1,721,001 research outputs found
Optical characterization and analysis of the gas/surface adsorption phenomena on phthalocyanines thin films for gas sensing application
No full textZn(II) tetra-4-(2,4-di-t-amylphenoxy)-phthalocyanine (1a), Zn(II) tris-(2,4-di-t-amylphenoxy)-[4-(4-mercapto-phenylimino-methyl)-
phenoxy] (1b) and Zn(II) tris-(2,4-di-t-amylphenoxy)-[4-(4-formyl)-phenoxy] (1c) phthalocyanine were synthesized. The molecular structures
were confirmed by LC–MS, 1H NMR, FT-IR and UV–vis spectra. Spin coated layers of these phthalocyanines have been used as optochemically
interactive materials for the detection of volatile organic compounds (VOCs) in the UV–vis spectral range. An optical characterization
in controlled atmosphere have been carried out by acquiring the absorption spectra of the phthalocyanine complexes both in dry-air and in the
presence of different volatile organic compounds in order to study the optical sensing properties of these thin organic layers towards specific
volatile organic compounds. The optical absorption spectra have been analyzed by using a deconvolution analysis centered on the Q and Soret
bands. The results of the optical VOCs sensing tests showed interesting differentiation in the optical responses depending on the peripheral
substituents of the macromolecules. Morphologic analyses were performed by atomic force microscopy (AFM). The VOC/surface absorption
processes were also analyzed in order to understand the VOC-detection mechanisms
UV-VIS Absorption Optosensing Materials Based on Metallophthalocyanines thin films
No full textThin films of different metallophthalocyanines (MPcs) [Zn(II) tetra-4-(2,4-di-t-amylphenoxy)-phthalocyanine (ZnPc); Cu(II) tris-(2,4-ditamylphenoxy)-(
12-hydroxy-1,4,7,10-tetraoxadodecyl)-phthalocyanine (CuPc) and Ru(II) tetra-4-(2,4-di-t-amylphenoxy)-phthalocyanine
(RuPc)] have been used as chemically interacting materials for sensing application of volatile organic compounds (VOCs). As transduction
technique of the sensor responses to the considered VOCs, the variation of the UV-Vis optical absorption spectra was used. The results of
vapour-sensing tests in controlled atmosphere are here discussed. Glass substrates were covered with the different synthesised metallophthalocyanines
in thin film form by using spin coating technique in order to generate stable and reproducible sensing layers having good
response and selectivity depending on both the central metal ion of the molecules and the peripheral substituents of the macrocycles. A
promising selectivity towards some alcohols, alkanes, esters, chetones and aldehydes has been found
“New substituted phthalocyanines as conductive gas sensors ”
No full textSECOND INTERNATIONAL CONFERENCE ON PORPHYRINS AND PHTHALOCYANINES. KYOTO TERRSA, KYOTO, JAPAN, 30 JUNE- 5 JULY , 2002. P-23
A novel multisensing optical approach based on a single phthalocyanine thin films to monitoring volatile organic compounds
No full textThis paper reports the use of optical trasduction techniques to characterise solid state chemo-optical sensors prepared by Langmuir–Sch ̈afer technique (LS) in thin film form based onto Cu(II) tris-(2,4-di-t-amylphenoxy)-(12-hydroxy-1,4,7,10-tetraoxadodecyl)-phthalocyanine macromolecules CuPcOH as active layers. The study consists in the UV–vis optical absorption monitoring of the active LS layers in the presence of specific five volatile organic compounds (VOCs) mixed in dry air in controlled atmosphere; in particular tert-butylamine, methanol, ethanol, hexane and ethyl acetate, all analytes of interests in the food quality control. The UV–vis spectra have been monitored by recording the dynamic variation in the integral of the absorbance curves in well defined spectral regions: 300–400 nm, 550–600 nm, 600–640 nm, 640–700 nm, covering the whole spectrum and centred around the typical absorption bands of phthalocyanine thin films. This simultaneous UV–vis four channel monitoring allowed to use only one active layer as sensing element where each selected spectral region generates independent sensors. The dependency of the above mentioned outputs towards the analytes has been discussed. A base optical characterisation of the investigated LS thin films has been performed
Synthesis of Tailored Phthalocyanines and Their Application as Spin Coated Films in Volatile Organic Compounds Detection
No full text29H,31H-(2,4-di-t-amylphenoxy)phthalocyanine, Zn(II) tetra-4-(2,4-di-t-amylphenoxy)phthalocyanine and Zn(II) tris-(2,4-di-t-amylphenoxy)-[4-(4-mercapto-phenyliminomethyl)-phenoxy]phthalocyanine were synthesized and their mol. structures were confirmed by LC-MS, 1H NMR, FTIR and UV-visible spectra. Spin coated layers of these phthalocyanines were used as optochem. interactive materials for volatile org. compds. detection in the UV-visible spectral range. The results show a good sensitivity and selectivity depending on both the metal and the peripheral substituents. Optical sensitivity towards tert-butylamine, diethylamine, dibutylamine, 2-butanone and HOAc was monitored
Spin-coated thin films of metal porphyrin-phthalocyanine blend for an optochemical sensor of alcohol vapours
Full text linkOrganic thin films based on a blend of two types of metal-co-ordinated macromolecules, i.e. Zn(II) tetra-4-(2,4-di-tert-amylphenoxy)phthalocyanine (ZnPc) and Cu(II) tetrakis(p-tert-butylphenyl)porphyrin (CuP) have been deposited by spin-coating and used as optical chemically interacting materials for the detection of methanol, ethanol and isopropanol vapours. This paper reports the use of a specific optical technique consisting of the selection of four specific spectral regions taken in the UV-Vis spectral range corresponding to the typical Q and Soret bands of the phthalocyanine and porphyrin macromolecules and their corresponding blends. The variations in the absorption peaks obtained by the exposure of the single ZnPc and Cup sensing layers to the considered vapours in controlled atmosphere have been analysed and compared with those derived from a thin film obtained by mixing the two metal complexes in an appropriate ratio. The performance of the heterogeneous sensing layer (i.e. ZnPc/CuP blend)-based sensor evaluated in term of response and selectivity is different from that of single homogeneous films
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