Poly Bis Research Articles

Synthesis and Electrochemical Properties of a Novel Aniline-Based Polyorganodisulfide

From facile preparation method and available low-cost raw materials, we have synthesized a novel kind of aniline-based organodisulfide bis(2-aminobenzyl) disulfide (OABD) and its homopolymer (POABD). The polymer POABD was characterized by Fourier transform infrared spectroscopy (FT-IR) and cyclic voltammetry. The cyclic voltammetry tests reveal that the redox of the S-S bonds behavior in the anodic and cathodic peak potentials differences for poly(bis(2-aminobenzyl) disulfide) is 70 mV. The results indicated that poly(bis(2-aminobenzyl) disulfide) has an excellent electrochemical reversibility.

석조문화재 보존.복원에 적용될 에폭시 수지의 경화 시 반응열 제어 및 안정성 향상 연구

The exothermic cure kinetics of epoxy resin was controlled by hardener containing fast and slow curing agents. The epoxy risen comprises hydrogenated bisphenol A-based epoxide (HBA), fast curing agent (FH) and slow curing agent poly(propyleneglycol)bis(2-aminopropylether) (SH). Talc was used as an inorganic additive. In the process of curing, cure kinetics along with temperature was monitored by differential scanning calorimeter (DSC) and thermocouple to show that the temperature increase was well controlled by adjusting the hardener mixture. Additionally, bending and tensile strengths of the epoxy/talc composites were also measured to be lower and higher with the amount of the talc inorganic additive, respectively. It is thus concluded that the increase in the temperature during exothermic curing reaction and mechanical properties of epoxy resins are tuned by optimizing hardener mixture for successful stone conservation.

Dielectric spectroscopy of polyazomethine with vinylene moieties in the main chain

We have explored the dielectric properties of polyazomethine with vinylene moieties in the main chain (PAZ-PV). The dialdehyde 2,5-bis(hexyloxy)-1,4-bis[(2,5-bis(hexyloxy)-4-formyl-phenylenevinylene]benzene was polymerised in solid-state with the diamine poly(1,4-butanediol)bis(4-aminobenzoate). The polymer obtained exhibited liquid crystal properties. The molecular dynamics and phase transitions including the liquid crystal phase of PAZ-PV were investigated by dielectric spectroscopy. The dielectric constant decreases with a decrease in the temperature, except in the nematic phase region, where a slight increase was observed. The temperatures of the phase transitions were well seen and were compared with differential scanning calorimetry (DSC) and polarised optical microscopy experiments. All values determined from dielectric data were a few degrees higher than those obtained in previous measurements (DSC).

Selective extraction of genotoxic impurities and structurally alerting compounds using polymeric ionic liquid sorbent coatings in solid-phase microextraction: Alkyl halides and aromatics

A series of polymeric ionic liquids (PILs) possessing varied chemical makeup and composition were applied as selective solid-phase microextraction (SPME) sorbent coatings for the analysis of genotoxic impurities (GTIs) and related structurally alerting compounds, namely, alkyl halides and aromatics. In addition to exploiting two previously synthesized PILs as selective coatings, two new PILs, namely, N,N-didecyl-N-methyl-d-glucaminium poly(2-methyl-acrylic acid 2-[1-(3-{2-[2-(3-trifluoromethanesulfonylamino-propoxy)-ethoxy]-ethoxy}-propylamino)-vinylamino]-ethyl ester) (poly([DDMGlu][MTFSI])), and poly(1-vinyl-3-propylphenylimidazolium) chloride (poly([VPPIM][Cl])), were designed, synthesized, and their selectivity examined in the extraction of the selected analytes. The glucaminium-based coating was developed to exploit the hydrogen bond-acidic hydroxyl groups within the carbohydrate moiety of the PIL in addition to dispersive capabilities resulting from the cation and anion. The poly([VPPIM][Cl]) coating was tailored to possess π–π interaction capabilities through the phenyl functionality while also containing the hydrogen bond-basic chloride anion. Calibration studies were performed via headspace extraction to determine the sensitivity and limit of detection (LOD) for all analytes with respect to each PIL-based sorbent coating and compared to the polyacrylate (PA) and polydimethylsiloxane (PDMS) sorbent coatings. PILs containing the chloride anion exhibited high selectivity for aniline-based compounds. The glucaminium-based PIL exhibited good sensitivity for larger aliphatic alkyl halides. The poly(1-4-vinylbenzyl-3-hexadecylimidazolium) bis[(trifluoromethyl)sulfonyl] imide (poly([VBHDIM][NTf2])) PIL coating demonstrated superior selectivity for larger aliphatic/aromatic analytes. The LODs of both commercial and PIL-based coatings for the two classes of GTIs ranged from low part-per-billion (ppb) to mid part-per-trillion (ppt) levels. Recovery studies were performed at two concentration levels within the linear range in order to validate the accuracy of the technique. Scanning electron micrographs were obtained for three PIL-based coatings following approximately 70 extraction/desorption steps, wherein the fiber coatings were observed to be largely smooth and intact.

