An Introduction to Plastics and Rubbers in Collections

Blank, Sharon

doi:10.2307/1506193

Cited by 14 publications

(8 citation statements)

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“…Also, many plastics are not of archival quality, because they contain plasticizers (up to 20-50%), UV inhibitors, dyes, and other additives, which may gasoff or deteriorate over time, or the plastics are coated on the surface (Sturm 2006;Shashoua 2008, p. 58). Several factors accelerate natural deterioration of plastics in the presence of oxygen, viz, UV-light, increased relative humidity above 50%, heat, stress, and pollutants like ozone, sulfur dioxide, and formaldehyde (Blank 1990;Oosten 2002b). Deteriorating plastics can be recognized visually by "cracking, warping, crazing, delamination, liquid surface deposits, solid surface deposit, discoloration and crumbling", olfactory by "a distinctive smell", and tactilly by "a sticky surface" (citations from Oosten 2002b;Shashoua 2008).…”

Section: Traysmentioning

confidence: 99%

“…The problem of deteriorating museum items, especially related to plastics, adhesives, consolidants, and varnishes is not unique to natural history collections (Baker 1995) but happens in museums of fine arts as well (Blackshaw & Ward 1982;Horie 1983Horie , 2011Jackson 1982;Koob 1982;Witte 1983;Blank 1990;Robson 1992;Griffith 1996;Keneghan 1996;Mills & White 1999;Oosten 2002aOosten , 2002bShashoua 2008). Here, the preventive (= passive) approach is to create a storage environment minimizing deterioration processes and to avoid substances that have been proven to become instable over a limited time frame; the interventive (= active) approach is to apply conservation techniques that are reversible if ever possible, and well documented (Horie 1983(Horie , 2011Mills & White 1999;Michalski 2002;Davison 2003;Shashoua 2008).…”

Section: Introductionmentioning

confidence: 99%

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Collection management and study of microscope slides: Storage, profiling, deterioration, restoration procedures, and general recommendations

Neuhaus

Schmid

Riedel

2017

Zootaxa

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A wide range of aspects concerning microscope slides, their preparation, long-time storage, curatorial measures in collections, deterioration, restoration, and study is summarized based on our own data and by analyzing more than 600 references from the 19th century until 2016, 15 patents, and about 100 Materials Safety Data Sheets. Information from systematic zoology, conservation sciences, chemistry, forensic sciences, pathology, paleopathology, applied sciences like food industry, and most recent advances in digital imaging are put together in order to obtain a better understanding of which and possibly why mounting media and coverslip seals deteriorate, how slides can be salvaged, which studies may be necessary to identify a range of ideal mounting media, and how microscope studies can benefit from improvements in developmental biology and related fields. We also elaborate on confusing usage of concepts like that of maceration and of clearing. The chemical ingredients of a range of mounting media and coverslip seals are identified as much as possible from published data, but this information suffers in so far as the composition of a medium is often proprietary of the manufacturer and may vary over time. Advantages, disadvantages, and signs of deterioration are documented extensively for these media both from references and from our own observations. It turns out that many media degrade within a few years, or decades at the latest, except Canada balsam with a documented life-time of 150 years, Euparal with a documented life-time of 50 years, and glycerol-paraffin mounts sealed with Glyceel, which represents almost the only non-deteriorating and easily reversible mount. Deterioration reveals itself as a yellowing in natural resins and as cracking, crystallization, shrinkage on drying or possibly on loss of a plasticizer, detachment of the coverslip, segregation of the ingredients in synthetic polymers, as well as continued maceration of a specimen to a degree that the specimen virtually disappears. Confusingly, decay does not always appear equally within a collection of slides mounted at the same time in the same medium. The reasons for the deteriorative processes have been discussed but are controversial especially for gum-chloral media. Comparing data from conservation sciences, chemical handbooks, and documented ingredients, we discuss here how far chemical and physical deterioration probably are inherent to many media and are caused by the chemical and physical properties of their components and by chemicals dragged along from previous preparation steps like fixation, chemical maceration, and physical clearing. Some recipes even contain a macerating agent, which proceeds with its destructive work. We provide permeability data for oxygen and water vapor of several polymers contained in mounting media and coverslip seals. Calculation of the penetration rate of moisture in one example reveals that water molecules reach a specimen within a few days up to about a month; this lays to rest extensive discussions about the permanent protection of a mounted specimen by a mounting medium and a coverslip seal. Based on the ever growing evidence of the unsuitable composition and application of many, and possibly almost all, mounting media, we strongly encourage changing the perspective on microscope slides from immediate usability and convenience of preparation towards durability and reversibility, concepts taken from conservation sciences. Such a change has already been suggested by Upton (1993) more than 20 years ago for gum-chloral media, but these media are still encouraged nowadays by scientists. Without a new perspective, taxonomic biology will certainly lose a large amount of its specimen basis for its research within the next few decades. Modern non-invasive techniques like Raman spectroscopy may help to identify mounting media and coverslip seals on a given slide as well as to understand ageing of the media. An outlook is given on potential future studies. In order to improve the situation of existing collections of microscope slides, we transfer concepts as per the Smithsonian Collections Standards and Profiling System, developed for insect collections more than 25 years ago, to collections of slides. We describe historical and current properties and usage of glass slides, coverslips, labels, and adhesives under conservational aspects. In addition, we summarize and argue from published and our own experimental information about restorative procedures, including re-hydration of dried-up specimens previously mounted in a fluid medium. Alternatives to microscope slides are considered. We also extract practical suggestions from the literature concerning microscope equipment, cleaning of optical surfaces, health risks of immersion oil, and recent improvements of temporary observation media especially in connection with new developments in digital software.

