F-MWCNTs

Pande et al. (25) also reported significant improvements in the flexural properties of MWCNT-PMMA composites prepared by in-situ polymerization method. They observed a maximum reinforcing effect of CNTs at 3 wt% for a-MWCNT and at 1.8 wt% for f-MWCNT. The flexural strength for the two cases was about 90 MPa as compared to about 64 MPa from two step method... 

Figure 7.11. Microstructure of the 1.8 wt% f-MWCNT-PMMA composite. Reprinted with permission from John Wiley Sons, Inc (25).

Pande et al. 2009 (25) MWCNT CVD As-synthesized and functionalized In situ polymerization CNT Loading levels 0.06 to 4.8 wt% Bulk Composites A maxima was observed in flexural strength for both a-CNT-PMMA and f-CNT-PMMA composites Flexural Flexural Strength Modulus Wt.% MPa GPa 0 58 1.97 a-3 90 2.7 f-1.8 94 2.8 Thermal stability increased by 65°C by adding CNT FTIR revealed presence of H-bonding interactions between PMMA and -COOH groups present in f-MWCNT... 

Kessler and co-workers synthesized norbornene-functionalized MWCNT (f-MWCNTs) (Scheme 5.9), and prepared bulk composites of f-MWCNTs/poly(dicyclopentadiene) (DCPD) by in situ ROMP of f-MWCNTs in the presence of DCPD and Grubbs catalyst for 2 h at 70 °C followed by 90 min at 170 °C. A cross-linked polymeric network was instantaneously formed, and the mechanical properties with low loadings (<0.5 wt%) of f-MWCNTs were studied. A remarkable increase in tensile toughness (925% increase over the neat polyDCPD) with only 0.4 wt% f-MWCNTs was found, and the corresponding elongation at break significantly increased from 5.75 to 51.8%. The DSC results demonstrated an increase in with the addition of f-MWCNTs.Using the same method, they subsequently... 

Scheme 5.8 Functionalization of SWNTs with polynorbornene by ROMP. prepared reinforced poly(5-ethylidene-2-norbornene) (ENB) f-MWCNTs...

CS-based mixed matrix membranes and nanocomposite membranes are much useful in heavy metal removal. Salehi et al. [82] synthesized amine functionalized multiwalled carbon nanotubes (F-MWCNTs) and utilized to prepare novel CS/polyvinyl alcohol (PVA) thin adsorptive membranes for copper ion removal from water. Copper ion adsorption on the membranes was more favorable at higher CNT contents as well as increased temperatures. The adsorption capacity of the membrane containing 2 wt.% CNTs (20.1 mg/g at 40°C) was almost twice as large as that of the plain membrane (11.1 mg/g). Salehi et al. [83] used PE glycol and amino-modified MWCNTs to modify CS/PVA thin adsorptive membranes for copper ion adsorption. Adsorption capacity of CS/PVA membrane was increased from 11 to 30 mg/g by the addition of 5 wt.% PEG to the blend. Addition of CNTs,... 

Table 10.1. Comparison of mechanical properties for MWCNT/PC and f-MWCNT/PC nano-composites [48]...

Figure 39.7 TEM micrographs of (a and b) as-received f-MWCNTs, (c) dried siiica powder, and (d) sintered silica powder and composition anaiysis (inset) of the arrowed nanotube. (Reproduced from Ref. [25].)...

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