Gels for the Conservation of Cultural Heritage

Baglioni, Piero; Berti, Debora; Bonini, Massimo; Carretti, Emiliano; Pérez, María del Carmen Casas; Chelazzi, David; Dei, Luigi; Fratini, Emiliano; Giorgi, Rodorico; Natali, Ilaria; Arroyo, Marcia Carolina

doi:10.1557/opl.2012.97

Cited by 12 publications

(9 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Ideal cleaning systems must allow high control and selectivity of the cleaning action. The use of gelled systems, which has been recently introduced in the conservation practice, is one of the most successful strategies to achieve highly effective and non-invasive cleaning [1][2][3][4][5]. Most gels used in the conservation practice are physical gels [6][7][8][9]; more recently, chemical gel formulations have been introduced [10][11][12][13][14][15].…”

Section: Introductionmentioning

confidence: 99%

Poly(vinyl alcohol)/poly(vinyl pyrrolidone) hydrogels for the cleaning of art

Bonelli

Poggi

Chelazzi

et al. 2019

Journal of Colloid and Interface Science

Self Cite

View full text Add to dashboard Cite

The cleaning of modern and contemporary paintings is a delicate and challenging operation. Many contemporary paintings exhibit rough, clotted and pitted surfaces, where the removal of soil is difficult. Gels are among the most efficient tools to achieve controlled and efficient cleaning of works of art. However, most gels used in the conservation practice are too rigid to adapt rough surfaces, or too mechanically weak to be removed without leaving polymer residues. Several formulations of physically cross-linked poly(vinyl alcohol) (PVA)-based hydrogels, obtained by cast-drying or freeze-thawing of aqueous polymeric solutions, were formulated and characterized. The viscoelastic properties, porosity, and crystallinity of the gels were studied, along with the behavior of water inside the polymeric network. It was shown that the properties of the gels were improved through blending with poly(vinyl pyrrolidone) (PVP). The most promising gel formulation, in terms of mechanical properties and water retentiveness, was assessed for the removal of soil from an alkyd painting mock-up. A traditional gel, gellan gum, was also tested as a reference system. The effectiveness of soil removal was investigated by 2D Fourier transform infrared (FTIR) microscopy, using a Focal Plane Array (FPA) detector. In conclusion, it was shown that the newly developed formulation grants the residue-free removal of soil from rough and irregular artistic surfaces, overcoming the limits of traditional cleaning methods.

show abstract

Section: Introductionmentioning

confidence: 99%

Poly(vinyl alcohol)/poly(vinyl pyrrolidone) hydrogels for the cleaning of art

Bonelli

Poggi

Chelazzi

et al. 2019

Journal of Colloid and Interface Science

Self Cite

View full text Add to dashboard Cite

show abstract

“…Although the removal of contaminants from delicate surfaces can be achieved with dry (e.g., laser ablation, 23,24 microfiber cloths, 25 and polymeric micropillars 26 ) and wet (e.g., solvents, surfactants, 27 and microemulsions 28 ) methods, gels have been shown to be a gentle and effective strategy. 22,29,30 However, the contact between soft cleaning materials (e.g., gels) and substrates has not been investigated in relation to cleaning efficacy.…”

Section: Introductionmentioning

confidence: 99%

Maximizing Contact of Supersoft Bottlebrush Networks with Rough Surfaces To Promote Particulate Removal

