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Micrometers Long (micrometer + long)
Selected AbstractsAligned Nanofibers: Epitaxial Growth of Highly Oriented Fibers of Semiconducting Polymers with a Shish-Kebab-Like Superstructure (Adv. Funct.ADVANCED FUNCTIONAL MATERIALS, Issue 17 2009Mater. Highly oriented fibers of regioregular poly(3-alkylthiophene)s with a "shish-kebab" morphology are prepared by epitaxy on long needles of 1,3,5-trichlorobenzene grown in liquid pyridine, as described on page 2759 by Brinkmann et al. The superstructure of the fibers consists of a highly oriented thread-like core several hundreds of micrometers long, the "shish", onto which lateral crystalline nanofibrils made of folded polymer chains, the "kebabs", are connected in a periodic way. [source] Epitaxial Growth of Highly Oriented Fibers of Semiconducting Polymers with a Shish-Kebab-Like SuperstructureADVANCED FUNCTIONAL MATERIALS, Issue 17 2009Martin Brinkmann Abstract Highly oriented fibers of regioregular poly(3-alkylthiophene)s (P3ATs) showing a "shish-kebab" morphology are prepared by oriented epitaxial crystallization in a mixture of 1,3,5-trichlorobenzene (TCB) and pyridine. The superstructure of the P3AT fibers consists of an oriented thread-like core several hundreds of micrometers long, the "shish", onto which lateral crystalline fibrils made of folded polymer chains, the "kebabs", are connected in a periodic way with a periodicity in the range 18,30,nm. The P3AT-chain axis is oriented parallel to the fiber axis whereas the ,-stacking direction is oriented perpendicular to it. The oriented character of the shish-kebab fibers results in polarized optical absorption and photoluminescence. The formation of oriented precursors by epitaxial orientation of polymer chains onto long needles of a molecular crystal,TCB in the present case,appears to be an original alternative to the crystallization usually performed under external flow conditions. [source] The Selective Heating of Iron Nanoparticles in a Single-Mode Microwave for the Patterned Growths of Carbon Nanofibers and NanotubesADVANCED FUNCTIONAL MATERIALS, Issue 8 2009Tamara Druzhinina Abstract The fast and cheap synthesis of carbon nanotubes is addressed in a large number of recent publications. At the same time, microwave-assisted synthesis has also gained interest. Besides the fact that reaction kinetics can be positively influenced by the use of microwave irradiation and advanced reaction conditions can be applied, absorption of microwave radiation depends on the material properties, thus resulting in a selective heating mechanism. The selective heating process allows for locally created temperatures high enough to promote the growth of carbon nanofibers and nanotubes on patterned iron catalyst layers. The resulting fibers are micrometers long, and can be synthesized in short time scales of a few minutes, yielding dense films of carbon fibers with uniform height. Here, the selective heating of surface bound iron nanoparticles is investigated in more detail, and experimental evidence for this effect is provided by utilizing a self-assembled monolayer of n -octadecyltrichlorosilane, which acts as a sensitive indicator for locally elevated temperatures. Special emphasis is placed on the development of an improved and controllable experimental setup that permits the safe and fast fabrication of the desired carbon objects. [source] 94 An obligate(?) heterokont biflagellate parasite in codium fragileJOURNAL OF PHYCOLOGY, Issue 2003T. F. Lee Specimens of Codium fragile (Suringar) Hariot ssp. tomentosoides were collected from 9 sites in New England, and Long Island, New York at intervals throughout the years 1999-2003. Segments were removed from the thalli and chopped into fine fragments, mostly individual utricles and medullary filaments. Fragments were incubated in enriched seawater in dim light at 15C, 12:12 LD. Within 2,3 days, in almost all cases (more than 300) motile cells formed in many of the utricles and filaments. These were 10,15 micrometer elongated biflagellate heterokont cells. They appeared to consume the chloroplasts, and within 24 hours were reduced to colorless cells, about 5 micrometers long. These cells are unable to grow in Codium chloroplast suspensions. They appear to be always associated with Codium thalli, despite attempts to clean the thalli, and were never seen in utricles or filaments of intact plants. Their ultrastructure is under investigation and will be reported on here. [source] Growing SiC Nanowires on Tyranno-SA SiC FibersJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 4 2004Wen Yang A new in situ process for growing SiC nanowires on Tyranno-SA SiC fibers (2-D, plain-woven) was developed using the thermal decomposition of methyltrichlorosilane in hydrogen. The process was performed using a chemical vapor infiltration system. ,-SiC nanowires ,100-nm thick and several tens of micrometers long were successfully synthesized on the fibers. The growing of the SiC nanowires suggests a conditions-dependent process. [source] | ||||||||||