Optoacoustic measurements of the porosity of paper samples with foxings

Abstract

The goal of this work is to investigate the porosity of old paper with foxings. Initially, paper samples are characterized using the conventional absorption and Fourier transform infrared spectroscopies. Optoacoustic method based on laser excitation of short ultrasound transients is used for porosity measurements. The paper porosity is calculated using the theory of two-component mixture with the experimentally determined sound speeds in paper samples saturated with liquids. An increase in the porosity in foxing stains on paper in comparison with the foxing-free fragments is clearly demonstrated.

Contribution to the characterization of foxing stains on printed books using infrared spectroscopy and scanning electron microscopy energy dispersive spectrometry

“…This observation is consistent with what was observed by Balakhnina et al (2012). They consider it, as an oxidation of paper in foxed areas and noted that this oxidation is significantly higher than the general oxidation of paper.…”

Considerations about foxing stains in three paper collections ranging from the 16th to the 20th century

“…Foxing research from the last six years has undoubtedly linked fungal activity to foxing stains [8][9][10][11][12][13][14][15][16]. Some of these authors [9][10] have also reported a clear increase in porosity and humidity in the interior of the foxing stains.…”

“…Foxing research from the last six years has undoubtedly linked fungal activity to foxing stains [8][9][10][11][12][13][14][15][16]. Some of these authors [9][10] have also reported a clear increase in porosity and humidity in the interior of the foxing stains. Sclocchi and co-workers [16], on a study on gelatine-silver foxed photographs, added new insight to the foxing question by documenting a close interaction between the microorganisms and the inorganic materials used in the items' production and proposing that the appearance of the stains depended from the settlement and growth of halotolerant fungi and bacteria that produced localized hot spots of organic material on gelatine.…”

Single-pulse two-threshold laser ablation of historical paper

“…A laser pulse is absorbed in a layer the thickness of which is determined by radiation wavelength, absorption coefficient of paper and its porosity (scattering coefficient). The porosity can be determined using several methods including optoacoustics [35]. We assume that the scattering coefficient remains unchanged owing to the smallness of ablated mass.…”