RADIJACIJSKA OBRADA STARENIH MODELNIH UZORAKA … · vlakna. Cellulose is known to be prone to...
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RADIJACIJSKA OBRADA STARENIH MODELNIH UZORAKA TEKSTILA RADIJACIJSKA OBRADA STARENIH MODELNIH UZORAKA TEKSTILA RADIATION TREATMENT OF ARTIFICIALLY AGED MODEL TEXTILES RADIATION TREATMENT OF ARTIFICIALLY AGED MODEL TEXTILES I. Pucić I. Pucić 1 1 , K. Kavkler , K. Kavkler 2 2 , B. Mihaljević , B. Mihaljević 1 1 1 Ruđer Bošković Institut Ruđer Bošković Institut , Zagreb, , Zagreb, Croatia Croatia 2 Institute for the Protection of Cultural Heritage of Slovenia, Restoration Centre, Poljanska 40, 1000 Ljubljana, Slovenia Institute for the Protection of Cultural Heritage of Slovenia, Restoration Centre, Poljanska 40, 1000 Ljubljana, Slovenia e-mail: e-mail: [email protected] [email protected] , , [email protected] [email protected] , [email protected] , [email protected] PROTEIN-BASED TEXTILE / TEKSTIL PROTEINSKE OSNOVE PROTEIN-BASED TEXTILE / TEKSTIL PROTEINSKE OSNOVE CONCLUSIONS: CONCLUSIONS: the changes in even the most senstitive materials were slight although the applied the changes in even the most senstitive materials were slight although the applied dose was relativlely high; dose was relativlely high; cellulose - based textiles (linen and cotton) are more sensitive to irradiation than cellulose - based textiles (linen and cotton) are more sensitive to irradiation than protein-based ones (silk, wool); protein-based ones (silk, wool); irradaition of CH textiles to doses needed for fungi control should be safe. irradaition of CH textiles to doses needed for fungi control should be safe. CELLULOSE-BASED TEXTILE / TEKSTIL CELULOZNE OSNOVE CELLULOSE-BASED TEXTILE / TEKSTIL CELULOZNE OSNOVE SEM mikrografije uzoraka lana: nestaren i neozračen (lijevo), staren i neozračen (sredina lijevo), nestaren i ozračen s 120 SEM mikrografije uzoraka lana: nestaren i neozračen (lijevo), staren i neozračen (sredina lijevo), nestaren i ozračen s 120 kGy (sredina desno) te staren i ozračen s 120 kGy (desno). Na ozračenim uzorcima vidljiva su oštećenja kutikule a i oštećena kGy (sredina desno) te staren i ozračen s 120 kGy (desno). Na ozračenim uzorcima vidljiva su oštećenja kutikule a i oštećena vlakna. vlakna. Cellulose is known to be prone to radiation degradation so the changes in thermal properties of irradiated linen and cotton. Cellulose is known to be prone to radiation degradation so the changes in thermal properties of irradiated linen and cotton. Although 120 kGy is relatively high dose temperature of maximum rate of mass decrease in TGA is only slightly lower than in Although 120 kGy is relatively high dose temperature of maximum rate of mass decrease in TGA is only slightly lower than in unirradiated sample. In DSC thermograms (not shown) of both aged and irradiated samples of cotton and linen a high unirradiated sample. In DSC thermograms (not shown) of both aged and irradiated samples of cotton and linen a high temperature peak appears that is not present in unirradiated fresh sample. In aged linen samples that peak shifts to lower temperature peak appears that is not present in unirradiated fresh sample. In aged linen samples that peak shifts to lower temperature and its heat significantly increases. On the other hand damage to fiber strucuture, primarily to cuticule, and temperature and its heat significantly increases. On the other hand damage to fiber strucuture, primarily to cuticule, and even some destruciton of complete fiber is obvious in SEM micrographs. Since about 20 times lower dose is needed for even some destruciton of complete fiber is obvious in SEM micrographs. Since about 20 times lower dose is needed for fungi control it can safely be proposed that the change to textile would not be greater than that caused by ageing itself. fungi control it can safely be proposed that the change to textile would not be greater than that caused by ageing itself. SEM micrograps of linen samples: unaged and unirradiated (left), aged and unirradiated (center left), unaged and irradiated SEM micrograps of linen samples: unaged and unirradiated (left), aged and unirradiated (center left), unaged and irradiated 120 kGy (center right) and aged and irradiated 120 kGy (right). Damaged cuticule and some destroyed fibers are visible in 120 kGy (center right) and aged and irradiated 120 kGy (right). Damaged cuticule and some destroyed fibers are visible in irradiated samples. irradiated samples. Poznato je da celuloza degradira pod djelovanjem zračenja pa su promjene toplinskih svojstava i stabilnosti lanenog platna i Poznato je da celuloza degradira pod djelovanjem zračenja pa su promjene toplinskih svojstava i stabilnosti lanenog platna i pamuka bile očekivane. Unatoč relativno visokoj dozi od 120 kGy temperatura maksimuma gubitka mase u TGA je samo malo pamuka bile očekivane. Unatoč relativno visokoj dozi od 120 kGy temperatura maksimuma gubitka mase u TGA je samo malo niža nego kod neozračenog uzorka. U DSC termogramima (nisu prikazani) zračenih kao i starenih uzoraka pamuka i lanenog niža nego kod neozračenog uzorka. U DSC termogramima (nisu prikazani) zračenih kao i starenih uzoraka pamuka i lanenog platna pojavljuje se visokotemperaturni maksimum kojeg nema u neozračenom nestarenom uzorku. Kod starenih uzoraka platna pojavljuje se visokotemperaturni maksimum kojeg nema u neozračenom nestarenom uzorku. Kod starenih uzoraka lanenog platna taj maksimum pomiče se prema nižoj temperaturi a toplina mu raste. SEM mikrografije pokazuju oštećenja lanenog platna taj maksimum pomiče se prema nižoj temperaturi a toplina mu raste. SEM mikrografije pokazuju oštećenja strukture vlakna u ozračenim uzorcima, najviše kutikule ali i mjestimično pucanje cijelih vlakana. Slične promjene iako strukture vlakna u ozračenim uzorcima, najviše kutikule ali i mjestimično pucanje cijelih vlakana. Slične promjene iako manje izražene vidljive su i u neozračenom starenom uzorku pa se kod skoro 20 puta manje doze potrebne za kontrolu manje izražene vidljive su i u