Block surface morphology

Annis B K, Noid D W, Sumpter B G, Reffner J R and Wunderlich B 1992 Application of atomic force microscopy (AFM) to a block copolymer and an extended chain polyethylene Makromol. Chem., Rapid. Commun. 13 169 Annis B K, Schwark D W, Reffner J R, Thomas E L and Wunderlich B 1992 Determination of surface morphology of diblock copolymers of styrene and butadiene by atomic force microscopy Makromol. Chem. 193 2589... 

Puskas, J.E., Antony, P., Kwon, Y., Kovar, M., and Norton, P.R. Study of the surface morphology of polyisobutylene-based block copolymers by atomic force microscopy, J. Macromol. Sci., Macromol. Symp., 183, 191-197, 2002. 

Nanoscale Surface Morphology of PS-b-P4VP Block Copolymer Films... 

Nanoscale Surface Morphological Change of PS-b-P4VP Block Copolymer Films Induced by Site-Selective Doping of a Photoactive Chromophore... 

For symmetric PS-fo-P4VP (20 000 19 000) diblock copolymer films with the wormlike phase separation structures, the TCPP-doped films were irradiated using one laser shot with a fluence of 150 mJ cm in air. The ablation phenomenon is observed for this irradiation fluence (Figure 12.5c and f), but it is difficult to conclude that this is a selective ablation of the doped-P4VP parts. We cannot deny the possibility that the decomposition of the P4VP parts affects the PS parts because of the existence of large interfaces between the two symmetric blocks in wormlike structures. Thus, for the site-selective ablation of diblock copolymer films, the surface morphology of the phase separation structures is one of the most important parameters. 

Poisoning is caused by chemisorption of compounds in the process stream these compounds block or modify active sites on the catalyst. The poison may cause changes in the surface morphology of the catalyst, either by surface reconstruction or surface relaxation, or may modify the bond between the metal catalyst and the support. The toxicity of a poison (P) depends upon the enthalpy of adsorption for the poison, and the free energy for the adsorption process, which controls the equilibrium constant for chemisorption of the poison (KP). The fraction of sites blocked by a reversibly adsorbed poison (0P) can be calculated using a Langmuir isotherm (equation 8.4-23a) ... 

Zhang X, Berry BC, Yager KG, Kim S, Jones RL, Satija S, Pickel DL, Douglas JE, Karim A (2008) Surface morphology diagram for cylinder-forming block copolymer thin films. ACS Nano 2 2331-2341... 

When a chemical variety of a linear block copolymer is increased to three different components, an intricate diversity of structures becomes possible [188, 189], This is due to considerable increase in the number of involved polymer-polymer and polymer-surfaces interaction parameters. The studies on thin film behavior of ABC terpolymers are rare, even though they may potentially be more versatile than binary block copolymer morphologies due to the increased complexity. 

Additionally, a progression of the successful coating process is illustrated by SEM (Fig. 2). These images reveal the surface morphology of SBH microparticles during the coating process. Comparison between the particles coated with one and six layers of polyelectrolytes indicates the efficiency of the polymer deposition. Cracks in the particles are completely covered with the polyelectrolytes. As a result, the better protection of metal hydride could be achieved due to blocking of the access to the SBH surface by the deposited polyelectrolyte layers. 

The surface morphologies of these block copolyurethanes differ from their bulk morphologies (4-6). Because the surface controls the interaction of a vascular implant with blood, the surface structure and its relation to the bulk structure of the same material was determined also. Originally, ESCA was explored to study the surface structure because the depth of penetration was within the first 100 A. The low surface depth of penetration and subtle shifts in binding energies that result in peak splittings of the elemental spectra appeared to make this an attractive method to study the chemical and bonding environments of the elements (40). 

Fig. 3 Schematic representation of two possible surface morphologies, a Hexagonally arranged semi-spheres of B block (island morphology) b parallel oriented semi cylinders of B (ribbon morphology) (Reproduced with permission from [36]. Copyright 1999 American Chemical Society)...

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