MWNT-COOH

Oxidized mulli-walled carbon nanotuve (MWNT-COOH)... 

GSA-CNT and GSA-SDS/FMWNT composite blocks are fabricated in the same manner using the FM method as previously described in Chap. 3 with an addition 0. 042 and 0.084 wt% of MWNT-COOH (FMWNT) into an aqueous gelatin solution. A total of 24 composite blocks comprising 144 specimens are tested for the same properties as previously described using the same experimental techniques but for only high compressive strains at 33.3 and 44.4 % since the interest is on the response of the composites under high compressive strain with the addition of very insignificant amounts (max. 0.084 wt%) of FMWNT. 

Tzavalas S, Drakonakis V, Mouzakis D E, Fischer D and Gregoriou V G (2006) Effect of Carboxy-Functioiialized Multiwall Nanotubes (MWNT-COOH) on the Crystallization and Chain Conformations of Poly(ethylene terephthalate) PET in PET-MWNT Nanocomposites, Macromolecules 39 9150-9156. 

Figure 20.11 (1) Possible interaction of hydrogen bonding existed between for PPy chain and MWNT-COOH. (2) TEM micrographs of...

Kim et al. studied the effect of sulfonated multiwalled carbon nanotubes (s-MWNTs)/SPES composite membranes on the membrane properties, including the proton conductivity, WU, mechanical properties, and methanol for direct methanol fuel cells (DMFCs) [57], The s-MWNTs were prepared by the oxidation of MWNTs with H2SO4 and HNO3, followed by treatment of MWNTs-COOH with SOCI2, and finally the reaction of MWNTs-COCl with aminomethanesulfonic acid (Scheme 4.23). 

In another example, Baskaran et al. used MWNT-COOH to attach the ATRP initiator, hydroxyethyl 2-bromoisobutyrate the initiator-modified MWNT was then used for the in situ ATRP of PS and PMMA from MWNTs [56]. 

MWNTs MWNT s—COOH MWNTs-COCI MWNTs-OH... 

Analogous results have been recently obtained by other research groups. The effect of -COOH- and phenol-functionalized CNTs on mechanical, dynamic mechanical and thermal properties of polypropylene (PP) nanocomposites were considered, and the results confirmed in both cases that the percentage crystallinity was found to increase on phenol and carboxylic functionalization of MWNTs. 

As for the benzenesulfonate-modified MWNTs (CNT-C H-SO H) (Figure 8.2), the length of the CNTs had been mainly remained during the functionalization process. So, they could not be wrapped into the conducting polymer as the CNT-COOH. After the CNT-CgH -SO H was used as the co-surfactant and co-dopant for the chemical oxidative emulsion... 

Similarly, Saeed and Park [65] synthesized PA 6-multiwaIl carbon nanotubes (MWNTs) nanocomposites via the in-situ polymerization technique, using pristine and COOH-functionalized MWNTs. Based on SEM morphology analysis, it was shown that the COOH-functionalized MWNTs were better dispersed in the PA 6 matrix than the pristine ones, owing to the covalent attachment of PA 6 molecular chains to the side walls of MWNTs, which could act as in-situ compatibilizers in the nanocomposites and enhance the dispersion of MWNTs. In terms of physical properties, the crystallization of nanocomposites was increased compared to that of virgin PA 6, due to the nucleation effect of MWNTs, while the thermal stability under nitrogen of the nanocomposites was superior. Turning to the mechanical properties of the nanocomposites, the uniformly dispersed MWNTs improved the tensile properties because of the reinforcement effect. 

Finally, Yan et cd. [66] utilized the in-situ anionic ring-opening polymerization to prepare monomer casting PA 6-MWNTs nanocomposites. The typical functionalization process of MWNTs by COOH groups was not therein applied, as the... 

Multi-wall carbon nanotubes (MWNTs) were also used as the reinforcing phase in LCP nanocomposites prepared by means of melt blending technique in a twin-screw extruder equipped with an ultrasonic unit to facilitate MWCNT dispersion (Kumar and Isayev, 2010). The role of ultrasonication was positive and resulted in increased structural as well as rheological properties because of the better-dispersed nanofiller. MWCNT were also used in LCP blends with polycarbonate (PC) (Mukherjee et al., 2009) and PEI (Nayak, Rajasekar, and Das, 2010). In the first case, PC/LCP/MWNTs nanocomposites containing as-received or modified (COOH-MWNT) carbon nanotubes were prepared through the melt process in an extruder and then compression molded. The incorporation of functionalized MWCNTs improved thermal, structural, dynamic-mechanical, and electrical properties of the composites, in particular in blends with treated MWCNTs. MWCNTs were also used, both unmodified and surface treated with SiC particles, to improve dispersion in PEI/LCP blends prepared by melt blending. In the ternary systan, viscosity in the blend with modified MWCNTs was found to be lower than the ternary blend with pure MWCNTs, probably because modified MWCNTs improved the fibrillation of LCP compared to pure MWCNTs. Nanocomposite matrices have not been used to prepare foams yet. 

Optical microscope images of 1 wt% MWNT/PEG composite films. The CNT dispersion was governed by either surface modification via COOH functionalization, or by surfactant adsorption (a) MWNT/PEG, (b) oxidized MWNT/PEG, (c) MWNT/PEG with Tween-80, (d) MWNT/PEG with Pluronic P-65, and (e) MWNT/PEG... 

As is well known to all, chemical functionalization disrupts the extended n conjugation of CNTs and consequently reduces the electrical conductivity of functionalized CNTs. Silane-functionalized CNT/epoxy nanocomposites exhibited lower electrical conductivity than did untreated CNT composites at the same content of CNTs. In 2005, Cho and co-workers observed that the electrical conductivity of the surface-functionalized MWNT composites was lower than that of the untreated MWNT composites with the identical content of CNTs. This is attributed to the increased defects in the lattice stmaure of carbon-carbon bonds on the surface of CNTs due to the acid treatment. Generally, the severe functionalization of CNTs can sigrtificantly lower the conductivity of the composites. However, several researchers have foimd that the fimaionalization of CNTs could improve the electrical conductivity of the composites. In 2005, Tambutri and co-workers reported that the functionalization of SWNTs with -COOH and -OH groups enhanced the conductivity of composites compared to untreated SWNTs. 

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