neozračenom starenom uzorku pa se kod skoro 20 puta manje doze potrebne za kontrolu gljivica mogu očekivati promjene manje onih koje uzrokuje samo starenje. gljivica mogu očekivati promjene manje onih koje uzrokuje samo starenje. ZAKLJUČCI: ZAKLJUČCI: promjene u materijaliam uzoraka bile su neznatne iako je primjenjena doza bila promjene u materijaliam uzoraka bile su neznatne iako je primjenjena doza bila relativno visoka; relativno visoka; tekstili s celuloznom osnovom (lan i pamuk) osjetljiviji su prema zračenju u odnosu tekstili s celuloznom osnovom (lan i pamuk) osjetljiviji su prema zračenju u odnosu na one s proteinskom osnovom (svila, vuna); na one s proteinskom osnovom (svila, vuna); ozračivanje baštinskog tekstila dozama potrebnim za kontrolu gljivica može se ozračivanje baštinskog tekstila dozama potrebnim za kontrolu gljivica može se smatrati sigurnim. smatrati sigurnim. Zračenje do 120 kGy nema utjecaja na toplinsku stabilnost svile a naročito vune. To je pomalo neočekivano jer su proteini Zračenje do 120 kGy nema utjecaja na toplinsku stabilnost svile a naročito vune. To je pomalo neočekivano jer su proteini njihove osnove, sericin i fibroin kod svile te keratin kod vune, osjetljivi prema zračenju iako manje od celuloze. Iako njihove osnove, sericin i fibroin kod svile te keratin kod vune, osjetljivi prema zračenju iako manje od celuloze. Iako temperature i topline određene DSC-om pokazuju da zračenje utječe na transformacije u svili i vuni to ne mora nužno temperature i topline određene DSC-om pokazuju da zračenje utječe na transformacije u svili i vuni to ne mora nužno rezultirati oštećenjima jer kompleksna struktura animalnih vlakana očito pruža znatnu zaštitu proteinskoj komponenti. Na rezultirati oštećenjima jer kompleksna struktura animalnih vlakana očito pruža znatnu zaštitu proteinskoj komponenti. Na SEM mikrografijama ozračene vune uočavaju se samo manja oštećenja. Zanimljivo je da UV-stareni uzorak vune nema SEM mikrografijama ozračene vune uočavaju se samo manja oštećenja. Zanimljivo je da UV-stareni uzorak vune nema oštećenja unatoč visokoj dozi. oštećenja unatoč visokoj dozi. SEM mikrografije uzoraka vune: nestarena i neozračena (lijevo), starena i neozračena (sredina lijevo), nestarena i ozračena s SEM mikrografije uzoraka vune: nestarena i neozračena (lijevo), starena i neozračena (sredina lijevo), nestarena i ozračena s 120 kGy (sredina), starena i ozračena s 120 kGy (sredina desno) te UV-starena i ozračena s 120 kGy (desno). Na ozračenim 120 kGy (sredina), starena i ozračena s 120 kGy (sredina desno) te UV-starena i ozračena s 120 kGy (desno). Na ozračenim uzorcima vidljiva su manja oštećenja kutikule osim kod uzorka koji je bio UV-staren. uzorcima vidljiva su manja oštećenja kutikule osim kod uzorka koji je bio UV-staren. SEM micrograps of wool samples: unaged and unirradiated (left), aged and unirradiated (center left), unaged and irradiated SEM micrograps of wool samples: unaged and unirradiated (left), aged and unirradiated (center left), unaged and irradiated 120 kGy (center), aged and irradiated 120 kGy (center right), UV-aged and irradiated 120 kGy (center right). Slight damage of 120 kGy (center), aged and irradiated 120 kGy (center right), UV-aged and irradiated 120 kGy (center right). Slight damage of cuticule is visible in irradiated samples except the UV-aged one. cuticule is visible in irradiated samples except the UV-aged one. Thermal stability of silk and especially wool seems to be unaffected by irradiation to 120 kGy. This is somewhat unexpected Thermal stability of silk and especially wool seems to be unaffected by irradiation to 120 kGy. This is somewhat unexpected because the corresponding proteins – sericin and fibroin in silk and keratin in wool - are by themselves sensitive to because the corresponding proteins – sericin and fibroin in silk and keratin in wool - are by themselves sensitive to irradiation although less than cellulose. Temperatures and heats determined by DSC indicate that transformation of silk and irradiation although less than cellulose. Temperatures and heats determined by DSC indicate that transformation of silk and wool are slightly influenced by irradiation. Those changes are not neccesary related to degradation because complex wool are slightly influenced by irradiation. Those changes are not neccesary related to degradation because complex structure of animal fibers obviously offers significant protection to protein component. SEM micrographs of wool show only structure of animal fibers obviously offers significant protection to protein component. SEM micrographs of wool show only slight damage. It is interesting that UV-aged wool sample shows no damage despite high dose. slight damage. It is interesting that UV-aged wool sample shows no damage despite high dose. 1 Gy 1 mGy 1 kGy 1 MGy BIOLOGIC EFFECTS BIOLOGIC EFFECTS EFFECTS UPON MATERIALS EFFECTS UPON MATERIALS 25 kGy - sterility dezinsection lethal dose for humans color change radiolysis polimerysation degradation 3 mSv 3 mSv annually - natural background dose dose D fungicide effect fungicide effect bactericide effect bactericide effect IRRADIATION EFFECTS AND THE ABSORBED DOSE IRRADIATION EFFECTS AND THE ABSORBED DOSE 6 mSv 6 mSv annually - natural background + medical application dose range for dose range for CH object treatment CH object treatment Tekstilni objekti kulturne baštine posebno su podložni biološkim oštećenjima Tekstilni objekti kulturne baštine posebno su podložni biološkim oštećenjima izazvanim insektima, gljivicama, plijesnima i bakterijama koje ih nastanjuju i izazvanim insektima, gljivicama, plijesnima i bakterijama koje ih nastanjuju i uzrokuju kemijske promjene. Može doći do promjene oksidacijskih stanja i uzrokuju kemijske promjene. Može doći do promjene oksidacijskih stanja i depolimerizacija prirodnih polimera od kojih se sastoje tekstilni materijali. Posljedice depolimerizacija prirodnih polimera od kojih se sastoje tekstilni materijali. Posljedice mogu biti promjene boja, pogoršanja mehaničkih svojstava pa čak i potpuno mogu biti promjene boja, pogoršanja mehaničkih svojstava pa čak i potpuno propadanje tekstila [1]. Većina postupaka zaštite samo djelomično rješava problem propadanje tekstila [1]. Većina postupaka zaštite samo djelomično rješava problem često uz primjenu toksičnih spojeva. često uz primjenu toksičnih spojeva. Iskustva sterilizacije medicinskih pomagala i farmaceutika osnova su radijacijske Iskustva sterilizacije medicinskih pomagala i farmaceutika osnova su radijacijske obrade baštinskih predmeta. Za uklanjanje insekata primjenjuju se doze do 0,5 kGy, obrade baštinskih predmeta. Za uklanjanje insekata primjenjuju se doze do 0,5 kGy, 4-10 kGy za gljivice dok 5-20 kGy osigurava mikrobiološku dekontaminaciju. 