Evaluation of the dielectric properties of grease containing copolymers and ester

AbstractPoly(1‐octadecene‐co‐maleic anhydride) bis behanate ester, poly(1‐octadecene‐co‐maleic anhydride) bis stearate ester, and ethylene glycol bis stearate ester were prepared and their structures were confirmed by IR spectroscopy. Wax gel was prepared from base oil blend (base lube oil grade 260/290, transformer oil) and microcrystalline wax in ratio 2.3 : 1, respectively, in the presence of antioxidant and anticorrosion additives in ratio of 0.1–2%. Atactic polypropylene was added in mixture with the above copolymers and ester to the wax gel in different proportions. Dielectric constant, dielectric loss, and volume resistivity at frequency range of 1–103 kHz 35°C have shown better results than that of wax gel alone. The grease which includes poly(1‐octadecene‐co‐maleic anhydride) bis behanate ester in mixture with atactic polypropylene recorded the best results. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

Synthesis of Polylactide-b-Poly (Dimethyl Siloxane) Block Copolymers and Their Blends with Pure Polylactide

The synthesis of polylactide (PLA)-b-poly (dimethyl siloxane) (PDMS) linear block copolymers and their use in blends with pure-PLA are described. PLA-b-PDMS linear block copolymers were obtained by the transesterification reaction in chloroform solution between poly(dimethyl siloxane) bis (2-aminopropyl ether) (molecular weight 2,000 Da) with PLA in the presence of stannous octoate. Molecular weights (Mw) of the block copolymers were varied from 53,800 to 63,600 Da while that of pristine PLA was 73,600 Da. The copolymers obtained were purified by fractional precipitation and then characterized by 1H NMR, FTIR, GPC, viscometry and DSC techniques. Blends of pure PLA with PLA-b-PDMS block copolymers displayed improved elastic properties (elongation up to 140%) compared to pure PLA (elongation ~9%). Thermal, mechanical and morphological characterization of the blends were also conducted.

Orientational disorder and geometrical isomeric effect on nonlinear optical properties of poly bis(glycine)cadmium chloride

Poly bis(glycine)cadmium chloride (BGCC) crystals of both undoped and doped with thiourea (Tu) were grown from saturated solutions by a slow evaporation technique. The geometrical isomerism of the octahedral BGCC molecule is investigated using single crystal XRD, powder XRD and FT-IR. The significant difference between the two isomers namely facial ( fac) and meridional ( mer), is explained in terms of the different point group symmetries of C 3 and C 1, respectively. The loss of point group symmetry from C 3 to C 1 is attributed for the observed powder second-harmonic generation (SHG). Semi-empirical calculations from the optimized geometrical parameters also supported non-linear optical properties of the material.

