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Rheoreversible hydrogels in paper restoration processes: a versatile tool.

Mazzuca C, Micheli L, Marini F, Bevilacqua M, Bocchinfuso G, Palleschi G, Palleschi A - Chem Cent J (2014)

Bottom Line: Rheoreversible hydrogels are intriguing materials because their application and removal is not invasive and does not require a liquid treatment that could induce damage to the paper.These hydrogels have been applied in the cleaning of both new and aged paper samples and their cleaning efficiency has been established.Near infrared spectroscopy spectra were coupled with a chemometric analysis to achieve a better interpretation of data.This work constitutes a preliminary step towards focused study in the development of α-cyclodextrin/polymer hydrogel family which will allow cleaning of paper artifacts with peculiar characteristics.

View Article: PubMed Central - HTML - PubMed

Affiliation: Dipartimento di Scienze e Tecnologie Chimiche, Università di Roma "Tor Vergata", Via della Ricerca Scientifica snc, Rome 00133, Italy. antonio.palleschi@uniroma2.it.

ABSTRACT

Background: Paper based artworks are probably ones of the most difficult materials to restore, because of their complexity and fragile structure. Cleaning of paper artifacts, one of the process commonly carried out during restoration, usually involves the use of solvents (organic or not), that may cause several troubles, like swelling and dissolution of some components, and may also be harmful to the users.

Results: Innovative procedure for cleaning paper artworks is reported in this paper. It is based on the use of rheoreversible, biocompatible hydrogels containing poly(ethylene oxide) or poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) and α-cyclodextrin. We have studied two types of polymer with different hydrophobic properties in order to obtain two different hydrogels with slightly different cleaning capabilities. Our overall strategy has been to develop innovative systems based on these hydrogels so as to better confront the problems that a restorer faces during the cleaning of paper samples. Rheoreversible hydrogels are intriguing materials because their application and removal is not invasive and does not require a liquid treatment that could induce damage to the paper.

Conclusions: These hydrogels have been applied in the cleaning of both new and aged paper samples and their cleaning efficiency has been established. Moreover, by comparison with traditional methods, the greater efficacy of the proposed procedure has been demonstrated.To assess the cleaning efficacy of these hydrogels, a multidisciplinary approach, combining non-invasive spectroscopic infrared techniques together with scanning electron microscopy, chromatographic (HPLC) analysis and pH investigations has been used. Near infrared spectroscopy spectra were coupled with a chemometric analysis to achieve a better interpretation of data.This work constitutes a preliminary step towards focused study in the development of α-cyclodextrin/polymer hydrogel family which will allow cleaning of paper artifacts with peculiar characteristics.

No MeSH data available.


Related in: MedlinePlus

mid-FTIR ATR spectra of soiled paper samples, aged and cleaned. The figure shows in panel A the results obtained for paper samples untreated (red line), treated with PEO hydrogel (black line), or with PLU hydrogel (blue line); and in panel B untreated (red line) and washed with water (green line).
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Figure 9: mid-FTIR ATR spectra of soiled paper samples, aged and cleaned. The figure shows in panel A the results obtained for paper samples untreated (red line), treated with PEO hydrogel (black line), or with PLU hydrogel (blue line); and in panel B untreated (red line) and washed with water (green line).

Mentions: The experiments discussed above (as to the effect of aging of the samples following hydrogel treatment) provide evidences that these cleaning procedures do not promote premature aging of treated papers. However, the majority of paper samples eventually subjected to restoration are already aged. To reproduce these conditions we have artificially aged the filter paper strips impregnated with linseed oil and then used our hydrogels to clean these “aged” samples. The efficiency of hydrogel cleaning under these circumstances was then compared to that of a standard cleaning method, namely washing with water. Analysis by mid-FTIR ATR spectroscopy is able to show the two hydrogels, and particularly PLU, have partially removed the oil, while the water treatment was not able to do so (Figure 9). Indeed, in this respect, the absorbance ratio between two peaks, one at 5747 nm due to oil, and the other at about 10111 nm mainly due to cellulose, seems to be particularly diagnostic. This ratio changes only slightly, going from 1.16 for the untreated sample to 1.12 for paper cleaned with standard method. By contrast, the ratio is lowered to 1.02 for a sample treated with PEO, and falls sharply to 0.32 in the case of the sample cleaned with the PLU hydrogel. These data indicate PLU as a far more efficient agent for oil removal.


