Conductive polymer nanotubes, controlled

Abidian, M. R., et al. (2006), Conducting-polymer nanotubes for controlled drug release, Adv. Mater., 18,405-409. 

Abidian M, Martin D (2005) Controlled Release of an Anti-Inflammatory Drug Using Conducting Polymer Nanotubes for Neural Prosthetic Applications. In MRS Symposium M, p 1. San Francisco. 

A method for preparing conducting polymer nanotubes that can be used for precisely controlled dmg release was reported by Abidian et al. [80]. The fabrication process... 

Figure 15.5 Left SEM image ofPEDOT nanotubes on a neural probe tip Right mass release of dexamethasone from poly(lactide-co-glycolide) (PLGA) fibers (black), PEDOT-coated PLGA nanoscale fibers without electrical stimulation (red), and PEDOT-coated PLGA nanoscale fibers with electrical stimulation of 1 Vat the times with the circled data. (Reprinted with permission from Advanced Materials, Conducting-polymer nanotubes for controlled drug release by M. R. Abidian, D.-H. Kim and D.C. Martin, 18, 4, 405-409. Copyright (2006) Wiley-VCH)...

By changing the doping level, dopant, and template-dissolving solvents, the electrical and optical properties of the nanotubes and nanowires can be controlled. The diameters of the conducting polymer nanotubes and nanowires are in the range 100-200 nm, depending on the diameter of the nanoporous template used, it was found that the polymerization was initiated from the wall-side of the AAO template. The synthesized nanotubes have an open end at the top with the filled end at the bottom. As polymerization time increases, the nanotubes will be filled and nanowires will be formed with the length increased. For example,... 

Conducting Polymer Nanotubes for Controlled Drug Delivery... 

Controlled electrochemical synthesis of conductive polymer nanotubes in a porous alumina template has been studied as a function of monomer concentration and potential in the case of PEDOT the electropolymerization leads either to solid nanowires or to hollow nanotubes depending on the template pore diameter, the applied oxidation potential and the monomer concentration [265], Nanowires are formed at slow reaction rate and high concentration monomer supply in fact monomeric molecules should have enough time to diffuse into and fill the pores, from the bulk solution. On the other hand, nanotubes are predominantly formed with fast reaction rate and low monomer concentration, because the monomers that diffuse from the bulk solution can be deposited along the pore wall thanks to the interaction of the polymer with the wall surface. 

This is a powerful and controllable method to synthesize the nanostructure materials of inorganic semiconductors, metals, and polymers. In the hard template method, the growth of the nanostructures takes place within the pores or channel of template membrane by polymerization and then the template is removed after the polymerization. The porous membrane is the basic and most important part of the hard template method. Porous membrane such as polycarbonate and alumina can be used as the hard template to produce conducting polymer nanotubes and nanowires as shown in Fig. 9. 

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