Copolymers monolayers

Luzinov I. et al., Microtribological behaviour of tethered block copolymer monolayers, Polym. Prepr., 41, 1499, 2000. 

Further modification of the above nanostructures is useful for obtaining new functional materials. Thirdly, we apply the dopant-induced laser ablation technique to site-selectively doped thin diblock copolymer films with spheres (sea-island), cylinders (hole-network), and wormlike structures on the nanoscale [19, 20]. When the dye-doped component parts are ablated away by laser light, the films are modified selectively. Concerning the laser ablation of diblock copolymer films, Lengl et al. carried out the excimer laser ablation of diblock copolymer monolayer films, forming spherical micelles loaded with an Au salt to obtain metallic Au nanodots [21]. They used the laser ablation to remove the polymer matrix. In our experiment, however, the laser ablation is used to remove one component of block copolymers. Thereby, we can expect to obtain new functional materials with novel nanostmctures. 

In this chapter, the focus is largely on experimental and theoretical studies of micellization in a range of solutions of model block copolymers prepared by anionic polymerization. A discussion of both neutral and ionic block copolymers is included, and features specific to the latter type are detailed. The adsorption of block copolymers at the liquid interface is also considered in this chapter. Recent experiments on copolymer monolayers absorbed at liquid-air and liquid-liquid interfaces are summarized, and recent observations of surface micelles outlined. Thus this chapter is concerned both with bulk micellization and the surface properties of dilute copolymer solutions. 

Finally, we note that in a very recent work Heuberger et al. investigated protein-resistant copolymer monolayers of PEG grafted to poly(L-lysine) (PLL) (PLL-g-PEG) in terms of the role of water in surface grafted PEG layers [159], interaction forces and morphology [160], compressibility, temperature dependence and molecular architecture [161], PEG is often used in biomedical applications in order to create protein-resistant surfaces but the mechanisms responsible for the protein-repelling properties of PEG are not fully understood. 

Goncalves da Silva AM, Filipe EJM, d Oliveira JMR, Martinho JMG (1996) Interfacial behavior of poly(styrene)-poly(ethylene oxide) diblock copolymer monolayers at the air-water interface, hydrophilic block chain length and temperature influence. Langmuir 12 6547-6553... 

Matsen M W 1999 Elastic properties of a diblock copolymer monolayer and their relevance to bicontinuous microemulsion J. Chem. Phys. 110 4658... 

Matsuoka, H., Suetomi, Y, Kaewsaiha, P., et al., 2009. Nanostructure of a poly(acrylic acid) brush and its transition in the amphiphilic diblock copolymer monolayer on the water surface. Langmuir 25 (24), 13752-13762. 

Figure 8.17. Photoinduced modification of 2-D MPS nanostructures of the tri-block copolymer monolayer on mica, (a) Initial cis-rich state, (b) trans-rich state after UV irradiation, and (c) successive cis-rich state after visible light irradiation.

The result, Eq. (43), can also be used to calculate the elastic constants of interfaces in ternary diblock-copolymer systems [100]. The saddle-splay modulus is found to be always positive, which favors the formation of ordered bicontinuous structures, as observed experimentally [9] and theoretically [77,80] in diblock-copolymer systems. In contrast, molecular models for diblock-copolymer monolayers [68,69], which are applicable to the strong-segregation limit, always give a negative value of k. This result can be understood intuitively [68], as the volume of a saddle-shaped film of constant thickness is smaller than... 

PS-PAA monolayers turned out to be an excellent template for polyelectrolyte layer-by-layer (LbL) deposition [85]. In contrast to a lipid monolayer, the block copolymer film enabled monolayer viscosity measurements after adsorption of each added layer. In addition, it seems that the viscoelastic properties of the polyelectrolyte multilayer are dominated by the properties of the underlying block copolymer monolayer. 

Biotinylated copolymers of 3-undecylthiophene and 3-thienylmethanoI using streptavidin as a cross-linker protein is an electroactive matrix for the attachment of a photoactive protein, phycoerythrin. The biotinylation of the copolymer improves the film forming properties and results in a stable mono-layer. The phycoerythrin binding to the biotinylated copolymer monolayer can be monitored through fluorescence microscopy at the air-water interface [451]. 

Most of the approaches mentioned in the previous section lead to the immobilisation of a copolymer monolayer. However, the thickness of the coating can be increased by adding a comonomer unit that allows cross-Unking. According to this concept, different chemical mechanisms were reported. 

As an example it has been shown that the refractive index of submicrometer thick coatings can be controlled by growing copolymer monolayer from surfaces. 

Figure 24 Optical wavequide spectra (p-polarized light) of copolymer monolayers prepared from styrene and MMA with varying PMMA content top to bottom x(PMMA) = 0.22, 0.45, 0.65, 0.86, and 1.00.

Figure 25 Refractive indices of copolymer monolayers (styrene/MMA) as a function of the PMMA content. The values were determined from the optical waveguide spectra shown in Fig. 24. The solid line was theoretically predicted from the copolymerization...

A ferrocene derivative was synthesised with a pyrrole group attached to ferrocene through an alkyl chain (Figure 14.38). This molecule was mixed with 3-hexadecylpyrrole and spread onto FeCla containing water to form a copolymer monolayer. The monolayer was deposited on an electrode surface the resulting modified electrode can be used for reoxidising reduced glucose oxidase [264,265]. 

Figure 26 Surface pressure of a spirobenzopyran—methylmethacrylate copolymer monolayer versus time during irradiation with successive UV and visible light pulses. Surface concentration = 0.875 mg m , water subphase at pH 1.0.

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