Carbon nanotubes covalent grafting

Acrylic acid-grafted polylactide (PLA-g-AA) and multihydroxyl-functionalized multiwalled carbon nanotubes have been melt blended to improve thermal stability and mechanical properties of the composite. The formation of a covalent bond (ester linkage) resulted in a significant improvement in compatibility [98]. Alternatively, carboxylic acid-functionalized multiwalled carbon nanotubes were grafted onto PLEA by a one-step in situ polycondensation reaction [99]. 

Covalent Grafting in Carbon Nanotube/PEEK Nanocomposites... 

Another approach to covalently attach carbon nanotubes is based on the chemical modification of a PEEK matrix which allows further covalent interaction with functionalized carbon nanotubes. In 2007 Babaa et al. (40) proposed a route to covalently graft commercial MWCNTs by using this approach. The process initiates by dissolution of PEEK in concentrated H2S04, leading to functionalization yields of 70%. MWCNTs covalently functionalized with... 

The other immobilization methods include carbon nanotubes and nanoparticles. PolyCglycidyl methacrylate)-grafted multiwalled carbon nanotubes (MWNT) were covalently attached to A-butyl imidazolium bromide. An indium tin oxide (ETO) electrode coated with such MWNT-IL successfully immobilized tyrosinase and showed sensing response toward phenol at the range of 0.01-0.08 mM at ambient pH and temperature [60]. Similarly, glassy carbon (GC) electrode was coated with... 

Covalent Grafting of Ionic Liquids onto Carbon Nanotubes... 

Polymer Grafting of Carbon Nanotubes by Con-trolled/Living Radical Polymerization Polymer grafting techniques that use direct covalent functionalization methods, such as radical reactions, have been developed in order to avoid the problems associated with the functionalization of CNTs using acids. These grafting techniques eliminate the need for nanotube pretreatment before the functionalization and allow attachment of polymer molecules to pristine tubes without altering their original structure. 

Double-walled carbon nanotubes consist of a particular set of nanotubes because their morphology and properties are comparable to those of SWNT but they have considerably superior chemical resistance. Prominently, it is important when grafting of chemical functions at the surface of the nanotubes is required to achieve new properties of the CNT. In this processing of SWNT, some C=C double bonds will be broken by covalent functionalization, and thus, both mechanical and electrical properties of nanotubes will be modified. About of DWNT, only the outer shell is modified. 

Qin et al. [114] prepared functionalized single-walled carbon nanotubes (SWNTs) through treatment of polystyrene via the grafting-to method. The results showed that the PS was covalently attached to the side walls of SWNTs. The poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) was functionalized with glycidyl methacrylate (GMA) via atom transfer-radical polymerization (ATRP) and the BaTiOs nanoparticles were modified by amino-terminated silane molecules. Then, the nanocomposites with high dielectric coti-stant and high thermal conductivity were prepared by a grafting to method [115]. 

Wei P-J, Yu G-Q, Naruta Y, Liu J-G. Covalent grafting of carbon nanotubes with a biomi-metic heme model compound to enhance oxygen reduction reactions. Angew Chem Int Ed 2014 53 6659-63. 

GonzAlez Seligra P, Nuevo F, Lamanna M, Fama L (2013) Covalent grafting of carbon nanotubes to PLA in order to improve compatibility. Compos B Eng 46 61-68 Goyanes S, Aranguren M, Garcia N, Fama L, Ribba L, Dufresne A (2010) International Patent No 20.100.100.044... 

Carbon nanotubes 1. Mostly used carbon nanomaterials 2. Be easily covalently or non-covalently functionalized Oxidized CNTs can be grafted via creation of amide bonds, N2-plasma and radical addition SPE, MSPE, SPME, LDI substrate, p-SPE, SRSE 9 9... 

To date, they have been synthesized by two pathways (Figure 1.7) (a) the graftin approach, in which preformed polymers are linked to the fullerene unit, and (b) the graft-from approach, in which the polymeric chains grow-up from the surface of properly functionaUzed fullerene-derivatives. Notably, both approaches have also been employed for the covalent functionalization of single-waUed carbon nanotubes (Chapter 12). 

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