Selective functionalization of carbon nanotubes based upon distance traveled

Method and system for functionalizing a collection of carbon nanotubes (CNTs). A selected precursor gas (e.g., H.sub.2 or NH.sub.3 or NF.sub.3 or F.sub.2 or CF.sub.4 or C.sub.nH.sub.m) is irradiated to provide a cold plasma of selected target particles, such as atomic H or F, in a first chamber. The target particles are directed toward an array of CNTs located in a second chamber while suppressing transport of ultraviolet radiation to the second chamber. A CNT array is functionalized with the target particles, at or below room temperature, to a point of saturation, in an exposure time interval no longer than about 30 sec. The predominant species that are deposited on the CNT array vary with the distance d measured along a path from the precursor gas to the CNT array; two or three different predominant species can be deposited on a CNT array for distances d=d1 and d=d2>d1 and d=d3>d2

Functionalization of carbon nanotubes

Method and system for functionalizing a collection of carbon nanotubes (CNTs). A selected precursor gas (e.g., H.sub.2 or F.sub.2 or C.sub.nH.sub.m) is irradiated to provide a cold plasma of selected target particles, such as atomic H or F, in a first chamber. The target particles are directed toward an array of CNTs located in a second chamber while suppressing transport of ultraviolet radiation to the second chamber. A CNT array is functionalized with the target particles, at or below room temperature, to a point of saturation, in an exposure time interval no longer than about 30 sec

Functionalization of Carbon Nanotubes

Method and system for functionalizing a collection of carbon nanotubes (CNTs). A selected precursor gas (e.g., H2 or F2 or CnHm) is irradiated to provide a cold plasma of selected target species particles, such as atomic H or F, in a first chamber. The target species particles are d irected toward an array of CNTs located in a second chamber while suppressing transport of ultraviolet radiation to the second chamber. A CNT array is functionalized with the target species particles, at or below room temperature, to a point of saturation, in an exposure time interval no longer than about 30 sec. *Discrimination against non-target species is provided by (i) use of a target species having a lifetime that is much greater than a lifetime of a non-target species and/or (2) use of an applied magnetic field to discriminate between charged particle trajectories for target species and for non-target species

Optical constraints of kerogen from 0.15 to 40 microns: Comparison with meteoritic organics

Kerogens are dark, complex organic materials produced on the Earth primarily by geologic processing of biologic materials, but kerogens have chemical and spectral similarities to some classes of highly processed extraterrestrial organic materials. Kerogen-like solids were proposed as constitutents of the very dark reddish surfaces of some asteroids and are also spectrally similar to some carbonaceous organic residues and the Iapetus dark material. Kerogen can thus serve as a useful laboratory analog to very dark, spectrally red extraterrestrial materials; its optical constants can be used to investigate the effects of particle size, void space and mixing of bright and dark components in models of scattering by dark asteroidal, cometary, and satellite surfaces. Measurements of the optical constants of both Type 2 kerogen and of macromolecular organic residue from the Murchison carbonaceous chondrite via transmission and reflection measurements on thin films are reported. The real part of the refractive index, n, is determined by variable incidence-angle reflectance to be 1.60 + or - 0.05 from 0.4 to 2.0 micrometers wavelength. Work extending the measurement of n to longer wavelengths is in progress. The imaginary part of the refractive index, k, shows substantial structure from 0.15 to 40 micrometers. The values are accurate to + or - 20 percent in the UV and IR regions and to + or - 30 percent in the visible. The k values of organic residues were also measured from the Murchison meteorite. Comparison of the kerogen and Murchison data reveals that between 0.15 and 40 microns, Murchison has a similar structure but no bands as sharp as in kerogen, and that the k values for Murchison are significantly higher than those of kerogen