4-10 kGy za gljivice dok 5-20 kGy osigurava mikrobiološku dekontaminaciju. Prednosti radijaciijske obrade su: Prednosti radijaciijske obrade su: visoka pouzdanost, djeluje po cijelom volumenu objekta visoka pouzdanost, djeluje po cijelom volumenu objekta istovremeno djeluje na sve štetne organizme u svim fazama njihova razvoja istovremeno djeluje na sve štetne organizme u svim fazama njihova razvoja bez neželjenih promjena u skoro svim materijalima bez neželjenih promjena u skoro svim materijalima netoksična, ozračeni objekti ne postaju radioaktivni netoksična, ozračeni objekti ne postaju radioaktivni prodire kroz ambalažu prodire kroz ambalažu ovisi o samo apsorbiranoj dozi koju je lako kontrolirati ovisi o samo apsorbiranoj dozi koju je lako kontrolirati postupak relativno brz i veći broj objekata se može tretirati istovremeno postupak relativno brz i veći broj objekata se može tretirati istovremeno provodi se na sobnoj temperaturi a po potrebi na povišenoj temperaturi (radi provodi se na sobnoj temperaturi a po potrebi na povišenoj temperaturi (radi povećanja osjetljivost zagađivača) ili u smrznutom stanju povećanja osjetljivost zagađivača) ili u smrznutom stanju uz konzervaciju moguća i konsolidacija uz konzervaciju moguća i konsolidacija Textile cultural heritage (CH) objects are especailly susceptible to biological damage Textile cultural heritage (CH) objects are especailly susceptible to biological damage by insects, fungi, molds and bacteria that inhabit those objects and produce by insects, fungi, molds and bacteria that inhabit those objects and produce chemical changes. Changes in oxidation states and/or depolymerization of natural chemical changes. Changes in oxidation states and/or depolymerization of natural polymers that textiles consist of occurr resulting in discoloration, detrioration of polymers that textiles consist of occurr resulting in discoloration, detrioration of mechanical properties and even full decomposition [1]. Most treatment methods mechanical properties and even full decomposition [1]. Most treatment methods include application of toxic compounds while only partially solving the problem. include application of toxic compounds while only partially solving the problem. Irradiation treatment is based on the experience gathered in sterilization of medical Irradiation treatment is based on the experience gathered in sterilization of medical devices and pharmacuticals. Doses of 0.5 kGy provide desinsection, 4-10 kGyare devices and pharmacuticals. Doses of 0.5 kGy provide desinsection, 4-10 kGyare applied for fungi control and up to 5-20 kGy if complete microbiological applied for fungi control and up to 5-20 kGy if complete microbiological decontamination is needed. The advantages of radiation treatment are: decontamination is needed. The advantages of radiation treatment are: highly efficient throught the volume of the object highly efficient throught the volume of the object simultaneous treatment of all biodetriorants at every development stage simultaneous treatment of all biodetriorants at every development stage almost no unwanted chages in treated materails almost no unwanted chages in treated materails nontoxic, objects do not become radioactive nontoxic, objects do not become radioactive penetrates the packaging penetrates the packaging depends soleyly on absrobed dose taht is easily controlled depends soleyly on absrobed dose taht is easily controlled several objects can be treated simulatenously several objects can be treated simulatenously usually performed at room temperature, but temperature may be higher (to usually performed at room temperature, but temperature may be higher (to increase sesnsitivity of biodetriorants) or object may be frozen increase sesnsitivity of biodetriorants) or object may be frozen provides conservation, might be used for consolidation provides conservation, might be used for consolidation U U 60 60 Co izvoru gama zračenja u Laboratoriju za radijacijsku kemiju i dozimetriju Instituta "Ruđer Bošković" u Zagrebu više od Co izvoru gama zračenja u Laboratoriju za radijacijsku kemiju i dozimetriju Instituta "Ruđer Bošković" u Zagrebu više od 20 godina se provodi obrada objekata kulturne baštine od drva, papira, tekstila, kože itd. [2]. U tom periodu efikasno su 20 godina se provodi obrada objekata kulturne baštine od drva, papira, tekstila, kože itd. [2]. U tom periodu efikasno su dezinficirani brojni tekstilni artefakti dozom manjom od 2 kGy. Neštetnost viših doza potrebnih za kontrolu kontaminacije dezinficirani brojni tekstilni artefakti dozom manjom od 2 kGy. Neštetnost viših doza potrebnih za kontrolu kontaminacije gljivicama potrebno je potvrditi ispitivanjima djelovanja zračenja na tekstilna vlakna i pokazati da li takva obrada zadovoljava gljivicama potrebno je potvrditi ispitivanjima djelovanja zračenja na tekstilna vlakna i pokazati da li takva obrada zadovoljava visoke standarde konzervatora obzirom na neželjene promijene. Stoga su u prikazanom istraživanju visoke standarde konzervatora obzirom na neželjene promijene. Stoga su u prikazanom istraživanju ispitivani modelni uzorci ispitivani modelni uzorci tekstilnih materijala koji se najčešće javljaju u objektima kulturna baštine – svile, pamuka, lana i vune. Ti modelni uzorci tekstilnih materijala koji se najčešće javljaju u objektima