anselmi, c. et al. cyclododecane as a temporary con solid ant. 2008

8/7/2019 Anselmi, C. Et Al. Cyclododecane as a Temporary Con Solid Ant. 2008

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Evaluationof Cyclododecaneas a temporaryconsolidantfor CulturalHeritagemateralsChiaraAnselmiPhD Chensfry/Past Doc, SMAArtc/oDipi4imentodi Chinica, Uniyerst'degliStu.li diPerugia,Pe"ugia,Iralt, [email protected] yPhD Chenistry/Posf Doc, 5tr4,4,4rtc/o Dpaimento.li Chimica, Unwrsit deBli Stu.JidiPerusia,Pe"usia,Italy, b.bd.daherr'@tdtkzt.conFedericaPrescittiPhD Chemisttj,/Post Dac, ktifuto CNRdi Scicnzee TecnolageMalecalari (ISTM,Dipatinento di Chinica, Uniyersit de&liStudli Perugia,Peruge,Iab),feler i [email protected] ICostanzaMilianiPhD Chenisy /Researcher,Istituto CNRdi ScienzeeTecnologieMoleolari(ISTM,Dipartimenadi Chinica, UntuersitdeglStudi di Perugia,Perugia,Ifaly,[email protected]/ChemistyPlatessar, Uniyersa degliStudi di Per gia, Petueia, Italy,[email protected]/Chemistt),Prcfessor, Unirers degli Studi di Perugia, Peruga,[email protected]

SUMMARY: Cyclododecane,(Ct,Hu), has been investisated Ior furure use in the lield afconsenatbn as a tenporuty consolidanr for fragile naterals af art hitraric inpartance insituatiotls oJ energency ftdnspo, excayation or handling. Ths contributian has prinarilyestablished the citeia Ior sobent applicdfon of white spirts a d cyclohetune \|hereassessnent of subsequent sublmation hds been fa owed utilzing partable mid,InfrarcdReectance Spectrascapy. Furthet dnatyses bj Prcfle NMR-MOUSE (Mobile UnlersatSuface Exploret) were use to sdn infomation on the depths of penetratan af thecyclododecane h dillercnt stone matices as well a: to folow its eyaporaron fTon withinthe nast potous oJ systens.KEI WORDS: Cyclalodecane, temporary cansoliddran, water repellent, transpotLporrahIe instrunentatianINTRODUCTIONCyclododecane,(CDD)a volrilecyclicalkane(CrrHr,r),hasbeen(seldon)adoptedfor usein th fild of conservationin the last 15 yearsas a temporary consolialant,sealanta,ndhydrophobicprolctivecoatingfor ftagilematerialsin situationsof transpor,excavationorhandling11.Literalureshowseveralpotentialusesof cyclododcanefor situatioswhere


