Plasma Functionalization of Carbon Nanotubes for the Synthesis of Stable Aqueous Nanofluids and Poly(vinyl alcohol) Nanocomposites

Abstract

Carbon nanotubes (CNTs) synthesized by direct thermal chemical vapor deposition growth from stainless steel mesh are surface functionalized via an Ar/O2/C2H6 capacitively coupled RF plasma discharge. The open and rigid network of CNTs allows for a high degree of the CNT surface to be treated. As a result, the aqueous nanofluids that are produced by removing the CNTs from the substrate are found to remain stable for extended periods of time (greater than six months). X‐ray photoelectron spectroscopy analysis revealed that oxygen comprised approximately 21 at.% of the functionalized CNT surface. Poly(vinyl alcohol)/CNT nanocomposites produced using the plasma functionalized CNTs are homogenous with excellent dispersion of the CNTs. Mechanically, the 0.75 wt.‐% functionalized‐CNT nanocomposite show 54 and 60% increases in tensile strength and modulus, respectively, over the neat polymer. Little to no change is seen in the degree of crystallinity or the glass transition and melting point temperatures of the nanocomposites. Finally, water content is found to have a significant effect on the polymer and composite's tensile properties. magnified image

The effect of carbon input on the morphology and attachment of carbon nanotubes grown directly from stainless steel

“…Unless otherwise specified the carbon injection was followed by an isothermal growth period of 30 min at 700°C, after which the system is cooled down to room temperature. Further details of the CVD setup can be found in Hordy et al [13].…”

“…In the first case, such as in sensor and electrode applications where the 3-dimentional CNT matrix is used as a means to increase the surface area, one requires strong attachment to the substrate in order to not loose performance capabilities over time [3]. In the second case however, where separation the CNTs from the substrate is required such as in nanofluid production, one would like to be able to remove as high a percentage of the CNTs as possible [13]. The mass of CNTs removed by means of ultrasonication was measured in order to evaluate the level of attachment of the CNTs to the substrate.…”

Multifunctionalized Carbon Nanotubes Polymer Composites: Properties and Applications

“…For instance, physical purification of CNTs by chitosan functionalization has been endorsed to be easy processing and also is efficient. Besides, the CNT-H 2 O interface direction, the ordered organization of lipid derivatives onto CNTs by supra molecular self-assembly by biopolymers on the CNT surface has noticed to be of tremendous effect on CNTs dispersion (Hordy et al 2013). Gum Arabia, the primeval biopolymer dispersant presented to stabilize SWCNTs (Yulong et al 2006;Rajdip et al 2002;Nadia et al 2005).…”

Effects of in‐situ functionalization of carbon nanotubes with bis(triethoxysilylpropyl) tetrasulfide (TESPT) and 3‐aminopropyltriethoxysilane (APTES) on properties of epoxidized natural rubber–carbon nanotube composites

“…It is noted that the certain number of polar functional groups on the CNT surface have been identified by FTIR and XPS measurements [6,[14][15][16]. Figure 2 shows the ATR-FTIR spectra of vulcanized pristine ENR, ENR-CNT-5, ENR-CNT-TESPT-5, and ENR-CNT-APTES-5 composites.…”