Conduction in Bi2O3-based oxide ion conductor under low oxygen pressure. II. Determination of the partial electronic conductivity

In order to investigate the partial electronic conduction in the high oxide ion conductor of the system Bi₂O₃-Y₂O₃ under low oxygen pressure, e.m.f. and polarization methods were employed. Although the electrolyte was decomposed when the \(P_{{\text{O}}_{\text{2}} }\) was lower than the equilibrium \(P_{{\text{O}}_{\text{2}} }\) of Bi, Bi₂O₃ mixture at each temperature, the ionic transport number was found to be close to unity above that \(P_{{\text{O}}_{\text{2}} }\) . The hole conductivity (σ _p) and the electron conductivity (σ _p) could be expressed as follows, $$\begin{gathered} \sigma _p \Omega cm = 5 \cdot 0 \times 10^2 \left( {P_{O_2 } atm^{ - 1} } \right)^{{1 \mathord{\left/ {\vphantom {1 4}} \right. \kern-\nulldelimiterspace} 4}} \exp \left[ { - 106 kJ\left( {RT mol} \right)^{ - 1} } \right] \hfill \\ \sigma _p \Omega cm = 3 \cdot 4 \times 10^5 \left( {P_{O_2 } atm^{ - 1} } \right)^{ - {1 \mathord{\left/ {\vphantom {1 4}} \right. \kern-\nulldelimiterspace} 4}} \exp \left[ { - 213 kJ\left( {RT mol} \right)^{ - 1} } \right] \hfill \\ \end{gathered} $$ These values were much lower than the oxide ion conductivity under ordinary oxygen pressure.     

[CuL(H2O)2]{[CuL][Fe(CN)6]}2·2H2O (L=3,10-Bis(2-hydroxyethyl)-1,3,5,8,10,12-hexaazacyclotetradecane): A Novel Three-Dimensional Coordination Polymer via H-Bonded Linkages of One-Dimensional Zigzag Chain

A complex with the formula [CuL(H₂O)₂]{[CuL][Fe(CN)₆]}₂·2H₂O, where L=3,10-bis(2-hydroxyethyl)-1,3,5,8,10,12-hexaazacyclotetradecane, has been synthesized and crystallographically characterized. The structure is composed of a one-dimensional zigzag chain of $\left\{ {[{\text{CuL}}][{\text{Fe(CN)}}_{\text{6}} ]} \right\}_2^{2 - } $ units, and [CuL(H₂O)₂]²⁺ units. The one-dimensional zigzag chain extents through ${\text{Cu}}{\kern 1pt} - {\kern 1pt} {\text{CN}} - {\kern 1pt} {\text{Fe}}{\kern 1pt} - {\kern 1pt} {\text{CN}} - {\kern 1pt} {\text{Cu}}$ linkages. The adjacent two polymer chains are linked by the ${\text{O}}{\kern 1pt} - {\kern 1pt} {\text{H}}{\kern 1pt} \cdot \cdot \cdot {\kern 1pt} {\text{N}}{\kern 1pt} \equiv {\kern 1pt} {\text{C}}{\kern 1pt} - $ hydrogen bonding between [CuL(H₂O)₂]²⁺ and [Fe(CN)₆]^3?, forming a 3D supramolecular structure with inner hydrophilic channels. Magnetic susceptibility measurements show no exchange interaction between the Cu(II) and Fe(III) ions due to the longer ${\text{Cu}}{\kern 1pt} - {\kern 1pt} {\text{N}}$ (axial) bond length.     