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.empordqLUn\ol idr.onanJrmp-egnJrionof l rrdre m Icralsur ob'ecr'rede':rbledrdhr,c bee pooo*d rd 'poraJhal l ) c ' red.br rhe'e(Lnntsol LrJtsrrearLneorog'caln " ' . ' " ' , ' " p o re ,r o no r ' l p a r r r i n 's r n a c' $ ' r l -a l ' ) e f " f i m p ' c g n re dg a u / e' r e"."t..ii* ".i.g "q'.""s t.eatmentspeitonneaon mediawirh diflerentdegreesof waterl.n"ir;'irv *. i" t"*r.s andpperandits useon architecturlstucturesl2-sl Thiswaxv."riJ ", ... "-p*"*" coulbegreatlvexploitertfurtherasrouliein lbisdisciplineduei" li" "."o*i'ii. uupou.p..'rui. which permiisit to subhne completelvwithin anappropiatetnnet6l elimiarinssubsequenrremovalbv phvsicalo chemicaloperalionsorunnecessarytreatmeDtof residuesor by-pfoductsCDDmavbe ideallyLLlillzedm lhisfieldsi1hasgoo{tlnl-fonringpropefies'lorvmelting" ' , , " , , ' " s o . ' i r . i r ' o l u b i l n in d re r .' o l u b r l i t )i 1 o rg d r ' r c5 , l ' r 1 r sa d l i r r l e" r 1 oior^rn 71.Yerron iTponrnr'vi" appricaror rsed'rrvre\ersiblelhr ' t)diocrr1 J' i ; ; i i . 'br; . ' tut, . i oe ,porie , i 'n"r '* ' ' , ' . or .1 be i"o' \e'r rr no' tporar-l ' f" ' ' * .r '*" i , ' * ." ' " ' ." i . " ' h. loseldredf)d-oLJrbonsor peLrole'nerh'n'The,urrl f i lo of c)cloooJc,"nei. io|medeir\erb1 ruoIng v" rle n'olen.rtulerra'or,b)at lol i rp lheor|rarrcr ' Lenll e\Jp'reior ' salJrared"u Jlrol ul c]croJooecrnerre' . i1. ' . , i "" .r;. blrJer' cnbe erardedb\ choosnsoneurrl d l ' igl rrelr i rspoinr'ppl) 'ns,r In a norrersrdre.keeorru'be rreredo\jccrrn a con,a'nede': l ' :T:1", i :Dr;r; .r ' ;q rhe rcareduLecr Fonre\po'r ' reo elerated'etrperatue' ql l l har beenr"rn. ' " i " , 'hL f i l l l 'unlb-. ' ro hc ropographol rheslbsrrJrer" hicl-rr- i "ppl iedl l. uhee.r .c\cerr ' rrcsrin) vaD deperJrg on lhedpl l ' ronlrethoJ'Lhoier'LneD o ro s r \o f l h e ' J b s r r " l er r d l h e ra r t o l f i l f i o rm a l r o nl ) l l l l ' i cn rh )d ro p b o b fe l l e ( r 'l ; -J;,"1."" 'vrr l a melror \olrrebi ldrngtidordo- n solLlrons-urrhlou boi l i l '.o,veir\ ,rhere.por,rreou\L\roofalronol sol \errprodu'


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EXPERIMENTALReagentsandsamplepreparatonAl1chemicalreagenlsusedwereof analyticalgrdewherepossibleand usedas received.Cyclododecanewaspurchasedftom CTSs.r.l.Italy.Whjtespiritwasacquiredfrom PHASEs.r.l.Italy, specializedin producfsutilizedin restorationandcyclohexaneliom J.T. Bker.Stone samples obtained from a local manufaclurer,Pemgia, of Canara marblescmx5cnax2cmwercpolishedusing a gmdedsilicon carbidepaper(240 C). The CDDsolulionwaspreparedulilizing l/l w/v in solvent,followedby gentleheatingandaccuratesplayinsovertheeniireavailablesurface.Methodsof characterzatonPortable mid-lnfrared Retleclance SpectroscopyNon invsivein$aredinvestigaiionshavebeencalriedouf with a compactportableFT IRJASCOVIRar00qpec'rophoromererr50x50\5ULm: J5 kgweighl ' .equippedwirhd f iberopticexlension.lhe opticalbenchis madeof a Midac llluminatorIR radiationsource,aMichelsoninterferometer,anda liquidnitrogencooledMCT (MercuryCadmiumTelluride)deleclor.The Remspecmid-in&aredfiber optic probe consistsof a bifurcatedcablecontaining19 chalcogenideglassbers,7 of which carythe infraredradiafiofrorn thesource1()the sample,while the other 12 collectthe radiationreflecledotTthe sample'surface.T}leacquirablespeclalrangeis 7000-900cri' at a resolutionof4 cm r. The fibleopticprobeis keptperpendicularto the suface(0"/0' geontry)al a dislanceof about"2-4mm.Theinvstigatedsamplearea,asdeteminedbytheprobediameler.is aboul20mm'.Thetotalreflectivily,R, due10thcombiddiftuseandspecularcomponents,is measuredusig the speclJuln&on an aluminiumminor plale for backgroundcotTectioD.ThespectrumintensilywasdefinedasthepseudoabsorbanceA' whereA' - log (l/R). Due10samplingprobe geometrycollectedsignals may confain bolh diftuse ad speclarreflections.WhiledifTusereflectioncancauseonly slightshiftsin absorplionbandposilion,as compaedro transmissionspeclra,specularditTusioDmay causderivaiiveor inverledbandshape(,"srsr,,ariel?effect).Thedatahavebeentrealedlo a conslantbaselineandthepseudoabsorbance(anaverageof3 pointswith relevnlerors at eachtimely interval)hasbeenfollowedfor characteristicbandsofCDD film andlhemarblmatrix.Profile NMR-MOUSE(Mobile [Jniversal Surface Explorer)TheProfileNMR MOUSE[1] 12] is a portableNMR sensoreqippedwith a sinsle-sidedpermanentmagnelanangementgeneralinga uniformslaticmagneticfieldgradientsuitablefor highresohionsamptep.ofilingup to depthsofabout7 nrm&om objectsplacednearby.Its size is approximafely100 ' 100 x 80 mn1r.The working frequncyis 11.6MH4threforethe signal is due to thedecayof hydrogennucleus-The NMR signal deivesftom athin slicecentered7 nlm abovethedeviceparallelto its surfce,wherthefield stngthis0.411T and the gradientis 20 T/In alongthe depthdirection.The slicevolumeextendsabou!10x 10mrr alongthe lateraldirections,a sizethaiis deteminedby thegeometyof

