Hopping conductivity in polymer matrix–metal particles composites

Psarras, G. C.

doi:10.1016/j.compositesa.2005.11.004

Cited by 267 publications

(200 citation statements)

References 43 publications

Supporting

Mentioning

182

Contrasting

Unclassified

Order By: Relevance

“…The dielectric parameters and conductivity were used to obtain more detailed information with regard to the microscopic structure of the composites. These values were calculated from the capacitance and conductance using the following equations: [32][33][34][35][36][37][38] e 0 ¼ C p material where e¢ and e 00 are the real and imaginary parts of the complex dielectric constant e * . The real part measures the alignment of the dipoles, and the imaginary part represents the energy required to align the dipoles and move the ions.…”

Section: Electrical and Dielectric Propertiesmentioning

confidence: 99%

Polyaniline-doped benzene sulfonic acid/epoxy resin composites: structural, morphological, thermal and dielectric behaviors

Belaabed

Lamouri

Naar

et al. 2010

Polym J

View full text Add to dashboard Cite

Conducting polymer composites, which are simply physical mixtures of an insulating polymer matrix and intrinsically conducting polymers, are promising new materials for various applications such as antistatic coatings, shielding and electromagnetic absorbers. In this context, a novel conducting composite was successfully produced. It is based on epoxy resin and polyaniline (PANI) doped in benzene sulfonic acid, which was used as conducting filler. The effect of PANI loading levels on the structural, morphological, thermal, electrical and dielectric properties was explored using techniques, such as Raman, Fourier transform infrared and ultraviolet-visible-NIR spectroscopy, X-ray diffraction, atomic force microscopy, scanning electron microscopy, thermogravimetric analysis and differential scanning calorimetry. The electrical behavior and morphology of the synthesized PANI revealed disorder and defects. In addition, as the applied voltage is increased, the current through the sample increases rapidly. The conductivity and dielectric properties were also investigated at room temperature in the frequency range of 1 MHz-1 GHz. The dielectric constant was shown to increase with increased loading at low frequencies and then decreases rapidly, reaching a constant value at higher frequencies. In addition, the AC conductivity of the prepared composites increases with the addition of PANI and is higher at high frequencies. Furthermore, the stability of the composites was found to be influenced by increasing the amount of PANI filler in the matrix.

show abstract

Section: Electrical and Dielectric Propertiesmentioning

confidence: 99%

Polyaniline-doped benzene sulfonic acid/epoxy resin composites: structural, morphological, thermal and dielectric behaviors

Belaabed

Lamouri

Naar

et al. 2010

Polym J

View full text Add to dashboard Cite

show abstract

“…This form of conduction is called the Variable Range Hopping (VRH). It has been observed frequently in both doped crystalline semiconductors and amorphous materials, and the temperature dependence of conductivity is given in the following form [16,17]:…”

Section: Resultsmentioning

confidence: 99%

“…The VRH model has been found as the main conductivity mechanism at a lower temperature region in many studies of conductive polymer composites [17,19,22]. Psarras [17] used two different hopping models to explain the charge transport properties of bisphenol type epoxy resin and iron powder composites -the VRH model and the Random Free-Energy Barrier (RFEB) model (also referred as the symmetric hopping model) proposed by Dyre [20,21].…”

Section: Resultsmentioning

confidence: 99%

“…where the parameter  0 can be considered the limiting value of conductivity at infinite temperature, T 0 is the characteristic temperature that determines the thermally activated hopping among localized states at different energies and is considered a measure of disorder [17,18]. VRH mechanism is a phononassisted charge carrier transport process.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Polyisoprene/Nanostructured Carbon Composites for Applications in Temperature Sensors

Knite

Zīke

Zavickis

et al. 2013

Material Science and Applied Chemistry

View full text Add to dashboard Cite

Abstract. The studies of electrical properties of the polyisoprene (PI) matrix/high structure carbon black (HSCB) composites (PCBC) with various concentrations (8, 9, 10 and 11 mass parts) of filler have been carried out in the temperature interval of 90K-330K. In this paper we focus on the investigation of direct current (DC) conductivity in a low-temperature region with negative temperature coefficient of resistivity (NTCR). It has been proven that variable range hopping (VRH) conduction is dominated by hopping of carriers among localized states in a low-temperature range. At higher temperatures the nearest neighbour hopping (NNH) conductivity or constant range hopping charge transport takes place. The reversibility as well as small hysteresis of resistance change versus temperature indicates prospective temperature sensor application for PCBC.

