Graft polymer, conductive

Ding, J. F, Chuy, C. and Holdcroft, S. 2002. Enhanced conductivity in morphologically controlled proton exchange membranes Synthesis of macromonomers by SFRP and their incorporation into graft polymers. Macromolecules 35 1348-1355. 

SIP-driven polymer brush library fabrication leverages the fact that the polymerization initiation species are permanently bound to the substrate. Since the initiators are tethered, controlled delivery of monomer solution to different areas of the substrate results in a grafted polymer library. In NIST work, initiators bound via chlorosilane SAMs to silicon substrates were suitable for conducting controlled atom transfer radical polymerization (ATRP) [53] and traditional UV free radical polymerization [54, 55]. Suitable monomers are delivered in solution to the surface via microfluidic channels, which enables control over both the monomer solution composition and the time in which the solution is in contact with the initiating groups. After the polymerization is complete, the microchannel is removed from the substrate (or vice versa). This fabrication scheme, termed microchannel confined SIP ([t-SIP), is shown in Fig. 10. In these illustrations, and in the examples discussed below, the microchannels above the substrate are approximately 1 cm wide, 5 cm long, and 300-500 [tm high. 

Kizilyar, N., U. Akbulut, L. Toppare, M.Y. Ozden, and Y. Yagd. 1999. Immobilization of invertase in conducting polypyrrole/polytetrahydrofuran graft polymer matrices. Synth Met 104 45. 

In their next study, Kawakami et al. addressed issues surrounding the design of the PEM for fuel cells, and more specifically, the role of the polymer architecture in proton conductivity and gas permeability [266]. Erom the previous study, Kawakami et al. showed that the polymer architecture (for example, graft polymer structures) helped enhance proton conductivity and suppressed gas permeability [260]. Taking that idea one step further, they synthesized and examined the PEM properties of sulfonated block (S-b-Pl), graft (S-g-PI), random-graft (S-rg-PI), and... 

Conducting polymer-grafted fabrics can be characterized by various techniques to ascertain the structure of the grafted polymer. 

Electron spin resonance (ESR) has an even longer standing history in the investigation of adsorption layers than NMR methods, due to the higher sensitivity. Its disadvantage is to require a spin probe, that can disturb the local molecular environment, which is a critical issue on molecular dimensions in monolayers. ESR and NMR methods can be considered complementary sources of information, and some of the very early NMR studies of grafted polymers at interfaces were in fact conducted complementarily to ESR [10]. A review of the application of ESR techniques to polymers at solid interfaces is given by Hommel [II]. 

Markedly, surface-initiated ATRP provides the opportunity to use a variety of functional monomers, to tailor the composition and thickness of the brushes, and to prepare multiple functional surfaces. For example, Zhang et al. prepared poly(methyl methacrylate) (PMMA), poly(acrylamide) (PAAM), and their diblock copolymer (PMMA/PAAM) on the surface of PET film by surface-initiated ATRP [59]. The results indicated that the surface properties of PET film were greatly improved by grafted polymer, the surface of PET film modified by PAAM was hydrophilic, and the surface of PET film modified by diblock copolymer was amphiphilic. This kind of modified PET film may be applied as biocompatible materials, amphiphilic functional film, or conductive film. 

In their efforts to use various fluoropolymer films to develop PCMs, Scherer and co-workers [51] prepared PVDF-g-PSSA membranes in comparison with their counterparts based on ETFE films. PVDF films were activated from y-radiation (dose of 20 kGy at dose rate of 5.9 kGy h ) at room temperature in air and grafting of styrene with peroxidation method interestingly occurred at 60°C. The influence of the base polymer properties on the grafting behavior was addressed [52], Sulfonation of the grafted films conducted with chlorosulfonic acid/dichloromethane mixture at room temperature. The PEMFC performance of PVDF-based membranes was found to be inferior to their ETFE-based counterparts [52],... 

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