Reaction in the silver zinc cell

An adiabatic calorimeter was used to measure the thermodynamics of the silver zinc cell. The charge and discharge reactions were shown to take place in two stages involving the production of argentous oxide and argentic oxide respectively. No thermal evidence was found to suggest the existence of a higher oxide of silver. The cell reactions were (1) $$2{\text{Ag + ZnO}} \leftrightharpoons {\text{Ag}}_{\text{2}} {\text{O + Zn, }}\Delta {\text{H = 158}} \cdot {\text{7 kJF}}^{ - {\text{1}}}$$ (2) $${\text{Ag}}_{\text{2}} {\text{O + ZnO}} \leftrightharpoons {\text{Ag}}_{\text{2}} {\text{O}}_{\text{2}} {\text{ + Zn, }}\Delta {\text{H = 176}} \cdot 1{\text{ kJF}}^{ - {\text{1}}}$$ If the cell was left on open circuit for a long period, or the positive electrodes heated, reaction (2) was suppressed and the discharge took place via reaction (1), without any reduction in capacity.     

The effect of position of ester group on critical micelle concentration of ester-linked sulfonates

The critical micelle concentration (CMC) of sodium alkyl sulfoacetates and β-sulfopropionates, and sodium salt of 2-sulfo ethyl ester, 3-sulfo propyl ester and 4-sulfo butyl ester of fatty acids have been determined by the electrical conductance of each aqueous solution. The relation between CMC value and number of total methylene groups (N) for the C_n ^*H_2n ^*+₁COO(CH₂)₃ SO₃Na and C₉H₁₉COO(CH₂)_n ^**SO₃Na (n^*=9, 10 and 11. n^**=2, 3 and 4) can be formulated as follows. $$\begin{gathered} \log {\text{CMC = - 0}}{\text{.293N + 1}}{\text{.778}} \hfill \\ {\text{for C}}_{\text{n}} *{\text{H}}_{{\text{2n}}} *_{ + ^1 } {\text{COO (CH2) 3SO3Na}} \hfill \\ {\text{log CMC = - 0}}{\text{.147 N + 0}}{\text{.011}} \hfill \\ {\text{for C9H19 COO (CH2) n **SO3Na}} \hfill \\ \end{gathered} $$ From these equations it was determined that the methylene unit situated between ester and sulfonate groups is equivalent to 0.5 methylene groups in its effect on CMC. For a given number of carbon atoms in the alkyl chain, the log CMC value increased regularly with a change in the ester group away from the terminal position to more central positions in the hydrocabon chain. The two different types of ester-linkages (RCOO-and ROCO-) have no apparent effect on the CMC value.     

Determination of equilibrium silver sulphate concentration in the system Cu-H2SO4-CuSO4-H2O-Ag2SO4-Ag as a function of composition

The value of the ratio \(\gamma _{{\text{Cu}}^{{\text{2 + }}} } /\gamma _{{\text{Ag}}^{\text{ + }} }^2 \) ( \(\gamma _{{\text{Cu}}^{{\text{2 + }}} } ,\gamma _{{\text{Ag}}^{\text{ + }} } \) -are the mean activity coefficients of copper and silver ions, respectively) was calculated from the measured emf of the cell $${\text{Cu(Hg)|H}}_{\text{2}} {\text{SO}}_{\text{4}} {\text{ (}}c_{\text{x}} {\text{)}} - {\text{CuSO}}_{\text{4}} {\text{ (}}c_{\text{y}} {\text{)|Hg}}_{\text{2}} {\text{SO}}_{\text{4}} {\text{, Hg}}$$ and the solubility of Ag₂SO₄ in H₂SO₄ (c _x) and CuSO₄ (c _y) solutions. The concentration of H₂SO₄ in the solution was varied from 0.5 to 2.1 mol dm^?3 that of CuSO₄ from 0.4 mol dm^?3 to saturation. The results were presented as a function: $$\frac{{\gamma _{{\text{Cu}}^{{\text{2 + }}} } }}{{\gamma _{{\text{Ag}}^{\text{ + }} }^2 }} = a_0 + a_1 c_{\text{x}} + a_2 c_{\text{y}} + a_3 c_{\text{x}}^{\text{2}} + a_4 c_{\text{x}} c_{\text{y}} + a_5 c_{\text{y}}^2 .$$ This function allows the estimation of the equilibrium silver ion concentration \(c_{{\text{Ag}}^{\text{ + }} }^{{\text{eq}}} \) in solutions containing both H₂SO₄ and CuSO₄ in the presence of metallic copper. The function is also very useful for the estimation of the \(c_{{\text{Ag}}^{\text{ + }} }^{{\text{eq}}} \) near a working copper electrode.     

