the pollutant gases were investigated using a 3D microscope. Moreover, qualitative and semi-quantitative analyses were performed by Fourier-Transform Infrared (ATR-FTIR) spectroscopy, focusing on the degradation reactions and surface mapping evaluation. In order to fully exploit the chemical information on these materials contained in the ATR-FTIR spectra, multivariate analysis was carried out. In particular, Principal Component Analysis (PCA) enabled verifying the main spectral differences between the unaged and aged samples. Moreover, Analysis-of-Variance-Simultaneous Component Analysis (ASCA) was carried out to understand the influence of gas type, relative humidity, and inorganic pigment type on the deterioration process of the binders.

Crystal structure analyses at atomic resolution and FTIR spectroscopic studies of cytochrome c oxidase have yet not revealed protonation or deprotonation of key sites of proton transfer in a time-resolved mode. Here, a sensitive technique to detect protolytic transitions is employed. In this work, probing a proton-loading site of cytochrome c oxidase from Paracoccus denitrificans with time-resolved Fourier transform infrared spectroscopy is presented for the first time. For this purpose, variants with single-site mutations of N131V, D124N, and E278Q, the key residues in the D-channel, were studied. The reaction of mutated CcO enzymes with oxygen was monitored and analyzed. Seven infrared bands in the &ldquo, fast&rdquo, kinetic spectra were found based on the following three requirements: (1) they are present in the &ldquo, phases of N131V and D124N mutants, (2) they have reciprocal counterparts in the &ldquo, slow&rdquo, kinetic spectra in these mutants, and (3) they are absent in &ldquo, kinetic spectra of the E278Q mutant. Moreover, the double-difference spectra between the first two mutants and E278Q revealed more IR bands that may belong to the proton-loading site protolytic transitions. From these results, it is assumed that several polar residues and/or water molecule cluster(s) share a proton as a proton-loading site. This site can be propionate itself (holding only a fraction of H+), His403, and/or water cluster(s).

The aim of the study was to modify the surface free energy (SFE) of meta- (mAr) and para-aramid (pAr) yarns by their activation in low-pressure air radio frequency (RF) (40 kHz) plasma and assessment of its impact on the properties of the yarns. After 10 and 90 min of activation, the SFE value increased, respectively, by 14% and 37% for mAr, and by 10% and 37% for pAr. The value of the polar component increased, respectively by 22% and 57% for mAr and 20% and 62% for pAr. The value of the dispersion component for mAr and pAr increased respectively by 9% and 25%. The weight loss decreased from 49% to 46% for mAr and 62% to 50% for pAr after 90 min of activation. After 90 min, the specific strength for mAr did not change and for pAr it decreased by 40%. For both yarns, the 10 min activation in plasma is sufficient to prepare their surface for planned nanomodification.

This paper presents a spectroscopic study of emulsions generated with a laser-assisted device. Fourier transform infrared (FTIR), Raman and UV&ndash, Vis&ndash, NIR reflectance spectra of emulsions, recorded before and after exposure to laser radiation were used to characterize the effect of laser irradiation. The paper also presents a comparison between the calculated IR spectra and the experimental FTIR spectra of an emulsion&rsquo, s components. FTIR measurements allowed the identification of absorption bands specific to each of the emulsions&rsquo, components. Moreover, it enabled the observation of destabilization of the emulsion in real-time. Raman spectroscopy allowed the observation of the modifications at a molecular level, by identifying the vibrations of the representative functional groups and the polymerization of sodium tetradecyl sulfate (STS) molecules by analyzing the evolution of the carbonyl band. UV&ndash, NIR reflectance spectra of emulsions before and after exposure to laser radiation showed that the physical characteristics of the emulsions changed during irradiation&mdash, the dimensions of the droplets decreased, leading to an emulsion with a better time stability. These results proved that the employed spectroscopy techniques were powerful tools in emulsion analysis.

