Polymers schematic structure

Lastly, we consider a class of compounds called ladder polymers, which are made up of a double-stranded backbone that is linked at regular intervals into rings so that the schematic structure is... 

Schematic energy level diagrams of a metal/polymer/metal structure before and after the layers are in contact are shown in the top two drawings of Figure 11-6. Before contact, the metals and the polymer have relative energies determined by the metal work functions and the electron affinity and ionization potential of the polymer. After contact there is a built-in electric field in the structure due to the different Schottky energy barriers of the asymmetric metal contacts. Capacitance-voltage measurements demonstrate that the metal/polymer/metal structures are fully depleted and therefore the electric field is constant throughout the bulk of the structure [31, 35]. The built-in potential, Vhh i.e. the product of the constant built-in electric field and the layer thickness may be written...

Fig. 11. The schematic structure of a comb polymer q arms of molecular weight are attached with regular spacing to a backbone of molecular weight...

Figure 2.8 Schematic of common polymer chain structures...

Figure 1 Schematic structures of micelle and liposome, their formation and loading with a contrast agent, (a) A micelle is formed spontaneously in aqueous media from an amphiphilic compound (1) that consists of distinct hydrophilic (2) and hydrophobic (3) moieties. Hydrophobic moieties form the micelle core (4). Contrast agent (asterisk gamma- or MR-active metal-loaded chelating group, or heavy element, such as iodine or bromine) can be directly coupled to the hydrophobic moiety within the micelle core (5), or incorporated into the micelle as an individual monomeric (6) or polymeric (7) amphiphilic unit, (b) A liposome can be prepared from individual phospholipid molecules (1) that consists of a bilayered membrane (2) and internal aqueous compartment (3). Contrast agent (asterisk) can be entrapped in the inner water space of the liposome as a soluble entity (4) or incorporated into the liposome membrane as a part of monomeric (5) or polymeric (6) amphiphilic unit (similar to that in case of micelle). Additionally, liposomes can be sterically protected by amphiphilic derivatization with PEG or PEG-like polymer (7) [1].

An analogous method was used to obtain a new class of macromolecular stereoisomers The hemitactic polymers (99-101). This term refers to a head-to-tail vinyl polymer in which the tertiary carbon atoms constitute two distinct series one, which includes monomer units 1,3,5, 7,..., possesses strict steric regularity, whereas the other, with monomer units 2, 4, 6, 8,. .., is completely at random. In such polymers only one in every two tertiary atoms is influenced by an ordering rule 58 and 59 show the schematic structure of the hemiisotactic and hemisyndiotactic polymers where the white circles indicate the positions of disordered s ubstituents. The hemiisotactic polypropylene was obtained by Farina, Di Silvestro, Sozzani and Savar6 (99, 101) by nonste-reoselective reduction,of. isotactic frans-l,4-poly-2-methylpentadiene. 

Problem 8.44 (a) Write a schematic structure for the mer of the polymer from head-to-tail reaction of 2-methyl-1,3-butadiene, (b) Account for this orientation in polymerization, (c) Show how the structure is deduced from the product... 

Figure 6.7 (a) Schematic structure of the two polymorphs of [Au (C = C-C6H4-4-N02)(PCy3)] showing the dimer (E-form) (left) or polymer (N-form) (right) arrangements, (b) Representation of the geometry of adjacent molecules in the crystal. 

Figure 16-6 (a) Schematic structure of the starch-iodine complex. The amylose chain forms a helix around l6 units. [Adapted from A T. Calabrese and A. Khan, "Amylose-lodine Complex Formation with Kl Evidence for Absence of Iodide Ions Within the Complex." J. Polymer Sci. 1999, A37,2711.] (fc>) View down the starch helix. Showing iodine inside the helix.8 [Figure kindly provided by R. D. Hancock, [rower Engineering, Sett Lake City.]... 

Fig. 17. Schematic structure of an LC side-chain polymer with embedded dyes (134).

Fig. 5 Schematic structure of hyperbranched polymer with dendritic (D), linear (L) and teminal (T) units...

Figure 4.11 Schematic representation of the conversion of stranded poly(diacetylene)s with a multiple-helical quaternary the supramolecular polymers into conjugated polymers under structure in the case of A. retention of the hierarchical structure, leading to four-... 

In addition to the infinite tubes, polycatenanes, and polyrotaxanes, all of which are polymeric complexes, a great number of silver coordination polymers with ID, 2D and 3D framework structures have been reported more recently. Selected examples and their specific topologies of some of these are listed in Table 11.1. Schematic structures of the corresponding organic ligands are shown in Figure 11.23.9,58-75... 

It should be remembered that the aim of this work was to produce defined layers with monosort functional groups, which can be used for grafting. Now, in contrast to the irregularly structured continuous-wave plasma polymers, the structure of pulsed plasma polymers was so much improved that partial or complete solubility was observed. Therefore, the further chemical processing in solvents and water led to dissolving the layer. Here, also chemically crosslinking copolymers as butadiene, di-vinylbenzene and trivinylcyclohexane were necessary as schematically shown in Fig. 9. 

Figure 2. Schematic structure of side chain liquid crystal polymers with dichroic dyes (imparting nonlinear optical properties) and mesogenic side groups.

FIG. 6.16 Schematic structure of liquid crystalline polymer with mesogenic group in the main chain. 

Figure 7. Schematic structure of the flexible All-polymer FET with optical transparency.

Figure VII-9 (a) The schematic structure of a polymer vertical microcavity laser, (b) The emission spectrum above and below the lasing threshold. (Taken from ref. 302)...

Figure VU-10 The schematic structure of a polymer distributed feedback laser.

Figure 10.12. Schematic structure of filled and crystallized LDPE. [Adapted, by permission, from Singhal A, Fina L J, Polymer, 37, No. 12, 1996, 2335-43.]...

Figure 11-6. Schematic electron energy diagrams of metal/ polymer/metal structures. The structures are shown before contact (upper panel), after contact in equihbrium (central panel), and after contact with a bias equal to the built-in potential applied to the structure (lower panel).

The schematic structure of a microball is shown in Fignre 5.14. The outermost layer of a microball is a hydration layer that makes the microball stable in water so that it will not precipitate. The middle, crosslinked polymer layer gives the microball some elasticity and deformabiUty. The inner layer is a core that gives the microball some strength when it blocks a pore throat (Snn et al., 2006). 

Figure 1.4 Schematic structures of thermoplastic and thermoset polymers.

Figure 11.5. Schematic structure models of possible continuous seam structures in a (continuous) polymer matrix. [Reproduced from ref 69 with kind permission of Carl Hanser ]...

Fig. 3.34. STM image of the supramolecular [2]rotaxane polymer (a) and its schematic structure (b).

Figure 12 Schematic structures of linear and branched polymers.

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