Dendritic polymers morphology

Fig. 4 and Fig. 5 show the surface morphologies aftm photo-ablation of PMMA/pyrene, and CMS, CMS/pyrene respectively. In these figures a copper-mesh mask was used in contact with the polymer films for the gena-atkm of sharp etch patterns. For PMMA/pyrene films, in the low pyrene concentration range, the etched surface is quite rough with dendritic and needle-like structures as well as solidified droplets on the bottom of the irradiated areas present although the edges of the etched features are reasonably sharp (Fig. 4a). When the laser fiuence is increased, the etched surface becomes cleaner and more smooth. At a high pyrene concentration, clean and sharp etch patterns can be obtained at a relatively low fiuence, e.g., at a = 1.04 x 10 cm and F = 0.3 J/cm as shown in Fig. 4b. In most cases, periodic structures are observed near the edges of the wire mask, which most likely result from the optical diffraction effect of the wires.

$Fig. 4 and Fig. 5 show the surface morphologies aftm photo-ablation of PMMA/pyrene, and CMS, CMS/pyrene respectively. In these figures a copper-mesh mask was used in contact with the polymer films for the gena-atkm of sharp etch patterns. For PMMA/pyrene films, in the low pyrene concentration range, the etched surface is quite rough with dendritic and needle-like structures as well as solidified droplets on the bottom of the irradiated areas present although the edges of the etched features are reasonably sharp (Fig. 4a). When the laser fiuence is increased, the etched surface becomes cleaner and more smooth. At a high pyrene concentration, clean and sharp etch patterns can be obtained at a relatively low fiuence, e.g., at a = 1.04 x 10 cm and F = 0.3 J/cm as shown in Fig. 4b. In most cases, periodic structures are observed near the edges of the wire mask, which most likely result from the optical diffraction effect of the wires.$

As noted above, various morphologies have been documented for dendritic and hyperbranched liquid crystal polymers, and this topic has recently received intense interest [ 14-27, 62-70]. Although the exhaustive revision of this area is outside the scope of this article, several types can be easily identified ... [Pg.15]

Microstructure is a key aspect for polymers in general, and for polyurethanes (PUs) in particular. The morphology of PUs is governed by the formation of hard and soft domains and their intercalation. Consequently, new microstructures can be developed using dendritic and hyperbranched (HB) polymers in PU systems. [Pg.218]

Besides the structures already discussed, more complex morphologies may be obtained from the growth of polymer crystals from solutions. The structure that emerges from the crystallization of a polymer is a function of a complex interaction of factors that include the type of solvent, solution temperature, concentration, and polymer molecular weight. Some examples of these structures include spiral growth, dendrites, and hedrites. [Pg.101]

Fig. 4 Novel drug delivery systems using stimuli-responsive polymers, (a) Morphology changes of poly(2-isopropyl- 2-oxazoline) (PiPrOx) and poly(benzyl ether)dendrons dendritic-linear block copolymers conjugates are Temperature- and pH-dependent.[105] (Copyright 2012, Royal Society of Chemistry) (b) Protein-binding-induced disassembly of dendron-based micelles. This inducible micelle disassembly is selective to the targeted protein and the disassembly can mediate release of the encapsulated therapeutic drugs.[106] (Copyright 2010, American Chemical Society)...

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