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toxic than its acyclicanaloguez hexaeconsideredinsieadto be a neurotoxicsolvent.Cyclohexane'sboilingpoinl (81'C)appearedto be ableto conjugatetheeaseof applicationto sufficiently fast evaporalion.Ideed we found the crystals fomed wilh cyclohxanetobe nore squamouslike than reedlelike, ensuringbefter surfacecoveragevisually.Funhemore, different concentrationsof CDD in cyclohexanehave beenexanined, findingl/i w/v to be the nore satisfyingratio. Becausethis concentrationrepresenlsanoverstuatedsolution,gentle heating for a few secondsis necessary10 obtain ahomogeneoussohfion.

Figuel d: Opticalmiooscopeiaeesxl00 mag.a) natml Caran marble,b) CDD brushedapplication,c) CDD moltenandporredon surfaced) CDD spruyedatplicatio.

In the effort of conparison, white spirits, a solvent nomally employed in restorationenvirornents,afthoughdisplaying a greatertoxiciry, was utilizd to monitor the differentbehavior of solvents.wlite spirits is a linear and branchedalkane mixture wil a vriablecontentof aromatics(19% in our case)with a boiling rage betwen150-185"C.It wasobserved,by imagesat the optical microscope,that the solventroo can havea large effect onthe resultingmorphologyofthe cystalsl15l (figure2a-b)ofrhe CDD film whenthelatleris sprayedin solulion. This is consideredas an effeci of the parureterc in .he gowingcrystal system,such as the crystal bulk, solution buik and the bondary layer betweenlhecrystalandsolutionbulk containingthe interface[16].Thesolventcanbeassumed1oreducethe growih rate of cryslals and has 1obe removedfiom the surfacebefore the crylal faceThroughoutthe trialsof applicationandsolventchojce,fiber opticmid-FTIRwas abletodefinetheefiiciencyofthe film, i.e.whelheror nottheresultingfilrn coveredtheunderlyingmarblematrix sufiiciently,by thepresenceor absenceof characfedsticbandsof both theCDD and the marble. Fisure 3 displays speclraof a) natural Canara marble where, in the