Characterization, liquid crystalline behavior, electrochemical and optoelectrical properties of new poly(azomethine)s and a poly(imide) with siloxane linkages

New siloxane-containing poly(azomethine)s and a six-membered poly(imide) have been developed from siloxane-containing diamine with four different dialdehydes and 3,4,9,10-perylenetetracarboxylic dianhydride, and their thermotropic behavior, optoelectrical and electrochemical properties were examined. Mesomorphic behavior of the polymers was investigated via differential scanning calorimetry (DSC), polarizing optical microscopy (POM) and X-ray diffraction (WAXRD, SAXRD) studies. The electrochemical behavior of poly(azomethine)s and poly(imide) was studied by differential pulse voltammetry (DPV). The HOMO levels of these polymers were in the range of −5.13 to −5.90 eV. UV–vis properties of the polymers were investigated in solid state as thin films and in chloroform solution. Optical energy band gap ( E g opt. ) was calculated from absorption spectra and absorption coefficients α. The photoluminescence properties (PL) of obtained polymers were studied in chloroform solution. The investigated poly(azomethine)s emitted blue light, while the poly(imide) emitted green light. The polymers were irradiated with a test dose of 1 Gy Co-60 gamma-rays to detect their thermoluminescence properties in the temperature range of 50–200 °C. Polymer monolayer (ITO/polymer/Al) and bulk heterojunction (BHJ) (ITO/polymer:PCBM/Al and ITO/PEDOT:PSS/polymer:PCBM/Al) devices were prepared with PAZ and PI used as active layers and I– U curves were measured in the dark and during irradiation with light (under illumination of 1000 W/m 2). Poly(azomethine)s were blended with [6,6]-phenyl C 61 butyric acid methyl ester (PCBM). Selected properties of the investigated polymers with siloxane linkages were compared with the polymers ( PAZ1a– PAZ3a, PIa) prepared from the same dialdehydes or dianhydride and poly(1,4-butanediol)bis(4-aminobenzoate).

PEGylated hollow mesoporous silica nanoparticles as potential drug delivery vehicles

Herein we reported the PEGylated hollow mesoporous silica (HMS-PEG) nanoparticles as drug vehicles for drug delivery. Hollow mesoporous silica (HMS) nanoparticles with the diameter of ca. 100 nm were synthesized using the colloidal carbon spheres as templates, and HMS-PEG nanoparticles were successfully prepared by covalently grafting poly(oxyethylene)bis(amine) on amino-group modified HMS nanoparticles with p-phenylene diisothiocyanate (DITC) as a cross linker. HMS-PEG nanoparticles exhibited much better dispersity and stability in aqueous solution than HMS nanoparticles. In vitro cytotoxicity and cell uptake of HMS-PEG nanoparticles to Hela and NIH3T3 cells were evaluated. HMS-PEG nanoparticles have little in vitro cytotoxicity up to a concentration of 150 μg/ml, and the uptake amount of HMS-PEG nanoparticles is approximately two times than that of HMS nanoparticles in Hela and NIH3T3 cells. Doxorubicin hydrochloride (DOX), an anticancer drug, was loaded into HMS-PEG nanoparticles, and the DOX-loaded HMS-PEG nanoparticles had a sustained release property. Furthermore, the DOX-loaded HMS-PEG nanoparticles exhibited higher cytotoxicity than the DOX-loaded HMS nanoparticles against Hela and NIH3T3 cells. Therefore, the PEGylation of HMS nanoparticles is a promising strategy toward their potential application as drug delivery vehicles.

