Poly film polymer brushes

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. 

The polymer pair PVPON and PMAA was later used by Sukhishvih and coworkers to prepare hydrogen-bonded multilayer capsules and to discuss the effect of the substrate charge on the first adsorbed layer of the weak poly(carboxyhc acid) and the subsequent film growth [257]. Chen and coworkers used the same concept to prepare composite thin films by a hydrogen bonding assembly of polymer brushes and PVPON [258]. Spherical poly-... 

Huck et al. prepared Au NPs inside IL-based polyelectrolytes [70], The nanocomposite synthesis relies on loading the macromolecular film with AuCl precursor ions followed by their in situ reduction to Au nanoparticles. It was observed that the nanoparticles are uniform in size and are fully stabilized by the surrounding polyelectrolyte chains. Moreover, XRR analysis revealed that the Au NPs are formed within the polymer-brush layer. Interestingly, AFM experiments confirmed that the swelling behavior of the brush layer is not perturbed by the presence of the loaded NPs (Fig. 4.22]. The Au NP-poly-METAC nanocomposite is remarkably stable to aqueous environments, suggesting the feasibility of using this kind of nanocomposite systems as robust and reliable stimuli-responsive platforms. 

To create responsive membranes, poly(L-alanine) brushes were grown on the surface of the nanopores in silica colloidal films assembled on Pt electrodes (opal electrodes) according to Scheme 8.6 [33]. The polymerization time was varied from 7 min to 6 h to create polymer brushes of various lengths. 

The brush-gel polymer film is a submicrometer particulate layer with cross-linked polymer brushes. Nonporous particles with diameter of 350 nm, 700 nm, or 900 nm, modified with polyacrylamide, were applied on a silicon wafer as slurry to obtain a 15-pm thin layer. Coating with polyacrylamide brushes increased the capillary force for increased mobile-phase velocity and the overall separation performance. Three fluorescence-labeled proteins were separated with a sinapinic acid containing mobile phase for subsequent detection via MALDl [35], A second modification of this brush-gel polymer was manufactured by cross-linking poly(glycidyl methacrylate) and di(ethylene glycole)dimethacrylate to graft the thin layer covalently on the glass substrate and to manipulate the separation characteristic. The separation of a fluorescent dye mixture was performed on this layer and the ability for a multiple reuse was shown [36]. 

Surface-grafted, brushlike polymers can dramatically modify the lubricious properties of surfaces. The ability to bind a significant amount of solvent in a surface layer is thought to be one of the key mechanisms for low-friction, polymer-brush films. A brush composed of water-soluble, biocompatible polymers, such as poly(ethylene glycol), in an aqueous environment can provide an oil-free, environmentally friendly, food-compatible lubricious surface. 

The extremely low friction achieved on PLL(20)-g[2.9]-PEG(5) films in SFA experiments is not a unique property of this specific copolymer but has also been observed for other grafted poly(ethylene glycol) films as well as for other polymer-brush systems in a good solvent, such as grafted polystyrene in toluene. The osmotic pressure, which leads to strong repulsive forces as the polymer brushes are compressed, effectively prevents the direct contact of the solid surfaces. At comparable solid surface separations, thin films of water or aqueous salt solutions have been shown to retain a shear fluidity characteristic of the bulk liquid. In a control experiment, this was also observed in 10 mM HEPES buffer solution (data not shown). 

Li, Tan, D., Zhang, X., Tan, H., Ding, M., Wan, C., and Fu, Q. 2010. Preparation and characterization of nonfouling polymer brushes on poly(ethylene tere-phthalate) film surfaces. Colloids and Surfaces B Biointerfaces 78 343-50. 

Preparation and Characterization of Nonfouling Polymer Brushes on Poly (Ethylene Terephthalate) Film Surfaces... 

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