Mobile hydrogen concentration

Ion binding reduces the repulsive forces between the charged groups on the polyanion but, unless the counterions are site-bound, the repulsive osmotic forces are not affected. At full neutralization the coulombic forces along the polymer chain become zero. However, the polymer does not contract, because the osmotic forces remain unless, of course, all the cations become site-bound. (Of course, in the case of a free weak acid the concentration of mobile hydrogen ions is very small and the polymer adopts a compact form.)... 

Device quality a-Si H made by HWCVD (as they termed it) was first reported by Mahan et al. [19, 527], They obtained n-Si H with hydrogen concentrations as low as 1%. Deposition rates as high as 5 nm/s [528] and 7 nm/s [529] have been achieved for n-Si H of high quality. In order to obtain device quality material it was shown by Doyle et al. [525] that the radicals that are generated at the filament (atomic Si and atomic H) must react in the gas phase to yield a precursor with high surface mobility. Hence, the mean free path of silane molecules should be smaller than the distance between filament and substrate, d(s- Too many reactions between radicals and silane molecules, however, result in worse material. In fact, optimal film properties are found for values of pdf of about 0.06 mbar-cm [530, 531]. 

Figure 3 shows a graph of a as a function of the ratio i/n(0) of the surface concentration of mobile hydrogen to the concentration of traps I. The passivation depth L is given, according to (50), by... 

A convenient concept for introducing the surface boundary condition into the mathematical formulation of migration theory is that of what may be called a diffusional offset length d. Suppose that the external and surface conditions are describable by a set of parameters X, which we do not need to specify in detail we also allow the surface conditions to depend on the internal hydrogen concentration just beneath the surface. If the hydrogen complexes that are continually forming in the crystal are sufficiently immobile, the balance between inflow and outflow across the surface will depend only on X and on the concentration no(0) of H0 just beneath the surface. (If mobile H+ or H are present, the statement just... 

Another family of inhibitors, hydrogen-donating agents such as iso-propyl and 1,4-di-ivo-propyl benzenes, was investigated by Lamouroux in order to reduce the formation of TBP-TBP dimers, which exhibit a very high plutonium retention of TBP (47). The presence of at least one mobile hydrogen on the iso-propyl group could produce a benzylic tertiary radical stabilized by resonance. The addition of such compounds reduced the concentration of the TBP-TBP dimers by about 50%. 

One family of ionic liquids that has to date only been sparsely investigated for use with conducting polymers is the protic ionic liquids, where the cation has one or more mobile hydrogen atoms. A recent manuscript by Bi ak detailed the synthesis of 2-hydroxy ethylammonium formate [109], which melts at — 82 °C and has a room-temperature ionic conductivity of 3.3 mS cm-1, and reported the ability of this protic ionic liquid to dissolve poly(aniline) (17gmL ) and poly(pyrrole) (no concentration specified). The dissolution of conducting polymers into any solvent is of significant interest for a variety of reasons, such as improving their processability and ease of incorporation into different devices. 

The proportion of tautomers in 1,2,3-triazole (the parent molecule), as ascertained by H NMR (300 MHz), has been found to vary with concentration, temperature, and solvent [84JCS(P2)1025]. No similar study has been made of the 4-amino-1,2,3-triazoles, but crystallographic studies (see Section II,A) have revealed preferred sites of attachment of the ring-bound mobile hydrogen atom. However, crystal studies do not necessarily indicate the equilibria attained in solution. NMR and UV spectra of Sa revealed the presence of three tautomers, the proportions of which depended on the polarity of the solvents (75G583) (no assignments were made). 

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