63 research outputs found

    Polymer/carbon nanotube composites, methods of use and methods of synthesis thereof

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    Novel transparent composites composed of single wall carbon nanotubes incorporated into the matrix of a polymer are utilized in services wherein the composites are exposed to ionizing radiation, including galactic cosmic radiation. Accordingly, the composites are useful in deep space applications like space vehicles, space stations, personal equipment as well as applications in the biomedical arts and atom splitting research. The composites can be modified with organic dyes containing at least one phenyl ring and the resulting doped composite is useful as a radiation detector. The preferred polymer is poly(4-methyl-1-pentene)

    Processing and Performance of Polymeric Transparent Conductive Composites

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    Recent advances in microelectronic and optoelectronic industries have spurred interest in the development of reticulate doped polymer films containing “metallic” charge transfer complexes. In this study, such reticulate doped polymer films were prepared by exposing solid solutions of bis(ethylenedioxy) tetrathiafulvalene (BEDO-TTF) in polycarbonate (PC) to iodine, forming conductive charge transfer complexes. The resulting films exhibited room temperature conductivities ranging from 6.33 to  S    cm−1. The colored iodine complexes in the film were reduced by cyclic voltammetry yielding conductive, colorless, transparent films. We were intrigued to examine the dielectric properties of BEDO-TTF in solid solution in PC prior to formation of the charge transfer complex as no such studies appear in the literature. Dielectric analysis (DEA) was used to probe relaxations in neat PC and BEDO-TTF/PC. BEDO-TTF plasticized the PC and decreased the glass transition temperature. Two secondary relaxations appeared in PC films, whereas the transitions merged in the BEDO-TTF/PC film. DEA also evidenced conductivity relaxations above 180°C which are characterized via electric modulus formalism and revealed that BEDO-TTF increased AC conductivity in PC

    Variable water input controls evolution of the Lesser Antilles volcanic arc

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    Oceanic lithosphere carries volatiles, notably water, into the mantle through subduction at convergent plate boundaries. This subducted water exercises control on the production of magma, earthquakes, formation of continental crust and mineral resources. Identifying different potential fluid sources (sediments, crust and mantle lithosphere) and tracing fluids from their release to the surface has proved challenging1. Atlantic subduction zones are a valuable endmember when studying this deep water cycle because hydration in Atlantic lithosphere, produced by slow spreading, is expected to be highly non-uniform2. Here, as part of a multi-disciplinary project in the Lesser Antilles volcanic arc3, we studied boron trace element and isotopic fingerprints of melt inclusions. These reveal that serpentine—that is, hydrated mantle rather than crust or sediments—is a dominant supplier of subducted water to the central arc. This serpentine is most likely to reside in a set of major fracture zones subducted beneath the central arc over approximately the past ten million years. The current dehydration of these fracture zones coincides with the current locations of the highest rates of earthquakes and prominent low shear velocities, whereas the preceding history of dehydration is consistent with the locations of higher volcanic productivity and thicker arc crust. These combined geochemical and geophysical data indicate that the structure and hydration of the subducted plate are directly connected to the evolution of the arc and its associated seismic and volcanic hazards

    Partners No More: Relational Transformation and the Turn to Litigation in Two Conservationist Organizations

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    The rise in litigation against administrative bodies by environmental and other political interest groups worldwide has been explained predominantly through the liberalization of standing doctrines. Under this explanation, termed here the floodgate model, restrictive standing rules have dammed the flow of suits that groups were otherwise ready and eager to pursue. I examine this hypothesis by analyzing processes of institutional transformation in two conservationist organizations: the Sierra Club in the United States and the Society for the Protection of Nature in Israel (SPNI). Rather than an eagerness to embrace newly available litigation opportunities, as the floodgate model would predict, the groups\u27 history reveals a gradual process of transformation marked by internal, largely intergenerational divisions between those who abhorred conflict with state institutions and those who saw such conflict as not only appropriate but necessary to the mission of the group. Furthermore, in contrast to the pluralist interactions that the floodgate model imagines, both groups\u27 relations with pertinent agencies in earlier eras better accorded with the partnership-based corporatist paradigm. Sociolegal research has long indicated the importance of relational distance to the transformation of interpersonal disputes. I argue that, at the group level as well, the presence or absence of a (national) partnership-centered relationship determines propensities to bring political issues to court. As such, well beyond change in groups\u27 legal capacity and resources, current increases in levels of political litigation suggest more fundamental transformations in the structure and meaning of relations between citizen groups and the state

    Ionizing radiation resistant coatings

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    A mixture of a lacquer and carbon nanotubes that form a cross-linked network to convert excitation energy into non-chemistry inducing energy in a cured lacquer

    Self-healing polycarbonate containing polyurethane nanotube composite

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    Thermoplastic elastomers containing carbon nanotubes that is an autonomous, intrinsic, and reversible self healing polymer that requires no intervention to induce self healing, that requires no sequestered healing agents are added to the matrix, and is capable of multiple healing events

    Polymer/carbon nanotube composites, methods of use and methods of synthesis thereof

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    Novel transparent composites composed of single wall carbon nanotubes incorporated into the matrix of a polymer are utilized in services wherein the composites are exposed to ionizing radiation, including galactic cosmic radiation. Accordingly, the composites are useful in deep space applications like space vehicles, space stations, personal equipment as well as applications in the biomedical arts and atom splitting research. The composites can be modified with organic dyes containing at least one phenyl ring and the resulting doped composite is useful as a radiation detector. The preferred polymer is poly(4-methyl-1-pentene)

    Optical polymers

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    Polymer/carbon nanotube composites, methods of use and methods of synthesis thereof

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    Polymer/carbon nanotube composites including single-wall or multi-wall carbon nanotubes incorporated into the matrix of a polymer are provided. These composites can be used in environments exposed to galactic cosmic radiation. Accordingly, the composites are useful in deep space applications like space vehicles, space stations, personal equipment as well as applications in the biomedical arts and atom splitting research. The composites can be modified with organic dyes containing at least one phenyl ring and the resulting doped composite is useful as a radiation detector. The preferred polymer is poly(4-methyl-1-pentene). At low nanotube concentrations (i.e., about 0.5 wt % or less), the composites exhibit transparent optical qualities. At higher nanotube concentrations (i.e., about 0.6 wt % or more), the composites are non-transparent
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