kulturna baštine – svile, pamuka, lana i vune. Ti modelni uzorci ozračeni su visokom dozom gama zračenja, D=120 kGy u kontaktu s zrakom. Tako visoka doza izabrana je kako bi se ozračeni su visokom dozom gama zračenja, D=120 kGy u kontaktu s zrakom. Tako visoka doza izabrana je kako bi se osiguralo da se mogu detektirati sve promjene izazvane zračenjem kako bi ih se moglo prepoznati ukoliko se javljaju kod osiguralo da se mogu detektirati sve promjene izazvane zračenjem kako bi ih se moglo prepoznati ukoliko se javljaju kod primjene skoro 20 puta manjih doza potrebnih za kontrolu gljivica. primjene skoro 20 puta manjih doza potrebnih za kontrolu gljivica. Dio uzoraka je bio umjetno staren 25 dana u Vötsch Dio uzoraka je bio umjetno staren 25 dana u Vötsch Climatic Chamber, VC 0020 pri 80 °C i 65 % RH. Termička svojstva i stabilnost uzoraka mjerena su pretražnim kalorimetrom Climatic Chamber, VC 0020 pri 80 °C i 65 % RH. Termička svojstva i stabilnost uzoraka mjerena su pretražnim kalorimetrom Perkin Elemer Diamond DSC-om i termogravietrijski na Shimadzu TGA. Promjene na vlaknima promatrane su pretražnim Perkin Elemer Diamond DSC-om i termogravietrijski na Shimadzu TGA. Promjene na vlaknima promatrane su pretražnim elektronskim mikroskopom SEM, JEOL JSM-6060LV. elektronskim mikroskopom SEM, JEOL JSM-6060LV. [1] K. Kavkler, A. Demšar, Polym. Degrad. Stab. 97 (2012), 5; 786-792. [1] K. Kavkler, A. Demšar, Polym. Degrad. Stab. 97 (2012), 5; 786-792. [2] B. Katušin-Ražem, D. Ražem, M. Braun, Radiat. Phys. Chem. 78 (2009), 7/8; 729-731. [2] B. Katušin-Ražem, D. Ražem, M. Braun, Radiat. Phys. Chem. 78 (2009), 7/8; 729-731. 60 60 Co gamma irradiation facility at Laboratory for Radiation Chemistry and dosimetry of the Ruđer Bošković Institute in Co gamma irradiation facility at Laboratory for Radiation Chemistry and dosimetry of the Ruđer Bošković Institute in Zagreb, Croatia provides treatment of cultural heritage (CH) objects made of wood, paper, textile, leather etc for more than Zagreb, Croatia provides treatment of cultural heritage (CH) objects made of wood, paper, textile, leather etc for more than 20 years [2]. During that period numerous textile artifacts were efficiently disinfected by irradiation to dose of less than 2 20 years [2]. During that period numerous textile artifacts were efficiently disinfected by irradiation to dose of less than 2 kGy. However, the application of higher doses for the control of fungi needs to be justified by investigating the effects of kGy. However, the application of higher doses for the control of fungi needs to be justified by investigating the effects of irradiation on textile fibers and to determine whether the treatment complies to the high standards of conservator specialists irradiation on textile fibers and to determine whether the treatment complies to the high standards of conservator specialists considering undesirable changes. Because of that considering undesirable changes. Because of that the most common textile materials in CH artifacts - silk, cotton, linen and the most common textile materials in CH artifacts - silk, cotton, linen and wool were selected as model samples. The samples were γ-irradiated to a high dose, D=120 kGy, in contact with air. Such wool were selected as model samples. The samples were γ-irradiated to a high dose, D=120 kGy, in contact with air. Such high dose was chosen to ensure that all radiation effects can be detected and recognized if appear in samples irradiated to high dose was chosen to ensure that all radiation effects can be detected and recognized if appear in samples irradiated to almost 20 times lower doses needed for fungi control. almost 20 times lower doses needed for fungi control. A part of the samples was artificially aged using Vötsch Climatic A part of the samples was artificially aged using Vötsch Climatic Chamber, Type VC 0020 at 80 °C and 65 % RH.for 25 days. Thermal properties and stability of the samples were determnined Chamber, Type VC 0020 at 80 °C and 65 % RH.for 25 days. Thermal properties and stability of the samples were determnined using differential calorimetry, Perkin Elemer Diamond DSC, and termogravietry, Shimadzu TGA. Fiber changes were using differential calorimetry, Perkin Elemer Diamond DSC, and termogravietry, Shimadzu TGA. Fiber changes were observed by a scanning electron microscope JEOL JSM-606OLV. observed by a scanning electron microscope JEOL JSM-606OLV. [2] B. Katušin-Ražem, D. Ražem, M. Braun, Radiat. Phys. Chem. 78 (2009), 7/8; 729-731. [2] B. Katušin-Ražem, D. Ražem, M. Braun, Radiat. Phys. Chem. 78 (2009), 7/8; 729-731. [1] K. Kavkler, A. Demšar, Polym. Degrad. Stab. 97 (2012), 5; 786-792. [1] K. Kavkler, A. Demšar, Polym. Degrad. Stab. 97 (2012), 5; 786-792. linen aged linen cotton linen aged linen cotton 370 302 303 298 -3,83 -23,26 -290,74 -342,43 350 349 345 343 341 341 neozračeni / unirradiated 120 kGy lan stareni lan pamuk lan stareni lan pamuk DSC Peak T/ °C DSC ΔH / J/g diff TGA Peak T/ °C aged UV-aged silk silk wool wool aged UV-aged silk silk wool wool 58 63 96 88 77 75 96 94 52,29 21,64 89,67 142,45 128,74 146,09 69,29 47,06 251 256 251 255 6,43 10,04 5,93 5,94 362 364 332 327 370 365 339 331 -2,54 -37,38 -32,3 -8,99 -17,76 -25,46 -8,02 -10,89 325-333 320-331 529-536 525-538 317-331 314-321 529-536 525-538 neozračeni / unirradiated 120 kGy starena UV-starena svila svila vuna vuna starena UV-starena svila svila vuna vuna DSC Peak T/ °C DSC ΔH / J/g DSC Peak T/ °C DSC ΔH / J/g DSC Peak T/ °C DSC ΔH / J/g diff TGA Peak T/ °C flax 0 kGy flax 120 kGy UV aged flax 0 kGy UV aged flax 120 kGy 250 300 350 400 450 500 550 T / ºC m / mg 250 300 350 400 450 500 550 cotton 0 kGy cotton 120 kGy T / ºC m / mg 50 150 250 350 450 550 650 silk 0 kGy silk 120 kGy UV aged silk 0 kGy UV aged silk 120 kGy wool 0 kGy wool 120 kGy thermally aged wool 0 kGy thermally aged wool 120 kGy UV aged wool 0 kGy UV aged wool 120 kGy 20 120 220 320 420 520 620
Transcript of RADIJACIJSKA OBRADA STARENIH MODELNIH UZORAKA … · vlakna. Cellulose is known to be prone to...
