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Inclusion complex formation between polyaniline with emeraldine base and β-cyclodextrin has been studied by the frequency-domain electric birefringence (FEB) spectroscopy in a solution of N-methyl-2pyrrolidone (NMP) and by scanning tunneling microscopy (STM). The FEB results show that polyaniline in the solution with cyclodextrin changes its conformation from coil to rod at low temperature (below 275 K), and some rodlike images are observed on a substrate by STM. These results suggest that cyclodextrins are threaded onto polyaniline and confine the conformation of the polymer chain to a rodlike one. Furthermore, it is found that the threaded cyclodextrins prevent the chemical oxidation, i.e., doping of polyaniline by iodine. This indicates formation of a new inclusion complex, a conjugated conducting polymer covered by insulated cyclic molecules, namely, "insulated molecular wire".

Abstract. This letter aims at justifying the stochastic equations in terms of the number density variable, which are still controversial, via complementing Dean's approach [Dean D S 1996 J. Phys. A 29 L613]. Our course is twofold: First, we demonstrate that standard manipulations straightforwardly transform the stochastic equation of density operator, derived by Dean, to the Fokker-Planck equation for the (c-number) density distribution functional P ({ρ}, t). Moreover, we verify the associated static solution of P ({ρ}, t) with the help of the conditional grand canonical partition function.

Liquid-liquid phase separation and crystallization ͑or solid-liquid phase separation͒ both occur in protein solutions. By adopting egg-white lysozyme for a model system, we compared two types of diagrams, a phase diagram of the liquid-liquid phase separation and a morphological diagram of protein crystals. By superimposing these diagrams, we distinguished two types of white precipitates, urchinlike spherulites arising from the crystallization and protein-rich droplets from the liquid-liquid phase separation. Furthermore, we observed a transformation from the protein-rich droplets to the spherulites, and simultaneously an unusual pattern evolution of the protein-rich phase unlike the conventional phase separation of typical binary mixtures. This is understood in terms of the competition between the crystallization and the liquid-liquid phase separation.