Anti-graffiti nanocomposite materials for surface protection of a very porous stone

Licchelli, Maurizio; Malagodi, Marco; Weththimuni, Maduka L.; Zanchi, Chiara

doi:10.1007/s00339-014-8356-9

Cited by 32 publications

(21 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, there have been published a few previous studies on such innovative treatments and their potential for use on built heritage where they provided an efficient protection with minimal modification of the historic substrate. Such studies have been mainly focussed on limestones and sandstones [6,[21][22][23][24][25] with uneven results. The effectiveness of these products on granites has been even less well explored.…”

Section: Introductionmentioning

confidence: 99%

Effectiveness of commercial anti-graffiti treatments in two granites of different texture and mineralogy

Pozo-António

Rivas

Jacobs

et al. 2018

Progress in Organic Coatings

View full text Add to dashboard Cite

This paper presents a study of the efficiency of two chemically different anti-graffiti coatings (sacrificial and permanent anti-graffiti products) on two different compositional and textural granitic stones, Rosa Porriño and Albero.First, both uncoated and coated surfaces of the granites were characterized using stereomicroscopy and scanning electron microscopy, static contact angle measurements, colour spectrophotometry and gloss measurements. Results showed that both anti-graffiti products increased the static contact angle of the surfaces. The permanent anti-graffiti made them waterrepellent without causing notable colour changes.Second, effectiveness of the anti-graffiti products was evaluated by means of the removal of two different spray graffiti paints (blue and silver colours) on both granites protected with the abovementioned anti-graffiti products. The cleaning procedures were those recommended by the manufacturers. Fourier Transform Infrared spectroscopy and the previously mentioned techniques were used to assess the cleaning efficiency of the coated surfaces by detecting or not the presence of graffiti remains. As a result, textural differences in the granites, chemical composition of the graffiti paints and removal time were found to be the key parameters controlling the effectiveness of graffiti removal. On Albero granite, more residues of paint were found in its fissure system. Blue graffiti based on alkyd and polyester resins was more readily removed than silver paint. In general terms, graffiti extraction was more effective 30 days after painting than 3 days after.

show abstract

Section: Introductionmentioning

confidence: 99%

Effectiveness of commercial anti-graffiti treatments in two granites of different texture and mineralogy

Pozo-António

Rivas

Jacobs

et al. 2018

Progress in Organic Coatings

View full text Add to dashboard Cite

show abstract

“…Water-based nano-composite, obtained by dispersing low amounts (up to 5 wt %) of MMT (neat or organically modified) nano-particles into a cross-linked fluorinated polyurethane based on perfluoropolyethers, were analyzed as possible anti-graffiti coating for Leccese stone, a very porous stone characteristic of Apulian region [21]. It was found that organically modified MMT when introduced (in particular at 3 wt %) in the polymeric matrix is able to supply a high hydrophobicity to the stone and a stable anti-graffiti effect for black acrylic spray paint; this latter, in fact, can be easily removed from the stone using MEK (methyl ethyl ketone) solvent, leaving the stone surface substantially unaffected from an aesthetical and morphological point of view, even after repeated staining/cleaning cycles (as shown in Figure 3).…”

Section: Montmorillonite/stonementioning

confidence: 99%

Novel Attribute of Organic–Inorganic Hybrid Coatings for Protection and Preservation of Materials (Stone and Wood) Belonging to Cultural Heritage

Frigione

Lettieri

2018

Coatings

View full text Add to dashboard Cite

In order to protect a material belonging to Cultural Heritage (i.e., stone, wood) from weathering, and in turn to preserve its beauty and historical value for the future generations, the contact with external harmful agents, particularly water, must be avoided, or at least limited. This task can be successfully obtained with the use of a protective organic coating. The use of nano-metric reinforcing agents in conventional polymeric coatings demonstrated to be a successful route in achieving better protective performance of the films and improved physical properties, even in extreme environments. The present paper would, therefore, review the more recent findings in this field. Generally speaking, when a hydrophobic product is applied on its surface, the stone material will absorb less water and consequently, less substances which may be harmful to it. An efficient organic coating should also supply wear and abrasion resistance, resistance to aggressive chemicals, excellent bond to the substrate; finally, it should be also able to guarantee vapor exchange between the environment and the material interior, i.e., the material should keep the same water vapor permeability as if it was un-protected. To regard to the conservation of wood artifacts, protective treatments for wood will preserve the material from environmental agents and biological attack. Hence, potential advantages of hybrid (organic–inorganic) nano-composite coatings for stone/wood have been found to be: Enhanced mechanical properties in comparison to the pure polymeric matrix, due to the reinforcing effect of the nano-filler; superior barrier properties (the presence of the nano-filler hinders the ingress of water and/or potentially harmful chemicals); optical clarity and transparency. It has been found that the efficacy of a nano-filled coating strongly depends on the effectiveness of the method used to uniformly disperse the nano-filler in the polymeric matrix. Furthermore, the presence of nano-particles should not impair the viscosity of the organic matrix, in order to employ the conventional techniques of application for coatings.

show abstract

“…On the other hand, physical, chemical, and biological processes may act, in isolation or in combination, yielding to the loss of surface integrity or even to structural failure. To provide protection against graffiti, many polymer-based coatings, displaying suitable properties (mainly oleo/hydrophobicity), have been formulated [ 12 , 13 , 14 , 15 , 16 ], but actually the anti-graffiti action needs to be proved on the particular stone material requiring protection. Biodeterioration caused by birds is another main cause of damage for stone materials in buildings, statues, and monuments [ 17 , 18 ], especially in historic city centers.…”

Section: Introductionmentioning

confidence: 99%

Novel Nano-Filled Coatings for the Protection of Built Heritage Stone Surfaces

Lettieri

Masieri²,

Frigione

2021

Nanomaterials

View full text Add to dashboard Cite

An experimental nano-filled coating, based on a fluorine resin containing SiO2 nano-particles, was applied on calcareous stones, representative of materials used in buildings and monuments of the Mediterranean basin; for comparison purposes, two commercial products were applied on the same substrates. The efficacy of the protective treatments was assessed by analyzing different characteristics of the three experimental/commercial products, i.e., color changes and permeability to water vapor to evaluate the treatments’ harmlessness; capillary water absorption and water stone contact angle to evaluate the protection against water ingress; oleophobicity of the treated surfaces and the behavior under staining by acrylic blue-colored spray paint and felt-tip marker to verify the anti-graffiti action. Finally, the properties of the treated stone surfaces were analyzed also after the application of pancreatin, used to simulate bird excreta (guano). The protective coatings were found to promote graffiti removal, reducing also the detrimental effects due to simulated guano. The experimental nano-filled product, in addition, was able to provide outstanding performance but using smaller amounts of product in comparison to commercial systems.

show abstract

Anti-graffiti nanocomposite materials for surface protection of a very porous stone

Cited by 32 publications

References 31 publications

Effectiveness of commercial anti-graffiti treatments in two granites of different texture and mineralogy

Effectiveness of commercial anti-graffiti treatments in two granites of different texture and mineralogy

Novel Attribute of Organic–Inorganic Hybrid Coatings for Protection and Preservation of Materials (Stone and Wood) Belonging to Cultural Heritage

Novel Nano-Filled Coatings for the Protection of Built Heritage Stone Surfaces

Contact Info

Product

Resources

About