Immobilization of immunoglobulin G in a highly oriented manner on a protein-A terminated multilayer system

In this study, we have fabricated a multilayer system consisting of 3-glycidoxypropyldimethylmethoxysilane (GPDS), poly(dimethylsiloxane) bis 3-aminopropyl terminated (PDMS) and protein-A on a silicon wafer surface for oriented immobilization of immunoglobilin G (IgG). The multilayer system with a different component in each layer was characterized by ellipsometry, contact-angle goniometer, X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) and fluorescence microscopy. The epoxy-terminated monolayer was formed by the chemisorption of GPDS molecules on the hydroxylated silicon surface. The PDMS film about 4.5 nm thick was produced on the GPDS-monolayer by the chemical reaction between the amine groups at the end of PDMS chain and the epoxy groups of GPDS molecules. By introducing the PDMS chains, the hydrophilic character of GPDS-monolayer decreased. Study of the time dependence of polymer grafting showed that the chemisorption of GPDS is fast, whereas at least 16 h is needed to generate the homogeneous PDMS layer. For immobilization of IgG molecules in a highly oriented manner, protein-A molecules were first chemically bound to an ultrathin (∼4.5 nm) PDMS reactive polymer layer and later used to capture IgG. It was shown that the existence of protein-A in the multilayer system has a strong influence on the binding properties of IgG not only in the efficiency of binding, but also in its specificity. In conclusion, the multilayer system with protein-A has the potential to be further developed into an efficient immunoassay protein chip.

Aliphatic–aromatic poly(azomethine)s with ester groups as thermotropic materials for opto(electronic) applications

We have explored the opto(electronic) and liquid crystal properties of a new series of semiconducting materials based on aliphatic–aromatic poly(azomethine)s. The structures of polymers were characterized by means of FTIR, 1H, 13C NMR spectroscopy, and elemental analysis. UV–vis properties of the thin films of the polymers were investigated on the quartz substrate. The lowest optical energy gap ( E g ) at 2.28 eV was found. The polymers were irradiated with a test dose of 2 Gy Co-60 gamma-rays to detect their thermoluminescence properties in the temperature range 25–200 °C. Mesomorphic behavior was investigated via differential scanning calorimetry (DSC) and polarizing optical microscopy (POM) studies. Being into consideration backbone geometry, all polymers, excepted polymer PAZ2, obtained from poly(1,4-butanediol)bis(4-aminobenzoate) and 9-(2-ethylhexyl)carbazole-3,6-dicarboxaldehyde, exhibited liquid-crystalline properties. Moreover, the electrical characterizations of bulk heterojunction (BHJ) and bilayer devices with the following architecture ITO/PEDOT/PAZ:TiO 2/Al were investigated. Additionally, devices without and with TiO 2 layer such as ITO/PAZ/Al and ITO/TiO 2/PAZ/Al were prepared and investigation in the dark and during irradiation with light (under illumination 1000 W/m 2). The sol–gel technique was applied to prepared TiO 2 layers and powders. Moreover, impedance spectroscopy at different temperatures for electrical properties measurement was used. Additionally, the compounds were tested using various AFM techniques such as Mode and Phase Imaging and local contrast force–distance curve measurement and roughness (Ra, Rms) along with skew and kurtosis are presented.

Synthesis and structural characterization of dendritic-linear PMA-APM-r-PS copolymers for a self-assembled microporous matrix

A set of dendritic-linear copolymers, poly(maleic anhydride-grafted-3,3′-dimethyl-(4-aminophenylazanediyl)bis(2-methylpropanoate))-random-polystyrene (PMA-APM-r-PS), was successfully prepared by copolymerization of the novel dendritic macromonomer, 4-(4-(bis(3-(4-(bis(3-methoxy-2-methyl-3-oxopropyl)amino)phenylamino)-2-methyl-3-oxopropyl)amino)phenylamino)-4-oxobut-2-enoic acid (MA-APM), with styrene monomer. The dendritic MA-APM macromonomer dendron 3,3′-dimethyl-(4-aminophenylazanediyl)bis(2-methylpropanoate) (APM) was then grafted by using the divergent growth method. FTIR, 1H NMR, and 13C NMR spectra were used to identify the structures of the dendron, the dendritic macromonomer, and the dendritic-linear PMA-APM-r-PS copolymer. Furthermore, microporous dendritic-linear PMA-APM-r-PS copolymer films were prepared by using solvent-induced phase separation at room temperature. We investigated the phase separation behavior and morphological structures of the dendritic-linear copolymer film as functions of dendritic GMA-HPAM segments in the content using SEM. Self-assembly of the dendritic-linear PMA-APM-r-PS copolymer in the MG2-X system, which represented the second generation dendron containing X wt % of the dendritic MA-APM segment, resulted in submicron phase segregation. Interestingly, the submicron phase segregation morphology of the MG2–43 sample presented a uniform size distribution of ordered-array structures. The results of this study demonstrate that controlling the appropriate macromonomer content via the grafting of a three-dimensional structure results in a self-assembly process that is capable of providing an ordered-array microporous morphology in a polymer film. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3290–3301, 2010

