Spherical structure

Figure 22.1 The amphiphilic nature of phospholipids in solution drives the formation of complex structures. Spherical micelles may form in aqueous solution, wherein the hydrophilic head groups all point out toward the surrounding water environment and the hydrophobic tails point inward to the exclusion of water. Larger lipid bilayers may form by similar forces, creating sheets, spheres, and other highly complex morphologies. In non-aqueous solution, inverted micelles may form, wherein the tails all point toward the outer hydrophobic region and the heads point inward forming hexagonal shapes.

Boal AK, Ilhan F, DeRouchey JE, Thum-Albrecht T, Russell TP, RoteUo VM. Self-assembly of nanoparticles into structured spherical and network aggregates. Nature 2000 404 746-748. 

A similar multifunctional macroinitiator was obtained by Puskas [65] in a radical copolymerization of S and 4-(l-hydroxy-l-methylethyl)styrene. The macroinitiator was then used to initiate the living cationic polymerization of IB. With relatively short backbone and 8-23 branches with Mn=10,000-20,000 g mob1, starlike structures, spherical in shape were obtained. The structure was verified by core destruction followed by SEC analysis of the surviving arms. 

The major caseins exist in milk as highly structured, spherical aggregates, consisting of 450 to 10,000 subunits (3), commonly referred to as micelles. The important physico-chemical properties of the micelles are summarized in Table 3. Casein micelles are synthesized in vivo by biochemically controlled processes., which have not been totally characterized (5). Even... 

Ceria NWs (1.2 nm in width) and tadpole-shaped nanocrystals (3.7 nm in width) are obtained by a nonhydrolytic sol-gel process in presence of diphenyl ether in a mixed high boiling solvent of oleic acid and oleyla-mine at 320 °C (Yu et al., 2005c Figure 7). The NWs reported by Yu et al. are among the thinnest ones known with a reasonable yield, showing a growth direction of [100] of the fluorite structure. Spherical ceria nanocrystals of 3.5 nm could also be obtained if oleic acid is absent from the system. 

To explain the existence of three types of domain structures (spherical, rodlike, and lamellar) in SI, SIS, and ISI block copolymers cast from dilute solution, Kawai et al. have assumed the formation of micellar structures at a critical con-... 

Morphological features have often been described imprecisely. For example, descriptions like "more or less round" have been used. To solve such a dilemma, the answers to two questions must be encoded (1) is the structure spherical or (2) is the structure elipsoidal If the shape of the structure is variable, positive answers to both questions are encoded. 

These planospherical convex (PSC) structures (spherical face on one side and a flat face on the other) can be isolated as nanolenses. CHQ lenses are... 

Regardless of the shape of any aggregated structure (spherical or cylindrical micelle or a bilayer), no point within the structure can be farther from the hydrocarbon-water surface than Ic- The critical chain length, is roughly equal to, but less than, the fully extended length of the alkyl chain. 

These investigations have demonstrated that cut-spherical POPC GVs formed in an alternating electric field for 2-A h are stable enough for microinjection experiments. Other morphological structures cannot be used for such experiments, such as the mushroom structures. Spherical GVs-preferably the cut-spheres-can be touched and punctured by a microneedle furthermore, after withdrawing the microneedle the GVs still retain their spherical shape. 

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