This paper presents an overview of the conservation state of the tawed white leather, parchment and reused parchment bookbindings from the Rare Book Collection of the Romanian Academy Library. The transdisciplinary study was jointly conducted by the researchers of INCDTP-ICPI and Manuscripts and Rare Book Department of the Romanian Academy Library. Over 50 bindings in alum-tawed (white) leather, parchment and reused parchment were analyzed in situ using specific non-invasive or micro-invasive analysis methods such as visual and microscopic analyses, thermal microscopy (imageMHT method), attenuated total reflection (ATR), Fourier transform infrared spectroscopy (FTIR), and X-ray Fluorescence Spectrometry (XRF). Based on these results, conservation sheets have been drawn up including damage status, threats and conservation recommendations for each investigated bookbinding. Two conservation sheets are illustrated for alum-tawed and re-used parchment bindings. This is the first Romanian study dedicated both to the artistic and material aspects of rare book bindings so far. KEY WORDS: bookbinding, alum-tawed leather, parchment, damage status, conservation reccommendations LEGĂTURI DE CARTE RARĂ DIN COLECŢIILE BIBLIOTECII ACADEMIEI ROMÂNE -STUDIU MULTIDISCIPLINARREZUMAT. Această lucrare prezintă o imagine de ansamblu asupra stării de conservare a legturilor de carte din piele albă argăsită, pergament şi pergament reutilizat din Colecţia de Carte Rară a Bibliotecii Academiei Române. Studiul transdisciplinar a fost realizat în comun de către cercetătorii din cadrul INCDTP-ICPI şi din cadrul Departamentului de Manuscrise şi Cărţi Rare al Bibliotecii Academiei Române. Peste 50 de legături din piele argăsită cu alaun (albă), pergament şi pergament refolosit au fost analizate in-situ utilizând metode specifice de analiză neinvazivă sau microinvazivă, cum ar fi analize vizuale şi microscopice, microscopie termică (metoda imageMHT), reflexie totală atenuată (ATR), spectroscopie în infraroşu cu transformată Fourier (FTIR) şi spectrometrie de fluorescenţă de raze X (XRF). Pe baza acestor rezultate, au fost întocmite fişe de conservare, care includ starea de deteriorare, riscuri şi recomandări de conservare pentru fiecare legătură de carte studiată. Două fişe de conservare sunt ilustrate pentru legături din pergament argăsite cu alaun şi reutilizate. Acesta este primul studiu românesc de până acum dedicat atât aspectelor artistice, cât şi aspectelor materiale ale legăturilor de carte rară. CUVINTE CHEIE: legătură de carte, piele argăsită cu alaun, pergament, stare de deteriorare, recomandări de conservare RELIURES DE LIVRES RARES DES COLLECTIONS DE LA BIBLIOTHÈQUE DE L'ACADÉMIE ROUMAINE -ÉTUDE MULTIDISCIPLINAIRE

Leather artefacts in historical collections and old leather bookbindings in archives and libraries frequently show a variety of visible changes which alter their appearance and ability to be used, such as powdery surface, weakened structure, complete or partial loss of the grain layer. However, historical leather stabilization and consolidation yet represent a challenging problem for conservators due to the sensitivity of collagen to the action of most of the conservation and restoration formulations currently used. In this paper we report our recent research concerning the development of halloysite nanoparticles dispersions for enhancing the hydrothermal stability of weakened historical vegetable tanned leather. The effects of halloysite nanotubes (HNTs) dispersed in various aqueous and non-aqueous mediums on the thermal stability of collagen in historical leather were tested using thermal microscopy, thermogravimetry and micro differential scanning calorimetry. Unilateral nuclear magnetic resonance was used to evaluate the changes in water dynamics due to collagen matrix interaction with dispersion media. The treated samples were also characterized using infrared spectroscopy and scanning electron microscopy. The analytical assessment confirmed the leather thermal stability increase and a partial recovery of fibres cohesion, thus validating the use of HNT dispersions as a basic tool for the preservation of collagen-based materials. Further functionalisation and encapsulation using antimicrobials, fungicides and pH adjustment nanoparticles will deliver novel and more durable HNTs-based conservation treatments.

In this study NMR MOUSE and micro DSC techniques were used to investigate the interaction between collagen and various vegetable tannins during leather making process with the aim of gaining a deeper understanding of different water environment in relation to tannin type. We have previously showed that relaxation times may provide useful information on collagen matrix properties. The vegetable tanned leathers were obtained by patented techniques inspired from ancient recipes at the National R&D Institute for Textile and Leather, ICPI Division, Bucharest using various vegetable extracts such as myrobalan, gambier and chestnut. Longitudinal and transversal relaxation times T1 and T2eff were measured using a PM2 portable NMR-MOUSE with 20.05 MHz frequency. Micro DSC measurements were carried out with a high-sensitivity SETARAM Micro-DSC III in the temperature range (5 to 95) °C at 0.5 K min-1 heating rate. The investigated leathers showed significant differences in the values of spin-spin (T2eff) and spin-lattice (T1) relaxation times depending on tannin type that well corelates with the variation of the calorimetric parameters (denaturation temperature and enthalpy, peak shape). These results highlight the complementarity of the information obtained by the two techniques and open new ways for both designing new leather assortments and analyses of historical and archaeological leather.

Historical leathers, in a huge variety of items as footwear and garments, bookbinding, wall tapestry, upholstery, harnesses, armours, storage vessels, household tools, cases, musical instruments, toys, ritual objects are regarded as important testimonials of our cultural heritage. It is vital therefore that these objects remain well preserved along with all the knowledge involved, from their material aspects and value use to historical, cultural and artistic values. One of the most difficult challenges in leather conservation concerns with consolidation and pH control. To set up a novel green protocol for the long-term protection of historical and archaeological leather we have investigated the filling and stabilization process of vegetable-tanned leathers treated with various mixtures based on halloysite nanotubes (HNTs).

The paper refers to a composition with antifungal and antibacterial effect in order to test new materials for preserving heritage objects on collagen support with bactericidal/antifungal role, essential oils-based from Vetrice (Tanacetum vulgare, Compositae family), having antifungal and antibacterial properties. The biocidal effect of plant extracts is due to the presence of constituent agents, such as alcohols, ethers, phenols, aldehydes, ketones, which makes them extremely effective against a wide range of microbial strains. The essential oil was obtained by boiling the plants through continuous hydrodistillation with Clevenger refrigerant. The testing of the antimicrobial efficiency of the plant extracts was performed on two strains of pathogenic fungi, respectively Trichophyton interdigitale and Epidermophyton floccosum. The microbial inoculum was mixed with the plant extract from various sources (leaves, flowers and mixed flower-leaves). All extracts were tested in duplicate according to the specific test standards, and the results were expressed as a mean percentage and logarithmic reduction between the readings on the two Petri plates corresponding to each sample. To quantify the antimicrobial efficacy, the degree of microbial and logarithmic reduction of each sample was calculated, relative to the initial cell concentration. The results of antimicrobial tests showed a high antifungal character of the extracts obtained from flowers, leaves and mixed flower-leaves.