Distribution and characterization of microplastics in beach sand from three different Indian coastal environments

The ID21 beamline (European Synchrotron Radiation facility, France) is a multi micro-analytical platform combining X-ray and infrared micro-probes, for characterization of elements, species, molecular groups and crystalline structures in complex materials. Applications are mainly in the fields of cultural heritage, life science, environmental and earth sciences, materials sciences. Here, we first present the status of instruments: (i) the scanning micro-spectroscopy end-station, operating from 2.0 to 9.2 keV, under vacuum and offering cryo conditions, for the acquisition of 2D micro X-ray fluorescence (μXRF) maps, single point micro X-ray Absorption Near Edge Structure (μXANES) spectra and speciation maps with sub-micrometric resolution; (ii) the XANES full-field end-station, operating in the same vacuum and energy conditions, for the acquisition of hyper-spectral radiographs of thin concentrated samples, resulting in speciation maps with micrometric resolution and millimetric field of view; (iii) the scanning micro-X-ray diffraction (μXRD)/μXRF end-station, operating at 8.5 keV, in air, for the acquisition of 2D crystalline phase maps, with micrometric resolution; and (iv) the scanning infrared microscope, operating in the mid-infrared range for the acquisition of molecular maps and some structural maps with micrometric resolution. Recent hardware and software developments are presented, as well as new protocols for improved sample preparation of thin sections. Secondly, a review of recent applications for the study of cultural heritage is presented, illustrated by various examples: determination of the origin of the color in blue Chinese porcelains and in brown Sevres porcelains; detection of lead in ink on Herculaneum papyri; identification and degradation of modeling materials used by Auguste Rodin and of chrome yellow pigments used by Vincent van Gogh. Cryo capabilities are illustrated by the analysis of plants exposed to chromate solutions. These examples show the variety of materials analyzed, of questions tackled, and particularly the multiple advantages of the ID21 analytical platform for the analysis of ancient and artistic materials.

The ID21 X-ray and infrared microscopy beamline at the ESRF: status and recent applications to artistic materials

Rooted in the long tradition of Raman spectroscopy of cultural heritage materials, in this work we provide a personal perspective on recent applications and new frontiers in sampling modalities, data processing, and instrumentation.

https://hal.archives-ouvertes.fr/hal-01455522/document

Raman Spectroscopy of cultural heritage Materials: Overview of Applications and New Frontiers in Instrumentation, Sampling Modalities, and Data Processing

Catalytic performance and the nature of surface adsorbates were investigated for high-surface-area ceria during the ethylbenzene oxidative dehydrogenation (ODH) reaction using CO2 as a soft oxidant. The high surface area ceria material was synthesized using a template-assisted method. The interactions among ethylbenzene, styrene, and CO2 on the surface of ceria and the role of CO2 for the ethylbenzene ODH reaction have been investigated in detail by using activity test, in situ diffuse reflectance infrared and Raman spectroscopy. CO2 as an oxidant not only favored the higher yield of styrene but also inhibited the deposition of coke during the ethylbenzene ODH reaction. Ethylbenzene ODH reaction over ceria followed a two-step pathway: ethylbenzene is first dehydrogenated to styrene with H2 formed simultaneously, and then CO2 reacts with H2 via the reverse water gas shift. The produced styrene can easily undergo polymerization to form polystyrene, which is a key intermediate for coke formation. In the abse...

https://lib.dr.iastate.edu/cgi/viewcontent.cgi?article=1299&context=ameslab_pubs

Role Of CO2 As a Soft Oxidant For Dehydrogenation of Ethylbenzene to Styrene over a High-Surface-Area Ceria Catalyst

