Carbon Nanotubes/Epoxy Nanocomposites for UV-Assisted Direct-Write Fabrication of Microstructures: Mechanical and Rheological Studies

摘要

We report on the preparation of biofunctionalized single-walled carbon nanotubern(BF-SWCNT)/epoxy nanocomposites with different mixing strategies. ThernSWCNTs were first purified by acidic treatment and then functionalized by graftingrnbiomaterials onto the SWCNTs surface. The BF-SWCNTs were dispersed within anrnepoxy resin by means of ultrasonication and/or three-roll mixing methods. It isrnfound that the mixing procedure consisting of ultrasonication and three-roll mixingrnis an effective method to disperse nanotubes within epoxy matrix. The biomaterialgraftingrnof SWCNTs surfaces along with their fair dispersion led to a significantrnincrease of viscosity of the nanocomposite suspensions which enabled the UVassistedrndirect-write fabrication of microfibers suspended between two pads and 3Drnfreeform helicoidal microsprings. Mechanical characterization of the slenderrnmicrofibers (150 μm diameter) at a nanotube load of 1wt%, under tension revealedrnconsiderable increase in both modulus (by ～93%) and strength (by 75%) comparedrnto the values for pure epoxy resin. These mechanical improvements are believed tornbe a consequence of the biomaterial-grafting of the nanotubes surfaces whichrnfacilitate load transfer and their fairly-dispersion into the epoxy matrix. Thernmanufactured nanocomposite microstructures containing BF-SWCNT could findrnapplications in biosensors, where other biomaterials and hazardous gaseous can berndetected by affecting the electrical conductivity of nanotube-reinforcedrnnanocomposite microstructures.