Neutron and X-ray diffraction have been used to structurally characterise the crystalline monolayer structures of hexane, octane, decane, dodecane and tetradecane adsorbed on graphite at sub-monolayer coverages and when coexisting with liquid alkane. The structures of all the molecules investigated at both coverages and low temperatures are isomorphous with rectangular unit cells of plane group pgg containing two molecules per cell. In both high-and low-coverage structures the molecules have their extended axes parallel to the surface. The plane of the carbon skeleton is found to be parallel to the graphite surface. The monolayers at sub-monolayer coverages are interpreted as uniaxially commensurate while those monolayers coexisting with the liquid are fully commensurate. Dodecane and tetradecane are exceptional: dodecane forms additional phases at high temperatures just prior to melting, at both low and high coverages. In these structures the molecules in the unit cell are parallel to each other with plane group cmm. Tetradecane only forms a single phase at high coverages in which the molecules appear to be parallel and upright, similar to the dodecane high temperature, high coverage phase.

A combination of neutron and X-ray diffraction has been used to structurally characterise the crystalline monolayer structures of all the alkanes with odd number of carbon atoms in their alkyl chains from pentane to pentadecane adsorbed on graphite. The structures of all the molecules investigated at submonolayer coverages are isomorphous with centred rectangular unit cells containing two molecules per cell in a parallel arrangement. This is a completely different structure from the ' herringbone ' arrangement of molecules found for the shorter ' even ' alkanes, such as hexane, octane and decane. The monolayers at sub-monolayer coverages are interpreted as uniaxial commensurate with the underlying graphite while those monolayers coexisting with the liquid, while structurally similar, are fully commensurate. The difference between the two structures is a uniaxial compression in the b-direction with the monolayers coexisting with the liquids significantly more dense than at submonolayer coverages. In the low coverage structures the ' odd ' molecules have an all trans conformation with their extended axes parallel to the surface with the plane of the carbon skeleton also parallel to the graphite surface. At high coverages the carbon skeleton is no longer parallel to the graphite surface but significantly tilted. The longest alkanes, tridecane and pentadecane also show evidence of positional and/or rotational disorder at high coverages.

The combination of differential scanning calorimetry and incoherent elastic neutron scattering has been used to demonstrate the formation of solid layers adsorbed onto graphite from pure alkanes and binary alkane mixtures. We report enthalpies and temperatures of the monolayer transitions for pure alkanes and mixtures and note that the solid monolayers melt at approximately 1.1 times the melting point of the bulk liquid or solution. In the mixtures the longer alkane is found to be preferentially adsorbed with the formation of a solid monolayer even when it is present as the minor component in the solution and when the carbon chain lengths differ by only a single CH 2 group.

In this work, we present the behavior of solid monolayers of binary mixtures of alkanes and alcohols adsorbed on the surface of graphite from their liquid mixtures. We demonstrate that solid monolayers form for all the combinations investigated here. Differential scanning calorimetry (DSC) is used to identify the surface phase behavior of these mixtures, and elastic neutron incoherent scattering has been used to determine the composition of the mixed monolayers inferred by the calorimetry. The mixing behavior of the alcohol/alkane monolayer mixtures is compared quantitatively with alkane/alkane and alcohol/alcohol mixtures using a regular solution approach to model the incomplete mixing in the solid monolayer with preferential adsorption determining the surface composition. This analysis indicates the preferential adsorption of alcohols over alkanes of comparable alkyl chain length and even preferential adsorption of shorter alcohols over longer alkanes, which contrasts strongly with mixtures of alkane/alkane and alcohol/alcohol of different alkyl chain lengths where the longer homologue is always found to preferentially adsorb over the shorter. The alcohol/alkane mixtures are all found to phase separate to a significant extent in the adsorbed layer mixtures even when molecules are of a similar size. Again, this contrasts strongly with alkane/alkane and alcohol/alcohol mixtures where, although phase separation is found for molecules of significantly different size, good mixing is found for similar size species.

The thermal conductivities kappa of the crystalline phases and amorphous solid states of water as well as clathrate hydrates are summarized and discussed. In particular, this review concerns the unusual temperature T and pressure p behaviors of kappa for some phases and states, which include glass-like K for crystalline clathrate hydrates and crystal-like kappa for low-density amorphous ice. The latter result implies that glassy water and low-density amorphous ice are different states. The results for the various phases and states are in most cases described well by the equations: kappa = D x T(-x) and 1n kappa = E + F x p, under isobaric and isothermal conditions, respectively. All phases that exhibit negative values for F are known to amorphize upon pressurization at low temperatures. Ice XI, which is obtained by annealing ice Ih below 70 K, exhibits positive F, which indicates that this phase does not amorphize like ice Ih upon pressurization.

X-ray and neutron diffraction have been used to investigate the formation of solid crystalline monolayers of all of the linear carboxylic acids from C(6) to C(14) at submonolayer coverage and from C(8) to C(14) at multilayer coverages, and to characterize their structures. X-rays and neutrons highlight different aspects of the monolayer structures, and their combination is therefore important in structural determination. For all of the acids with an odd number of carbon atoms, the unit cell is rectangular of plane group pgg containing four molecules. The members of the homologous series with an even number of carbon atoms have an oblique unit cell with two molecules per unit cell and plane group p2. This odd-even variation in crystal structure provides an explanation for the odd-even variation observed in monolayer melting points and mixing behavior. In all cases, the molecules are arranged in strongly hydrogen-bonded dimers with their extended axes parallel to the surface and the plane of the carbon skeleton essentially parallel to the graphite surface. The monolayer crystal structures have unit cell dimensions similar to certain close-packed planes of the bulk crystals, but the molecular arrangements are different. There is a 1-3% compression on increasing the coverage over a monolayer.

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The reaction mechanism of a "SiO"-carbon composite-negative electrode for high-capacity lithium-ion batteries is examined by Si K-edge X-ray absorption near edge structure (XANES), 7 Li and 29 Si nuclear magnetic resonance (NMR), and scanning transmission electron microscopy (STEM) with Si L-edge electron energy loss spectroscopy (EELS) and energy dispersive X-ray spectroscopy (EDX). According to the analytical results, "SiO" consisting of nano-size Si particles dispersed in amorphous SiO 2 is converted to lithium-silicon alloys and lithium silicon oxides during the first charge in lithium-ion batteries, and the nano-size silicon particles surrounded by lithium silicon oxides are rechargeable for subsequent cycles. Molecular dynamics (MD) simulation of "SiO" is also carried out and shown that silicon particles grow during the first cycle and are surrounded by a good lithium-ion conductor of lithium silicon oxides. From these results, the reaction mechanism of "SiO" is discussed in terms of high-capacity negative electrodes for lithium-ion batteries.