The hierarchical structures of graft-type poly(ethylene-co-tetrafluoroethylene) (ETFE)-based polymer electrolyte membranes (ETFE-PEMs) were investigated using small- and ultrasmall-angle X-ray scattering experiments. The ETFE-PEMs with ion exchange capacities (IECs) <2.4 mmol/g possessed conducting graft domains around lamellar crystals, with a d-spacing of 21.8–29.1 nm, and oriented crystallites (lamellar grains) with short and long correlation distances of 218–320 and 903–1124 nm, respectively. The membranes with IECs > 2.7 mmol/g showed a new phase of crystallite network domains with a d-range of 225–256 nm, indicating a phase transition from oriented crystallite to crystallite network structures in the IEC range of 2.4–2.7 mmol/g. Noted that for the ETFE-PEMs with high IECs higher conductivity at 30% RH and compatible tensile strengths at 100% RH and 80 °C, compared with Nafion, originated from the well-interconnected ion channels around the crystallites and the remaining lamellar crystals and crystallites, respectively.

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In the present work, methyl viologen (1,1′-dimethyl-4,4′-bipyridinium dichloride) is used as a scavenger to estimate the radiolytic yields of water decomposition products from room temperature to 400 °C by pulse radiolysis method. {G(e aq -) + G(OH) + G(H)} has been studied using a 0.5 mM MV 2+ solution in the presence of 10 mM NaCOOH up to 200 °C and in the presence of 0.2 M ethanol up to 400 °C. The results show that the {G(e aq -) + G(OH) + G(H)} increases with temperature up to 350 °C at 25 MPa, while it depends also on pressure in supercritical conditions. The G(e aq -) was estimated using MV 2+ solutions in the presence of 0.2 M tert-butyl alcohol. The results agree well with the reported data up to around 300 °C at 25 MPa; however, in supercritical conditions a very significant density effect was observed. At a given temperature, G(e aq -) and {G(e aq -) + G(OH) + G(H)} decrease with increasing density while at a fixed density they decrease with increasing temperature.

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Thermal cracking of n-hexadecane in the mild temperature (330−375 °C) range has been investigated in liquid and gas phases. The kinetic data of liquid-phase cracking are shown to be very similar to those of gas-phase cracking. However, the pattern and distribution of the products are greatly phase dependent. In liquid-phase cracking, there is an equimolar distribution of n-alkane and 1-alkene products in the C3−C13 range at low conversion; when the conversion is increased, more alkanes than alkenes are produced. To the contrary, more alkenes than alkanes are always determined in products from gas-phase cracking. Liquid-phase cracking gives a low selectivity of gas products and a high selectivity of addition compounds (C18−C30), whereas gas-phase cracking produces a large amount of gas products and no addition compounds. The phase dependence of products can be interpreted in terms of a low concentration of hexadecane, under which β-scission occurs more preferentially than in liquid phase. Reaction mechanisms are suggested based on the product analysis to account for cracking behaviors of liquid-phase and gas-phase cracking.

Solvation of iodide and electrons in an ionic liquid (N,N,N-trimethyl-n-propylammonium bis(trifluoromethanesulfonyl)imide; TMPA-TFSI) was studied through the absorption spectra of the charge-transfer-to-solvent (CTTS) state of iodide and of solvated electrons. The interaction between the TMPA cation and iodide was strong, whereas electrons were weakly solvated in TMPA-TFSI. We followed electron photodetachment from iodide to the ionic liquid and formation of the solvated electrons by observing absorption in the visible and near-infrared regions using a nanosecond laser flash photolysis method. The quantum yield of the photodetachment in TMPA-TFSI was estimated to be 0.34, which is much higher than that in a high-concentration aqueous salt solution previously reported. We also examined a reaction of the solvated electrons with the ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (Bmim-TFSI) as a solute in TMPA-TFSI. The reaction rate was determined to be 5.3 x 10(8) M(-1) s(-1). The electrons before full solvation (dry electrons) reacted with Bmim cations efficiently. These observations suggest that the electrons in TMPA-TFSI can move easily before solvation.