This work measures the C and O K-edge x-ray absorption near-edge structure (XANES) spectra of hydrogenated amorphous carbon (a-C:H) films deposited at various baking temperatures Tb (Tb = 300–500 °C at 50 °C). The C–H σ* peak related to the content of the sp2 graphite-like bonding in the C K-edge spectra was found to yield to the C–H π* peak related to the sp3 diamond-like bonding at high temperature (500 °C). We find that the intensities of both the sp2 and sp3 features in the C K-edge XANES spectra decrease with increase of Tb, which suggests an increase of the defect concentration with Tb. The intensities of the O K-edge XANES spectra are found to decrease with increase of Tb, which suggests thermally induced decomposition of carbonyl contaminants on the surface. The elemental analysis C/O (or O/C) ratio was obtained from XPS spectra and indicates that films are not hydrogenated amorphous carbon but rather oxyhydrogenated amorphous carbon thin films.

Diamond-like carbon films were synthesized by electro-deposition technique from an organic liquid (a solution of alpha- and beta-pinenes in n-hexane) on silicon substrate at room temperature and at room pressure. The x-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectra, Raman spectra, photoluminescence (PL), and x-ray absorption near edge structure (XANES) spectra analysis were used to study the properties of the diamond-like carbon (as-deposited and annealed) films. The XRD measurement indicated that the film contains some diamond-crystalline phases whereas Raman spectra did not show any prominent diamond-like peak. PL intensity as higher for the as-deposited film and decreased with high-temperature vacuum annealing. FTIR spectra showed the presence of sp3 hybridization C–H bonds and their intensity decreases at higher annealing temperature. C and O K-edge XANES spectra showed that π* (sp2) intensity significantly decreases when the annealing temperature is 600 °C.

Several nondestructive characterization techniques (optical and photothermal deflection spectroscopy in the visible photon energy range, Raman spectroscopy, profilometry, photoluminescence, electron-spin-resonance characterization of the paramagnetic centers, etc.) are used to study the properties of the a-C:H:OH films deposited by the “dip” technique. With such a preparation method, the substrates are dipped in viscous mixtures of liquid carbon compounds. The subsequent baking in an oven at different temperatures (300–500 °C) allows the formation on a substrate of submicrometric thin solid films. The as-prepared material exhibits several characteristics that are comparable to that of floppy, polymer-like amorphous carbons. Transitions on many film properties (thicknesses, optical gaps, photoluminescence intensities, spin densities, g factors, relaxation times, etc.) were found between 300 and 350 and between 450 and 500 °C.

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The objective of this research is to define the fundamental structure-property relationships of water-swollen polymer hydrogel particles that are employed as internal curing agents in cementitious mixtures, in addition to reporting a novel synthesis procedure for combining pozzolanic materials with hydrogel particles. Solution polymerization was performed to incorporate amorphous nanosilica particles within acrylic-based polymer hydrogel particles of varying chemical compositions (i.e., monomer ratio of acrylic acid (AA) to acrylamide (AM)). Experiments were designed to measure the absorption capacity and kinetics of hydrogel particles immersed in pure water and cementitious pore solution, as well as determine the impact of particles on cement paste microstructure. While majority-AM hydrogel particles displayed relatively stable absorption values during immersion in pore solution, majority-AA hydrogel particles desorbed fluid over time, most likely due to the interactions of multivalent cations in the absorbed solution with the anionic polymer network. Interestingly, the addition of negatively charged nanosilica particles accelerated and enhanced this desorption response. When incorporated into cement paste, majority-AM hydrogel particles encouraged the formation of calcium hydroxide and calcium silicate hydrate within the void space previously occupied by the swollen particles. When nanosilica was added to the