The acidic components of Athabasca bitumen interfacial material (IM) were isolated and subsequently fractionated based on hydrophobicity by a modified aminopropyl silica (MAPS) method to determine whether low-molecularweight IM acids are preferentially ionized in negative-ion electrospray ionization (ESI (−)) and, thus, bias the compositional information obtained by direct infusion (dilute and shoot) mass spectral analysis. Characterization by negative-ion electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) revealed that MAPS fractionation of IM acids extends the detection of high-m/z (>600-Da) IM compounds by 2-fold, yields an approximate 10-fold increase in the number of assigned formulas, and exposes a continuum of acidic species that includes the first definitive identification of doubly charged acids in interfacial material. Comparison of the heteroatom contents of singly and doubly charged O x species, combined with the acid-targeted extraction procedure, strongly suggests that the chemical functionalities are similar for the two ion types and are largely composed of mono-and dicarboxylic acids. Excitation emission matrix spectroscopy (EEMS) revealed that the most hydrophobic IM fractions approach the size and aromaticity of bitumen asphaltenes, but despite the increase in hydrophobicity, these asphaltene-like acids form the tightest emulsions, as revealed in simple bottle tests. Thus, the most surfaceactive material from Athabasca bitumen comprises low-molecular-weight, acidic, resin-like species, as well as larger (highermolecular-weight) acidic asphaltene-like compounds.

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The role of the water content adsorbed to silica gel for the selective isolation of petroleum interfacially active material was examined. Systematic variation of the amount of water adsorbed on the silica surface and its effect on retained petroleum species (interfacially active) revealed that gravimetric yields of isolated interfacial material (IM) were inversely proportional to the amount of water loaded onto the silica gel. However, with the exception of the water-saturated silica gel (66.6% water g −1 silica gel), all silica gels investigated (11.1−53.8% water g −1 silica gel) were stained after IM isolation, indicating that >53.8% water g −1 silica gel is required to prevent irreversible, oil−silica interactions. Moreover, emulsion stability tests reveal that IM isolated from the water-saturated silica gel (66.6% water g −1 silica gel) forms the most stable emulsion relative to IM isolated from the unsaturated silica gels. Molecular-level analysis of isolated IM fractions as a function of the silica water loading by Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) exposes a gradual shift to a lower carbon number and double bond equivalents (DBE) in the interfacially active, O x S y , N 1 O x , and N 1 O x S 1 classes as a function of the increasing silica water content. The results suggest that lower carbon number/DBE, more surface-active compounds are isolated with the water-saturated silica gel. Conversely, IM O x species isolated with water saturated silica gel have similarly low carbon number ranges, but higher DBE, and occupy compositional space characteristic of asphaltenic species.

Lignin is one of the most abundant and inexpensive natural biopolymers. It can be efficiently converted to low cost carbon fiber, monolithic structures, or powders that could be used directly in the production of anodes for lithium-ion batteries. In this work, we report thermomechanical processing methods relevant for the conversion of lignin precursors into carbon fiber-based anode materials, the impact of lignin precursor modification on melt processing, and the microstructure of the final carbon material. Modification of softwood lignin produced functionalities and rheological properties that more closely resemble hardwood lignin thereby enabling the melt processing of softwood lignin in oxidative atmospheres (air). The conversion process encompasses melt spinning of the lignin precursor, oxidative stabilization, and a low temperature carbonization step in a nitrogen/hydrogen atmosphere. We determined resistivities of individual carbon fiber samples and characterized the microstructure by scanning electron microscopy. Neutron diffraction reveals nanoscale graphitic domains embedded in an amorphous carbon matrix. These unique structural characteristics make biomass-derived carbon fibers a suitable material for energy storage applications with enhanced electrochemical performance.

Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR MS) has been used to assign elemental formulas to tens of thousands of ions generated from petroleum samples. While elemental formulas can give insights on hydrogen deficiency or heteroatom content, they do not directly give structural information. Previous broadband collision-induced dissociation (CID) experiments yielded useful information on the aromatic cores of petroleum molecules. However, it is difficult to track parent-product correlations in broadband experiments. In this work, isomers and isobars in a single dalton window were isolated and subjected to CID to obtain more conclusive information on the core structures of the ions. Several aromatic ring class fractions of a heptane deasphalted vacuum residue (VR) and the associated asphaltene fraction were examined by CID mass spectrometry. A 15T FT-ICR mass spectrometer was used with atmospheric pressure photoionization to probe the structural features of each fraction. Ions that differ in mass by n*14 Da (or n*CH2 units) were selected for isolation to screen for differences within the same homologous series across the mass range of the sample. Each packet of ions was isolated and fragmented to reveal aromatic cores with some fragment ions retaining alkyl chains. The assigned molecular formulas from ultrahigh resolution MS combined with the structural information suggested by the liquid chromatography (LC) separation enabled greater confidence in proposed parent ion structures. In the measurements performed, single core and multicore fragment ions were observed for the deasphalted aromatic fractions whereas the asphaltene fraction produced primarily single core fragment ions.