Surface enhanced Raman spectroscopy (SERS) provides a useful sensory platform whereby target molecules at low concentration are identified, potentially detecting a single molecule. As a result, SERS has been widely applied in a variety of research endeavors using different substrates, one of which is a cellulose-based substrate. The unique properties of cellulose in its various forms make it an important component in the design of a SERS substrate. Being a flexible substrate with minimal SERS signal interference, paper-based cellulose templates are the most extensively explored form of cellulose in SERS substrate design, with innovative designs and applications. This review provides an overview of the fundamental tools of SERS enhancement, followed by a comprehensive appraisal of the various design principles associated with producing cellulose-based materials and their use as SERS substrates. Though cellulose in its various forms cannot provide the localized surface plasmon resonance required in SERS, it aids in aggregation and stabilization of plasmonic nanoparticles leading to “hot spots” for SERS signal enhancement. The unconventional techniques adopted in the designs are examined and the associated challenges are highlighted. The review demonstrates SERS applications of the substrates in diverse technologies such as bioanalysis, water quality assessment, food safety, adulteration of illicit drugs and dye identification in artworks. Ultimately, we envisage the need for a universal set standard to realize the ideal of designing SERS substrates from the perspective of end-user demand. This can be achieved through a re-evaluation of existing findings on cellulose-based SERS substrates.

A review of cellulose-based substrates for SERS: fundamentals, design principles, applications

Non-invasive identification of plastic materials in museum collections with portable FTIR reflectance spectroscopy: Reference database and practical applications

Synchrotron-based FTIR microspectroscopy for the mapping of photo-oxidation and additives in acrylonitrile–butadiene–styrene model samples and historical objects

Preparation of thin-sections of painting fragments: Classical and innovative strategies

Living, Isoselective Polymerization of Styrene and Formation of Stereoregular Block Copolymers via Sequential Monomer Addition

Cleaning is a fundamental phase of the conservation and maintenance activity of the cultural heritage. It is required to be highly effective in the removal of undesired deposits, controllable at every stage and gradable, selective, and completely respectful of the substrate. Moreover, cleaning procedures which can also assure to be harmless to the environment and the operators are particularly valued nowadays. According to these general guidelines, in the present work a sustainable approach for the cleaning of indoor surfaces of the cultural heritage is presented. A methodology based on agar gel was setup and preliminary tested on pilot areas. It has been then applied to the stone sculpted surfaces of the “Fuga in Egitto” high-relief of the Duomo of Milan. A multi-analytical approach was carried out during the setup phase to compare the efficacy of different cleaning conditions in terms of agar concentration, application time and presence of additives. Hence, spectrophotometric measurements, optical observations, ESEM-EDX analyses, Fourier Transform Infrared Spectroscopy, and X-Ray Diffraction were performed. Specific attention was paid to the aesthetic features of the sculpted surfaces before and after the cleaning. For this purpose, spectrophotometric data have been analysed by multivariate analysis techniques such as Principal Component Analysis and Hierarchic Cluster Analysis. The overall intervention has been monitored to evaluate the cleaning results and to confirm the absence of any damage to the stone substrate. The application of agar gel proved to be effective in removing soluble salts and soot particles, as well as very respectful of the valuable sculpted surfaces. This methodology is also totally safe for both the operators and the visitors, it is based on a natural and low-cost raw material, and it is low time-consuming. It can be therefore considered as a sustainable alternative to the traditional procedures.

/pdf/setup-of-a-sustainable-indoor-cleaning-methodology-for-the-45kfz3nvpb.pdf

Daniela Saviello

Papers

Non-invasive identification of plastic materials in museum collections with portable FTIR reflectance spectroscopy: Reference database and practical applications

Synchrotron-based FTIR microspectroscopy for the mapping of photo-oxidation and additives in acrylonitrile–butadiene–styrene model samples and historical objects

Preparation of thin-sections of painting fragments: Classical and innovative strategies

Living, Isoselective Polymerization of Styrene and Formation of Stereoregular Block Copolymers via Sequential Monomer Addition

Setup of a sustainable indoor cleaning methodology for the sculpted stone surfaces of the Duomo of Milan