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Effect of surface cationization on the conformal deposition of polyelectrolytes over cotton fibers 总被引:1,自引:0,他引:1
The effect of surface cationization on the conformal deposition of alternating nanolayers of poly(sodium styrene sulfonate)
(PSS) [Kleinfeld E, Ferguson G (1996) Chem Mater 8:1575–1578] and poly(allylamine hydrochloride) (PAH) over cotton fibers
is reported. Three different levels of cotton cationization were evaluated. Variations in the cationization degree were achieved
by manipulating the ratio of 3-chloro-2-hydroxy propyl trimethyl ammonium to NaOH. Experimental results obtained via Carbon–Hydrogen–Nitrogen–Sulfur
(CHNS) elemental analysis and X-ray Photoelectron Spectroscopy (XPS) indicated that the deposition process was not significantly
influenced by the degree of cotton cationization. The build up of further polyelectrolyte layers was found to be less sensitive
to variations in the cationic character of the substrates once a critical number of alternating layers was deposited. 相似文献
44.
An enhanced material-classification algorithm using turbulence-degraded polarimetric imagery is presented. The proposed technique improves upon an existing dielectric/metal material-classification algorithm by providing a more detailed object classification. This is accomplished by redesigning the degree-of-linear-polarization priors in the blind-deconvolution algorithm to include two subclasses of metals--an aluminum group classification (includes aluminum, copper, gold, and silver) and an iron group classification (includes iron, titanium, nickel, and chromium). This new classification provides functional information about the object that is not provided by existing dielectric/metal material classifiers. A discussion of the design of these new degree-of-linear-polarization priors is provided. Experimental results of two painted metal samples are also provided to verify the algorithm's accuracy. 相似文献
45.
Jonathan R. Dilworth Bryan D. Neaves Phillip Dahlstrom Jeffery Hyde Jon A. Zubieta 《Transition Metal Chemistry》1982,7(5):257-260
Summary The complex [Bu
4
n
N][Mo2O2Cl5(SPh)2] has been prepared by reaction of [Bu
4
n
N][MoO(SPh)4] with stoichiometric amounts of HCl and characterised by single crystal X-ray structure analysis. The dimer is bridged by two oxo-groups and one chloride and each Mo has pseudo-octahedral co-ordination. The related compound [Mo2O3(SPh)2(S2CNMe2)2] was synthesised by reaction of [MoO2(S2CNMe2)2] with thiophenol in methanol and has also been characterised crystallographically. In this case the triple-bridge consists of two thiophenolate sulphurs and one oxo-group, each molybdenum having pseudo-octahedral geometry. These structures are compared with other triply-bridged species. 相似文献
46.
Michael Hyde Andrew J. Saterlay Shelley J. Wilkins John S. Foord Richard G. Compton Frank Marken 《Journal of Solid State Electrochemistry》2002,6(3):183-187
Nanofilm deposits of a porous Sn(IV) oxide are formed by anodic electrodeposition on a polished boron-doped diamond electrode
immersed in an aqueous Sn2+ solution. Mechanically and electrochemically stable deposits of 10–15 nm thickness are formed irrespective of the Sn2+ concentration and mass-transport enhancement by power ultrasound. Atomic force microscopy images indicate the presence of
a smooth and noncrystalline film, which is stable under ambient conditions. n-type semiconducting characteristics are observed
for the aqueous solution redox couples Fe(CN)6
3–/4– and Ru(NH3)6
3+/2+. However, preliminary results from voltammetric experiments indicate that the small and neutral organic molecule N,N,N′,N′-tetramethylphenylenediamine is able to diffuse through the porous film to undergo oxidation directly at the surface of the
boron-doped diamond electrode.
Electronic Publication 相似文献
47.
At high frequencies, e.g., Q- and W-bands, it is advantageous to make the axial length of loop-gap resonators (LGRs) at least as long as a free-space wavelength. The opposite scaling of capacitance and inductance with LGR length suggests that the length of an LGR can be increased without limit, with the axial radio frequency (rf) field profiles and resonance frequency independent of length. This scaling is accurate for resonator dimensions much less than one free-space wavelength. When the resonator length approaches one-tenth of a free-space wavelength, the rf field uniformity degrades. From one-tenth to one free-space wavelength, computer simulations and experimental measurements show that the axial magnetic field energy density profile is peaked in the center of the LGR, gradually decreases from 25 to 50% at a distance one radius from the end, and rapidly there-after. The nonuniformity is of two types. One type, in the vicinity of one radius of the end, is caused by the flaring of the field as it curves from the central loop to the end region, into the larger return loop(s). The other type, in the central part of the resonator, is caused by impedance mismatch at the ends of the LGR. The LGR may be viewed as a strongly reentrant (ridge) waveguide nearly open at both ends and supporting a standing wave. A transmission line model relates the central nonuniformity to the fringing capacitance and inductance at the ends of the resonator. This nonuniformity can be eliminated in several ways including modifying the ends of the LGR by adding a small metal bridge or a dielectric ring. These uniformity trimming elements increase the fringing capacitance and/or decrease the fringing inductance. With trimmed ends, LGRs can be made many free-space wavelengths long. The maximum resonator length is determined by the proximity in frequency of the fundamental LGR mode to the next highest frequency mode as well as the quality factor. Results of this theory are compared and conformed with finite-element simulations. This theory connects the uniform LGR with the uniform field cavity resonators previously introduced by this laboratory. 相似文献
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50.
The structure of 1,3-dehydro-5-adamantyl cation and its isoelectronic boron analogue 1,3-dehydro-5-boraadamantane as well as some related adamantane systems, hitherto unknown as persistent long-lived species, were investigated by using the density functional theory (DFT) method. (13)C and (11)B NMR chemical shifts of the compounds were also calculated using the IGLO method. Stabilization of the systems due to homoconjugation is discussed. 相似文献