Polymer brushes acrylate

In a series of papers, Matsuda et al. [291-295] employed RAFT-SIP with immobilized benzyl N,N-diethyldithiocarbamate to form polymer brushes from styrene, methacrylamides, acrylamides and acrylates, NIPAM and N-vinyl-2-pyrrolidone on various surfaces. The SIP is initiated by UV irradiation of the surface-bonded dithiocarbamates. Thermoresponsive polymer brushes were prepared by the polymerization of NIPAM and investigated by XPS, wetting experiments and mainly SPM [294]. Patterned polymer brush layers were also prepared. When chloro-methyl styrene was used as a comonomer, RAFT-SIP resulted in branching. By control of the branching, spatio-resolved hyperbranching of a controllable stem/ branch design was realized (Fig. 9.32) [293, 295]. 

An alternative photo-SIP approach was described by Kang and coworkers, where they used an argon plasma to oxidize alkylthiolate SAMs on planar gold [55]. The plasma treatment oxidized carboxy-terminated SAMs to peroxide moieties. UV irradiation in the presence of acryhc acid and allylpentafluorobenzene yielded ultra-thin graft layers of 6-7nm. The poly(acrylic acid) layers were found to adsorb Fe " ions from solution. This particular photoinitiation method yields low-density polymer brush films. 

Fig. 39 Illustration of LBL fabrication of polyfvinylpyrrolidone) (PVPON) and spherical polymer brushes with a poly(methylsilsesquioxane) (PSQ) core and poly(acrylic acid) (PAA) corona. Reprinted with permission from [258], 2006 American Chemical Society...

Figure 6. Interaction of a water droplet with 200 micron features of a patterned polymer brush prepared by surface-initiated polymerization. The unusual wetting profile is due to preferential interaction of the water droplet with the polymery lie acid) brush domains (light) and complete non-wetting of the hydrophobic poly(tert-butyl acrylate) domains (dark).

Several interesting new concepts for the design of CdSe nanocrystal based polymer solar cells have been introduced recently. Snaith et al. have infiltrated CdSe nanocrystals into polymer brushes and demonstrated EQEs of up to 50% [256]. In this case the poly(triphenylamine acrylate) (PTPAA) chains were directly grown from the substrate by a surface-initiated polymerization on tethered initiator sites (Fig. 58). The authors pronounced the wide applicability of this method for the design of nanocrystal-polymer functional blends [256]. 

Hb polymer brushes can be conveniently prepared by surface-initiated ATRP-SCVP of a suitable inimer from an initiator-functionalized surface. Mori et al. describe the synthesis of hb poly(2-(2-bromopropionyloxy)ethyl acrylate and 2-(2-bromoisobutyryloxy)ethyl methacrylate. " Another approach is presented by different groups employing halloysite nanotubes and GMS or 2-(bromoacetyloxy)ethyl... 

Figure 49 General synthetic scheme of magnetic and semiconducting hybrid nanowires templated from core-shell molecular bmshes (a) a molecular brush with a PAA core and a PriBA shell (b) the PAA core neutralized into poly(sodium acrylate) (c) a polychelate consisting of a polymer brush and Fe, Fe, or Cd ions and (d) a hybrid nanowire of a polymer bmsh with a wire-like assembly of magnetic/semiconducting nanopartides in its core. Reprinted from Zhang, M. Muller, A. H. E. J. Pofym. Sci. Part A Polym. Chem. 2005, 43 (16), 3461-3481, with permission from Wiley-VCH. ...

Zhao and Shipp synthesized poly(styrene-block-butyl acrylate) (PSBA) by sequential ATRP. BMP was intercalated into the individual layers of clay by ion exchange, and Cu(I)Br complexed by BPMODA was used as the transition metal catalyst After two-step ATRP, PSBA polymer brushes on the clay surface were prepared (Figure 10.2). Their transmission electron microscopy (TEM) result indicated that a mixture of exfoliated and intercalated structures was produced in the nanocomposite. On the surface of clay layers, the block copolymer chains can form nano-sized domains (2 to 5nm), which is much smaller than the size of self-assembly... 

Brzozowska et al. [18] reported on the stability of the polymer brushes formed by adsorption of ionomer complexes on hydrophilic and hydrophobic surfaces. The ionomer complexes or micelles consisted of oppositely charged polyelectrolyte blocks (poly(acrylic acid) and poly(N-methyl-2-vinyl pyri-dinium iodide)), and a neutral block (poly(vinyl alcohol)) or neutral grafts (poly(ethylene oxide)). The results showed that adsorbed micellar layers were relatively weakly attached to hydrophobic surfaces and much stronger... 

SC-SET-LRP and SC-ATRP of a Series of Amino (Meth)Acrylate Polymer Brushes... 

Currently, there has been only one report in the literature concerning ATRP of 2-(dimethylamino)ethyl acrylate (DMAEA) which involved homogeneous (bulk) polymerization (instead of polymer brush) formation [54]. To the authors knowledge, the only LRP technique applied in the s)mthe-sis of PDMAEA polymer brushes is nitroxide-mediated radical polymerization [55-57]. The first synthesis of PDMAEA brushes from Si substrates by SC-ATRP used a CuCl/CuCl2/Me6TREN/2-bromopropionyl type initiator catalyst system and reaction temperature of 70°C. PDMAEA dry layer thicknesses reached 34 5.9 nm after 72 h. 

Reaction Conditions and Average Dry Polymer Brush Thicknesses (with 95% Confidence Intervals) for SC-LRP of Poly(Amino (Meth)Acrylate) Brushes from Si-SAM Substrates Using ATRP and SET-LRP Methods... 

Ding, S., Floyd, J. A., Walters, K., Comparison of Surface Confined ATRP and SET-LRP Syntheses for a Series of Amino (Meth)acrylate Polymer Brushes on Silicon Substrates, J. Polvm. Sci. A Polum. Chem. 2009,47,6552-6560. 

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