Selective extraction of CO 2 from simulated flue gas using polymeric ionic liquid sorbent coatings in solid-phase microextraction gas chromatography

The CO 2 selectivity of two polymeric task-specific ionic liquid sorbent coatings, poly(1-vinyl-3-hexylimidazolium) bis[(trifluoromethyl)sulfonyl]imide [poly(VHIM-NTf 2)] and poly(1-vinyl-3-hexylimidazolium) taurate [poly(VHIM-taurate)], was examined using solid-phase microextraction (SPME) for the determination of CO 2 in simulated flue gas. For comparison purposes, a commercial SPME fiber, Carboxen™-PDMS, was also studied. A study into the effect of humidity revealed that the poly(VHIM-taurate) fiber exhibited enhanced resistance to water, presumably due to the unique mechanism of CO 2 capture. The effect of temperature on the performance of the PIL-based and Carboxen fibers was examined by generating calibration curves under various temperatures. The sensitivity, linearity, and linear range of the three fibers were evaluated. The extraction of CH 4 and N 2 was performed and the selectivities of the PIL-based and Carboxen fibers were compared. The poly(VHIM-NTf 2) fiber was found to possess superior CO 2/CH 4 and CO 2/N 2 selectivities compared to the Carboxen fiber, despite the smaller film thicknesses of the PIL-based fibers. A scanning electron microscopy study suggests that the amine group of the poly(VHIM-taurate) is capable of selectively reacting with CO 2 but not CH 4 or N 2, resulting in a significant surface morphology change of the sorbent coating.

Highly selective GC stationary phases consisting of binary mixtures of polymeric ionic liquids

GC stationary phases composed of binary mixtures of two polymeric ionic liquids (PILs), namely, poly(1-vinyl-3-hexylimidazolium) bis[(trifluoromethyl)sulfonyl]imide (poly(ViHIm-NTf(2)))/poly(1-vinyl-3-hexylimidazolium) chloride (poly(ViHIm-Cl)) and poly(1-vinyl-3-hexadecylimidazolium) bis[(trifluoromethyl)sulfonyl]imide (poly(ViHDIm-NTf(2)))/poly(1-vinyl-3-hexadecylimidazolium) chloride (poly(ViHDIm-Cl)), were evaluated in terms of their on-set bleed temperature and separation selectivity. A total of six neat or binary PIL stationary phases were characterized using the solvation parameter model to investigate the effects of the polymeric cation and anion and PIL composition on the system constants of the resulting stationary phases. The hydrogen bond basicity of the mixed poly(ViHIm-NTf(2))/poly(ViHIm-Cl) stationary phases was enriched linearly with the increase in the poly(ViHIm-Cl) content. Results revealed that tuning the composition of the stationary phase allowed for fine control of the retention factors and separation selectivity for alcohols and carboxylic acids as well as selected ketones, aldehydes, and aromatic compounds. A reversal of elution order was observed for particular classes of analytes when the weight percentage of the chloride-based PIL was increased.

