Karbon dioksit tayininde kullanılmak üzere indikatörlerin modifikasyonu ve çeşitli polimer matrikslerde denenmesi

Abstract

Genel sensör tasar%mlar%n%n ço)unda, dissosiyasyona u)ram%. veya u)ramam%. halleri farkl%absorpsiyon ve emisyon maksimumu gösteren zay%f asidik yap%daki pH indikatöleri kullan%l%r.Bu çal%.mada, pH ölçümleri için dimetilamino gruplar% içeren modifiye floresans Schiffbazlar%; N1,N2-bis{(E,2E)-3-[4-dimetilamino)fenil]-2 propeniliden}-1,2-etandiamin (SB-I),N1{(E,2E)-3-[4-dimetilamino)fenil]-2- propeniliden }-N4,N4-dimetil?1,4-benzen-diamin(SB-II), 4-{(1E, 3E)-3-[(4-klorofenil)imino]-1-propenil}-N,N-dimetilanilin (CPIPA) ve N,Ndimetil?4-{(1E,3E)-3-[(4-nitrofenil)imino]-1-propenil}anilin (NPIPA) kullan%lm%.t%r. Sözkonusu Schiff bazlar% etilselüloz (EC) ve polivinilklorür (PVC) kat% fazlar%nda denenmi.tir.Schiff bazlar%n%n spektral karakterizasyonu, kuantum verimi ve asitlik sabiti (pKa)hesaplamalar% yayg%n kullan%lan çözgenlerde, PVC ve EC kat% matrikslerindegerçekle.tirilmi.tir.mmobilize Schiff bazlar% SB-I (pKa= 4.27 PVC'de), SB-II (pKa= 10.68PVC'de), CPIPA (pKa= 10.32 PVC'de) ve NPIPA (pKa= 8.8 PVC'de) s%ras%yla 2.0?7.0, 8.0?12.0, 7.0?12.0 ve 8.0?12.0 pH aral%klar%nda protona absorpsiyon ve emisyon .iddetindekide)i.melere dayal% optik yan%t vermi.tir.Çözelti faz% ile kar.%la.t%r%ld%)%nda boyalar%n immobilizasyonun bu materyallerin floresans%n%artt%rd%)% görülmü.tür. Sensör filmlerin yan%tlar% çal%.ma aral%)%nda tamamen tersinirdir veyan%t süreleri 1 dakikadan azd%r.ncelenen modifiye indikatörlerden NPIPA'n%n karbon dioksit denemelerindekullan%labilece)i belirlenmi. ve EC matrikste gaz faz%nda karbon dioksit yan%t% test edilmi.tir.Sensör bile.imlerinin gaz faz%nda karbon dioksite yan%t% perfloroasit (PFA) vetetrabutilamonyum hidroksit (TBAOH) varl%)%nda ve yoklu)unda incelenmi.tir.

In most of the common designs, pH optodes rely on weak acidic dyes whose dissociated andundissociated forms have different absorption or emission maxima. In this workdimethylamino bearing fluorescent rich Schiff bases N1,N2-bis{(E,2E)-3-[4-dimethylamino)phenyl]-2-propenylidene}-1,2-ethanediamine (SB-I), N1{(E,2E)-3-[4-dimethylamino)phenyl]-2-propenylidene}-N4,N4-dimethyl-1,4-benzene-diamine (SB-II), 4-{(1E, 3E)-3-[(4-cholorphenyl)imino]-1-propenyl}-N,N-dimethylaniline (CPIPA) and N,Ndimethyl-4-{(1E,3E)-3-[(4-nitrophenyl)imino]-1-propenyl}aniline (NPIPA) have been usedfor pH sensing in the solid matrices of ethyl cellulose (EC) and plasticized PVC. Spectralcharacterization, quantum yield and acidity constant (pKa) calculations of the Schiff baseswere performed in the conventional solvents or in the solid matrices of PVC and EC. Theimmobilized Schiff bases SB-I (pKa= 4.27 in PVC), SB-II (pKa= 10.68 in PVC), CPIPA(pKa= 10.32 in PVC) and NPIPA (pKa= 8.8 in PVC) exhibited absorption and emission basedoptical response to proton in the pH range of 2.0-7.0, 8.0-12.0, 7.0-12.0 and 8.0-12.0respectively.Immobilization of the dye effectively enhanced the fluorescence of these materials comparedto solution. Responses of the sensor slides were fully reversible within the dynamic workingrange and the response times were less than 1 min.Also, NPIPA was tested for carbon dioxide determinations in ethyl cellulose matrix. Theresponse of the sensor composition to gaseous carbon dioxide has been evaluated in theabsence and presence of the perfluoro compound (PFC) and tetrabutylammonium hidroxide(TBAOH).