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A pulsed Nd : YAG laser ablation of FeS in water and ethanol produces FeS-derived colloidal nanoparticles that absorb onto immersed porous ceramic substrates and create solar-light photocatalytic surfaces. The stability, size distribution and zeta potential of the nanoparticles were assessed by dynamic light scattering. Raman, UV-Vis and XP spectroscopy and electron microscopy reveal that the sol nanoparticles have their outmost layer composed of ferrous and ferric sulphates and those produced in water are made of high-pressure orthorhombic FeS, cubic magnetite Fe3O4 and tetragonal maghemite γ-Fe2O3, while those formed in ethanol contain hexagonal FeS and cubic magnetite Fe3O4. Both colloids absorb solar light and their adsorption to porous ceramic surfaces creates functionalized ceramic surfaces that induce methylene blue degradation by daylight. The laser induced process thus offers an easy and efficient way for the functionalization of porous surfaces by photocatalytic nanoparticles that avoids aggregation in the liquid phase. The formation of an orthorhombic high-pressure FeS phase stable under ambient conditions is the first example of high-pressure structures produced by laser ablation in liquid without the assistance of an electric field. [ABSTRACT FROM AUTHOR]

• Cleaning of submicron particles from cellulose-based materials was investigated. • Suitability of the CO 2 snow jet was compared with traditional dry cleaning methods. • The jet was effective in removing submicron particles, including those embedded. • Mechanical dry cleaning methods were almost ineffective for these particles. • The jet did not alter surface properties of uncoated materials. Library collections are mostly made of porous cellulose-based materials such as papers and textiles. Submicron particles, representing up to 90% of particulate matter (PM) mass in libraries and archives, deposit on book surfaces and can also penetrate into small openings, including inter-fibre spaces. These particles can cause degradation of archival documents and therefore it is necessary to clean them. An alternative method of cleaning using the CO 2 snow jet was tested and compared with six traditional mechanical dry cleaning techniques. Different types of papers and textiles (bookbinding cloths) commonly used in library collections were treated with the jet using a newly developed automatic system. Measurements included the assessment of particle removal efficiency and possible degradation of the cellulose materials. The method was verified using real archival documents. Results revealed that the jet was effective in removing submicron particles, including those embedded in the fibrous surface. The CO 2 snow jet did not alter the surface properties of uncoated papers and textiles, whereas the degradation of coated samples was probably caused by surface temperature decrease after the CO 2 snow application. In contrast, the mechanical dry cleaning methods were almost ineffective for the submicron PM. Moreover, the mechanical techniques alter the surface by leaving visible crumbs of the cleaning material, releasing fibers, and changing of fibers structure. The results indicate that CO 2 snow jet cleaning using the automatic system is a suitable method for common types of papers and textiles with uncoated surfaces. [ABSTRACT FROM AUTHOR]