RADIJACIJSKA OBRADA STARENIH MODELNIH UZORAKA TEKSTILARADIJACIJSKA OBRADA STARENIH MODELNIH UZORAKA TEKSTILARADIATION TREATMENT OF ARTIFICIALLY AGED MODEL TEXTILESRADIATION TREATMENT OF ARTIFICIALLY AGED MODEL TEXTILES
I. PucićI. Pucić11, K. Kavkler, K. Kavkler22, B. Mihaljević, B. Mihaljević11
11Ruđer Bošković InstitutRuđer Bošković Institut, Zagreb, , Zagreb, CroatiaCroatia
22Institute for the Protection of Cultural Heritage of Slovenia, Restoration Centre, Poljanska 40, 1000 Ljubljana, SloveniaInstitute for the Protection of Cultural Heritage of Slovenia, Restoration Centre, Poljanska 40, 1000 Ljubljana, Slovenia
e-mail: e-mail: [email protected]@irb.hr, , [email protected]@rescen.si, [email protected], [email protected]
PROTEIN-BASED TEXTILE / TEKSTIL PROTEINSKE OSNOVEPROTEIN-BASED TEXTILE / TEKSTIL PROTEINSKE OSNOVE
CONCLUSIONS:CONCLUSIONS: the changes in even the most senstitive materials were slight although the applied the changes in even the most senstitive materials were slight although the applied
dose was relativlely high;dose was relativlely high; cellulose - based textiles (linen and cotton) are more sensitive to irradiation than cellulose - based textiles (linen and cotton) are more sensitive to irradiation than
protein-based ones (silk, wool); protein-based ones (silk, wool); irradaition of CH textiles to doses needed for fungi control should be safe.irradaition of CH textiles to doses needed for fungi control should be safe.
CELLULOSE-BASED TEXTILE / TEKSTIL CELULOZNE OSNOVECELLULOSE-BASED TEXTILE / TEKSTIL CELULOZNE OSNOVE
SEM mikrografije uzoraka lana: nestaren i neozračen (lijevo), staren i neozračen (sredina lijevo), nestaren i ozračen s 120 SEM mikrografije uzoraka lana: nestaren i neozračen (lijevo), staren i neozračen (sredina lijevo), nestaren i ozračen s 120 kGy (sredina desno) te staren i ozračen s 120 kGy (desno). Na ozračenim uzorcima vidljiva su oštećenja kutikule a i oštećena kGy (sredina desno) te staren i ozračen s 120 kGy (desno). Na ozračenim uzorcima vidljiva su oštećenja kutikule a i oštećena vlakna. vlakna.
Cellulose is known to be prone to radiation degradation so the changes in thermal properties of irradiated linen and cotton. Cellulose is known to be prone to radiation degradation so the changes in thermal properties of irradiated linen and cotton. Although 120 kGy is relatively high dose temperature of maximum rate of mass decrease in TGA is only slightly lower than in Although 120 kGy is relatively high dose temperature of maximum rate of mass decrease in TGA is only slightly lower than in unirradiated sample. In DSC thermograms (not shown) of both aged and irradiated samples of cotton and linen a high unirradiated sample. In DSC thermograms (not shown) of both aged and irradiated samples of cotton and linen a high temperature peak appears that is not present in unirradiated fresh sample. In aged linen samples that peak shifts to lower temperature peak appears that is not present in unirradiated fresh sample. In aged linen samples that peak shifts to lower temperature and its heat significantly increases. On the other hand damage to fiber strucuture, primarily to cuticule, and temperature and its heat significantly increases. On the other hand damage to fiber strucuture, primarily to cuticule, and even some destruciton of complete fiber is obvious in SEM micrographs. Since about 20 times lower dose is needed for even some destruciton of complete fiber is obvious in SEM micrographs. Since about 20 times lower dose is needed for fungi control it can safely be proposed that the change to textile would not be greater than that caused by ageing itself.fungi control it can safely be proposed that the change to textile would not be greater than that caused by ageing itself.
SEM micrograps of linen samples: unaged and unirradiated (left), aged and unirradiated (center left), unaged and irradiated SEM micrograps of linen samples: unaged and unirradiated (left), aged and unirradiated (center left), unaged and irradiated 120 kGy (center right) and aged and irradiated 120 kGy (right). Damaged cuticule and some destroyed fibers are visible in 120 kGy (center right) and aged and irradiated 120 kGy (right). Damaged cuticule and some destroyed fibers are visible in irradiated samples.irradiated samples.
Poznato je da celuloza degradira pod djelovanjem zračenja pa su promjene toplinskih svojstava i stabilnosti lanenog platna i Poznato je da celuloza degradira pod djelovanjem zračenja pa su promjene toplinskih svojstava i stabilnosti lanenog platna i pamuka bile očekivane. Unatoč relativno visokoj dozi od 120 kGy temperatura maksimuma gubitka mase u TGA je samo malo pamuka bile očekivane. Unatoč relativno visokoj dozi od 120 kGy temperatura maksimuma gubitka mase u TGA je samo malo niža nego kod neozračenog uzorka. U DSC termogramima (nisu prikazani) zračenih kao i starenih uzoraka pamuka i lanenog niža nego kod neozračenog uzorka. U DSC termogramima (nisu prikazani) zračenih kao i starenih uzoraka pamuka i lanenog platna pojavljuje se visokotemperaturni maksimum kojeg nema u neozračenom nestarenom uzorku. Kod starenih uzoraka platna pojavljuje se visokotemperaturni maksimum kojeg nema u neozračenom nestarenom uzorku. Kod starenih uzoraka lanenog platna taj maksimum pomiče se prema nižoj temperaturi a toplina mu raste. SEM mikrografije pokazuju oštećenja lanenog platna taj maksimum pomiče se prema nižoj temperaturi a toplina mu raste. SEM mikrografije pokazuju oštećenja strukture vlakna u ozračenim uzorcima, najviše kutikule ali i mjestimično pucanje cijelih vlakana. Slične promjene iako strukture vlakna u ozračenim uzorcima, najviše kutikule ali i mjestimično pucanje cijelih vlakana. Slične promjene iako manje izražene vidljive su i u neozračenom starenom uzorku pa se kod skoro 20 puta manje doze potrebne za kontrolu manje izražene vidljive su i u neozračenom starenom uzorku pa se kod skoro 20 puta manje doze potrebne za kontrolu gljivica mogu očekivati promjene manje onih koje uzrokuje samo starenje.gljivica mogu očekivati promjene manje onih koje uzrokuje samo starenje.
