Improvement of Mechanical Strength,Thermal Stability,Swelling,Moisture Content of Triple Network Hydrogels by Carbon Nanotubes

摘要

In this study,we prepared a novel carbon nanotubes reinforced three network hydrogels composed of carbon nanotubes,polyacrylic acid(PAA),agar and polyvinyl alcohol(PVA),consisting of an agar gel as the first physical network,a PAA-Fe~(3+) gel as the second physical network and a polyvinyl alcohol as the third physical network.The surface modification of MWCNTs was carried out by oxyfluorination to introduce the functional groups on the hydrophobic MWCNTs.Agar/PAA-Fe~(3+)/PVA/MWCNTs hydrogels with high tensile and compression strength(σf of 1.5 Mpa,εf of 14.24 mm/mm) and (σf of 1.69 Mpa,the deformation of 80%),thermal stability,low-swelling,high moisture content properties were successfully prepared by a simple three-step method.The addition of carbon nanotubes has significantly improved the thermal stability of the gels,its thermogravimetric curve drops obviously until 387°C.Under the joint action of hydrogen bonding and ion coordination interaction,the gel achieves a perfect balance of swelling and moisture content.The research provide a new method to improve mechanical,swelling,thermal stability,moisture content ability by adjusting the compositions and interactions in the gels.