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spectalregionextendingom 16001o1400cm ', thev3tundamentalsiretchingvibmtionoftheCOr' ion is obsened.Thisbehaviouris, mainly,the specularcompoenl,whichcausesmajor distofions to occur in thespectra,and evidnt in this caseis the so calledre.ststrdhlnband[17].Figure3b) showsa spectrrmofpure CDD, wiih numerouschatacteristicbndsfrom 950-1500cmr at 966, 1041,1076,1162and 1245cmr mosfly attributedtoasymnetricC-C sletchingmodesofvibration1181.Spectrumc) showsthemarbletreatedwith CDD, indicafingthe completecoverageof the marblematrix. d) insteadshowsspecfmof male treatedwith CDD afteronewek,wheretheCDD is nearlyall sublimedrevealis the marble undemeath.

Fisu.e2-brOpticalmicroscopeimagcsx100mag.of CDD aplied after24h in a) cyclohexane,

II --*- --tlt t'"^ (

t1b / \ J IL

Wavnumb6.(cm)Figue 3a-d: FTIR reflectdce spectE of a) natunl Camrateaiedarbleandd) sublimcdCDD onmrble. CDD stada.d. c) CDD


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From this. olher lhan lhe chemical nature ol lhe CDD aDdsolveDlcompositionsll9l, rhefilm fonnalion ad subsequentsublimation of the CDD ca be monjtored through badsboth charactcristicof tbe CDD, such as the afbrecnlioDedband at 1245 cn1j, and of Lhemarble subfrate al 1562 cm', hig1ighled in figure 3, that play inporraDt roles inconLrollingthe surfacesluctureof the film which cansi'nply defeminethe efticiecy oflhefilm fomed with eachsolvenl(ilgure 4) .From figure 4a, it is possibteliotn lbe chracte stic peak of CDD to Dote that both thesolutions of CDD/whiie spirils aDd CDD/cyclohexanebehave differently on the marblesurfaceuDderroom lenperalure ad pressure,where the rate of lbnnalion ofthe CDD filmis relatedto the evaporationoftbe solventwhich is obse\,ed1( ]slabilizeaftef circa 6 hous.

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Flgure4: Plolofpscudoabsorbanceoflnfraredpeakal a)1245cm r andb) 1562cm againr Lime(hou6)ofmarblebearedrvithCDD/Fhitcspi|itsd CDDhyclohexnreqrcctivclyFollowing such.tbe monltoring oIlhe CDD/cycbhexae film sublimalionoccursconstatlyafler 72 hoursand the peak at 1245 c111'is no loDgerobseNedafte 96 hours. The opticalmicroscopegives an insjghl of this subhnlior lvhere the film is punctured$,ilh holescrealis icreasinsly large lslandsolexposed marble (fisure 5a).

FiSne5a b: Opticairic.oscolennagesxl00 mag.ofCDD ptlied alter9 houNnr a)cyclohcranc,b) rvhitespnits.

