Transmission electron microscopy solution self-assembly

Goldraich M, Talmon Y (2000) Direct-imaging cryo-transmission electron microscopy in the study of colloids and polymer solutions. In Alexandridis P, Lindman B (eds) Amphiphilic block copolymers self assembly and applications. Elsevier, Amsterdam... 

Kimura, Shirai and coworkers used two chiral dimeric porphyrins 95 and 96 to investigate their self-assembling behavior [162,163]. While incorporation into fibers made of the alkylamide derivatives of (fl,fl)-DACH, 95 formed stable well-resolved fibrous assemblies as visualized by transmission electron microscopy, the fluorescence of which was not quenched by external electron acceptors [162]. However, the induced CD was not detected indicating an inability of 95 to form chirally orientated aggregates under the applied conditions. In contrast, 96 was able to produce optically active inter molecular self-assemblies with an enhanced chiroptical response through the //-oxo bridging in an alkali solution, while intramolecular //-oxo dimer formation was excluded on the basis of steric reasons [163]. 

PPO repeating units self-assemble into a supramolecular honeycomb-like layered structure, in which perforations are filled by coil segments. When cast from dilute CHCR solution onto a carbon support film, honeycomb-like supramolecular structure was observed, as revealed by transmission electron microscopy (TEM), in which coil perforations are packed on a hexagonal symmetry with distances between perforations of approximately 10 nm (Figure 14a). 

Figure 18). Unexpectedly, an LC phase was detected for the nonglobally amphipathic helix of -peptide A. To understand this uniqne feature of A to form an LC phase in aqueous solution, Gelhnan and coworkers systematically studied the contribution of the different side chains of A to the intermolecnlar interactions. It was disclosed that the presence of aromatic residues in the nonglobally amphiphilic -peptide plays a crucial role in the formation of the LC phase in water. They also found that the reduction in the net charge of the peptides led to the enhancement of LC phases. In addition, cryo-TEM (transmission electron microscopy) provided evidence that liquid crystallinity of -peptide A results from its self-assembly into nanofibers. 

The overall morphology of the wax copolymer aggregates at the micrometric scale was also investigated by optical and transmission electron microscopy as complementary techniques for the USANS investigations. The results obtained allowed the clarification of the self-assembled structures in solution of the crystalhne-amorphous random copolymers. This has led to a broader understanding of wax crystal modification and control in solution than previously available. As noted, SANS is the required technique to study these hydrocarbon mixtures since contrast is easily achieved via the judicious mixture of hydrogenated and deuterated materials. As detailed experimentation has shown [7-18], this experimental capacity is vital for a complete... 

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