| 1. |
- Chiavari, C, et al.
(författare)
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Atmospheric corrosion of historical organ pipes: The influence of environment and materials
- 2008
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Ingår i: Corrosion Science. - : Elsevier BV. - 0010-938X. ; 50:9, s. 2444-2455
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Tidskriftsartikel (refereegranskat)abstract
- The corrosion of lead-rich pipes in historical organs in different parts of Europe has been investigated. The influence of the environment and the composition and microstructure of the pipe metal was studied. Pipe Corrosion was documented by visual inspection (boroscope). The corrosion attack and the composition and microstructure of the metal were characterized by OM, SEM, XRD, IC and FAAS. It is shown that the degree of corrosion of the pipes is correlated to the concentration of gaseous acetic and formic acid in the organ. The organic acids are emitted by the wood from which the wind system is built. It is also shown that pipe corrosion decreases with increasing tin content in the range 0-4% (wt). Possible conservation strategies are discussed. (c) 2008 Elsevier Ltd. All rights reserved.
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| 2. |
- Giorgi, R., et al.
(författare)
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Nanoparticles of calcium hydroxide for wood deacidification: Decreasing the emissions of organic acid vapors in church organ environments
- 2009
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Ingår i: Journal of Cultural Heritage. - : Elsevier BV. - 1296-2074 .- 1778-3674. ; 10:2, s. 206-213
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Tidskriftsartikel (refereegranskat)abstract
- Acetic and formic acid vapors emitted from woodwork in historical organs are very important corrosive agents for lead pipes. These acids are slowly released from the wood both during playing and when the pipes are silent. To inhibit this emission process. the wood surface can be modified, by creating a protective layer with alkaline features. However, a coating of wood is not recommended since this could modify the appearance and create a layer not perfectly compatible with the substrate. For this reason, we propose to use some innovative nanotechnology that has been successfully applied for the deacidification of wood samples coming from the Vasa shipwreck. Application of calcium (or magnesium) hydroxide nanoparticles, with sizes ranging from 30-150 nm, allowed a homogeneous distribution of particles through the surface layer of wood simply by soaking (or spraying) it in a alcohohc (or mixed with less polar solvents) dispersion of nanoparticies. Nanoparticles do not modify the wood appearance and distribute randomly within the first layers of wood. The small size of particles accounts for the high reactivity with CO2 from the air, to give the alkaline reserve of carbonates that provide high efficacy in the neutralization of gaseous acids. The emission of volatile organic compounds (VOC) from the treated wood was determined by using an emission test cell, Field and Laboratory Emission Cell (FLEC). The results show that the emissions of acetic acid vapor from nanoparticles treated wood was very low (
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| 3. |
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| 4. |
- Niklasson, Annika, 1977, et al.
(författare)
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Air Pollutant Concentrations and Atmospheric Corrosion of Organ Pipes in European Church Environments
- 2008
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Ingår i: Studies in Conservation. - 0039-3630 .- 2047-0584. ; 53:1, s. 24-40
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Tidskriftsartikel (refereegranskat)abstract
- Abstract: The atmospheric environment inside and outside historical organs in several European regions is reported. In each region, comparisons were made between an instrument suffering organ pipe corrosion and an organ without corrosion problems. Concentrations of acetic acid (ethanoic acid), formic acid (methanoic acid), acetaldehyde (ethanal), formaldehyde (methanal) and other volatile organic compounds in the organ environment were determined using active sampling. Temperature and relative humidity were recorded. In addition, polished metal samples that mimic the material used in the historical organ pipes have been exposed in the organ wind systems for up to 22 months. High concentrations of acetic acid and formic acid vapours are present in the wind system of the corroded organs. Acetaldehyde and formaldehyde are also present in smaller amounts. The main source of acetic acid is the wood from which the wind system is built. In contrast, formic acid is generated in the chruch environment outside the wind system. The results show that the two organic acids play an important role in the atmospheric corrosion of organ pipes. It is suggested that the corrosion of lead pipes in historical organs can be effectively reduced by removing the sources of gaseous acetic acid and formic acid in the wind system and in the chruch environment.