Packed-bed reactor with continuous recirculation of electrolyte

A comparison of calculated and experimental parameters for the packed-bed reactor working with recirculation of the electrolyte is given. A simple mathematical model was applied and the applicability of the relation $$c = c^0 {\text{ exp(}} - k_1 At/V{\text{) for }}V_c \ll V_R $$ was tested. For the investigated reactor a dimensionless relation has been established from experimentalI-E curves for the single pass mode $$(Sh) = 0 \cdot 5(Re)^{0 \cdot 7} (Sc)^{0 \cdot 33} .$$ For pure practical engineering requirements these two equations together give us a satisfactory way of predicting the concentration-time dependence.     

A simple and efficient oxidation system for the oxidation of alcohols utilizing Oxone® as oxidant catalyzed by polymer-supported 2-iodobenzamide

$\begin{array}{l}{\hbox{R}^1\hbox{R}^2\hbox{CHOH}} \\ {\hbox{RCH}_2\hbox{OH} }\end{array} \dynrightarrow{Oxone}{\hbox{CH}_3\hbox{CN/H}_2\hbox{O}, 70^{\circ}\hbox{C}} \begin{array}{l}{\hbox{R}^1\hbox{R}^2\hbox{CO}} \\ {\hbox{RCOOH}} \end{array} A simple and environmentally friendly procedure for the oxidation of alcohols is presented utilizing Oxone^? (2KHSO₅ · KHSO₄ · K₂ SO₄) as oxidant and polymer-supported 2-iodobenzamide as catalyst in CH₃CN/H₂O mixed solvents.     

[CuL(H2O)2]{[CuL][Fe(CN)6]}2·2H2O (L=3,10-Bis(2-hydroxyethyl)-1,3,5,8,10,12-hexaazacyclotetradecane): A Novel Three-Dimensional Coordination Polymer via H-Bonded Linkages of One-Dimensional Zigzag Chain

A complex with the formula [CuL(H₂O)₂]{[CuL][Fe(CN)₆]}₂·2H₂O, where L=3,10-bis(2-hydroxyethyl)-1,3,5,8,10,12-hexaazacyclotetradecane, has been synthesized and crystallographically characterized. The structure is composed of a one-dimensional zigzag chain of units, and [CuL(H₂O)₂]²⁺ units. The one-dimensional zigzag chain extents through linkages. The adjacent two polymer chains are linked by the hydrogen bonding between [CuL(H₂O)₂]²⁺ and [Fe(CN)₆]^3–, forming a 3D supramolecular structure with inner hydrophilic channels. Magnetic susceptibility measurements show no exchange interaction between the Cu(II) and Fe(III) ions due to the longer (axial) bond length.     

Raman study of chain deformation in polypropylene

Summary Raman spectroscopy was used to study the transfer of energy that occurs among the internal vibrations of crystalline isotactic polypropylene as it is compressed. The group was found to play a significant role in the subsequent chain deformation.     

Electrochemical redox reactions of chromium and iron ions in molten NaCl–2CsCl eutectic for pyro-reprocessing of nuclear fuels

