Sensors for liquids based on conductive immiscible polymer blends

Narkis, M.; Srivastava, Surabhi; Tchoudakov, R.; Breuer, O.

doi:10.1016/s0379-6779(00)00187-9

Cited by 110 publications

(66 citation statements)

References 14 publications

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“…The study of the PTC effect attracted much attention in recent years because of the perspectives of applications, namely for temperature sensors, materials for production of thermistors, self-regulating heaters, etc [8][9][10][11][12][13]. The nature of the PTC effect is not definitively clear, but it is generally accepted that the sharp increase of resistance with increase of temperature is caused by the thermal expansion of the thermoplastic matrix near the melting temperature.…”

Section: Introductionmentioning

confidence: 99%

PTC effect and structure of polymer composites based on polyethylene/polyoxymethylene blend filled with dispersed iron

Mamunya

Muzychenko

Lebedev

et al. 2006

Polymer Engineering & Sci

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The temperature dependence of resistivity, structure, and thermal expansion of composites based on polyethylene/polyoxymethylene (PE/POM) blends filled with dispersed iron (Fe) have been studied. The dependence of conductivity on filler content shows percolation behavior, with the values of the percolation thresholds equal to 21 vol% for PE‐Fe, 24 vol% for POM‐Fe, and 9 vol% for the filled blend PE/POM‐Fe, with two‐step character of the conductivity curve. The evolution of structure of the composite PE/POM‐Fe demonstrates transition from polymer matrix POM‐Fe, with inclusions of PE through cocontinuous phases of both POM‐Fe and PE, to PE matrix, with inclusions of POM‐Fe. Such a structure occurs due to localization of the filler only in one of the polymer phases, namely in POM. Measurements of the coefficient of thermal expansion α show the presence of two values of α: higher value (equal to α of PE) and lower value (equal to α of POM‐Fe), the transition between them corresponding to the structure with cocontinuous phases. The PE/POM‐Fe composites demonstrate double‐positive temperature coefficient (PTC) effect, with the presence of two transitions and a plateau between them. In such a system, two contributions to the PTC effect coexist: the first contribution originates from the thermal expansion of the nonconductive PE phase with higher value of the coefficient α, which leads to the break of the continuity of the conductive POM‐Fe phase; the second contribution originates from the break of the conductive structure of the filler inside the POM‐Fe phase because of the morphological changes in the vicinity of the melting temperature of POM. The double PTC effect is explained in terms of these two processes (thermal expansion and melting). POLYM. ENG. SCI., 47:34–42, 2007. © 2006 Society of Plastics Engineers

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Section: Introductionmentioning

confidence: 99%

PTC effect and structure of polymer composites based on polyethylene/polyoxymethylene blend filled with dispersed iron

Mamunya

Muzychenko

Lebedev

et al. 2006

Polymer Engineering & Sci

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“…Sensitivity to a mentioned liquids was also observed in a case of polymer blends of high impact polystyrene (as a matrix) and ethylene-co-vinyl acetate (as a dispersed phase) containing carbon black (electrically conductive filler) [6]. The filaments of thermoplastic polyurethane-carbon black compunds displayed an increase in resistance upon exposure to various alcohols (methanol, ethanol, and 1-propanol) [4]. The same effect, combined with excellent reproducibility and recovery behavior has been shown for extruded PP/thermoplastic polyurethane blends containing CB [7].…”

Section: Introductionmentioning

confidence: 77%

“…A principle of operation these devices is based on a change of their electrical properties upon exposure to a studied sample. In a sensor technology both the intrisically conducting polymers (their conductivity can be changed by doping) and composites (electrically insulating polymer matrix with a conductive filler) are applied [1][2][3][4][5][6][7][8][9][10][11].…”

Section: Introductionmentioning

confidence: 99%

“…There are few studies reported in the literature on electrically conductive polymer composites as sensing materials for organic liquids. For example, carbon black-filled polyethylene, poly(vinyl chloride), poly(butadiene) or poly(tetrafluoroethylene) composites were proposed as sensing materials for liquid samples [4]. The immiscible polymer blends of polypropylene (PP), Nylon 6 and carbon black (CB) have been used to produce a series of electrically conductive filaments by a capillary rheometer process.…”

Section: Introductionmentioning

confidence: 99%

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Polymer composites as sensing materials for liquid organic solvents – preliminary results

et al. 2011

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Carbon black-filled polymer composites were investigated as sensing materials for organic liquids. Polypropylene and polystyrene which were selected as matrices and various amounts of carbon black were considered as the main factors influencing sensitivity of the composites in view of the percolation theory. Disposable filaments were produced of these materials. Change in their electrical resistivity was measured upon immersion in benzene, toluene, xylene, ethylbenzene and their mixtures. It has been found that studied materials were sensitive to the composition of liquid mixtures of organic solvent. Relationships between the filament response and volumetric fraction of the components were presented. The studied materials have shown promising sensing properties, which suggest their applicability for identification and quantification of multicomponent organic liquids.

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“…[5][6][7][8] On the other hand, Narkis et al 9 have reported the solvent sensing by use of conductive carbon black/polymer composite. Lews et al 10,11 and Zhang et al [12][13][14][15] have also reported the solvent vapor sensing behavior of carbon black/amorphous polymer composites.…”

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confidence: 99%

Novel Contamination and Gas Sensor Materials from Amphiphilic Polymer-Grafted Carbon Black

Morohashi

Nakanoya

Iwata

et al. 2006

Polym J

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ABSTRACT:The responses of electric resistance of composites prepared from amphiphilic polymer-grafted carbon blacks to contamination in solution and solvent vapor were investigated. The electric resistance of the composite prepared from poly(N-isopropylacrylamide) (PNIPAM)-grafted carbon black drastically increased when the composite was dipped in n-hexane containing contamination, such as methanol, THF, dioctyl phthalate, and chloroform, and returned to the initial resistance when it was transferred to dry air. The logarithm of the electric resistance of the composite was linearly proportional to chloroform concentration in n-hexane. The electric resistance of the composite drastically increased in organic polar solvent vapor, such as methanol, THF, and chloroform and returned to the initial resistance when it was transferred to dry air. But the response to non-polar solvent vapor, such as n-hexane, was very small. The logarithm of electric resistance of the composite was linearly proportional to humidity. In addition, electric resistance of the composite prepared from poly(diethylacrylamide) (PDEAA)-grafted carbon black also drastically increased when the composite was dipped in n-hexane containing contamination, such as methanol, trichloroethane, THF, chloroform, and benzene, and returned to the initial resistance when it was transferred to dry air. Based on the results, it was found that the composites could be used as a novel contamination sensor in n-hexane and gas sensor.

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Sensors for liquids based on conductive immiscible polymer blends

Cited by 110 publications

References 14 publications

PTC effect and structure of polymer composites based on polyethylene/polyoxymethylene blend filled with dispersed iron

PTC effect and structure of polymer composites based on polyethylene/polyoxymethylene blend filled with dispersed iron

Polymer composites as sensing materials for liquid organic solvents – preliminary results

Novel Contamination and Gas Sensor Materials from Amphiphilic Polymer-Grafted Carbon Black

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