In-situ characterization of bulk carbon nanotube behavior in a sheet under tensile load

摘要: Abstract The present study characterizes orientation changes of randomly oriented nanotubes in carbon nanotube (CNT) sheet under externally applied tensile load. loads were using a microtester placed inside scanning electron microscope (SEM) that allowed in-situ observations morphological the CNT as load increased. It was observed entangled CNTs align themselves along loading direction. aligned eventually form separate distinct bundles prior to catastrophic failure. alignment is permanent and irreversible. overall stiffness strength also increases with increasing alignment. Reloading fully tension exhibits very stiff behavior higher Young’s modulus proportional limit when compared virgin goes through an phase evaluated be 40 MPa, while pre-existing 95 MPa. Raman spectroscopy confirmed exhibited preferential direction after testing. fails closer grip region where constraints created by prevent full resulting weaker near comparison rest sheet.