Interactive effects between carbon allotrope fillers on the mechanical reinforcement of polyisoprene based nanocomposites

Interactive effects of carbon allotropes on the mechanical reinforcement of polymer nanocomposites were investigated. Carbon nanotubes (CNT) and nano-graphite with high shape anisotropy (nanoG) were melt blended with poly(1,4- cis-isoprene), as the only fillers or in combination with carbon black (CB), measuring the shear modulus at low strain amplitudes for peroxide crosslinked composites. The nanofiller was found to increase the low amplitude storage modulus of the matrix, with or without CB, by a factor depending on nanofiller type and content. This factor, fingerprint of the nanofiller, was higher for CNT than for nanoG. The filler-polymer interfacial area was able to correlate modulus data of composites with CNT, CB and with the hybrid filler system, leading to the construction of a common master curve. © BME-PT

Filler networking of a nanographite with a high shape anisotropy and synergism with carbon black in poly(1,4-cis-isoprene) based nanocomposites

ABSTRACTA nanoGraphite (nanoG) having a high surface area and a high shape anisotropy, defined as the ratio between the crystallite dimensions in a direction orthogonal and parallel to structural layers, was used to prepare nanocomposites based on poly(1,4-cis-isoprene) (IR), in the neat polymer matrix and in the presence of carbon black (CB). Tensile and dynamic-mechanical measurements showed that nanoG forms a filler network at a relatively low concentration in neat IR and a hybrid filler network at a lower nanoG concentration in the presence of CB. A synergistic effect between the two carbon allotropes was found: composites containing both fillers present initial modulus values much higher than those calculated through the simple addition of the initial moduli of the composites containing only CB or nanoG.</jats:p

Segmentación supervisada y no supervisada de zonas costeras en secuencias de videos

El procesamiento de imágenes y video para el estudio de fenómenos naturales es una de las técnicas más usadas para extraer información cualitativa y cuantitativa que sirve de apoyo a la toma de decisiones económicas, políticas, sociales y ambientales. En este trabajo se presenta el desarrollo de un sistema de análisis no supervisado para la segmentación y medición de áreas costeras basado en el procesamiento de video. El mismo en principio fue testeado para determinar automáticamente las áreas que conforman un sector la playa de Monte Hermoso en función de la marea. Los videos usados como datos de entrada fueron captados con videocámaras de bajo costo y procesados en equipos convencionales empleando un lenguaje estándar de programación y bibliotecas de visión por computadora. La segmentación se realizó mediante el empleo de algoritmos de clasificación supervisados y no supervisados sobre imágenes promedios extraídas de cada video. Los datos experimentales que se obtienen mediante el empleo de métodos supervisados y no supervisados muestran resultados similares. Por lo tanto es posible reconocer las zonas y estimar un valor del área de la playa empleando cualquiera de estos algoritmos..Sociedad Argentina de Informática e Investigación Operativ

Hybrid filler systems in rubber nanocomposites

In this chapter, hybrid filler systems in rubber nanocomposites are discussed, starting from the definition of a hybrid system. In particular, the chapter is dedicated to systems based on the combination of nano- and nanostructured fillers, that have been largely investigated in the literature and have, in some cases, found commercial applications. They are those based on either organoclay or carbon nanotubes or nanographite as the nanofillers and either carbon black or silica as the nanostructured fillers. Structure and aspects of the nanocomposites, such as curing, tensile, and dynamic-mechanical properties, tear and abrasion resistance, electrical and thermal conductivity, and impermeability, are discussed. Synergistic effects by the nanofillers on the nanocomposites properties are presented, attempting a rationalization on the basis of the available data