ZAKLJUČCI:ZAKLJUČCI: promjene u materijaliam uzoraka bile su neznatne iako je primjenjena doza bila promjene u materijaliam uzoraka bile su neznatne iako je primjenjena doza bila
relativno visoka;relativno visoka; tekstili s celuloznom osnovom (lan i pamuk) osjetljiviji su prema zračenju u odnosu tekstili s celuloznom osnovom (lan i pamuk) osjetljiviji su prema zračenju u odnosu
na one s proteinskom osnovom (svila, vuna); na one s proteinskom osnovom (svila, vuna); ozračivanje baštinskog tekstila dozama potrebnim za kontrolu gljivica može se ozračivanje baštinskog tekstila dozama potrebnim za kontrolu gljivica može se
smatrati sigurnim.smatrati sigurnim.
Zračenje do 120 kGy nema utjecaja na toplinsku stabilnost svile a naročito vune. To je pomalo neočekivano jer su proteini Zračenje do 120 kGy nema utjecaja na toplinsku stabilnost svile a naročito vune. To je pomalo neočekivano jer su proteini njihove osnove, sericin i fibroin kod svile te keratin kod vune, osjetljivi prema zračenju iako manje od celuloze. Iako njihove osnove, sericin i fibroin kod svile te keratin kod vune, osjetljivi prema zračenju iako manje od celuloze. Iako temperature i topline određene DSC-om pokazuju da zračenje utječe na transformacije u svili i vuni to ne mora nužno temperature i topline određene DSC-om pokazuju da zračenje utječe na transformacije u svili i vuni to ne mora nužno rezultirati oštećenjima jer kompleksna struktura animalnih vlakana očito pruža znatnu zaštitu proteinskoj komponenti. Na rezultirati oštećenjima jer kompleksna struktura animalnih vlakana očito pruža znatnu zaštitu proteinskoj komponenti. Na SEM mikrografijama ozračene vune uočavaju se samo manja oštećenja. Zanimljivo je da UV-stareni uzorak vune nema SEM mikrografijama ozračene vune uočavaju se samo manja oštećenja. Zanimljivo je da UV-stareni uzorak vune nema oštećenja unatoč visokoj dozi. oštećenja unatoč visokoj dozi.
SEM mikrografije uzoraka vune: nestarena i neozračena (lijevo), starena i neozračena (sredina lijevo), nestarena i ozračena s SEM mikrografije uzoraka vune: nestarena i neozračena (lijevo), starena i neozračena (sredina lijevo), nestarena i ozračena s 120 kGy (sredina), starena i ozračena s 120 kGy (sredina desno) te UV-starena i ozračena s 120 kGy (desno). Na ozračenim 120 kGy (sredina), starena i ozračena s 120 kGy (sredina desno) te UV-starena i ozračena s 120 kGy (desno). Na ozračenim uzorcima vidljiva su manja oštećenja kutikule osim kod uzorka koji je bio UV-staren. uzorcima vidljiva su manja oštećenja kutikule osim kod uzorka koji je bio UV-staren.
SEM micrograps of wool samples: unaged and unirradiated (left), aged and unirradiated (center left), unaged and irradiated SEM micrograps of wool samples: unaged and unirradiated (left), aged and unirradiated (center left), unaged and irradiated 120 kGy (center), aged and irradiated 120 kGy (center right), UV-aged and irradiated 120 kGy (center right). Slight damage of 120 kGy (center), aged and irradiated 120 kGy (center right), UV-aged and irradiated 120 kGy (center right). Slight damage of cuticule is visible in irradiated samples except the UV-aged one.cuticule is visible in irradiated samples except the UV-aged one.
Thermal stability of silk and especially wool seems to be unaffected by irradiation to 120 kGy. This is somewhat unexpected Thermal stability of silk and especially wool seems to be unaffected by irradiation to 120 kGy. This is somewhat unexpected because the corresponding proteins – sericin and fibroin in silk and keratin in wool - are by themselves sensitive to because the corresponding proteins – sericin and fibroin in silk and keratin in wool - are by themselves sensitive to irradiation although less than cellulose. Temperatures and heats determined by DSC indicate that transformation of silk and irradiation although less than cellulose. Temperatures and heats determined by DSC indicate that transformation of silk and wool are slightly influenced by irradiation. Those changes are not neccesary related to degradation because complex wool are slightly influenced by irradiation. Those changes are not neccesary related to degradation because complex structure of animal fibers obviously offers significant protection to protein component. SEM micrographs of wool show only structure of animal fibers obviously offers significant protection to protein component. SEM micrographs of wool show only slight damage. It is interesting that UV-aged wool sample shows no damage despite high dose. slight damage. It is interesting that UV-aged wool sample shows no damage despite high dose.
1 Gy1 mGy 1 kGy 1 MGy
BIOLOGIC EFFECTSBIOLOGIC EFFECTS
EFFECTS UPON MATERIALSEFFECTS UPON MATERIALS
25 kGy -sterility
dezinsection
lethal dose forhumans
color change
radiolysis
polimerysation
degradation
3 mSv3 mSv annually- natural background
dose dose DD
fungicide effect fungicide effect
bactericide effectbactericide effect
IRRADIATION EFFECTS AND THE ABSORBED DOSEIRRADIATION EFFECTS AND THE ABSORBED DOSE
6 mSv6 mSv annually- natural background+ medicalapplication
dose range for dose range for CH object treatmentCH object treatment
Tekstilni objekti kulturne baštine posebno su podložni biološkim oštećenjima Tekstilni objekti kulturne baštine posebno su podložni biološkim oštećenjima izazvanim insektima, gljivicama, plijesnima i bakterijama koje ih nastanjuju i izazvanim insektima, gljivicama, plijesnima i bakterijama koje ih nastanjuju i uzrokuju kemijske promjene. Može doći do promjene oksidacijskih stanja i uzrokuju kemijske promjene. Može doći do promjene oksidacijskih stanja i depolimerizacija prirodnih polimera od kojih se sastoje tekstilni materijali. Posljedice depolimerizacija prirodnih polimera od kojih se sastoje tekstilni materijali. Posljedice mogu biti promjene boja, pogoršanja mehaničkih svojstava pa čak i potpuno mogu biti promjene boja, pogoršanja mehaničkih svojstava pa čak i potpuno propadanje tekstila [1]. Većina postupaka zaštite samo djelomično rješava problem propadanje tekstila [1]. Većina postupaka zaštite samo djelomično rješava problem često uz primjenu toksičnih spojeva. često uz primjenu toksičnih spojeva.
