Elastic properties of a swollen polyacrylamide (PAAm) gel doped with various multiwalled carbon nanotube (MWNT) contents

Abstract

The toughness UT and shear modulus S of polyacrylamide (PAAm) multiwalled carbon nanotube (MWNTs) composites were studied with various MWNT contents. These composites were prepared via free radical crosslinking copolymerization with different amounts of MWNT varying in the range between 0.1 and 50 wt.-%. The MWNT content dependency of the shear modulus of the composites due to volume phase transition was measured using tensile testing at 30 degrees C. It was observed that the composite preserves the ability to undergo the volume phase transition and its elastic modulus is strongly dependent on the MWNT content. The observed shear modulus first increased and then decreased above 1 wt.-% MWNT content during such loading tests. The toughness showed exactly the reverse behavior dependent on the MWNT content, as compared to the elasticity and as expected.