Polystyrene brushes

The preparation of structured polystyrene brushes was carried out following the same procedures, only the irradiation was performed through a stencil mask with circular openings of 800 nm radius that was placed on the NET covered substrate. 

Fig. 9.22 a) SEM micrograph of polystyrene brushes generated via SIP on a substrate that was irradiated through a stencil mask with a coarse grid with 50 pm periodicity. Each square contains an array of circular holes of 1.5 pm dots (2.5 pm periodicity), b) SPM... 

Fig. 9.25 S urface topography of grafted polystyrene brushes layer after soxh-let extraction as probed by SPM. a) Typical scan (10x10) p,m with detailed scans as marked in the overview along with the dept profile analysis along the indicated lines (Reprinted with permission from [194] R. Jordan, A. Ul-man, j.F. Kang, etaL,J, Am. Chem. Soc. 1999, 121, 1016-1022. Copyright 1999 American Chemical Society.

Zhao B (2004) A combinatorial approach to study solvent-induced self-assembly of mixed poly (methyl methacrylate)/polystyrene brushes on planar silica substrates effect of relative grafting density. Langmuir 20 11748-11755... 

Fig. 9 A topographic thickness map generated with a scanning eUipsometer (iElli2000, Nanofilm Technologie, GmbH) of a polystyrene brush with an average thickness of 140 0.6 nm over an area of 100 x 193 p.m. The area within the square is very smooth, with a standard deviation of 4 A. (Reproduced with permission from [52] Wiley)...

In the case of work on phenylhthium anionic initiators, the first reported work by Jordan et al. involved the use of a SAM of biphenyllithium moieties on gold substrates to initiate anionic polymerization of styrene [26]. The thickness of the resulting dry polystyrene brush, as estimated by ellipsometry... 

Fig. 10 Variation in thickness of polystyrene brush with [TiCU] [114]...

Fig. 35. Equilibrium profile of a polystyrene (Mw=91 K) droplet on a polystyrene brush (Mw=91 K) surface of a PMMA/PS film as obtained by tapping mode SFM [301]. The dewetting occurred after annealing of the PS film at 150 °C during 20 h. Courtesy of A. Mourran and L. Leibler...

Practically all observations [241-243, 245,249, 261, 262,264] of the entropy driven brush stretching (see Eq. 59) have been performed for polystyrene brushes immersed in an identical, except for the isotopic status, PS matrix. The change in the conformational properties of the brush has been observed as a function of surface coverage o [241-243,245,249,261,262,264] and/or host matrix degree of polymerization P [241,243]. These studies were initiated in 1992 by us [241] and two other groups [249,262]. Here we resume the results of these reports focusing on the verification of the schematic conformation diagram (InP/ln N vs lno/ln N) predicted by theory [232, 239, 267] and presented in Fig. 35. 

Figure 3.31. The master curve of force profiles for polystyrene brushes attached to mica surfaces and surrounded by a good solvent for the polymer. Relative molecular masses are in the range 26 500 Mi 660 000. After Taimton et al. (1990).

Figure 6.5. A force-distance profile obtained using the surface forces apparatus for the force between two mica surfaces each bearing a physically adsorbed polystyrene brush, of relative molecular mass 140000, in toluene. The solid line is a fit to equation (6.1.14). After Taunton et al. (1990).

Figure 6.9. Volume fraction profiles of an end-grafted polystyrene brush, of relative molecular mass 105 000, imder various solvent conditions (O, toluene at 21 C and cyclohexane at A, 53.4 °C , 31.5 °C o, 21.4 °C and A, 14.6 "C), deduced from neutron reflectivity measurements (all the solvents are deuterated). Toluene at 21 °C is a good solvent and the solid line is the classical parabolic profile. The theta temperature for d-cyclohexane is 34 °C and the dashed line is the elliptical profile predicted by analytical self-consistent field theory for theta conditions. After Karim et al. (1994).

Figure 6.14. Segment density profiles of a deuterium-labelled polystyrene brush of relative molecular mass 100000 in contact with polystyrene matrices of a variety...

Sheiko SS, Gerle M, Fischer K et al (1997) Wormlike polystyrene brushes in thin films. Langmuir 13 5368-5372. doi 10.1021Aa970132e... 

SEC trace of a typical experiment run on these molecular brushes has shown that there is lS-16% of unimer left after polymerization this could be due to unfunctional oligostyrene in the macromonomer. Therefore the typical conversion is around 80% as there is no attempt to separate the imimer from polystyrene brush. 

Maas, J. H., Cohen Stuart, M. A., Sieval, A. B., Zuilhof, H., Sudhblter, E. J. R. (2003). Preparation of polystyrene brushes by reaction of terminal vinyl groups on silicon and silica surfaces. Thin Solid Films, 426, 135-139. 

Investigation of the force profile between two surfaces covered by adsorbed polystyrene brushes [57] showed that the profile can be described by Eq. (68), obtained for a semidilute concentration regime [57] ... 

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