Rheoreversible hydrogels in paper restoration processes: a versatile tool.

Mazzuca C, Micheli L, Marini F, Bevilacqua M, Bocchinfuso G, Palleschi G, Palleschi A - Chem Cent J (2014)

mid-FTIR ATR spectra of soiled paper samples, aged and cleaned. The figure shows in panel A the results obtained for paper samples untreated (red line), treated with PEO hydrogel (black line), or with PLU hydrogel (blue line); and in panel B untreated (red line) and washed with water (green line).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3926867&req=5

Figure 9: mid-FTIR ATR spectra of soiled paper samples, aged and cleaned. The figure shows in panel A the results obtained for paper samples untreated (red line), treated with PEO hydrogel (black line), or with PLU hydrogel (blue line); and in panel B untreated (red line) and washed with water (green line).
Mentions: The experiments discussed above (as to the effect of aging of the samples following hydrogel treatment) provide evidences that these cleaning procedures do not promote premature aging of treated papers. However, the majority of paper samples eventually subjected to restoration are already aged. To reproduce these conditions we have artificially aged the filter paper strips impregnated with linseed oil and then used our hydrogels to clean these “aged” samples. The efficiency of hydrogel cleaning under these circumstances was then compared to that of a standard cleaning method, namely washing with water. Analysis by mid-FTIR ATR spectroscopy is able to show the two hydrogels, and particularly PLU, have partially removed the oil, while the water treatment was not able to do so (Figure 9). Indeed, in this respect, the absorbance ratio between two peaks, one at 5747 nm due to oil, and the other at about 10111 nm mainly due to cellulose, seems to be particularly diagnostic. This ratio changes only slightly, going from 1.16 for the untreated sample to 1.12 for paper cleaned with standard method. By contrast, the ratio is lowered to 1.02 for a sample treated with PEO, and falls sharply to 0.32 in the case of the sample cleaned with the PLU hydrogel. These data indicate PLU as a far more efficient agent for oil removal.

Bottom Line: Rheoreversible hydrogels are intriguing materials because their application and removal is not invasive and does not require a liquid treatment that could induce damage to the paper.These hydrogels have been applied in the cleaning of both new and aged paper samples and their cleaning efficiency has been established.Near infrared spectroscopy spectra were coupled with a chemometric analysis to achieve a better interpretation of data.This work constitutes a preliminary step towards focused study in the development of α-cyclodextrin/polymer hydrogel family which will allow cleaning of paper artifacts with peculiar characteristics.

View Article: PubMed Central - HTML - PubMed

Affiliation: Dipartimento di Scienze e Tecnologie Chimiche, Università di Roma "Tor Vergata", Via della Ricerca Scientifica snc, Rome 00133, Italy. antonio.palleschi@uniroma2.it.

ABSTRACT

Background: Paper based artworks are probably ones of the most difficult materials to restore, because of their complexity and fragile structure. Cleaning of paper artifacts, one of the process commonly carried out during restoration, usually involves the use of solvents (organic or not), that may cause several troubles, like swelling and dissolution of some components, and may also be harmful to the users.

Results: Innovative procedure for cleaning paper artworks is reported in this paper. It is based on the use of rheoreversible, biocompatible hydrogels containing poly(ethylene oxide) or poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) and α-cyclodextrin. We have studied two types of polymer with different hydrophobic properties in order to obtain two different hydrogels with slightly different cleaning capabilities. Our overall strategy has been to develop innovative systems based on these hydrogels so as to better confront the problems that a restorer faces during the cleaning of paper samples. Rheoreversible hydrogels are intriguing materials because their application and removal is not invasive and does not require a liquid treatment that could induce damage to the paper.

Conclusions: These hydrogels have been applied in the cleaning of both new and aged paper samples and their cleaning efficiency has been established. Moreover, by comparison with traditional methods, the greater efficacy of the proposed procedure has been demonstrated.To assess the cleaning efficacy of these hydrogels, a multidisciplinary approach, combining non-invasive spectroscopic infrared techniques together with scanning electron microscopy, chromatographic (HPLC) analysis and pH investigations has been used. Near infrared spectroscopy spectra were coupled with a chemometric analysis to achieve a better interpretation of data.This work constitutes a preliminary step towards focused study in the development of α-cyclodextrin/polymer hydrogel family which will allow cleaning of paper artifacts with peculiar characteristics.

No MeSH data available.


Related in: MedlinePlus