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Section: Traysmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Collection management and study of microscope slides: Storage, profiling, deterioration, restoration procedures, and general recommendations

Neuhaus

Schmid

Riedel

2017

Zootaxa

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“…policloruro de vinilo, policloruro de vinilideno) y por lo tanto deberían ser evitados (Williams et al 1998). La idoneidad de algunos plásticos para ser usados en conservación ha sido publicada por Blank (1990). En particular, Montero & Diéguez (1991 informaron el reemplazo de las cajas de cartón y el uso de contenedores de polietileno y de poliestireno en las colecciones paleontológicas del Museo Nacional de Ciencias Naturales de Madrid (Figura 1a) y Benamy & Daeschler (1992) señalaron el uso del foam (espuma de polietileno expandido) en las colecciones de paleovertebrados y paleoinvertebrados de la Academy of Natural Sciences of Philadelphia.…”

Section: Contenedoresunclassified

“…La tabla 2 resume las características de los materiales recomendados para la conservación (Blank 1990;Corral 1999;Chapman & Mason 2003;Davidson & Alderson 2009;Davidson & Brown 2012) y utilizados en las colecciones paleontológicas del IANIGLA.…”

Section: Tintasunclassified

Materiales de almacenamiento de las colecciones paleontológicas del IANIGLA-CCT CONICET Mendoza (Argentina)

Devincenzi

Azar

2019

RMLP

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El deterioro al que están expuestas las colecciones paleontológicas es minimizado a menudo hasta por la propia comunidad científica y muchas veces, particularmente en Argentina, es desconocido. El objetivo de este trabajo es reseñar algunos conceptos sobre la conservación preventiva de las colecciones paleontológicas, relacionados con los materiales utilizados (plásticos, adhesivos, papel y tinta), y presentar los avances realizados, en ese sentido, en el almacenamiento de los ejemplares tipo de las colecciones de Paleoinvertebrados, Paleovertebrados y Paleobotánica que se encuentran resguardados en el repositorio del IANIGLA-CCT CONICET Mendoza. Este repositorio almacena actualmente 10 holotipos y 46 paratipos procedentes de sedimentitas paleozoicas y mesozoicas del centro-oeste de Argentina, y un holotipo y un paratipo procedentes de secuencias sedimentarias cámbricas de México. Si bien la falta de financiamiento institucional específico para cualquier colección paleontológica representa un impedimento para neutralizar los daños potenciales que deba afrontar, también lo es la desinformación sobre el comportamiento de los materiales de almacenamiento. Por ello, es importante que, en Argentina, la Ciencia de los Materiales pueda incursionar en el campo de la conservación de este tipo de colecciones de historia natural, tal como sucede desde hace décadas en otros países.

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“…Cleaning is one of the most delicate operations in a restoration procedure as it interacts with the final surface of the artwork, and for PMMA objects it is carried out more frequently to preserve the clarity of the polymer sheet. The application of different abrasives is often used to restore the original transparency 5…”

Section: Introductionmentioning

confidence: 99%

An AFM contribution to the understanding of surface effects caused by ageing and cleaning on acrylic glass. The Shadows by Lourdes Castro, a case study

Sá

Ferreira

Melo

et al. 2011

Surface & Interface Analysis

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Atomic Force Microscopy (AFM) was used to study the ageing and cleaning effects on the surface of acrylic glass sheets (PMMA) like the ones used by the Portuguese artist Lourdes Castro. Measurements were done in transparent (colourless and blue) samples. The samples were aged in a SolarBox; cleaning and polishing products, similar to the ones applied by the artist, were used. From the AFM images the craze/scratch phenomena in the pristine samples surface was confirmed. The experiments led to an increase of the surface roughness, more pronounced for the polished samples due to the presence of granular features. These modifications are due to the interaction of the acrylic sheets with the polishing products, which seems to be stronger in the coloured samples. These findings are useful to define the best strategy to prolong the longevity of such materials, in particular the works of art created by Lourdes Castro.

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An Introduction to Plastics and Rubbers in Collections

Cited by 14 publications

References 0 publications

Collection management and study of microscope slides: Storage, profiling, deterioration, restoration procedures, and general recommendations

Collection management and study of microscope slides: Storage, profiling, deterioration, restoration procedures, and general recommendations

Materiales de almacenamiento de las colecciones paleontológicas del IANIGLA-CCT CONICET Mendoza (Argentina)

An AFM contribution to the understanding of surface effects caused by ageing and cleaning on acrylic glass. The Shadows by Lourdes Castro, a case study

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