Possible Sources for Methane and C2-C5 Organics in the Plume of Enceladus

In this paper we consider six possible sources of CH4 and other low-mass (C2 - C5) organics in the plume of Enceladus: initial endowments of cometary organics or Titan- like tholin, in situ production by Fisher-Tropsch type reactions, water-rock reactions, or microbiology, and thermogenesis from heavier organics already present. We report on new laboratory results C2 hydrocarbons released on thermogenesis of laboratory tholin and Fisher-Tropsch type synthesis. Tholin heating produced ratios of CH4/C2H4 and CH4/C2H6 of about 2 for temperatures up to 450 C and about 6 for a temperature of 650 C. Low pressure Fisher-Tropsch type experiments produced CH4/C2H4 of approx 1.5, similar to previous results. No C2H2 was produced by either process. Tests of gas production by four strains of methanogens confirmed the absence of any detectable production of non-methane hydrocarbons. Cometary endowment, Fisher-Tropsch type synthesis, and Titan-like tholin incorporation could be primary inputs of organics and subsequent thermal processing of any of these all are possible sources of low mass organics in the plume. Biological production and water-rock reactions are an alternative source of CH4. Neither water-- ]rock reactions or thermal processing of biomass could be a source C2 . C5 organics due to the low interior pressures. The confirmed detection of CO and C2H2 in the plume of Enceladus would provide an important constraint on sources as we have identified no process . other than the initial volatile component of cometary organics which can supply these gases. Precise determination of the relative concentrations of C1 - C5 hydrocarbons may provide additional constraints on sources but a detailed isotopic analysis of C and H in these organics and a search for amino acids constitute the next important steps in resolving the sources of the organics in Enceladus' plume

Optical constants of solid methane

Methane is the most abundant simple organic molecule in the outer solar system bodies. In addition to being a gaseous constituent of the atmospheres of the Jovian planets and Titan, it is present in the solid form as a constituent of icy surfaces such as those of Triton and Pluto, and as cloud condensate in the atmospheres of Titan, Uranus, and Neptune. It is expected in the liquid form as a constituent of the ocean of Titan. Cometary ices also contain solid methane. The optical constants for both solid and liquid phases of CH4 for a wide temperature range are needed for radiative transfer calculations, for studies of reflection from surfaces, and for modeling of emission in the far infrared and microwave regions. The astronomically important visual to near infrared measurements of solid methane optical constants are conspicuously absent from the literature. Preliminary results are presented on the optical constants of solid methane for the 0.4 to 2.6 micrometer region. Deposition onto a substrate at 10 K produces glassy (semi-amorphous) material. Annealing this material at approximately 33 K for approximately 1 hour results in a crystalline material as seen by sharper, more structured bands and negligible background extinction due to scattering. The constant k is reported for both the amorphous and the crystalline (annealed) states. Typical values (at absorption maxima) are in the .001 to .0001 range. Below lambda = 1.1 micrometers the bands are too weak to be detected by transmission through the films less than or equal to 215 micrometers in thickness, employed in the studies to date. Using previously measured values of the real part of the refractive index, n, of liquid methane at 110 K, n is computed for solid methane using the Lorentz-Lorenz relationship. Work is in progress to extend the measurements of optical constants n and k for liquid and solid to both shorter and longer wavelengths, eventually providing a complete optical constants database for condensed CH4