Dating of clay bricks (adobe) and plasters is a relevant topic not only for building historians in the Pannonian region. Especially in vernacular architecture in this region, clay with straw amendments is a dominant construction material. The paper presents the potential of the molecular decay of these amendments to establish prediction tools for age based on infrared spectroscopic measurements. Preliminary results revealed spectral differences between the different plant parts, especially culms, nodes, and ear spindles. Based on these results, a first prediction model is presented including 14 historic samples. The coefficient of determination for the validation reached 62.2%, the (RMSE) root mean squared error amounted to 93 years. Taking the limited sample amount and the high material heterogeneity into account, this result can be seen as a promising output. Accordingly, sample size should be increased to a minimum of 100 objects and separate models for the different plant parts should be established.

Samples of hemoglobin in deuterium oxide solution (D2O) and in bidistilled H2O water solution, both at the concentration of 100 mg/ml, were exposed to a static magnetic field at 100 mT; analogous samples were exposed to 50 Hz magnetic field at 1 mT. Fourier Transform Infrared (FTIR) Spectroscopy was used to analyze separately the response of the secondary structure of this protein (diluted in both aqueous solutions) to separated exposure to both magnetic fields. The most relevant result which was observed after exposures was the significant increasing in intensity of the Amide I band, which was already explained in previous studies assuming that proteins α-helix aligned along the direction of the applied magnetic field due to its large dipole moment. In particular, in this study it was shown that hydrogen/deuterium exchange induced a reduction of the increasing of Amide I vibration band. This result can be explained assuming that Amide hydrogens of hemoglobin exchange with solvent deuterium atoms, causing an increase in mass of the protein and a correlated increasing in inertia of the α-helix, reducing significantly the torque effect of the applied magnetic field.

Lenticular, ellipsoidal and flat tubular hematite particles were precipitated from ferric nitrate solutions in presence of minor amounts of Al, Si, Mg and organic acids (oxalic, citric and tartaric). Particle shape identification was performed using Atomic Force Microscopy (AFM) and Transmission Electron Microscopy (TEM). Arsenate adsorption onto hematite with different morphologies was studied in batch experiments and through vibrational spectroscopy. Three bands assigned to As(V)–O–Fe at, respectively, 920, 895 and 820 cm−1 were in agreement with sorption data indicating inner-sphere complexes. As(V) adsorption kinetics was well described by a general model for diffusion into microporous surface sites showing large difference among the studied hematite samples. The maximum As(V) adsorption occurred near pH 4.0 while at alkaline pH there was a significant decrease of adsorption as confirmed by the shift of infrared As–O stretching bands of arsenate group. A change from tetrahedral Td symmetry to more stable symmetric groups such as C3v (monodentate complex), C2v (bidentate binuclear) or C1v (edge-sharing, bidentate binuclear) was deduced for As(V) sorbed on hematite. Fast arsenate adsorption was higher on ellipsoidal hematite particle with a dominant non basal (1 1 0) face. On the contrary, electrostatic attraction interaction could explain the fast As(V) adsorption on platy morphology characterized by basal face (0 0 1). Despite the discrepancy between theoretical considerations and experimental observations, the present contribution could lead to better understanding of the role played by hematite morphology on surface complexation model to describe arsenic adsorption behavior. Diffusional mass transport models applied to As sorption systems can explain such divergence due to: (i) external mass transport across the boundary layer surrounding the particle; (ii) diffusional mass transfer within the internal structure of the adsorbent particle by a nanopore, (iii) heterogeneity of the surface site. These findings are relevant to understanding the rates of interfacial processes involving arsenate sorption that can be take into account in mass transport models used for the removal of arsenic from contaminated water or wastewaters.

The sorption of Carbon dioxide in the prototype metal-organic framework CuBTC was examined in detail by FTIR spectroscopy. The spectra were collected in-situ under isothermal equilibrium conditions at two different temperatures (308 and 273 K). The results were analyzed by difference spectroscopy (DS) and 2D correlation spectroscopy (2D-COS). In particular, 2D-COS was employed to improve the resolution of the spectral profiles and to verify the occurrence of multiple molecular species. The spectroscopic monitoring of the sorption process provided precise quantitative data as well as relevant molecular-level information. Distinct interaction sites were identified in the framework structure, in agreement with first-principles simulations. A minor fraction of probe molecules characterized by a gas-like behavior was identified by analysis of the v 2 frequency range. (C) 2018 Elsevier B.V. All rights reserved.

