CNE GEL FOR GREEN EAR SYNDROME? A STUDY ON...
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A CNE G EL FOR G REEN E AR S YNDROME ? A STUDY ON COPPER CORROSION STAIN REMOVAL FROM POLY ( VINYL CHLORIDE ) Dawn Wallace, Aaron Shugar, and Jonathan Thornton SUNY – Buffalo State, Art Conservation Department Further analysis will be done using a scanning electron microscopy (SEM) and mapping the elemental copper and its migration within the samples. Artificial aging will help predict the long-term effects on the PVC samples, such as crazing of the surface, cross-linking and yellowing. Gas Chromotography-Mass Spectroscopy (GC-MS) be employed on the swabs saved from Day 1 and Day 4 to determine whether plasticizers were leached from the PVC during treatment. ACKNOWLEDGEMENTS–The authors would like to thank J.J. Chen for her help with imaging, the Andrew W. Mellon Foundation, National Endowment for the Humanities, and Buffalo State College Tuition Grant for educational funding. Comparison of spectra for before and after samples. On left, B1 before (red) and after (green). Middle, D1 before (red) and after (green). On right, D1 swab and salicylic acid control. Depth of Cu in PVC Before m After m Change m B1 (SA) 13.7 87.0 73.3 B2 (SA) 13.1 101.6 88.5 B3 (BP) 14.4 53.4 38.9 B4 (BP) 7.3 76.2 69.0 D1 (SA) 3.1 154.9 151.8 D2 (SA) 0.3 137.1 136.8 D3 (BP) 3.5 85.5 82.0 D4 (BP) 0 75.9 75.9 The Barbie™ head on the right has extreme “green ear syndrome” from wearing metal earrings. Below, UVC induced illumination displays the area and penetration of the stain Dawn™ dolls with green staining at the knees. The dolls have articulated legs with copper alloy metal joints, seen below in x-radiograph. Sample Method %Weight Change B1 Stained, Salicylic acid, sun +0.76 B2 Stained, Salicylic acid +0.65 B3 Stained, Benzyl Peroxide, sun -1.21 B4 Stained, Benzyl Peroxide -1.21 D1 Stained, Salicylic acid, sun +0.49 D2 Stained, Salicylic acid +0.77 D3 Stained, Benzyl Peroxide, sun -1.67 D4 Stained, Benzyl Peroxide -1.47 Table 1: Sample identification, method of treatment and % weight changes before and after test are presented. The salicylic acid had some gain, possibly due to residue left on the surface. The benzoyl peroxide showed an overall decrease in weight indicating loss of material (B = Barbie, D = Dawn). B1, salicylic acid, before and after B4, benzyl peroxide, before and after D4, benzyl peroxide before and after D2 and D3, UVC induced fluorescence, before and after Salicylic acid treated samples displayed nominal visible difference in normal illumination (top left). The benzoyl peroxide samples had diminished stains, but also loss in material color, a result noted in public use and common from bleaching agents (top and bottom right). Sample D4 demonstrates a change in stain color. In UVA-induced illumination the samples had minor fluorescence, while in UVC, the salicylic acid treatment had significant fluorescence, most likely due to dyes present in the acne gel (bottom left). The removal of copper corrosion stains within plasticized poly(vinyl chloride) is of concern to both conservators and collectors of popular vinyl dolls such as Barbie™ and Dawn™. Where the conservation field is hesitant to perform intervention treatments on plastics, public collectors are actively trying treatment methods that employ acne topical gels. Two gels, one with salicylic acid and the other with benzoyl peroxide, were tested according to these amateur methods to determine their ability to remove corrosion stains. The results were observed using normal and fluorescence induced illumination, and X-ray fluorescence spectroscopy (XRF). Four stained samples were taken from both Barbie™ and Dawn™ dolls along with an additional fifth control sample. Each sample was weighed before and after treatment. Two of each were tested with Neutrogena containing 2% salicylic acid and the other two Clearasil with 10% benzyl peroxide. In addition, one of the pair was placed in sunlight with the gel, per suggested public methods. The gel was applied to half the sample, set over night and then rinsed with de-ionized water. This progressed over 20 days, after which all samples were soaked in de- ionized water for 24 hours. The spectra obtained after treatment for both the Barbie and Dawn samples (left) display diminished Cu and Zn peaks, and the Dawn samples also have a reduction in Ca. The swab retained from the D1 sample Day 1 treatment was analyzed and found to contain Cu and Zn. To exclude contaminants, comparison spectra were obtained from a cotton swab, swab with salicylic acid, and swab with benzoyl peroxide and found to not contain Cu or Zn. To determine the depth of extracted copper, attenuation calculations were made for copper photons travelling through PVC. Since the copper is not evenly dispersed throughout the PVC, a theoretical starting point using spectra with the best α/β ratio of K lines was used (D4) and the rest normalized accordingly. The data was collected from area-under-peak for the copper K-lines, and the calculations determined in microns. The change in m represents the increased distance copper traveled and thus removal from the PVC. The salicylic tests show the greatest extraction of copper, and thus stain. To download our poster scan here:
Transcript of CNE GEL FOR GREEN EAR SYNDROME? A STUDY ON...
