Volume 77, Issue 5

Cyclic olefin copolymers comprise a new class of polymeric materials showing properties of high glass-transition temperature, optical clarity, low shrinkage, low moisture absorption, and low birefringence. There are several types of cyclic olefin copolymers based on different types of cyclic monomers and polymerization methods. In this work, we have analyzed the chemical structure of the currently commercialized cyclic olefin copolymers by 13 C NMR, and investigated their glass-transition temperatures and surface characteristics. It was observed that the glass-transition temperature, T g , of cyclic olefin copolymers depended on the bulkiness of the main chain, and the number of rings had an important role in increasing the bulkiness of cyclic olefin copolymers. Cyclic olefin copolymers with polar substituents such as ester or ether groups showed high surface energy per area and peel strength.

Several workers from various institutions in six countries have prepared thin films and colloidal polyaniline dispersions. The films were produced in situ on glass supports during the oxidation of anilinium chloride with ammonium peroxydisulfate in water. The average thickness of the films, assessed by optical absorption, was 125 ± 9 nm, and the conductivity of films was 2.6 ± 0.7 S cm –1 . Films prepared in 1 mol l –1 HCl had a similar thickness, 109 ± 10 nm, but a higher conductivity, 18.8 ± 7.1 S cm –1 . Colloidal polyaniline particles stabilized with a water-soluble polymer, poly( N -vinylpyrrolidone) [poly(1-vinylpyrrolidin-2-one)], have been prepared by dispersion polymerization. The average particle size, 241 ± 50 nm, and polydispersity, 0.26 ± 0.12, have been determined by dynamic light scattering. The preparation of these two supramolecular polyaniline forms was found to be well reproducible.

The scientist must be sure that, within a stated context, the terms used in articles, publications, or the daily conversation among colleagues are intended by all in the same precise way, without any possible ambiguity. As already pointed out by “Nomenclature for sampling in analytical chemistry (IUPAC Recommendations 1990)” [4], it is not acceptable that scientists are not able to orient themselves in a sampling or analytical process. This can occur if the terms used are not well defined. Moreover, to better appreciate the development of new theories or concepts, progressive updates can be necessary. To this end, on the basis of the existing terminology documents and of the most recent knowledge in the field of soil sampling, an updated terminology in sampling (specifically, soil sampling) is recommended.

Rules for numbering (C 60 - I h )[5,6]fullerene and (C 70 - D 5h(6) )[5,6]fullerene were codified in a publication “Nomenclature for the (C 60 - I h )[5,6] and (C 70 - D 5h(6) )[5,6]fullerenes” published in Pure Appl. Chem. 74 (4), 629–695 (2002). The current publication contains recommendations for numbering a wide variety of fullerenes of different sizes, with rings of different sizes, from C 20 to C 120 , and of various point group symmetries, including low symmetries such as C s , C i , and C 1 , as well as many fullerenes that have been isolated and well characterized as pristine carbon allotropes or as derivatives. These recommendations are based on the principles established in the earlier publication and aim at the identification of a well-defined and preferably contiguous helical pathway for numbering. Rules for systematically completing the numbering of fullerene structures for which a contiguous numbering pathway becomes discontiguous are presented.