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Title:KINETICS OF CELLULOSE DEGRADATION STUDIED USING SIZE EXCLUSION CHROMATOGRAPHY
Authors:Balažic Fabjan, Aneta (Author)
Kolar, Jana (Mentor) More about this mentor... New window
Files:.pdf Aneta_Balazic_Fabjan.pdf (1,33 MB)
 
Language:English
Work type:Master's thesis (m2)
Tipology:2.09 - Master's Thesis
Organization:FAN - Faculty of Applied Sciences
Abstract:For more than five centuries, paper has been the predominant carrier of information and numerous medieval manuscripts bear witness of its durability. However, increasing demand for paper led to several changes in its production in the 19th century. High quality rag fibres were replaced by inferior wood-originating ones. Acid manufacturing technology was introduced which, due to its simplicity and low cost, continued to be used until the end of the 20th century. Inherently stable paper rapidly degrades in the presence of acids and its decay is further promoted by the poor storage conditions and environmental pollutants. As a result, the amount of degraded paper in libraries, archives and museums is reaching enormous proportions. In order to prolong the usable time of the vast quantities of original materials, paper collections may be deacidified and/or stored at lower temperatures. While preservation options are known, lack of the competent comparative studies leaves collection keepers hesitant of their use. The introductory part of the project is focused on development of analytical methodologies and model materials, representative of historical acid paper. As uniqueness and inherent value of cellulose-based cultural heritage limits the use of analytical methodologies to the non-destructive or micro-destructive ones. A new methodology for determination of the condition of paper was developed. The analytical technique-size exclusion chromatography for the first time allows us to reproducible determine the condition of paper which contains a significant amount of wood derived lignin. A few fibres suffice for the analysis, which renders the methodology suitable for characterisation of historical materials. The results of the research will represent the effect of deacidification processes with use of micro destructive analytical methodologies. As written word is all what we have for our legacy from generation to generation, evaluating preservation strategies for decaying collections, safekeeping and long term access to the endangered written cultural heritage is one of the most important facts.
Keywords:paper, size exclusion chromatography, kinetics, deacidification process
Year of publishing:2016
Source:Nova Gorica
COBISS_ID:4488699 Link is opened in a new window
URN:URN:SI:UNG:REP:B7JPCPJG
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Secondary language

Language:Slovenian
Title:DOLOČITEV HITROSTI RAZGRADNJE CELULOZE Z UPORABO VELIKOSTNE IZKLJUČITVENE KROMATOGRAFIJE
Abstract:Obstojnost zapisov je povezana z obstojnostjo materiala, na katerem je informacija zapisana. Papir, ki so ga v Evropi izdelovali od srednjega veka do 19. stoletja, je izjemno obstojen material. Da kisline pospešujejo razgradnjo papirja, so odkrili že v 19. stoletju, ko so opazili, da se je do tedaj izdelan papir, v nasprotju z ročno izdelanimi papirji iz prejšnjih stoletij, pospešeno razgrajeval. Poglavitni razlog za povečano neobstojnost papirjev je bila njihova kislost, ki jo je povzročil postopek klejenja v kislem s smolnim milom in aluminijevem sulfatom. Spremembe v načinu proizvodnje v 19. stoletju pa so izjemno skrajšale njegovo življenjsko dobo. Takšen papir pa ima poleg krajših celuloznih vlaken tudi pH vrednost v kislem območju, kar lahko vodi do popolne razgradnje. V svetovnem merilu se knjižnice in arhivi srečujejo z enakim problemom- kako ohraniti pisno kulturno dediščino, ki zelo hitro propada. Masovno razkislinjenje in hramba gradiva pri nizkih temperaturah, sta znana postopka za upočasnitev kislinske razgradnje papirja. S pojmom razkislinjenje označujemo postopek nevtralizacije kislin, ki so prisotne v papirju. Namen je podaljšati gradivu njegovo obstojnost uporabo. Pregledi stanja fondov, ki so jih izvedli v nekaterih ameriških knjižnicah že v osemdesetih letih, so dali srhljive rezultate: 25-30% knjižnega gradiva je bilo zaradi krhkosti papirja že neuporabnega. Analize so pokazale, da knjige v teh knjižnicah propadejo za okoli 85% v 22 letih. Tekom raziskovalnega dela, ki je potekalo v okviru raziskovalnega projekta 6. Okvirnega programa Evropske komisije PaperTreat, smo odločili za pregled gradiva, ki ga hrani Narodna in univerzitetna knjižnica, s čimer smo hoteli dobiti natančne podatke o tem, koliko gradiva je natisnjenega na t.i. kislem papirju in v kakšnem stanju je papir iz določenega obdobja. Zaradi enkratnosti in neobnovljivosti številnih predmetov kulturne dediščine na papirju smo pri njihovi karakterizaciji pogosto omejeni na neporušne ali mikro-porušne analitske metode. Pregled stanja gradiva smo opravili z vlakninsko analizo, pH in molske mase z uporabo velikostne izključitvene kromatografije in viskozimetrije. Pri raziskovalnem delu smo z študijem hitrosti razgradnje celuloze v papirju, tudi z večjo vsebnostjo lignina, saj predstavlja znaten delež v knjižnih zbirkah 19. in 20. stoletja, določili stabilizacijo postopka razkislinjenja. Tipičen obsega stabilizacije opazimo pri pogojih uporabe (20 ° C) v primerjavi z neobdelanim papirjem. Podatki pridobljeni tekom dela nam omogočajo oblikovanje najprimernejše strategije varovanja gradiva.
Keywords:papir, velikostna izključitvena kromatografija, razkislinjenje, hitrost razgradnje


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