Polymer grafting with pretreatment methods

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. 

Polymer grafting is often initiated from radicals that are generated throngh surface pretreatment as previously described. Monomers were then easily polymerized from radicals that initiated the reaction (Fig. 6.2). This two-step method is considered as an indirect method. The presence of reactive groups on the grafting is essential to further create binding with molecules that have specific biological effect. 

After a few minutes irradiation with a high pressure mercury lamp at about 50 C, a rather complete cover of grafted acrylic acid, acrylamide and other vinyl monomers could be obtained. In later experiments a continuous grafting method has been developed where a tape or a fiber bundle after suitable pretreatment is grafted by UV irradiation for a few seconds. Homopolymer formed is removed by washing and grafted polymer analyzed by dye absorption, IR reflection and ESCA spectroscopy. 

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