Mechanical properties of three-dimensional microstructures infiltrated by carbon nanotube/epoxy nanocomposite under shear flow

Three-dimensional interconnected microfluidic channels fabricated by the direct-write method were infiltrated with SWCNT/epoxy nanocomposites under high shear flow to mechanically characterize the effect of single-walled carbon nanotubes (SWCNTs) spatial orientation in thermosettingmatrix nanocomposites. The micron-size fugitive ink filaments were deposited layer by layer in order to form a scaffold followed by its encapsulation by an epoxy resin. Threedimensional interconnected microfluidic channels were then obtained by heat curing the encapsulated epoxy followed by fugitive ink removal by liquefying it at high temperature under vacuum. To debundle the Laser-Ablated single-walled carbon nanotubes (La-SWNTs), nitric acid treatment following introduction of protoporphyrin IX as surfactant were done to prevent reclustering of the CNTs after separation. La-SWNTs were then mixed with ultraviolet-curable epoxy using a threeroll mill machine to achieve a well-dispersed nanocomposite. The nanocomposites were then infiltrated within the empty channels at high pressures to induce shear. High shear flow infiltration of nanocomposites will cause the CNTs to be aligned in the direction of the channels where an increase in shear leads to an increase in CNT alignments. Finally, in order to mechanically investigate the effectiveness of the infiltration technique and the orientation of SWCNTs, tensile and threepoint bending tests were done.