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| 5. |
- Niklasson, Annika, 1977
(författare)
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Atmospheric Corrosion of Historic Lead Organ Pipes
- 2007
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The atmospheric corrosion of lead is investigated, with the aim to improve the understanding of the environmental degradation of historical organ pipes. Fieldwork is combined with laboratory investigations. The field studies included characterization of the organ environment and exposures of lead coupons. The environment inside the organ wind system of instruments suffering corrosion was mapped and compared with instruments unaffected by corrosion, in five countries in Europe. In the heavily corroded organs, relatively high concentrations of acetic and formic acid vapours were present, and large amounts of carboxylates accumulated on the lead coupons. The organic acids are emitted from woodwork in the organs.The effect of acetic and formic acid vapours in the ppb range of the atmospheric corrosion of pure lead was investigated under well controlled conditions in the laboratory. The combined effect of acetic and formic acid vapours was also examined. The influences of temperature, relative humidity, inorganic air pollutants (NO2 and SO2) and particulates (NaCl) were studied as well. Corrosion rate was measured gravimetrically and the corrosion products were analysed by XRD, ESEM, FIB, ion chromatography and quantitative carbonate analysis. The mechanism of corrosion attack is addressed.Traces of acetic acid vapour strongly accelerate lead corrosion. Mass gain is linear with time and depends linearly on the acetic acid concentration. Corrosion showed a relatively weak dependence on relative humidity in the range 50 - 95%. Lead corrosion was inversely related to temperature; mass gain was 50% higher at 4.0 ºC than at 22.0 ºC. The corrosion rate increased with decreasing temperature in the range 22.0 - 4.0 ºC. It is proposed that lead suffers electrochemical corrosion in the presence of traces of acetic acid vapour. The corrosion products were unevenly distributed. Lead acetate oxide hydrate (Pb(CH3COO)2∙2PbO∙H2O), plumbonacrite (Pb10O(OH)6(CO3)6), litharge (a-PbO) and massicot (b-PbO) were identified by X-ray diffraction.Formic acid vapour is also corrosive towards lead, although somewhat less so than acetic acid. In this instance the corrosion products, consisting of plumbonacrite and lead formate hydroxide (Pb(HCOO)(OH)), are evenly distributed. The combination of acetic and formic acid has a slightly synergistic effect on lead corrosion, which resulted in a more localized attack than for the acetic and formic acid exposures.The results show that acetic and formic acid vapours emitted from woodwork in the organs are decisive in the corrosion of historical organs. Methods for mitigating organ corrosion are discussed. The work in this thesis is a basis for formulating conservation strategies for historical organs.
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| 6. |
- Niklasson, Annika, 1977, et al.
(författare)
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Atmospheric corrosion of lead - The influence of formic acid and acetic acid vapors
- 2007
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Ingår i: Journal of the Electrochemical Society. - 1945-7111 .- 0013-4651. ; , s. 618-625
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Tidskriftsartikel (refereegranskat)abstract
- The present laboratory study investigates the influence of low concentrations of formic acid vapor and the combination of acetic and formic acid vapors on the atmospheric corrosion of lead. The samples were exposed to synthetic air with careful control of relative humidity (95%), temperature (22.00 degrees C), flow conditions and the concentration of formic acid (160 ppb), acetic acid (170 ppb) and CO2 (350 ppm). Exposure time was one, two and four weeks. Corrosion products were analyzed by gravimetry, ion chromatography, quantitative carbonate analysis, X-ray diffraction and environmental scanning electron microscopy. Cross sections of the corroded surface were prepared by focused ion beam milling. Formic acid vapor is very corrosive toward lead, although somewhat less so than acetic acid. The corrosion products, consisting of plumbonacrite (Pb10O(OH)(6)(CO3)(6)) and lead formate hydroxide [Pb(HCOO)(OH)], are evenly distributed. The combination of acetic and formic acid has a synergistic effect on lead corrosion. The corrosion products found were plumbonacrite and massicot (beta-PbO) together with an unidentified phase. Corrosion attack in the mixed pollutant exposure is more localized compared to the acetic and formic acid exposures, clearly indicating the electrochemical nature of corrosion.
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| 7. |
- Niklasson, Annika, 1977
(författare)
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Atmospheric Corrosion of Lead. The Influence of Organic acid Vapours and Inorganic Air Pollutants. A contribution Towards Understanding the Environmental Degradation of Historic Organ Pipes
- 2005
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis presents different perspectives on the atmospheric corrosion of lead, aiming at a better understanding of the environmental degradation of historical organ pipes. Corroded organ pipes from the field have been analyzed and the environment inside the organ wind system has been mapped. Comparably high concentrations of organic acid vapours are present in heavily corroded organs. In addition, acetaldehyde and formaldehyde are present in smaller amounts. To verify the connection between environmental parameters and corrosion effects, the field work is combined with laboratory investigations. The effect of sub-ppm concentrations of acetic and formic acid vapours on lead corrosion was investigated. The effect of NO2 and SO2 was also studied. The samples were exposed to synthetic air with careful control of relative humidity, temperature, concentration of air pollutants and flow conditions. Exposure times were between one and four weeks. Corrosion rate was measured gravimetrically and the corrosion products were analysed by X-ray diffraction, environmental scanning electron microscopy, ion chromatography and quantitative carbonate analysis. The atmospheric corrosion of lead is strongly accelerated by traces of acetic acid vapour. Mass gain is linear with time and depends linearly on the acetic acid concentration. It is suggested that the corrosion of lead in the presence of traces of acetic acid vapour is electrochemical in nature. The corrosion products detected by X-ray diffraction were plumbonacrite, Pb10O(OH)6(CO3)6, lead acetate oxide hydrate, Pb(CH3COO)2∙2PbO∙H2O, and lead oxide, PbO. Formic acid is slightly less corrosive than acetic acid. In this case, the main corrosion product were lead formate hydroxide, Pb(HCOO)(OH) and plumbonacrite.In comparison to the organic acids, NO2 and SO2 are far less corrosive towards lead. This implies that emissions of NO2 and SO2 from traffic and combustion of fossil fuels are of minor importance for the atmospheric corrosion of lead. The results imply that acetic and formic acid vapours emitted from woodwork in the organs are very important corrosive agents for lead pipes in historical organs. Keywords: Atmospheric corrosion, lead, organ pipe, acetic acid, formic acid, lead acetate, lead formate, NaCl
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| 8. |
- Niklasson, Annika, 1977, et al.
