The engineering aspects associated with nanocomposite development are strongly dependent on the final properties that can be achieved as well as on their processability. Both features are affected by the average distribution of nanofiller in the matrix, or in other words by its dispersion. Furthermore, characterization of intercalation or exfoliation of organic modified montmorillonite (omMMT) or graphene lamellae by X-ray or transmission electron microscopy cannot be easily related to nanocomposite macroscopic properties (mechanical, rheological etc.), the most relevant from an engineering point of view. On the other hand mechanical and rheological analysis shows that properties of nanocomposites are not only dependent from lamellar spacing but also the aspect ratio plays a key role. Even if single graphene sheets or single omMMT are not observed in the matrix bulk, a high aspect ratio of the filler can generate a significant improvement of macroscopic properties. Finally, the measurements of engineering properties of nanocomposites not only represent an objective but can provide information about the average degree of dispersion. Comparison of mechanical and rheological properties with simple mathematical models can be used to determine the average aspect ratio of nanofillers. It may be concluded that macrocharacterization can represent a valuable and complementary tool for the morphological characterization of nanocomposites being capable of providing information about the level of dispersion of nanocomposites.
The aspect ratio of nanofillers:A key properties affecting the performances of polymer matrix nanocomposites
ESPOSITO CORCIONE, Carola;GRECO, Antonio;MAFFEZZOLI, Alfonso;
2012-01-01
Abstract
The engineering aspects associated with nanocomposite development are strongly dependent on the final properties that can be achieved as well as on their processability. Both features are affected by the average distribution of nanofiller in the matrix, or in other words by its dispersion. Furthermore, characterization of intercalation or exfoliation of organic modified montmorillonite (omMMT) or graphene lamellae by X-ray or transmission electron microscopy cannot be easily related to nanocomposite macroscopic properties (mechanical, rheological etc.), the most relevant from an engineering point of view. On the other hand mechanical and rheological analysis shows that properties of nanocomposites are not only dependent from lamellar spacing but also the aspect ratio plays a key role. Even if single graphene sheets or single omMMT are not observed in the matrix bulk, a high aspect ratio of the filler can generate a significant improvement of macroscopic properties. Finally, the measurements of engineering properties of nanocomposites not only represent an objective but can provide information about the average degree of dispersion. Comparison of mechanical and rheological properties with simple mathematical models can be used to determine the average aspect ratio of nanofillers. It may be concluded that macrocharacterization can represent a valuable and complementary tool for the morphological characterization of nanocomposites being capable of providing information about the level of dispersion of nanocomposites.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
