L. Teodonio's research while affiliated with Istituto centrale per il restauro e la conservazione del patrimonio archivistico e librario and other places

Publications (11)

Article
Manuscripts, illuminated codex, books, documents and letters are composite materials, traces of the past starting from the invention of the writing. In this context, dating is one of the most important information for document attribution, and watermarked papeItaly'smarkers for studying their time-spatial distribution. In the Late Middle Ages, Ital...
Article
Full-text available
The Alessandrina Library was founded in 1667 by pope Alexander VII Chigi and is nowadays housed in the Campus of Sapienza University of Rome (Italy). Within its Ancient (mostly made of rag paper) and Modern (mostly made of contemporary paper) collections, it includes more than one million books produced from the XVI to the XXI century. In 2019, six...
Article
The discoloration of paper, due to the development of oxidized groups acting as chromophores in its chief component, cellulose, is responsible for severe visual degradation of works of art on paper. By adopting a diagnostic method based on in situ non-invasive optical reflectance spectroscopy and time-dependent density functional theory ab initio c...
Article
Disposable non-invasive and compatible real time monitoring tool was developed in order to follow the cleaning process of paper artwork directly in situ. This tool was based on a biocompatible cleaning hydrogel coupled with flow electrochemical diagnostic tool, suitable to verify in situ and in a simple way the assessment of degradation of artwork...
Article
Mapping the morphological and nano-mechanical properties of cellulose fibers within paper sheets or textile products at the nano-scale level by using atomic force microscopy is a challenging task due to the huge surface level variation of these materials. However this task is fundamental for applications in forensic or cultural heritage sciences an...
Article
The discoloration of ancient paper, due to the development of oxidized groups acting as chromophores in its chief component, cellulose, is responsible for severe visual degradation in ancient artifacts. By adopting a non-destructive approach based on the combination of optical reflectance measurements and time-dependent density functional theory ab...
Article
Paper is an important material for many applications. During the centuries, it has been the most widely used writing support and therefore paper degradation is a major issue for cultural heritage. The main component of paper is cellulose, one of the most abundant biomaterials on Earth. Cellulose oxidation is mainly responsible for the yellowing of...
Article
In this paper, we present a new noninvasive and nondestructive approach to recover scattering and absorption coefficients from reflectance measurements of highly absorbing and optically inhomogeneous media. Our approach is based on the Yang and Miklavcic theoretical model of light propagation through turbid media, which is a generalization of the K...
Article
We review here some of the most reliable and efficient computational theoretical ab initio techniques for the prediction of optical and electronic spectroscopic properties and show some important applications to molecules, surfaces, and solids. We investigate the role of the solvent in the optical absorption spectrum of indole molecule. We study th...
Article
Paper is the most widely used writing support due to the remarkable properties of its principal component - cellulose - one of the most abundant biomaterials present on Earth. However, due to the complexity of the material, an exhaustive picture of its degradation pathways is still missing. In this paper, we will present recent results and progress...

Citations

... Actually, some authors set out the deployment of wireless sensors after analysing all the factors involved in restricting signal propagation and coverage [11,12]. More recently, the authors of this paper proposed installed multiple thermo-hygrometers in a library repository after conducting microclimate field campaigns in different time slots to study the horizontal and vertical distributions of temperature and mixing ratio of moist air [13]. ...
... Oxidation of cellulose proceeds through the radical mechanism initiated by active oxygen species, and it is a complex process with many possible routes [5,9]. Oxidation induces ring opening and/or chain cleavage and is accompanied by the formation of carbonyl groups and chromophores [10,11] . 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 Depolymerization can be profoundly enhanced by acidic oxidation by-products such as carboxylic groups embedded into cellulose polymer [12]. These degradation processes, finally, result in the formation of a great number of low molecular mass-products, such as sugars like glucopyranose, or acid compounds, such as acetic, lactic, malic and succinic ones [13][14][15]. ...
... In recent years, much has been done to develop sampling protocols of paper artworks in order to preserve their fragility and to be able to perform diagnostic analysis in laboratory [37][38][39][40][41][42][43][44][45]. ...
... The potential of AFM nanomechanical measurements in the understanding of composites is currently helping the growth of the biocomposites field. Cellulose based composites have been widely studied by AFM, particularly with Peak Force Quantitative Nanomechanical (PF-QNM) mode [92] [93]. Khelifa and collaborators [94] have studied the evaluation of the structuration and mechanical properties of thin films such as acrylic/cellulose nanowhiskers (CNWs) composite films. ...
... Pristine cellulose does not absorb light above about 200 nm (below 6 eV) [8,18]. The yellow color seen in aged papers is mainly due to the fact that chromophores in paper absorb the higher energy band of visible light (corresponding to violet and blue) and largely scatter the yellow and red portion, thereby producing the characteristic yellow-brown hue [8,15,20,21]. ...
... Visible light, and particularly UV radiation (if not filtered out), can accelerate embrittlement of poor-quality paper and cause yellowing [22] and/or colour fading of most dyes, inks and colourants [23]. ...
... As far as the theoretical method is concerned test calculations of the relative concentrations of oxidized groups in paper samples were performed using several different exchange-correlation functional in the DFT method in order to evaluate the error (Reference [32]). The change in the relative concentrations resulting from the use of these functionals was estimated to be below 10% ...
... The overall uncertainty of the theoretical and experimental method described is therefore approximately 20%." Answer: reference [33], which shows the concentrations of chromophores of Leonardo da Vinci's Self-Portrait, was added at Page 10, line 58. ...
... Since paper has a finite thickness, two sets of spectra were measured: the first one obtained with the samples placed over background with reflectance close to 1, the second one obtained with the sample placed over a background with reflectance close to 0. Then, the Kubelka-Munk (KM) theory for the optical properties of inhomogeneous materials allows to calculate the reflectance R∞ that would have a layer of infinite thickness of the paper samples [32,[51][52][53]. From R∞, by using recent results developed within the K-M theory, it is possible to obtain the absorption coefficient α in cm -1 of the cellulose fibers of paper with a estimated uncertainty of about 10%. ...