Iskustva sterilizacije medicinskih pomagala i farmaceutika osnova su radijacijske Iskustva sterilizacije medicinskih pomagala i farmaceutika osnova su radijacijske obrade baštinskih predmeta. Za uklanjanje insekata primjenjuju se doze do 0,5 kGy, obrade baštinskih predmeta. Za uklanjanje insekata primjenjuju se doze do 0,5 kGy, 4-10 kGy za gljivice dok 5-20 kGy osigurava mikrobiološku dekontaminaciju. 4-10 kGy za gljivice dok 5-20 kGy osigurava mikrobiološku dekontaminaciju. Prednosti radijaciijske obrade su:Prednosti radijaciijske obrade su:
visoka pouzdanost, djeluje po cijelom volumenu objektavisoka pouzdanost, djeluje po cijelom volumenu objekta istovremeno djeluje na sve štetne organizme u svim fazama njihova razvojaistovremeno djeluje na sve štetne organizme u svim fazama njihova razvoja bez neželjenih promjena u skoro svim materijalima bez neželjenih promjena u skoro svim materijalima netoksična, ozračeni objekti ne postaju radioaktivni netoksična, ozračeni objekti ne postaju radioaktivni prodire kroz ambalažu prodire kroz ambalažu ovisi o samo apsorbiranoj dozi koju je lako kontroliratiovisi o samo apsorbiranoj dozi koju je lako kontrolirati postupak relativno brz i veći broj objekata se može tretirati istovremenopostupak relativno brz i veći broj objekata se može tretirati istovremeno provodi se na sobnoj temperaturi a po potrebi na povišenoj temperaturi (radi provodi se na sobnoj temperaturi a po potrebi na povišenoj temperaturi (radi povećanja osjetljivost zagađivača) ili u smrznutom stanjupovećanja osjetljivost zagađivača) ili u smrznutom stanju
uz konzervaciju moguća i konsolidacija uz konzervaciju moguća i konsolidacija
Textile cultural heritage (CH) objects are especailly susceptible to biological damage Textile cultural heritage (CH) objects are especailly susceptible to biological damage by insects, fungi, molds and bacteria that inhabit those objects and produce by insects, fungi, molds and bacteria that inhabit those objects and produce chemical changes. Changes in oxidation states and/or depolymerization of natural chemical changes. Changes in oxidation states and/or depolymerization of natural polymers that textiles consist of occurr resulting in discoloration, detrioration of polymers that textiles consist of occurr resulting in discoloration, detrioration of mechanical properties and even full decomposition [1]. Most treatment methods mechanical properties and even full decomposition [1]. Most treatment methods include application of toxic compounds while only partially solving the problem. include application of toxic compounds while only partially solving the problem.
Irradiation treatment is based on the experience gathered in sterilization of medical Irradiation treatment is based on the experience gathered in sterilization of medical devices and pharmacuticals. Doses of 0.5 kGy provide desinsection, 4-10 kGyare devices and pharmacuticals. Doses of 0.5 kGy provide desinsection, 4-10 kGyare applied for fungi control and up to 5-20 kGy if complete microbiological applied for fungi control and up to 5-20 kGy if complete microbiological decontamination is needed. The advantages of radiation treatment are:decontamination is needed. The advantages of radiation treatment are:
highly efficient throught the volume of the objecthighly efficient throught the volume of the object simultaneous treatment of all biodetriorants at every development stagesimultaneous treatment of all biodetriorants at every development stage almost no unwanted chages in treated materailsalmost no unwanted chages in treated materails nontoxic, objects do not become radioactive nontoxic, objects do not become radioactive penetrates the packaging penetrates the packaging depends soleyly on absrobed dose taht is easily controlleddepends soleyly on absrobed dose taht is easily controlled several objects can be treated simulatenouslyseveral objects can be treated simulatenously usually performed at room temperature, but temperature may be higher (to usually performed at room temperature, but temperature may be higher (to increase sesnsitivity of biodetriorants) or object may be frozenincrease sesnsitivity of biodetriorants) or object may be frozen
provides conservation, might be used for consolidationprovides conservation, might be used for consolidation
U U 6060Co izvoru gama zračenja u Laboratoriju za radijacijsku kemiju i dozimetriju Instituta "Ruđer Bošković" u Zagrebu više od Co izvoru gama zračenja u Laboratoriju za radijacijsku kemiju i dozimetriju Instituta "Ruđer Bošković" u Zagrebu više od 20 godina se provodi obrada objekata kulturne baštine od drva, papira, tekstila, kože itd. [2]. U tom periodu efikasno su 20 godina se provodi obrada objekata kulturne baštine od drva, papira, tekstila, kože itd. [2]. U tom periodu efikasno su dezinficirani brojni tekstilni artefakti dozom manjom od 2 kGy. Neštetnost viših doza potrebnih za kontrolu kontaminacije dezinficirani brojni tekstilni artefakti dozom manjom od 2 kGy. Neštetnost viših doza potrebnih za kontrolu kontaminacije gljivicama potrebno je potvrditi ispitivanjima djelovanja zračenja na tekstilna vlakna i pokazati da li takva obrada zadovoljava gljivicama potrebno je potvrditi ispitivanjima djelovanja zračenja na tekstilna vlakna i pokazati da li takva obrada zadovoljava visoke standarde konzervatora obzirom na neželjene promijene. Stoga su u prikazanom istraživanjuvisoke standarde konzervatora obzirom na neželjene promijene. Stoga su u prikazanom istraživanju ispitivani modelni uzorci ispitivani modelni uzorci tekstilnih materijala koji se najčešće javljaju u objektima kulturna baštine – svile, pamuka, lana i vune. Ti modelni uzorci tekstilnih materijala koji se najčešće javljaju u objektima kulturna baštine – svile, pamuka, lana i vune. Ti modelni uzorci ozračeni su visokom dozom gama zračenja, D=120 kGy u kontaktu s zrakom. Tako visoka doza izabrana je kako bi se ozračeni su visokom dozom gama zračenja, D=120 kGy u kontaktu s zrakom. Tako visoka doza izabrana je kako bi se osiguralo da se mogu detektirati sve promjene izazvane zračenjem kako bi ih se moglo prepoznati ukoliko se javljaju kod osiguralo da se mogu detektirati sve promjene izazvane zračenjem kako bi ih se moglo prepoznati ukoliko se javljaju kod primjene skoro 20 puta manjih doza potrebnih za kontrolu gljivica. primjene skoro 20 puta manjih doza potrebnih za kontrolu gljivica. Dio uzoraka je bio umjetno staren 25 dana u Vötsch Dio uzoraka je bio umjetno staren 25 dana u Vötsch Climatic Chamber, VC 0020 pri 80 °C i 65 % RH. Termička svojstva i stabilnost uzoraka mjerena su pretražnim kalorimetrom Climatic Chamber, VC 0020 pri 80 °C i 65 % RH. Termička svojstva i stabilnost uzoraka mjerena su pretražnim kalorimetrom Perkin Elemer Diamond DSC-om i termogravietrijski na Shimadzu TGA. Promjene na vlaknima promatrane su pretražnim Perkin Elemer Diamond DSC-om i termogravietrijski na Shimadzu TGA. Promjene na vlaknima promatrane su pretražnim elektronskim mikroskopom SEM, JEOL JSM-6060LV.elektronskim mikroskopom SEM, JEOL JSM-6060LV.