Basic electrochemical and spectroscopic properties of Cr³⁺, Cr²⁺, Fe³⁺, and Fe²⁺ were studied to analyze the cyclic redox reactions of Cr and Fe, which may decrease the current efficiency of the electro-winning method using NaCl–2CsCl melts. The formal redox potentials of the and couples, and , in NaCl–2CsCl melts at 923 K were spectroelectrochemically determined to be −0.648 ± 0.005 V and , respectively. These values were determined by measuring electromotive force and UV–VIS absorption spectra at varying concentration ratios of trivalent and divalent ions. Cyclic voltammetry was also carried out to examine the characteristics of the voltammograms for the and couples in NaCl–2CsCl melts. The determined by the spectroelectrochemical method was close to that determined by cyclic voltammetry . The effect of temperature on the in NaCl–2CsCl melts was studied by cyclic voltammetry in the range from 823 to 1,023 K . Diffusion coefficients of Cr³⁺ and Cr²⁺, and , were determined between 823 and 1,023 K to be and , respectively. Molar absorptivities of Cr³⁺ and Cr²⁺ in NaCl–2CsCl melts at 923 K were determined to be 77.8 ± 2.4 M⁻¹ cm⁻¹ at 17,670 cm⁻¹ and 48.0 ± 1.4 M⁻¹ cm⁻¹ at 9,170 cm⁻¹, respectively. In addition, the effects of these ions on the cyclic redox reaction of the pyro-reprocessing process were discussed.     

Studies concerning charged nickel hydroxide electrodes. VII. Influence of alkali concentration on anodic peak positions

After repetitive potential cycling employing a high positive potential limit (>700 mV wrt Hg/HgO/ KOH) three anodic and one cathodic peak can be observed using aβ-Ni(OH)₂ starting material. Anodic peaks found at 425, 470 and 555 mV in 5 mol dm^?3 KOH shift to less positive potentials as the alkali concentration is increased appearing at 365, 410 and 455 mV respectively in 12.5 mol dm^?3 KOH. Four anodic processes involving various pairs of coexisting phases within both theβ andα-/γ-phase system can be identified as summarized below in order of increasing positive potential: Peak A $$\begin{gathered} Peak A{\text{ }}U_\alpha ^A \to {\text{ }}V_\gamma ^A \hfill \\ Peak B{\text{ }}U_\beta ^B \to {\text{ }}V_\beta ^B \hfill \\ {\text{ }}\mathop C\limits^ + {\text{ }}U_\alpha ^C \to {\text{ }}V_\gamma ^C \hfill \\ Peak E{\text{ }}V_\beta ^B \to {\text{ }}V_\gamma ^E \hfill \\ \end{gathered} $$ Observed shifts in anodic and cathodic peak potentials are consistent with the known influence of alkali and water activity on the reversible potentials for the above processes.     

Solid state ionics—the electrochemical analog memory cell with solid electrolyte

A new type analog memory cell with variable output voltage has been proposed and its performance examined. The cell construction is $$\begin{gathered} {\text{Ag|RbAg}}_{\text{4}} {\text{I}}_{\text{5}} {\text{|(Ag}}_{\text{2}} {\text{Se)}}_{{\text{0}} \cdot {\text{925}}} {\text{(Ag}}_{\text{3}} {\text{PO}}_{\text{4}} {\text{)}}_{{\text{0}} \cdot {\text{075}}} {\text{|RbAg}}_{\text{4}} {\text{I}}_{\text{5}} {\text{|Ag}} \hfill \\ {\text{ }} \uparrow \hfill \\ {\text{ Pt}} \hfill \\ \end{gathered} $$ in which (Ag₂Se)_0.925(Ag₃PO₄)_0.075 is a mixed conductor exhibiting high ionic and electronic conductivity at room temperature. The potential difference between the silver electrode and the platinum electrode depends on the silver activity in the mixed conductor, and it is changed by passing the current between one silver electrode and the platinum electrode. The output voltage of the cell is changed in the range of 150 to 0 mV. At open circuit, the memorized cell voltage decreased by only 1% over several hours.     