(författare)
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Influence of acetic acid vapor on the atmospheric corrosion of lead
- 2005
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Ingår i: Journal of the Electrochemical Society. - : The Electrochemical Society. - 1945-7111 .- 0013-4651. ; 152:12, s. B519-B525
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Tidskriftsartikel (refereegranskat)abstract
- The present study investigates the influence of low concentrations of acetic acid vapor on the atmospheric corrosion of lead. The samples were exposed to synthetic air with careful control of relative humidity (95%), temperature (22.00 degrees C), acetic acid concentration (170-1100 ppb), CO2 concentration (350 ppm), and flow conditions. The exposure times were between 1 and 4 weeks. Mass gain results are reported. The corrosion products were analyzed by ion chromatography, quantitative carbonate analysis, and X-ray diffraction. The surface morphology of the exposed samples was investigated with environmental scanning electron microscope. The results show that low concentrations of acetic acid vapor are very corrosive toward lead. The mass gain is linear with time and depends linearly on the acetic acid concentration. It is suggested that the corrosion of lead in the presence of traces of acetic acid vapor is electrochemical in nature. The corrosion products found were plumbonacrite, Pb10O(OH)(6)(CO3)(6), lead acetate oxide hydrate (Pb(CH3COO)(2)center dot 2PbO center dot H2O), and lead oxide, PbO. (c) 2005 The Electrochemical Society.
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| 9. |
- Oertel, CM, et al.
(författare)
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Acetic Acid Vapor Corrosion of Lead-Tin Alloys Containing 3.4 and 15% Tin
- 2009
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Ingår i: Journal of the Electrochemical Society. - : The Electrochemical Society. - 1945-7111 .- 0013-4651. ; 156:12, s. C414-C421
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Tidskriftsartikel (refereegranskat)abstract
- Lead-tin alloy pipes in historic organs frequently suffer from damaging atmospheric corrosion. Organic acids emitted from the wood of organ cases had been established previously as the cause of deterioration in pure lead pipes. In the present study, lead-tin alloy samples containing 3.4 and 15 atom % tin were subjected to laboratory exposure experiments under atmospheres of 1100 ppb acetic acid, 350 ppm CO2, and 60 or 95% relative humidity (RH). Wet and dry corrosion mass gains were monitored, and corrosion product compositions and morphologies were characterized by grazing incidence angle X-ray diffraction and scanning electron microscopy. Cross sections were cut through corrosion sites using a focused ion beam milling method, and elemental information was obtained using wavelength dispersive and energy dispersive X-ray analyses. The corrosion products and morphologies observed in the alloys are the same as those reported for pure lead, but the corrosion susceptibilities of the alloys show a much stronger dependence on RH. The presence of 3.4 or 15 atom % Sn provides corrosion protection at moderate humidity, but this protective effect breaks down at high humidity. These findings highlight the importance of humidity control as well as pipe material selection in the conservation of historic and newly constructed organs.
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| 10. |
- Oertel, CM, et al.
(författare)
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Focused ion beam and electron microscopy analysis of corrosion of lead-tin alloys: Applications to conservation of organ pipes
- 2008
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Ingår i: Materials Research Society Symposium Proceedings. - 0272-9172. - 9781558999886 ; 1047, s. 115-125
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Tidskriftsartikel (refereegranskat)abstract
- Across Europe, lead-tin alloy organ pipes are suffering from atmospheric corrosion. This deterioration can eventually lead to cracks and holes, preventing the pipes from producing sound. Organ pipes are found in compositions ranging from >99% Pb to >99% Sn. For very lead-rich (>99% Pb) pipes, organic acids emitted from the wood of organ cases have previously been identified as significant corrosive agents. In order to study the role of alloy composition in the susceptibility of pipes to organic acid attack, lead-tin alloys containing 1.2-15 at.% Sn were exposed to acetic acid vapors in laboratory exposure studies. Corrosion rates were monitored gravimetrically, and corrosion product phases were identified using grazing incidence angle X-ray diffraction. In a new method, focused-ion beam (FIB) cross sections were cut through corrosion sites, and SEM and WDX were used to obtain detailed information about the morphology and chemical composition of the corrosion layers. The combination of FIB and SEM has made it possible to obtain depth information about these micron-scale layers, providing insight into the influence of acetic acid on alloys in the 1.2-15 at.% Sn range.
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