Elastomeric photo-actuators and their investigation by confocal laser scanning microscopy

0396102 - ÚMCH 2014 RIV GB eng J - Journal Article
Czaniková, K. - Ilčíková, M. - Krupa, I. - Mičušík, M. - Kasák, P. - Pavlova, Ewa - Mosnáček, J. - Chorvát Jr., D. - Omastová, M.
Elastomeric photo-actuators and their investigation by confocal laser scanning microscopy.
Smart Materials and Structures. Roč. 22, č. 10 (2013), 104001_1-104001_10. ISSN 0964-1726. E-ISSN 1361-665X
Institutional support: RVO:61389013
Keywords : nanocomposites * multiwalled carbon nanotubes * electron microscopy
Subject RIV: CD - Macromolecular Chemistry
Impact factor: 2.449, year: 2013

The photo-actuation behavior of nanocomposites based on ethylene–vinylacetate copolymer (EVA) and styrene–isoprene–styrene (SIS) block copolymer filled with well-dispersed and modified multiwalled carbon nanotubes (MWCNTs) is discussed in this paper. The nanocomposites were prepared by casting from solution. To improve the dispersion of the MWCNTs in EVA, the MWCNT surface was modified with a non-covalent surfactant, cholesteryl 1-pyrenecarboxylate (PyChol). To prepare SIS nanocomposites, the MWCNT surface was covalently modified with polystyrene chains. The good dispersion of the filler was confirmed by transmission electron microscopy (TEM). Special, custom-made punch/die molds were used to create a Braille element (BE)-like shape, which under shear forces induces a uniaxial orientation of the MWCNTs within the matrix. The uniaxial orientation of MWCNTs is an essential precondition to ensure the photo-actuating behavior of MWCNTs in polymeric matrices. The orientation of the MWCNTs within the matrices was examined by scanning electron microscopy (SEM). Nanocomposite BEs were illuminated from the bottom by a red light-emitting diode (LED), and the photo-actuation was investigated by confocal laser scanning microscopy (CLSM). When the BEs were exposed to light, a temporary increase in the height of the element was detected. This process was observed to be reversible: after switching off the light, the BEs returned to their original shape and height.
Permanent Link: http://hdl.handle.net/11104/0225105