Comportement electrochimique de NbCl5 en milieu NaCl-KCl pur et additionne d'ions fluorure

Dans le domaine de température 700–800°C, les solutions d'ions niobium obtenues par addition de NbCl₅ dans le melange équimolaire NaCl-KCl, sont réduites jusqu'au métal en une seule étape: $${\text{Nb(IV) }} + {\text{ 4e}}^ - \Leftrightarrow {\text{Nb(o)}}$$ Cet échange est réversible, il lui correspond le potentiel standard apparent: $$E_{Nb(IV)/Nb}^{'0} = - 0.64V(Ag - AgCl) \pm 0.01V$$ Les espéces Nb(iv) sont oxydées selon le processus réversible: $${\text{Nb(IV)}} \Leftrightarrow {\text{Nb(v)}} + {\text{e}}^ -$$ Le potentiel standard apparent associé est: $$E_{Nb(IV)/Nb}^{'0} = - 0.74V(Ag - AgCl) \pm 0.05V$$ L'ajout d'ions fluorure déstabilise le complexé NbCl₆ ^2? au profit du complexe NbF₆ ^2? . Ceci se traduit par un déplacement du pie cathodique vers des potentiels plus cathodiques mais le mécanisme de réduction comporte toujours une seule étape mettant en jeu quatre électrons. Dans ces milieux des dépôts de niobium métallique ont eté obtenus caractérisés par rayon X. In the 700–800°C temperature range, NbCl₅ solutions in equimolar NaCl-KCl mixtures are reduced to the metal through a single step: $${\text{Nb(IV)}} + 4{\text{e}}^ - \Leftrightarrow {\text{Nb(o)}}$$ This exchange is reversible and the corresponding apparent standard potential is: $$E_{Nb(IV)/Nb}^{'0} = - 0.64V(Ag - AgCl) \pm 0.01V$$ The Nb(iv) species are oxidized according to the following reversible process: $${\text{Nb(IV)}} \Leftrightarrow {\text{Nb(v)}} + {\text{e}}^ -$$ The associated apparent standard potential is: $$E_{Nb(IV)/Nb}^{'0} = - 0.74V(Ag - AgCl) \pm 0.05V$$ The addition of fluoride ions destabilizes the NbCl₆ ^2? complex and yields the NbF₆ ^2? complex. The cathodic peak potential moves toward more cathodic potentials, but the reduction mechanism still involves a single step with four electrons exchanged. In these media, metallic niobium deposits have been obtained, and characterized through X-ray analysis.     

The Effect of CO2 and H2O on the Kinetics of NO Reduction by CH4 Over Sr-Promoted La2O3

The influence of CO₂ and H₂O on the activity of 4% Sr-La₂O₃ mimics that observed with pure La₂O₃, and a reversible inhibition of the rate is observed. CO₂ causes a greater effect, with decreases in rate of about 65% with O₂ present and 90% in its absence, while with H₂O in the feed, the rate decreased around 35-40% with O₂ present or absent. The influence of these two reaction products on kinetic behavior can be described by assuming competitive adsorption on the surface, incorporating adsorbed CO₂ and H₂O in the site balance, and using rate expressions previously proposed for this reaction over Sr-promoted La₂O₃. In the absence of O₂, the rate expression is $$r_{N_2 } = \frac{{k'P_{{\text{NO}}} P_{{\text{CH}}_{\text{4}} } }}{{{\text{(1 + }}K_{{\text{NO}}} P_{{\text{NO}}} {\text{ + }}K_{{\text{CH}}_{\text{4}} } P_{{\text{CH}}_{\text{4}} } {\text{ + }}K_{{\text{CO}}_{\text{2}} } P_{{\text{CO}}_{\text{2}} } {\text{ + }}K_{{\text{H}}_{\text{2}} {\text{O}}} P_{{\text{H}}_{\text{2}} {\text{O}}} {\text{)}}^{\text{2}} }},$$ which yields a good fit to the experimental data and gives optimized equilibrium adsorption constants that demonstrate thermodynamic consistency. With O₂ in the feed, nondifferential changes in reactant concentrations through the reactor bed were accounted for by assuming integral reactor behavior and simultaneously considering both CH₄ combustion and CH₄ reduction of NO, which provided the following rate law for total CH₄ disappearance: $$(r_{{\text{CH}}_{\text{4}} } )_{\text{T}} = \frac{{k'_{{\text{com}}} P_{{\text{CH}}_{\text{4}} } P_{{\text{O}}_{\text{2}} }^{{\text{0}}{\text{.5}}} + k'_{{\text{NO}}} P_{{\text{NO}}} P_{{\text{CH}}_{\text{4}} } P_{{\text{O}}_{\text{2}} }^{{\text{0}}{\text{.5}}} }}{{{\text{(1 + }}K_{{\text{NO}}} P_{{\text{NO}}} {\text{ + }}K_{{\text{CH}}_{\text{4}} } P_{{\text{CH}}_{\text{4}} } {\text{ + }}K_{{\text{O}}_{\text{2}} }^{{\text{0}}{\text{.5}}} P_{{\text{O}}_{\text{2}} }^{{\text{0}}{\text{.5}}} {\text{ + }}K_{{\text{CO}}_{\text{2}} } P_{{\text{CO}}_{\text{2}} } {\text{ + }}K_{{\text{H}}_{\text{2}} {\text{O}}} P_{{\text{H}}_{\text{2}} {\text{O}}} {\text{)}}^{\text{2}} }}.$$ The second term of this expression represents N₂ formation, and it again fit the experimental data well. The fitting constants in the denominator, which correspond to equilibrium adsorption constants, were not only thermodynamically consistent but also provided entropies and enthalpies of adsorption that were similar to values obtained with other La₂O₃-based catalysts. Apparent activation energies typically ranged from 23 to 28 kcal/mol with O₂ absent and 31-36 kcal/mol with O₂ in the feed. With CO₂ in the feed, but no O₂, the activation energy for the formation of a methyl group via interaction of CH₄ with adsorbed NO was determined to be 35 kcal/mol.     