[1] K. Kavkler, A. Demšar, Polym. Degrad. Stab. 97 (2012), 5; 786-792.[1] K. Kavkler, A. Demšar, Polym. Degrad. Stab. 97 (2012), 5; 786-792.[2] B. Katušin-Ražem, D. Ražem, M. Braun, Radiat. Phys. Chem. 78 (2009), 7/8; 729-731.[2] B. Katušin-Ražem, D. Ražem, M. Braun, Radiat. Phys. Chem. 78 (2009), 7/8; 729-731.
6060Co gamma irradiation facility at Laboratory for Radiation Chemistry and dosimetry of the Ruđer Bošković Institute in Co gamma irradiation facility at Laboratory for Radiation Chemistry and dosimetry of the Ruđer Bošković Institute in Zagreb, Croatia provides treatment of cultural heritage (CH) objects made of wood, paper, textile, leather etc for more than Zagreb, Croatia provides treatment of cultural heritage (CH) objects made of wood, paper, textile, leather etc for more than 20 years [2]. During that period numerous textile artifacts were efficiently disinfected by irradiation to dose of less than 2 20 years [2]. During that period numerous textile artifacts were efficiently disinfected by irradiation to dose of less than 2 kGy. However, the application of higher doses for the control of fungi needs to be justified by investigating the effects of kGy. However, the application of higher doses for the control of fungi needs to be justified by investigating the effects of irradiation on textile fibers and to determine whether the treatment complies to the high standards of conservator specialists irradiation on textile fibers and to determine whether the treatment complies to the high standards of conservator specialists considering undesirable changes. Because of that considering undesirable changes. Because of that the most common textile materials in CH artifacts - silk, cotton, linen and the most common textile materials in CH artifacts - silk, cotton, linen and wool were selected as model samples. The samples were γ-irradiated to a high dose, D=120 kGy, in contact with air. Such wool were selected as model samples. The samples were γ-irradiated to a high dose, D=120 kGy, in contact with air. Such high dose was chosen to ensure that all radiation effects can be detected and recognized if appear in samples irradiated to high dose was chosen to ensure that all radiation effects can be detected and recognized if appear in samples irradiated to almost 20 times lower doses needed for fungi control.almost 20 times lower doses needed for fungi control. A part of the samples was artificially aged using Vötsch Climatic A part of the samples was artificially aged using Vötsch Climatic Chamber, Type VC 0020 at 80 °C and 65 % RH.for 25 days. Thermal properties and stability of the samples were determnined Chamber, Type VC 0020 at 80 °C and 65 % RH.for 25 days. Thermal properties and stability of the samples were determnined using differential calorimetry, Perkin Elemer Diamond DSC, and termogravietry, Shimadzu TGA. Fiber changes were using differential calorimetry, Perkin Elemer Diamond DSC, and termogravietry, Shimadzu TGA. Fiber changes were observed by a scanning electron microscope JEOL JSM-606OLV.observed by a scanning electron microscope JEOL JSM-606OLV.
[2] B. Katušin-Ražem, D. Ražem, M. Braun, Radiat. Phys. Chem. 78 (2009), 7/8; 729-731.[2] B. Katušin-Ražem, D. Ražem, M. Braun, Radiat. Phys. Chem. 78 (2009), 7/8; 729-731.[1] K. Kavkler, A. Demšar, Polym. Degrad. Stab. 97 (2012), 5; 786-792.[1] K. Kavkler, A. Demšar, Polym. Degrad. Stab. 97 (2012), 5; 786-792.
linen aged linen cottonlinen aged linen cotton
370 302 303 298-3,83 -23,26 -290,74 -342,43
350 349 345 343 341 341
neozračeni / unirradiated 120 kGylan stareni lan pamuk
lan stareni lan pamukDSC Peak T/ °CDSC ΔH / J/gdiff TGA Peak T/ °C
aged UV-aged silk silk wool wool
aged UV-aged silk silk wool wool
58 63 96 88 77 75 96 9452,29 21,64 89,67 142,45 128,74 146,09 69,29 47,06
251 256 251 2556,43 10,04 5,93 5,94
362 364 332 327 370 365 339 331-2,54 -37,38 -32,3 -8,99 -17,76 -25,46 -8,02 -10,89
325-333 320-331 529-536 525-538 317-331 314-321 529-536 525-538
neozračeni / unirradiated 120 kGy starena UV-starena
svila svila vuna vuna starena UV-starena
svila svila vuna vunaDSC Peak T/ °CDSC ΔH / J/gDSC Peak T/ °CDSC ΔH / J/gDSC Peak T/ °CDSC ΔH / J/gdiff TGA Peak T/ °C
flax 0 kGy
flax 120 kGy
UV aged flax 0 kGy
UV aged flax 120 kGy
250 300 350 400 450 500 550
T / ºC
m /
mg
250 300 350 400 450 500 550
cotton 0 kGy
cotton 120 kGy
T / ºC
m /
mg
50 150 250 350 450 550 650
silk 0 kGy
silk 120 kGy
UV aged silk 0 kGy
UV aged silk 120 kGy
wool 0 kGy
wool 120 kGy
thermally aged wool 0 kGy
thermally aged wool 120 kGy
UV aged wool 0 kGy
UV aged wool 120 kGy
20 120 220 320 420 520 620