show abstract

“…11 Materiais compósitos de uma matriz polimérica com partículas de metal aleatoriamente dispersadas são considerados como um sistema heterogêneo desordenado. 12 A formação de regiões de cargas livres em torno das partículas metálicas torna-se significante de acordo com a quantidade destas partículas na matriz polimérica.…”

Section: Geração De Cargas Eletrostáticasunclassified

Acúmulo de cargas elétricas em propelente sólido compósito com matriz de polibutadieno líquido hidroxilado

Manea¹,

Manea²,

Iha³

et al. 2014

Quím. Nova

View full text Add to dashboard Cite

. Composite solid propellants prepared with HTPB prepolymer -Hydroxyl Terminated Polybutadiene, AP -Ammonium Perchlorate as oxidizer and aluminum particles as an additive metal, have characteristics of high electrical resistivity. The loading process of the polymer matrix did not obtain homogeneity, resulting in clusters, mainly of metal particles. The effect of clustering in the composite was studied and observed experimentally, and this effect was one of the factors explaining the phenomenon of electrical charging of the composite. This electrical potential, when discharged abruptly, can generate an electric spark with sufficient energy for sustained ignition of a solid rocket motor.Keywords: composite solid propellant; static-charge accumulation; electrostatic discharge. INTRODUÇÃOA propulsão química utilizada em lançadores de satélites, espaçonaves e mísseis é designada como motores aeroespaciais que utilizam a energia das ligações químicas produzida inicialmente pela decomposição térmica das espécies químicas dos propelentes sólidos, líquidos ou híbridos. A configuração do propelente e do oxidante é diversa em cada motor e aplicável de acordo com as necessidades e características da missão a ser desenvolvida pelo engenho. O motor híbrido, normalmente, é uma configuração composta por um combustível sólido instalado numa câmara de combustão na qual é injetado o oxidante que pode estar no estado líquido ou gasoso. A reação de combustão, por ser exotérmica, produz gases quentes que ao expandirem são direcionados para a saída do tubo motor foguete onde está localizado o convergente-divergente do motor, produzindo assim empuxo. Na concepção do motor foguete com propulsão líquida, os propelentes, combustível e oxidante são armazenados separadamente no estado líquido, sendo bombeados para a câmara de combustão do motor onde ocorre a queima. Da mesma forma, essa queima gera gases quentes, e consequentemente, empuxo.Os motores foguetes que utilizam propelentes sólidos do tipo compósito são empregados como base para sistemas de propulsão otimizados, onde o volume de energia acumulado permite usar um engenho de menor porte quando comparado ao híbrido ou líquido. Nesse caso, o controle da velocidade da queima é exercido por meio da medida linear de queima do propelente, a qual é dependente da composição físico-química dos ingredientes do propelente, da geometria do grão e da pressão na câmara de combustão durante a operação do motor. 1 Os propelentes sólidos são composições onde matrizes poliméri-cas são carregadas sob a forma de um material compósito com uma quantidade elevada de partículas sólidas dispersas de forma aleató-ria nessa mesma matriz. No processamento do material, busca-se distribuir essas partículas sólidas, constituídas principalmente por espécies combustíveis e oxidantes, de forma homogênea para que ocorra um processo de combustão regular pela intima proximidade entre as espécies químicas envolvidas. Para obter uma força propulsiva maximizada utiliza-se uma quantidade mínima do polímero, suficiente para...

show abstract

Hopping conductivity in polymer matrix–metal particles composites

Cited by 267 publications

References 43 publications

Polyaniline-doped benzene sulfonic acid/epoxy resin composites: structural, morphological, thermal and dielectric behaviors

Polyaniline-doped benzene sulfonic acid/epoxy resin composites: structural, morphological, thermal and dielectric behaviors

Polyisoprene/Nanostructured Carbon Composites for Applications in Temperature Sensors

Acúmulo de cargas elétricas em propelente sólido compósito com matriz de polibutadieno líquido hidroxilado

Contact Info

Product

Resources

About