Alginate-biocide hydrogel for the removal of biofilms from calcareous stone artworks

Evaluation of Calcarenite Degradation by X-ray Photoelectron Spectroscopy Analysis inside the Rupestrian Church of San Pietro Barisano (Matera, Southern Italy)

“…The room was characterized in the past by the presence of numerous frescoes, now in a state of decay, beneath which extensive biological colonization is visible. Sample #9, shown in Figure 4 in the lower left, was taken from this room, with the sampling area chosen beside the fresco of San Canio Vescovo where a surface bio-cleaning operation was carried out with a hydrogel based on sodium alginate (5% by weight) containing Ca(ClO) 2 (0.4% by weight) [25,26].…”

Innovative Methodologies for the Conservation of Cultural Heritage against Biodeterioration: A Review

“…As for anthropogenic chemical degradation factors, it is pertinent to mention the presence of atmospheric gases and particulate matter, including carbon compounds (CO x ), sulfur compounds (SO x ), and nitrogen compounds (NO x ). Acid precipitation, along with atmospheric particulate deposition, represent primary degradation factors that significantly impact the preservation of stone materials exposed to the outdoor environment [11]. Among the forms of physical degradation are the formation of black crusts [69,70], chromatic alteration [71], etc.…”

“…A bacterial inhibition method should be adopted after a cleaning phase since it is aimed to protect the surface against further colonization over time. An alternative approach to the use of hypochlorite as a biocidal agent on stone substrates has been identified in order to mitigate the negative impact on such materials and preserve the health of the operators [11].…”

“…Even though traditional procedures with biocidal products act on microorganisms efficiently, they are harmful to the environment and the operator and therefore do not represent a sustainable alternative [10]. In fact, most biocidal products containing compounds such as acetone, ethanol, toluene, ethyl acetate, quaternary ammonium salts, etc., are toxic substances or pollutants that do not degrade easily and can remain in the environment for a long time [11], hence the need to develop innovative, sustainable, and safe products [12,13].…”

Sampling methods for outdoor sculptures: Comparison of swabs and cryogels by flow cytometry as novel alternatives for assessment and quantification of microbial contamination

“…In the continuous search for non-invasive and non-destructive sampling methods for CH objects, hydrogels and cryogels could represent an alternative for sampling stone surfaces and avoiding some of the drawbacks associated with swabbing. Polymeric hydrogels are already used in CH, usually containing variable concentrations of organic solvents, for cleaning easel paintings, sculptures and monuments [54][55][56][57]. As for cryogels, they usually have large pores, are made of inexpensive materials and can be produced in any desirable shape (blocks, cylinders, discs, etc.)…”