Knowledge of the techniques employed by artists, such as the composition of the paints, colour palette, and painting style, is of crucial importance not only to attribute works of art to the workshop or artist but also to develop strategies and measures for the conservation and restoration of the art. While much research has been devoted to investigating the composition of an artist's materials from a qualitative point of view, little effort has been made in terms of quantitative analyses. This study aims to quantify the relative concentrations of binders (acrylic and alkyd) and inorganic pigments in different paint samples by IR and Raman spectroscopies. To perform this quantitative evaluation, reference samples of known concentrations were prepared to obtain calibration plots. In a further step, the quantification method was verified by additional test samples and commercially available paint tubes. The results obtained confirm that the quantitative method developed for IR and Raman spectroscopy is able to efficiently determine different pigment and binder concentrations of paint samples with high accuracy.

Samples of a typical tetrameric protein, the hemoglobin, at the concentration of 150 mg/ml in bidistilled water solution, were exposed to a uniform magnetic field at 200 mT at different temperatures of 15 ∘ C , 40 ∘ C and 65 ∘ C . Fourier Transform Infrared Spectroscopy was used to analyze the response of the secondary structure of the protein to both stress agents, heating and static magnetic field. The most relevant result which was observed was the significant increasing in intensity of the Amide I band after exposure to the uniform magnetic field at the room temperature of 15 ∘ C . This result can be explained assuming that protein's α-helices aligned along the direction of the applied magnetic field due to their large dipole moment, inducing the alignment of the entire protein. Increasing of temperature up to 40 ∘ C and 65 ∘ C induced a significant reduction of the increasing in intensity of the Amide I band. This effect may be easily explained assuming that Brownian motion of the protein in water solution caused by thermal molecular agitation increased with increasing of temperature, contrasting the effect of the torque of the magnetic field applied to the protein in water solution.

The transition to a hydrogen economy requires the development of cost-effective methods for purifying hydrogen from CO. In this study, we explore the possibilities of Cu/ZSM-5 as an adsorbent for this purpose. Samples obtained by cation exchange from aqueous solution (AE) and solid-state exchange with CuCl (SE) were characterized by in situ EPR and FTIR, H2-TPR, CO-TPD, etc. The AE samples possess mainly isolated Cu2+ cations not adsorbing CO. Reduction generates Cu+ sites demonstrating different affinity to CO, with the strongest centres desorbing CO at about 350 °C. The SE samples have about twice higher Cu/Al ratios, as one H+ is exchanged with one Cu+ cation. Although some of the introduced Cu+ sites are oxidized to Cu2+ upon contact with air, they easily recover their original oxidation state after thermal treatment in vacuum or under inert gas stream. In addition, these Cu+ centres regenerate at relatively low temperatures. It is important that water does not block the CO adsorption sites because of the formation of Cu+(CO)(H2O)x complexes. Dynamic adsorption studies show that Cu/ZSM-5 selectively adsorbs CO in the presence of hydrogen. The results indicate that the SE samples are very perspective materials for purification of H2 from CO.

The optical and spectral properties of foams and emulsions provide information about their micro-/nanostructures, chemical and time stability and molecular data of their components. Foams and emulsions are collections of different kinds of bubbles or drops with particular properties. A summary of various surfactant and emulsifier types is performed here, as well as an overview of methods for producing foams and emulsions. Absorption, reflectance, and vibrational spectroscopy (Fourier Transform Infrared spectroscopy-FTIR, Raman spectroscopy) studies are detailed in connection with the spectral characterization techniques of colloidal systems. Diffusing Wave Spectroscopy (DWS) data for foams and emulsions are likewise introduced. The utility of spectroscopic approaches has grown as processing power and analysis capabilities have improved. In addition, lasers offer advantages due to the specific properties of the emitted beams which allow focusing on very small volumes and enable accurate, fast, and high spatial resolution sample characterization. Emulsions and foams provide exceptional sensitive bases for measuring low concentrations of molecules down to the level of traces using spectroscopy techniques, thus opening new horizons in microfluidics.