Polymeric Ionic Liquids as CO2 Selective Sorbent Coatings for Solid-Phase Microextraction

Two polymeric ionic liquids (PIL) were synthesized and employed as sorbent coatings in solid-phase microextraction (SPME) for the selective extraction of CO(2). The two coatings, poly(1-vinyl-3-hexylimidazolium) bis[(trifluoromethyl)sulfonyl]imide [poly(VHIM-NTf(2))] and poly(1-vinyl-3-hexylimidazolium) taurate [poly(VHIM-taurate)], exhibited varied selectivity toward CO(2) due to functional groups within in the PIL that imparted different mechanisms of CO(2) capture. Extraction efficiencies were compared to those of two commercial SPME fibers [poly(dimethylsiloxane) (PDMS) and Carboxen-PDMS]. The poly(VHIM-NTf(2)) PIL fiber exhibited comparable extraction efficiency at high CO(2) pressure compared to the Carboxen-PDMS fiber, even though the PIL-based fibers possessed much smaller film thicknesses. Calibration curves generated in pure CO(2) showed that the sensitivity of the poly(VHIM-NTf(2)) coating was comparable to that of the Carboxen-PDMS fiber with both PIL-based fibers exhibiting larger linear ranges and higher extraction-to-extraction reproducibility. The storage ability for selected fibers was examined and revealed that the PIL-based coatings exhibited superior capability in retaining the CO(2) sorbate on the fiber under different storage conditions, particularly for the poly(VHIM-taurate) PIL which reversibly captures CO(2) as a carbamate salt.

Determination of water pollutants by direct-immersion solid-phase microextraction using polymeric ionic liquid coatings

The determination of a group of eighteen pollutants in waters, including polycyclic aromatic hydrocarbons and substituted phenols, is conducted in direct-immersion solid-phase microextraction (SPME) using the polymeric ionic liquid (PIL) poly(1-vinyl-3-hexadecylimidazolium) bis[(trifluoromethyl)sulfonyl]imide as a novel coating material. The performance of the PIL fiber coating in the developed IL-SPME-gas chromatography (GC)-mass spectrometry (MS) method is characterized by average relative recoveries of 92.5% for deionized waters and 90.8% for well waters, average precision values (as relative standard deviations, RSD%) of 11% for deionized waters and 12% for well waters, using a spiked level of 5 ng mL(-1). The detection limits oscillate from 0.005 ng mL(-1) for fluoranthene to 4.4 ng mL(-1) for 4-chloro-3-methylphenol, when using an extraction time of 60 min with 20 mL of aqueous sample. The extraction capabilities of the PIL fiber have been compared with the commercial SPME coatings: polydimethylsyloxane (PDMS) 30 microm, PDMS 100 microm and polyacrylate (PA) 85 microm. The PIL fiber is superior to the PDMS 30 microm for all analytes studied. A qualitative study was also carried out to compare among the nature of the coating materials by normalizing the coating thickness. The PIL material was shown to be more efficient than the PDMS material for all analytes studied. The PIL coating was also adequate for nonpolar analytes whereas the PA material was more sensitive for polar compounds.

Ternary polymer electrolytes containing pyrrolidinium-based polymeric ionic liquids for lithium batteries

The electrochemical properties of solvent-free, ternary polymer electrolytes based on a novel poly(diallyldimethylammonium) bis(trifluoromethanesulfonyl)imide polymeric ionic liquid (PIL) as polymer host and incorporating PYR 14TFSI ionic liquid and LiTFSI salt are reported. The PIL–LiTFSI–PYR 14TFSI electrolyte membranes were found to be chemically stable even after prolonged storage times in contact with lithium anode and thermally stable up to 300 °C. Particularly, the PIL-based electrolytes exhibited acceptable room temperature conductivity with wide electrochemical stability window, time-stable interfacial resistance values and good lithium stripping/plating performance. Preliminary battery tests have shown that Li/LiFePO 4 solid-state cells are capable to deliver above 140 mAh g −1 at 40 °C with very good capacity retention up to medium rates.