ACNE GEL FOR GREEN EAR SYNDROME? A STUDY ON COPPER
CORROSION STAIN REMOVAL FROM POLY (VINYL CHLORIDE)
Dawn Wallace, Aaron Shugar, and Jonathan ThorntonSUNY – Buffalo State, Art Conservation Department
Further analysis will be done using a scanning electron microscopy (SEM) and mapping the elementalcopper and its migration within the samples. Artificial aging will help predict the long-term effects on thePVC samples, such as crazing of the surface, cross-linking and yellowing. Gas Chromotography-MassSpectroscopy (GC-MS) be employed on the swabs saved from Day 1 and Day 4 to determine whetherplasticizers were leached from the PVC during treatment.
ACKNOWLEDGEMENTS–The authors would like to thank J.J. Chen for her help with imaging, the Andrew W. Mellon Foundation, National Endowment for the Humanities, and Buffalo State College Tuition Grant for educational funding.
Comparison of spectra for before and after samples. On left, B1 before (red) and after (green). Middle, D1 before (red) and after (green). On right, D1 swab and salicylic acid control.
Depth of Cu in PVC
Before m After m Change m
B1 (SA) 13.7 87.0 73.3
B2 (SA) 13.1 101.6 88.5
B3 (BP) 14.4 53.4 38.9
B4 (BP) 7.3 76.2 69.0
D1 (SA) 3.1 154.9 151.8
D2 (SA) 0.3 137.1 136.8
D3 (BP) 3.5 85.5 82.0
D4 (BP) 0 75.9 75.9
The Barbie™ head on the right has extreme “green ear syndrome” from wearing metal earrings. Below, UVC induced illumination displays the
area and penetration of the stain
Dawn™ dolls with green staining at the knees. The dolls have articulated legs with copper alloy metal joints, seen below in x-radiograph.
Sample Method %Weight Change B1 Stained, Salicylic acid, sun +0.76B2 Stained, Salicylic acid +0.65B3 Stained, Benzyl Peroxide, sun -1.21B4 Stained, Benzyl Peroxide -1.21D1 Stained, Salicylic acid, sun +0.49D2 Stained, Salicylic acid +0.77D3 Stained, Benzyl Peroxide, sun -1.67D4 Stained, Benzyl Peroxide -1.47
Table 1: Sample identification, method oftreatment and % weight changes before andafter test are presented. The salicylic acid hadsome gain, possibly due to residue left on thesurface. The benzoyl peroxide showed anoverall decrease in weight indicating loss ofmaterial (B = Barbie, D = Dawn).
B1, salicylic acid, before and after
B4, benzyl peroxide, before and after
D4, benzyl peroxide before and after
D2 and D3, UVC induced fluorescence, before and after
Salicylic acid treated samplesdisplayed nominal visible differencein normal illumination (top left). Thebenzoyl peroxide samples haddiminished stains, but also loss inmaterial color, a result noted inpublic use and common frombleaching agents (top and bottomright). Sample D4 demonstrates achange in stain color. In UVA-inducedillumination the samples had minorfluorescence, while in UVC, thesalicylic acid treatment hadsignificant fluorescence, most likelydue to dyes present in the acne gel(bottom left).
The removal of copper corrosion stains withinplasticized poly(vinyl chloride) is of concern to bothconservators and collectors of popular vinyl dollssuch as Barbie™ and Dawn™. Where theconservation field is hesitant to perform interventiontreatments on plastics, public collectors are activelytrying treatment methods that employ acne topicalgels. Two gels, one with salicylic acid and the otherwith benzoyl peroxide, were tested according tothese amateur methods to determine their ability toremove corrosion stains. The results were observedusing normal and fluorescence induced illumination,and X-ray fluorescence spectroscopy (XRF).
Four stained samples were taken from both Barbie™and Dawn™ dolls along with an additional fifthcontrol sample. Each sample was weighed beforeand after treatment. Two of each were tested withNeutrogena containing 2% salicylic acid and theother two Clearasil with 10% benzyl peroxide. Inaddition, one of the pair was placed in sunlight withthe gel, per suggested public methods. The gel wasapplied to half the sample, set over night and thenrinsed with de-ionized water. This progressed over20 days, after which all samples were soaked in de-ionized water for 24 hours.
The spectra obtained after treatment for both the Barbie and Dawn samples (left) displaydiminished Cu and Zn peaks, and the Dawn samples also have a reduction in Ca. The swabretained from the D1 sample Day 1 treatment was analyzed and found to contain Cu and Zn. Toexclude contaminants, comparison spectra were obtained from a cotton swab, swab withsalicylic acid, and swab with benzoyl peroxide and found to not contain Cu or Zn.
To determine the depth of extracted copper, attenuationcalculations were made for copper photons travellingthrough PVC. Since the copper is not evenly dispersedthroughout the PVC, a theoretical starting point usingspectra with the best α/β ratio of K lines was used (D4) andthe rest normalized accordingly. The data was collected fromarea-under-peak for the copper K-lines, and the calculationsdetermined in microns. The change in m represents theincreased distance copper traveled and thus removal fromthe PVC. The salicylic tests show the greatest extraction ofcopper, and thus stain.
To download our poster scan here:
