Modeling carbon black/polymer composite sensors

Hua, Lei; Pitt, William G.; McGrath, Lucas K.; Ho, Clifford K.

doi:10.1016/j.snb.2007.02.041

Cited by 51 publications

(44 citation statements)

References 25 publications

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“…6 The electrical resistivity of such a composite critically depends on the volume fraction of the conducting filler particles that is well explained by the percolation theory. 7,8 Usually, general effective media (GEM) theory was used to optimize fitting of resistivity as a function of filler fraction such that the resistivity at any chosen filler fraction can be predicted.…”

Section: Introductionmentioning

confidence: 96%

Conductivity and piezoresistivity of conductive carbon black filled polymer composite

Wang

Ding

2010

J of Applied Polymer Sci

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Dispersing conductive carbon black (CCB) particles into silicone rubber (SR), we studied the conductivity and piezoresistivity of particles filled polymer composite. The experimental results show that the conductive percolation threshold and shape exponent of composite are effected on by filler's size and reduce with filler's size decreasing. The electrical resistance and Young's model of composite have different critical filler volume fraction to fall or increase. The compressing deformation is the main reason of the piezoresistivity of composite, but the piezoresistivity is more obvious when particles have larger size or polymer matrix has smaller Young's Model. A research was done to explain the piezoresistivity through comparing CCB/SR with CCB/high density polythene (HDP). The other interesting find is that the electrical resistance of composite decreases with time under an invariant load, showing ''electrical resistance creep'' behavior, which is due to the composite's compressing strain creep under uniaxial pressure.

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Section: Introductionmentioning

confidence: 96%

Conductivity and piezoresistivity of conductive carbon black filled polymer composite

Wang

Ding

2010

J of Applied Polymer Sci

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“…The response mechanism of the polymer-carbon black composite sensors is explained by percolation theory [70,71]. The resistivity of the polymer -CB composite is related to the content of carbon black in the film.…”

Section: Fig 6 Schematic Of Sensing Response Mechanism Of Conjugatedmentioning

confidence: 99%

Organic Molecule Based Sensor for Aldehyde Detection

Mallya

Ramamurthy

2015

Smart Sensors, Measurement and Instrumentation

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Abstract. Aldehydes are used in food and beverage industries, production of resins, soap and perfume industries. When used in excess quantity or found in products in undesired quantity this is a threat to humans. Hence it becomes very important to detect these VOCs even at lower concentration. The other sources of aldehyde are polluted air and water. Exposure to aldehyde can cause gene mutation and cancer. Conductometric sensors with metal oxide semiconductors as sensing films, cataluminesence based sensors, quartz crystal microbalance sensors, analytical methods such as HPLC have been used for the detection of aldehydes. These are sophisticated techniques require skilled staff to perform the tests. Chemiresistor is a simple method of fabrication of conductometric sensor. In this method the sensing layer is a film cast between two electrodes deposited on an insulating substrate. The response of the sensor to various analytes is monitored by recording the changes taking place in the sensing element. Organic molecule based sensors are low cost and operate at room temperature. Selectivity of the sensors to a particular analyte is an issue in sensors. An analyte molecule can interact with the various binding sites on a molecule. A molecule has to be designed and synthesized to be selective to a particular analyte of interest. This can be achieved by selecting a molecule which has a functional group that interacts with the analyte molecule. The mechanism of interaction of the analyte with the sensing molecule can be understood by doing molecular simulations. Molecular modelling allows monitoring the interaction of the analyte and sensing molecule. Here an example of organic molecule based sensor for selective interaction with aldehydes is illustrated.The organic molecule ophenylenediamine blended with carbon black as sensing element of the chemiresistor to decrease the resistance. Molecular modelling can be used to understand the interaction between aldehyde and o-phenylenediamine molecule.

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“…The response mechanism of the OPD-carbon black composite sensor in the experiment can be explained by the percolation theory. 39,40 The carbon black creates a continuous network in the OPD matrix. The carbon black particles are closer and hence the resistance of the composite decreases.…”

Section: Sensor Response Characteristics Of Various Vocsmentioning

confidence: 99%

Investigation of selective sensing of a diamine for aldehyde by experimental and simulation studies

Mallya

Ramamurthy

2014

Analyst

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An organic molecule--o-phenylene diamine (OPD)--is selected as an aldehyde sensing material. It is studied for selectivity to aldehyde vapours both by experiment and simulation. A chemiresistor based sensor for detection of aldehyde vapours is fabricated. An o-phenylene diamine-carbon black composite is used as the sensing element. The amine groups in the OPD would interact with the carbonyl groups of the aldehydes. The selectivity and cross-sensitivity of the OPD-CB sensor to VOCs--aldehyde, ketone and alcohol--are studied. The sensor shows good response to aldehydes compared to other VOCs. The higher response for aldehydes is attributed to the interaction of the carbonyl oxygen of aldehydes with -NH2 groups of OPD. The surface morphology of the sensing element is studied by scanning electron microscopy. The OPD-CB sensor is responsive to 10 ppm of formaldehyde. The interaction of the VOCs with the OPD-CB nanocomposite is investigated by molecular dynamics studies. The interaction energies of the analyte with the OPD-CB nanocomposite were calculated. It is observed that the interaction energies for aldehydes are higher than those for other analytes. Thus the OPD-CB sensor shows selectivity to aldehydes. The simulated radial distribution function is calculated for the O-H pair of analyte and OPD which further supports the finding that the amine groups are involved in the interaction. These results suggest that it is important and easy to identify appropriate sensing materials based on the understanding of analyte interaction properties.

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Modeling carbon black/polymer composite sensors

Cited by 51 publications

References 25 publications

Conductivity and piezoresistivity of conductive carbon black filled polymer composite

Conductivity and piezoresistivity of conductive carbon black filled polymer composite

Organic Molecule Based Sensor for Aldehyde Detection

Investigation of selective sensing of a diamine for aldehyde by experimental and simulation studies

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