Simulation of the nonbranched-chain addition of saturated free radicals to alkenes and their derivatives yielding 1: 1 adducts

A reaction scheme is suggested for the initiated addition process. The scheme includes the reaction between the free 1: 1 adduct radical and the unsaturated reactant, which is in competition with chain propagation through a reactive free radical (\({}^ \cdot P{\mathbf{ }}Cl_2 ,(CH_3 )_2 \mathop C\limits^\cdot {\mathbf{ }}OH\), etc.) and yields a low-reactivity free radical (\(CH_2 = C(CH_3 )\mathop C\limits^\cdot {\mathbf{ }}H_2 ,{\mathbf{ }}CH_2 = CH\mathop C\limits^\cdot {\mathbf{ }}HOH\), etc.) inhibiting the nonbranched-chain process. Simple rate equations containing one to three parameters to be determined directly are set up using quasi-steady-state treatment. These equations provide good fits for the nonmonotonic (peaking) dependences of the formation rates of the molecular addition products (1: 1 adducts) on the concentration of the unsaturated component in liquid homogeneous binary systems consisting of a saturated component (PCl₃, 2-propanol, etc.) and an unsaturated component (methylpropene, 2-propen-1-ol, etc.). The unsaturated compound in these systems is both a reactant and an autoinhibitor generating low-reactivity free radicals.     

The mechanism of manganese electrodeposition

The mechanism of manganese electrodeposition from a sulphate bath on to a stainless-steel substrate has been studied by using current efficiency data to resolve the totali-E curves. A simple, two-step electron transfer mechanism: $${\text{Mn}}^{{\text{ + + }}} + {\text{e}}\xrightarrow{{{\text{r}}{\text{.d}}{\text{.s}}}}{\text{Mn}}^{\text{ + }} $$ $${\text{Mn}}^{\text{ + }} + {\text{e}} \to {\text{Mn}}$$ is proposed to explain the following experimentally obtained parameters: cathodic and anodic transfer coefficients, reaction order and stoichiometric number. The mechanism also explains the effect of pH oni _o,Mn and on the corrosion currents.     

