Phase worm-like

Fig. 67 Schematic of phase behaviour for blend of novolac epoxy resin with nearly symmetric poly(methyl acrylate-co-glycidylmelhacrylate)-0-polyisoprene. Ordered L can be swollen with up to about 30% of resin before macroscopic phase separation occurs, producing heterogeneous morphologies containing various amounts of L, C, worm-like micelles and pristine epoxy. At lower concentrations, disordered worm-like micelles transform into vesicles in dilute limit. According to [201]. Copyright 2003 Wiley...

The collage of electron micrographs shown in Figure 19 Illustrates a probable transition from a nucleation and growth phase separation mechanism to a spinodal decomposition. The 7% PS sample shows more or less spherical PS domains, characteristics of nucleation and growth. However, a few domains appear to have some elliptical characteristics. When the PS content increases up to midrange, the shape of the PS domains becomes more obviously elliptical, suggestive of cross-sections of cylinders or other worm-like structures. As the PS content increases further, the... 

Fig. 10. Theoretical ternary phase diagram calculated from the scaled particle theory for worm-like hard spherocylinders with (Ni, N2) = (0.930,0.070), d = 1.52nm, q = 200nm, and ML = 2150 nm-1 [17]...

Panizzay, P., Cristobal, G., and Curely, J. "Phase separation in solution of worm-like micelles a dilute n—>0 spin-vector model". ]. Phys. Condens. Matter 10,11659-11678 (1998). 

Problem 2.4 Suppose a worm-like chain with diameter = 1.5 nm, persistence length kp = 100 nm, and length L = 20 nm is dissolved in a solvent. Estimate 02, the minimum volume fraction"of polymer needed to form a wholly nematic phase, it L is increased to 500 nm, and d and kp are kept the same, what is 02 ... 

In main-chain LCPs, molecular flexibility can be distributed more-or-less uniformly along the chain, as is the case for PBLG, HPC, or Vectra A, or it can be concentrated in flexible spacers, as in OQO(phenylsulfonyl)lU (see Fig. 11-2). The former are called persistently flexible molecules, and are often modeled by the worm-like chain, with a uniform bending modulus, while for the latter, a reasonable model might be the freely jointed chain (see Fig. 11-3 and Section 2.2.3.2). For a recent discussion of the phase behavior and dynamics of worm-like chains, see Sato and Teramoto (1996). 

Fig. 3.52 Left (a) Schematic of intermittent contact mode AFM and phase imaging right (b) intermittent contact AFM phase image of a 30 nm thin block copolymer films on silicon [(poly(isoprene)-b-poly(ferrocenyl dimethylsilane), 29 kg/mol/15 kg/mol], which displays a in-plane worm-like surface pattern of poly(ferrocenyl dimethylsilane) in a matrix of poly (isoprene). From the 2D FFT analysis (inset) an average repeat period of 33 nm was estimated. Reprinted with permission from [116]. Copyright 2000. American Chemical Society...

After hydrolysis of the films, different topographical and phase images are observed, as shown in Fig. 3.58 c and d. Block copolymer microphase separation is more pronounced and the phase images in particular reveal the presence of small features on top of the elevated worm-like features. These observations may be attributed to the fact that the PtBA groups have reacted to polyacrylic acid, which now swells due to uptake of water from the ambient air. The measured roughness increases to 5 nm. 

In Fig. 2, a variety of micelle structures are shown. Typical shapes of micelles are spherical, rod-like, and worm-like. At high concentrations of surfactant or at high concentrations of counterions, liquid crystals are usually formed. Hexagonal, cubic, and lamellar are common liquid crystal phases that occupy much of a... 

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