Striped pattern

Fig. XV-9. Fluorescence micrograph of the stripe patterns observed in a monolayer from a mixture of PA and SP-Bi-25 (20% by weight peptide) on a buffered saline subphase at 16 C and zero surface pressure. (From Ref. 55.)...

S. R. Lee and J. S. Kim, On the sublimit solution branches of the stripe patterns formed in counterflow diffusion flames by diffusional-thermal instability. Combust. Theory Model. 6(2) 263-278,2002. 

Qi, H. and Hegmann, T. (2006) Formation of periodic stripe patterns in nematic liquid crystals doped with functionalized gold nanopartides. Journal of Materials Chemistry, 16, 4197-4205. 

Contact lithography can be used to spatially control the photosubstitution process to form laterally resolved bicomponent films with image resolution below 10 pm. Dramatic changes occur in the colors and redox potentials of such ruthenium(II) complexes upon substitution of chloride for the pyridine ligands (Scheme 1). Striped patterns of variable colors are observed on addressing such films with a sequence of potentials. 

As mentioned before, the stripe pattern deteriorates slowly with increasing number of Cu layers, but it remains visible for a long time. Eventually Cu clusters emerge with normal fee structure. In Fig. 24 an STM image of Au(100) is shown, the surface of which is covered by a nominally thick Cu overlayer. On top of the wavy Cu phase, clusters with regular bulk structure have been formed. A similar situation is depicted in Fig. 25 for Cu on Ag(100), where a large Cu crystallite with a flat... 

Zebra mussel (Dreissena polymorpha) is a freshwater bivalve belonging to the Dreissenidae family. The common name, zebra, refers to the zebra stripes pattern on the shell and the scientific name, polymorpha, is derived from the many morphs or forms which occur in the shell color pattern, including albino and solid black or... 

The reconstructed surface (5 x 20) of platinum crystals contains as many atoms as 1.2 times the original surface (1 x 1) atoms, and hence the transformation of surface lattice in the reverse direction from (5 x 20) to (1 x 1) forces the excess siuface atoms to cohere in a striped pattern on the un-reconstructed (1 x 1) surface. 

Fig. 5 Fluorescence micrograph of siuface photo-graft-copolymerized with (W-dimethyl-amino) propyl acrylamide methiodide (DMAPAAmMel) by UV irradiation through the stripe-patterned projection mask and the neutral-density filter and subsequently stained with rose bengal, and the three-dimensional image, b of the distribution of the florescence intensity in the area shown in a...

Fig. 26. 50 50 block copolymer of styrene and methacrylate cast from 0.1 wt % solution in toluene onto a chemically heterogeneous surface with Au/Si02 stripes with 60 nm. Periodicity and the degree of order of the striped pattern revealed strong dependence on the molecular weight a 113,000 g/mol and b 177,000 g/mol. Courtesy of T.P. Russell... 

To achieve in-plane alignment in a lamellar block copolymer thin film, the lamellae have to be oriented perpendicular to the plane of the film in the first place. As we have shown earlier, in the block copolymer system S47H10M4382 perpendicular alignment of the lamellae is achieved spontaneously at zero electric field [9, 17]. In short, a thin brush layer of the block copolymer is adsorbed onto the (polar) substrate via the PHEMA middle block, resulting in a stripe pattern of the two majority components PS and PMMA. In thicker films, this brush layer seems to serve as a template for perpendicular lamellae [21, 22], This can be seen in Fig. 2a, which shows SFM images of a thin S47H10M4382 film annealed for... 

Figure 7a displays a SFM phase image of a spin-coated S47H10M4382 film that has a disordered surface structure. The ordering effect of the simultaneous solvent vapor annealing and application of a voltage between the electrodes is shown in Fig. 7b. After 6.5 h of treatment the stripe pattern appears highly ordered parallel to the electric field vector. Importantly, during the swelling of the film, the polar middle PHEMA block remains anchored to the substrate. This preserves the self-assembled stripe pattern of the two major PS and PMMA blocks (Fig. 7c).

Our approach is validated by comparison of the treatment time when the sample is treated continuously and step-wise for snapshot imaging. Since in both cases the complete orientation of the stripe pattern along the electric field vector is achieved within 6-7 h, we concluded that the quasi in situ treatment has no significant effect on the mechanism of the microdomain alignment and ordering. 

The patterns obtained were reported to be highly regular, having periodicities below 1 pm as can be seen in Fig. 16a-f. The striped pattern represents the negative of the wrinkled stamp with different wavelengths and amplitudes. 

The stability of 2D stripe patterns that are periodic along the same direction (here the x direction) as the forcing has been investigated numerically. For this purpose an ansatz similar to the one in ID has been chosen ... 

With directional quenching we present an effective mechanism to induce periodic stripe patterns in phase separating systems, where the wavelength of the patterns is uniquely selected by the velocity of a quench interface. If an additional spatially periodic modulation of the quench interface is introduced, cellular patterns can also be generated. 

In the case of the critical quench (iff) = 0, the orientation of the domains depends on the velocity of the quench interface (Fig. 32a-c). At small v, periodic patterns with domains perpendicular to the quench interface are formed (Fig. 32a). Then, for v above vc 0.45, the ID stripe patterns parallel to the quench interface appear (Fig. 32b-c). Finally, v > v eventually leads to irregular patterns similar to the case of a spatially homogeneous quench. 

In contrast, for the off-critical quench ((iff) 0 when v < v ) regular stripe patterns with domains parallel to the quench interface were always found (Fig. 32d-f). This situation is covered by a ID analysis presented before where the period of the structure is uniquely determined by the velocity of the quench interface. In the limit v —> 0 the periods of the patterns found in our numerical simulations agree with (73). For v > v irregular coarsening patterns, similar to the case of a spatially homogeneous quench, are observed. 

For systems where thermodiffusive effects can be neglected, we have presented results on the effects of directional quenching where the control parameter jumps the critical temperature from above to below and where the location of the jump is moved with a finite velocity v. We have shown how, by this method, regular structures are created during the process of phase separation behind the moving quench interface. Moreover, it was shown that the wavelength of periodic stripe patterns is uniquely selected by the velocity of the quench interface. If an additional spatially periodic modulation of the quench interface is introduced, cellular patterns can also be generated. 

Electrostatic interactions between fibrils and a surface can be exploited to create micron-sized patterns of fibrils. Mesquida and colleagues (2005) used this approach to selectively deposit fibrils onto negatively charged stripes of mica that were exposed between alternating stripes of deposited cationic poly-L-lysine, as shown in Figure 9. The striped pattern was formed by directing poly-L-lysine through the channels of a polydi-methysiloxane (PDMS) stamp that was placed in contact with the mica surface. 

Recently, it has been demonstrated [53] that at room temperature the Ge(0 01) surface does not show a uniform simple reconstruction, but instead an ordered striped pattern consisting of p(2 x 1) and c(4 x 2) domains (see Fig. 4). This striped pattern corresponds to a minimum free energy and can be fully explained in terms of a well-established strain relaxation theory [54]. With increasing temperature the p(2 x 1) domains grow at the expense of the c(4 x 2) domains. It requires extremely clean and defect-free surfaces to observe this phenomenon, which is probably the reason why it hasn t been observed before. In contrast to Ge(00 1) it is inherently difficult to prepare clean Si(00 1) surfaces with defect densities low enough for this pattern to develop. 

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