ABSORPTION CONTINUA OF BORON IODIDES

$^{\ast}$ Present address: Department of Chemistry, University of Toronto, Toronto 5. Canada. $^{1}$ R. S. Sharma, Bull. Acad. Sci. (Allahabad, India) 3, 87 (1933). S. C. Deb. Bull. Acad. Sci. (Allahabad, India) 1, 92 (1931-32). $^{2}$ W. C. Schumb, E. L. Gamble, and M. D. Banus, J. Am. Chem. Soc, 71,3225 (1949). $^{3}$ E. Miescher, Helv. Phys. Acta, 9, 693 (1936).Author Institution: Department of Physics, Syracuse UniversityThe absorption spectrum of $BI_{3}$ in the gaseous state showed a strong continuum in the region from A3150 to about $2500 {\AA}$. This continuum, due to the molecule $BI_{3}$ is in agreement with the value extrapolated from the known known continua of the related trihalides of boron and $aluminum.^{1}$ Following Schumb, Gamble, and $Banus,^{2}$ the lower iodides of boron were prepared in the absorption cell by passing an electrodeless discharge through $BI_{3}$ vapor. The absorption spectra of these lower iodides of boron revealed the existence of four continua in the regions $\lambda 2508-2790 {\AA}, \lambda 2821-2985 {\AA}, \lambda 3040-3203 {\AA}$, and $\lambda 3376-3585 {\AA}$. Of the continuum in the region $\lambda 3376-3585 {\AA}$ is the strongest, with a maximum at $\lambda 3456 {\AA}$. and the $\lambda 3040-3203 {\AA}$ continuum is the weakest. Previous work on the spectra of the diatomic halides of group III $elements^{3}$ has shown that the strongest continuum can be attributed to the diatomic molecule BI. It represents a $^{1}\Pi-^{1}\Sigma$ transition, with the upper $^{1}\Pi$ state repulsive. The dissociation energy of BI is approximately 3,5 ev if in its repulsive state it dissociates to $B(^{2}P_{1/2})$ and $1(^{2}P_{3/2})$, the lowest of the atomic states. If the molecule dissociates to $B(^{2}P_{1/2})$ and an excited $I(^{2}P_{1/2})$, then the dissociation energy is approximately 2.5 ev

INFRARED SPECTRA OF (CH3)3N(CH_{3})_{3}N AND (SiH3)3N(SiH_{3})_{3}N IN GAS, SOLID AND MATRIX PHASES∗^{\ast}

$^{\ast}$ This research was supported by the Air Force under Grant No. 277--63 monitored by the Air Force Office of Scientific Research of the Air Research and Development Command. $^{1}$ Hiroshi Yada, Jiro Tanaka, and Saburo Nagakura, J. Mol. Spectroscopy 9, 461 (1962). $^{2}$ S. H. Bauer and M. Blander, J. Mol. Spectroscopy 3, 132 (1959). $^{3}$ J. R. Barcello and J. Bellanto, Spectrochim, Acta 8, 27 (1959). $^{4}$ Dean W. Robinson, J. Am. Chem. Soc. 80, 5924 (1958). $^{5}$ Heinrich Kriegsmann and Walter Forster, Zeitschrift f\""{u}r Anorganische Chemic 298, 212 (1959).Author Institution: Department of Chemistry, State University of New York at Stony BrookGas, solid and matrix phase spectra of $(CH_{3})_{3}N$ and $(SiH_{3})_{3}N$ have been investigated in the region 4000 to $250 cm^{-1}$. Several previous $studies^{1, 2, 2}$ of the spectrum of $(CH_{3})_{3}N$ have been reported. None of these investigators gave a complete assignment of the vibrations due to overlapping bands in the gas phase spectrum. The present matrix results yield all of the expected fundamental absorptions assuming $C_{3v}$ symmetry for the molecule. The frequencies observed below $500 cm^{-1}$ are $433 cm^{-1}, 388 cm^{-1}, 293 cm^{-1}$ and $277 cm^{-1}$. While the frequencies at $433 cm^{-1}, 388 cm^{-1}$ and $293 cm^{-1}$ are assigned to $NC_{3}$ asymmetric deformation $\nu_{21}(E), NC_{3}$ symmetric deformation $\nu_{7}(A_{1})$, and $CH_{3}$ torsional $\nu_{22}(E)$ vibrations respectively, the frequency at $277 cm^{-1}$ can be interpreted only as due to the infrared inactive torsional $\nu_{11}(A_{2})$ vibration which has become active as a result of a lowering of symmetry in the solid. The observed fundamental frequencies of $(SiH_{3})_{3}N$ are in general agreement with the ones previously $observed^{4, 5}$ and suggests that the molecule belongs to the point group $C_{2}b$. Neither the $SiH_{3}$ torsional frequency $\nu_{18}(A^{\prime \prime})$ nor the $NSi_{3}$ deformation frequencies $\nu_{13}(E^{\prime})$ and $\nu_{17}(A^{\prime \prime})$ have been observed. They are assumed to lie below $250 cm^{-1}$. The special features of the solid spectra including the splitting of the degenerate vibrations will be discussed