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During the storage of celluloid pictures for animation films over half a century, an interleave paper adhered to acrylic paint. The purpose of this study is to establish a methodology to cleanly remove the paper from the paint. A layered film, a replica of the celluloid pictures, adhered with paper was prepared and immersed in water or ethanol. The effect of these solvents on the peeling behavior was investigated using a peel test. The maximum peel force for the dry layered film in was distributed at ~0.5 N, independently of the peel speed. The peel force was significantly reduced after the layered film was immersed in pure water or ethanol. A morphological observation revealed that the dry paper was peeled off via the cohesive failure of the paper. After the layered film was immersed in pure water, the paper was also peeled off via cohesive failure. The layered film immersed in ethanol was peeled off at the paper/paint interface. To clear the effect of the volume change in the paint on peel behavior, the relative volume was determined via image analysis. The relative volume of paint was 1.56 in pure water and 1.37 in ethanol. It can be considered that the large difference in the volume of paint induces a large shear stress at the paint/paper interface. [ABSTRACT FROM AUTHOR]

Calcium hydroxide nanoparticles dispersed in ethanol or 2-propanol have been proposed for deacidification treatments of cellulose-based supports and are currently adopted by many paper and paintings conservators. There is however a risk inherent in this treatment: the dispersion would acquire a highly alkaline pH in the presence of moisture, absorbed by the dispersing alcohol solvents or by the cellulose-based support. Consequently, conditions of potential risk would be created for the structural integrity of the cellulosic supports, for some organic film-forming materials and some colouring matter. The simple tests conducted in this study clearly demonstrate that this risk is real, and suggest a cautious attitude in evaluating the suitability of these nano-dispersions for the treatment of some works of art. [ABSTRACT FROM AUTHOR]

Cellulose oxidative and hydrolytical degradation is one of the greatest problems for the conservation of paper supports. To contrast these degradation processes, both deacidification and reduction of the oxidized functions are needed. Dealing with original documents, it is often impossible to perform the two mentioned treatments in aqueous solutions and in a distinct subsequent way, because of the fragility of the artifacts. After studying, in a separate way, an effective deacidifier (calcium propionate) soluble in ethyl alcohol and many reducers (boron complexes), able to act in different non-aqueous solvents, it was decided to test a simultaneous method of deacidification and reduction in ethanol. This paper presents the chemical-physical results obtained by applying simple deacidification and simultaneous deacidification-reduction on laboratory paper samples that were artificially aged and then re-measured after 10 and 15 years of natural aging. Results show that all alcoholic treatments are very effective: papers are stable also after a long period of both artificial and natural aging. [ABSTRACT FROM AUTHOR]

Potassium methyl siliconate (PMS) was investigated as a simple physicochemical modification in aged paper using silane coupling technique. The PMS-based solution was shown to favor penetration in the cellulose fibers on the paper with suitable uptakes being achieved at low concentrations. The studies of the physicochemical properties of the treated paper (mechanical strength and alkalinity) demonstrated that, besides the required deacidification feature and high level of alkali reserves, the immersion treatment by PMS allowed the enhancement of the mechanical intensities of paper arising from the interaction between Si-OH generated in hydrolysis of PMS and C-OH of cellulose on the paper. Adding ethanol into PMS solution could significantly improve mechanical properties of the aged paper treated by the formula apart from modifying the flatness of the paper. Optimized treatment process was achieved by altering the ratio of ethanol to water in PMS-based solutions. Contact angle measurements indicated the occurrence of hydrophobic character of the papers in immersion treatment with PMS-based solutions. The easy availability of the materials and simplicity of the method rendered it convenient for treatment for aged paper documents. [ABSTRACT FROM AUTHOR]

Bacterial cellulose (BC) synthesized by Gluconacetobacter sucrofermentans CECT 7291 seems to be a good option for the restoration of degraded paper. In this work BC layers are cultivated and purified by two different methods: an alkaline treatment when the culture media contains ethanol and a thermal treatment if the media is free from ethanol. The main goal of these tests was the characterization of BC layers measured in terms of tear and burst indexes, optical properties, SEM, X-ray diffraction, FTIR, degree of polymerization, static and dynamic contact angles, and mercury intrusion porosimetry. The BC layers were also evaluated in the same terms after an aging treatment. Results showed that BC has got high crystallinity index, low internal porosity, good mechanical properties and high stability over time, especially when purified by the alkaline treatment. These features make BC an adequate candidate for degraded paper reinforcement. [ABSTRACT FROM AUTHOR]

Highlights: [•] We prepared a series of paper sheets incorporating titania-anchored hollow silica. [•] The papers showed high photocatalytic activity in the degradation of ethanol. [•] A new model coupling mass transfer and UV penetration has been developed. [•] The simulated UV profiles suggest a strong UV attenuation within the paper thickness. [•] Counter- and co-current modes show comparable photocatalytic activities. [Copyright &y& Elsevier]

Abstract: A new composite paper with high photocatalytic performance has been successfully manufactured by introducing titania-anchored porous silica into cellulose fibres. The silica particles with an average size of 700nm were synthesized via CaCO3 templating and further employed as support to grow titania nanoparticles (5.2nm) by sol–gel synthesis with variable weight ratios. The photocatalytic materials have been characterized using various techniques including BET, XRD, Raman spectroscopy, SEM and TEM+EDX+ED microscopies. The composite TiO2/SiO2 particles have been further introduced in bulk paper to generate highly active photocatalytic TiO2-loaded papers. The activity of the papers has been demonstrated in the room-temperature degradation of ethanol (50–200ppm) under UV irradiation, showing a comparable activity to that of commercial TiO2-coated papers. The effect of the main textural variables during papermaking on the photocatalytic performance are discussed in detail. [Copyright &y& Elsevier]