Phosphorescent Polymer Light-Emitting Devices Doped with Red Iridium (III) Bis(2-phenyl-Isoquinoine)(2-acetyl-cyclohexane) Complex

Devices with a configuration of ITO/PEDOT/Ir-PIQCH (10 wt%) in Polymer/BAlq (30 nm)/Alq3(20 nm)/LiF (1 nm)/Al (120 nm) were fabricated. In the emitting layer, three different polymers, poly(N-(2-ethyhexyl)-3,6-dibromocarbazole-alt-aniline) (P(3,6-EHCZ-alt-Al)) ( 1 ), poly(bis[6-bromo-N-(2-ethylhexyl)-carbazole-3-yl-alt-aniline] (P(Bis-EHCZ-alt-Al)) ( 2 ) and poly(N-(2-ethyhexyl)-2,7-dibromocarbazole-alt-aniline) (P(2,7-EHCZ-alt-Al)) ( 3 ) were used as a host material, respectively, and new cyclometalated red phosphorescent iridium complex with phenyl-isoquinoline and 2-acetyl-cyclohexanone ligands (Ir-PIQCH) was employed as a guest material. Surface morphology of thin emitting films fabricated by spin-coating from the dilute solution was studied by using 3D optical analyzer. The average roughness of the surface was measured in the range of 1-2 nm to show the films uniformly formed. From the electroluminescent measurement, a red electrophosphorescence was observed with emission peak at approximately 620 nm, 624 nm or 632 nm for Ir-PIQCH doped P(3,6-EHCZ-alt-Al) ( 1 ), Ir-PIQCH doped P(Bis-EHCZ-alt-Al) ( 2 ) or Ir-PIQCH doped P(2,7-EHCZ-alt-Al) ( 3 ) device.

Thermal, optical, electrical and structural study of new symmetrical azomethine based on poly(1,4-butanediol)bis(4-aminobenzoate)

The synthesis, characterization and mesomorphism of new thermotropic imine prepared via condensation of biphenyl-4-carboxaldehyde with poly(1,4-butanediol)bis(4-aminobenzoate) was reported. The structure of imine was characterized by means FTIR, 1H, 13C NMR spectroscopy and elemental analysis; the results show an agreement with the proposed structure. The differential scanning calorimetry, polarizing optical microscopy and X-ray diffraction (WAXRD, SAXRD) were employed to evaluate their phase transitional behavior. The imine exhibited smectic A (SmA) and smectic B (SmB) mesophases. Liquid crystalline properties of the azomethine were studied additionally via UV–vis spectroscopy in the function of temperature (UV–vis(T)). The compound has one emission band at 360 nm and thermoluminescence emission occurs at about 500–600 nm wavelengths. Current–voltage measurements were performed on ITO/AZ/Alq 3/Al device with three different thickness of the film.

Chemiresistor sensors array optimization by using the method of coupled statistical techniques and its application as an electronic nose for some organic vapors recognition

An electronic nose (EN) based on an array of chemiresistors, combined with a preconcentrator unit, for the detection of some volatile organic vapors was developed. In order to choose the proper polymers, seven potential polymers were chosen from numerous available polymers according to the principle of the linear solvation energy relationship (LSER). Different possible sensors arrays (128 arrays) composed of these seven polymers were designed by full factorial design (FFD). Principal component analysis (PCA) showed that four of seven polymers had enough ability to recognize different gas classes. By using Hierarchical cluster analysis (HCA), the tested polymers were categorized into four main groups with respect to their recognition ability. Combination of the FFD with PCA and HCA, brought to the identification of 8 proper arrays containing four polymers in each array. Precisely evaluation of predicted arrays with respect to their calculated resolution factors showed that the electronic nose containing the polymers of 75% pheny125% methylpolysiloxane (OV25), hexafluoro-2-propanolsubstituted polysiloxane (SXFA), poly bis(cyanopropyl)-siloxane (SXCN) and poly(ethylene maleate) (PEM) was the most proper design for recognition of analytes of interest. The fabricated EN was used successively for target gas recognition at three different concentrations.