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coNcLUstoNsIt has been possible to prelininarily study ihe applicajive mefbods of clctododecaneindiffernl solvenlsso as 1o acquirean emcienr consolidaringfilm for an appropriareamounloftime. In order to poducean emergencyprolocol for the applicationofcyclododecanetomarblesu{aces it has bce possibleto slirdy rhe ffecr ofdifferenr sotveDtson the duratioDlJ1the film. From the numeroussolventsstudied, resutts have ben given for rhe use ofcyclohexae and common white spirits. These esulrs show that lhc CDD/cyclohexaesoluiion createsa fi1m thaLca be observedwirh FTIR and profile-NMR MOUSE unril arleast 96 hours,wheasthe CDD/while spii1solufion can be observedup to 140 hours. ILhas alsobeenpossible1oobseNe the decrcasingofthe thicknessofrhe layer and the vhuaieilcls ofsublimalion, suggestigthat rheCDD sublincs, leavingbehind icreasingly lryeislandsof exposedundc.lying marble. It is shown thr rhe characrerisrjcsof the fit aiedecisive.l'he thickcss and durationofthe fiim and its morphologicalcharacreisrics.rrethemosl critical factosfor its effecliveess.CurcDl researchhas taken these pchinary resutts io accounl and numeous orhrsolvents are being lesled for thei du.abiliry of lhe CDD consolidringfilm formalion.Prescntstudieson a Droreporous slone (37.5%) compredro thar of marble (t%) indicateat the evaporalionrlte doesnol only dependon rhe chemicalnatureofthe compoa{tbu ialsoo the sfruclureoflhe impregnatedsyslem.Penet.atinginto nrore poroussyrem [20]or rto a more degradedsystemappcarsto imply a more prolongedevapomtionmle rhanonnon poroussoundsystems.Exteml factorsaftecting Lherateofsubhnalion are also beingtale i o considealion.such as varialionsin temperalure.humidity ad ventilatjon.BIBLIOGRAPHICREFERENCES[1 ] KeynanD , ryb creens.. waacNewderer22(2000)3l2 l Hanslcircr,H M., Efahrungcnmii fliichtigenBjrdemiitetn.parI . ,Resr,,o5:( |995)3I + 19.Jl l Hngleitr,ll.M, Erfhrdngnmit flchtigeBrdcmifteln.par 2 esalf7r(1998)46E7.].[,+]Hangleite.,H M.,JgersE.,and.gcsE.,FlchrigeBnrdcnirtel.2r(1995).18592.[5 ] Itiby, G.,DasfliichtigcBidemitielCyclododcca.nrtuuro2:(1991)g.-nj.[6 ] MurosV., Hin J.,JAIC 2004.Volle.11,Numberl. Afictc 6 75 89.I7 l BrucklcR, ThomroJ.. NichohK.. Sr.ickle.C., JAIC 1919,Volme 38,Nnnbcr 2, Aficle 4 .1 6 2 1 7 5 .[8 ] JagcrsE. ,Jage.sE.,In: BritisbMuseum,Occasioalpperno.l3j, 1999Ed.OddyA., Caroll S. .[9 ] MajshJ.P,Risse.E.,I^IC 4l (2002)127-1.17.l0 l Ricdl,N., andG Hilbcrt.,Cyclododecanin Purzgefiidge.nesrr,1:(1998)494 99.Illl PerloJ. er a1.,P.olilesrvithmicroscopic.esolurionby si.sle{idcd NMR, J. Magn.Reson.l7.(2005)64- 70.ll2l Blnich B.. EssentialNMR,Spnnger,Bcdin,2005.I l3 ] NIOSHAVHO/ltcrationalprosEmoncbemicalsafeq,.tntemei:hlt!lhnw cdc.gov/iosltipcs/italian.htmlll4l KuzmnraN.P. ,MrynenkoL. L, ChugerovN. V., ZairsevaL C..GigorievA. N.,.YakushevichA. N, JoumalofAlloysandConponnds308(2000)158 162.ll5l weissbuchL, LeiserorvitzJ. ,LahavM.. H6 in: . Mesann (!d.), CrystatlizatioTechologyl landbook,Ma..el Dckkcr,New Yo.k, 1995.

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116lte. Hosta J.H.,CeelmanbR.M., van RosmalenaG.M., Joufralof CrysialGrowrh230(2001)277 281.[17] RicciC..Mllidi C..BrunetriB.G.,SgamelloulA., Talta 69(2006)l22l 1226[18]MichaeliaK. H., Hall R. H., BulmrJ.T., SpectochimicaActaPartA 59(2003)8l l- 824-[19]MajumdarP..websterD.C.,Polymer47 (2006)41724181.[20]SteiR.,KimmelJ.,MarincolaM.. K1en F.,JAIC 39(2000)355-169

anselmi, c. et al. cyclododecane as a temporary con solid ant. 2008

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