Structure and Biological Behaviors of Some Metallo Cationic Surfactants

In this study, different cationic surfactants were prepared by esterification with bromoacetic acid of different fatty alcohols, i.e., dodecyl, tetradecyl and hexadecyl species. The products were then reacted with diphenyl amine, and the resulting tertiary amines were quaternized with benzyl chloride to produce a series of quaternary ammonium salts. The metallocationic surfactants were prepared by complexing the cationic surfactants with nickel and copper chlorides. Surface tension of these surfactants were investigated at different temperatures. The surface parameters including critical micelle concentration (CMC), maximum surface excess (Γ _max), minimum surface area (A _min), efficiency (PC₂₀) and effectiveness (π _CMC) were studied. The thermodynamic parameters such as the free energy of micellization ( $\Updelta G_{\text{mic}}^{^\circ }$ ) and adsorption ( $\Updelta G_{\text{ads}}^{^\circ }$ ), enthalpy ( $\Updelta H_{\text{m}}^{^\circ }$ ), ( $\Updelta H_{\text{ads}}^{^\circ }$ ) and entropy ( $\Updelta S_{\text{m}}^{^\circ }$ ), ( $\Updelta S_{\text{ads}}^{^\circ }$ ) were calculated. FTIR spectra and ¹H-NMR spectra were obtained to confirm the compound structures and purity. In addition, the antimicrobial activities were determined via the inhibition zone diameter of the prepared compounds, which were measured against six strains of a representative group of microorganisms. The results indicate that these metallocationic surfactants exhibit good surface properties and good biological activity on a broad spectrum of microorganisms.     

Effect of PVC on low-polar isobutylene polymerization in the presence of BCl3

Summary The isobutylene polymerizations in the presence of BCl₃ were carried out in dichloromethane ([M]=7 mol/l) at-20°C in the presence and absence of PVC. The products of polymerizations in the absence of PVC are oligoisobutylenes with a narrow molecular weight distribution ; their structure was analyzed by ¹H-NMR spectroscopy. In addition to the signals assigned to known unsaturated terminal structures [ 4.62 and 4.82-CH₂C(CH₃)=CH₂, 5.12-CH=C(CH₃)₂], a new intense signal was found at 5.09 ppm and assigned to the structure-CH=C(CH₃)CH₂CH₃. A mixture of isobutylene homopolymers and PVC grafted with isobutylene (approx. 9.5% wt. isobutylene grafted) is formed in the presence of PVC.     

Micellization of Some Bile Salts in Binary Aqueous Solvent Mixtures

The micellization behavior of bile salts—sodium cholate and sodium deoxycholate was studied in aqueous methanol, ethanol and ethylene glycol mixtures (10–20 % v/v) over a temperature range (300–320 K) by surface tension and conductivity methods. Critical micelle concentration, extent of counter ion binding (α), interfacial property (A _min, ζ_max, π-CMC, $ \Updelta G_{\text{ad}}^{ \circ } $ ) and thermodynamic parameters ( $ \Updelta G_{\text{m}}^{ \circ } $ , $ \Updelta H_{\text{m}}^{ \circ } $ , $ \Updelta S_{\text{m}}^{ \circ } $ ) for the micellization process are reported and discussed.     

Behaviour of nitrate impurity in nickelcadmium cells

The oxidation-reduction behaviour of NO₃ ^?, NO₂ ^?, N₂O₂ ^2?, NH₂OH and NH₃ at a platinum electrode in alkaline solution has been investigated using cyclic voltammetry. The results have been compared with the corresponding behaviour of these species at charged, porous cadmium and nickel hydroxide electrodes in order to understand the likely behaviour of NO₃ ^? impurities in nickelcadmium cells. The reactions are shown to be irreversible processes and strongly dependent on the nature of the electrode surfaces. The reactions which are likely to be involved in a charged cell can be represented by the overall scheme: $${\text{NO}}_{\text{3}} ^\_ {\text{NO}}_{\text{2}} ^\_ {\text{NH}}_{\text{3}} \xrightarrow{{{\text{slow}}}}{\text{N}}_2 $$ It is suggested that the self-discharge of cells containing NO₃ ^? is limited by slow kinetic effects rather than by diffusion as previously supposed.