Duncan

Chan

Beers

2019

ACS Appl. Mater. Interfaces

View full text Add to dashboard Cite

Efficient removal of particulates from a rough surface with a soft material through a “press and peel” method (i.e., an adhesion and release approach) depends on good conformal contact at the interface; a material should be sufficiently soft to maximize contact with a particle while also conforming to rough surface features to clean the entire substrate surface. Here, we investigate the use of bottlebrush networksextremely soft elastomers composed of macromolecules with polymeric side chainsas materials for cleaning model substrates of varying roughness. Formed through free-radical polymerization of mono- and dimethacrylate functionalized polysiloxanes, these solvent-free supersoft elastomers exhibit moduli comparable to those of solvated gels, allowing for a lower moduli regime of elastomers to be used in contact experiments than previously possible. By varying the macromonomer to cross-linker ratio, we study the effect of modulus on conformal contact and cleaning for materials that are as soft as gels while minimizing/negating physical and/or chemical concerns that using a traditional material may involve (e.g., changes in component concentrations, solvent evaporation, and syneresis). We study cleaning efficacy by quantifying the conformal contact between soft materials and rough substrates via a contact adhesion-based measurement. These results give insight into the correlation between shear modulus and conformal contact with surfaces of varying feature height. Not only does a decrease in shear modulus leads to improved conformal contact with rough surfaces, but also it facilitates adhesion to particulates situated on the rough surface, thus aiding removal. We highlight this property control with a case study illustrating the removal of an artificial soil mixture from a rough, acrylic surface via peeling rather than rubbing, which can cause damage to delicate surfaces.

show abstract

“…Moreover, the control of the cleaning action is poor, as fluid retention is typically inadequate for application on highly sensitive substrates such as hydrophilic fibers, soluble inks, or dyes. Alternatively, in the past few years we have been proposing highly viscous polymer dispersions − and chemical gels − that allow controlled cleaning without leaving detectable dispersion/gel residues. In particular, the use of hydrogels based on semi-interpenetrated polymer networks (SIPNs) is advantageous because both the hydrophilicity and porosity of the gels can be tuned to optimize the swelling response and the liquid release kinetics .…”

Section: Introductionmentioning

confidence: 99%

Complex Fluids Confined into Semi-interpenetrated Chemical Hydrogels for the Cleaning of Classic Art: A Rheological and SAXS Study

Baglioni

Domingues

Carretti

et al. 2018

ACS Appl. Mater. Interfaces

Self Cite

View full text Add to dashboard Cite

The removal of aged varnishes from the surface of easel paintings using the common conservation practice (i.e., by means of organic solvents) often causes pigment leaching, paint loss, and varnish redeposition. Recently, we proposed an innovative cleaning system based on semi-interpenetrated polymer networks (SIPNs), where a covalently cross-linked poly(hydroxyethyl methacrylate), pHEMA, network is interpenetrated by linear chains of poly(vinylpyrrolidone), PVP. This chemical gel, simply loaded with water, was designed to safely remove surface dirt from water-sensitive artifacts. Here, we modified the SIPN to confine complex cleaning fluids, able to remove aged varnishes. These complex fluids are 5-component water-based nanostructured systems, where organic solvents are partially dispersed as nanosized droplets in a continuous aqueous phase, using surfactants. The rheological behavior of the SIPN and the nanostructure of the fluids loaded into the gel were investigated, and the mechanical behavior of the gel was optimized by varying both the cross-linking density and the polymer concentration. Once loaded with the complex fluids, the hydrogels maintained their structural and mechanical features, while the complex fluids showed a decrease in the size of the dispersed solvent droplets. Two challenging case studies have been selected to evaluate the applicability of the SIPN hydrogels loaded with the complex fluids. The first case study concerns the removal of a surface layer composed by an aged brown resinous patina from a wood panel, the second case study concerns the removal of a homogeneous layer of yellowed varnish from a watercolor on paper. The results show that the confinement of complex fluids into gels allowed unprecedented removal of varnishes from artifacts overcoming the limitations of traditional cleaning methods.

show abstract

Gels for the Conservation of Cultural Heritage

Cited by 12 publications

References 15 publications

Poly(vinyl alcohol)/poly(vinyl pyrrolidone) hydrogels for the cleaning of art

Poly(vinyl alcohol)/poly(vinyl pyrrolidone) hydrogels for the cleaning of art

Maximizing Contact of Supersoft Bottlebrush Networks with Rough Surfaces To Promote Particulate Removal

Complex Fluids Confined into Semi-interpenetrated Chemical Hydrogels for the Cleaning of Classic Art: A Rheological and SAXS Study

Contact Info

Product

Resources

About