Facile formation of water-insoluble cyclodextrin/Nafion composite films on solid surfaces

The water-insoluble poly-beta-cyclodextrin (poly-CD)/Nafion composite film was easily prepared by casting a mixed solution of poly-CD and Nafion onto substrate plates. FT-IR measurements showed that the 50/50 wt% poly-CD/Nafion composite film remained stable on the glass and quartz substrates after immersion in water for more than 3 h, while a pure poly-CD film was almost completely dissolved by immersion within 1 h. The film stability was also evaluated from the amount of p-nitrophenol (p-NP) inclusion in the film, which was determined from the decrease in UV-vis absorbance of the p-NP solution into which the film was immersed. The composition dependence of the inclusion amount showed that the film was stable up to 50 wt% CD, but became less stable with further increase in the CD concentration in the film. From the isotherms for the inclusion of p-NP and 1-naphthoate (1-Naph) into the film, the inclusion (stability) constants were determined to be 3.7x10(3) M(-1) and 1.9x10(2) M(-1), respectively. These results show that the selective inclusion of CD is retained after preparation of the composite film.     

On the chiral connection between the ferromagnet,the axisymmetric gravitational problem and the SU(2) vacuum gauge field

A single chiral structure is shown to underly several three-dimensional field equations of physics, e.g., the ferromagnet, the stationary axi-symmetric gravitational problem, and the vacuum SU(2) gauge field in the Coulomb gauge. This connection invites cross-fertilization of exact solutions. As illustrations, exact finite energy solutions are obtained for the ferromagnet via the corresponding Weyl, Kerr, and Tominatsu-Sato solutions of Einstein's gravitational equations. Comments are made on the “local gauge invariance” of the ferromagnet and the gravitational field.     

Observation of surface composition of copper-nickel alloy by auger spectra in the lower energy region (at around 100 eV)

The interaction of oxygen with a clean (110) molybdenum surface has been studied by LEED and RHEED. At room temperature two simple chemisorbed structures are found, at higher exposures a multiple order pattern is seen. At temperatures above 750 K a complex LEED pattern is observed. Initially a corresponding RHEED pattern is seen which has a different structure. Epitaxial oxide nucleation may be followed by RHEED but the initial process is not seen by LEED. More extensive epitaxial films are needed before oxide reflexions appear in the LEED pattern. The formation of an epitaxial oxide film is accompanied by the growth of {100} molybdenum facets. These may be seen after the film has been carefully evaporated away. The nuclei of oxide which form are shown by both RHEED and transmission microscopy of replicas to be characteristically shaped.     

Photodimerization of 1H-azepine-2,7-dione

1H-Azepine-2,7-dione 2 afforded photodimer 8 by irradiation using a high or low pressure mercury lamp. Photodimer 8 had a unique structure which must have formed with the prototropy in one of the two molecules of compound 2 . Measurement of the fluorescence spectra of 2 indicated a spectrum of the excimer during the dimerization of 2 . Irradiation of the dimer of 2 at its wave-length of maximal absorption failed to cause it to change into a monomer of 2 .