The automated Asphaltene Determinator coupled with saturates, aromatics, and resins (SAR-AD TM) s... more The automated Asphaltene Determinator coupled with saturates, aromatics, and resins (SAR-AD TM) separation is a powerful characterization tool initially designed for the rapid and repeatable analysis of asphalt bitumen and petroleum residua. By virtue of the evaporative light scattering detector (ELSD)-and the fact that saturates and a portion of aromatics do not contain chromophores making them undetectable in the 500 or 700 nm detectors-the complete quantification of petroleum fractions by this method is somewhat restricted to samples that do not contain a significant amount of volatiles. Crude oils can contain more than 70% of volatile material which is not detected by the ELSD. To overcome the SAR-AD volatiles limitation, a quantitative vacuum distillation method was developed to capture the volatiles and produce unaltered residua that do not lose volatiles in the ELSD. To complete the characterization, the volatiles are analyzed for their saturate, aromatic, and reactive olefin content by proton nuclear magnetic resonance spectroscopy (1 H NMR). The data from these two methods are combined in the form of a modified colloidal instability index to give a more complete profile of the original whole crude oils.
Polycyclic heavy hydrocarbons (HHs) such as coal, tar, and pitch are a family of materials with e... more Polycyclic heavy hydrocarbons (HHs) such as coal, tar, and pitch are a family of materials with extremely rich and complex chemistry, representing a massive opportunity for their use in a range of potential applications. The present work shows that optimal selection of initial HHs based on molecular constituents is essential in tuning the material for a particular and targeted electronic application. Combining the selection of feedstock chemistry (H:C and aromatic content) and controlling variable laser treatment parameters (laser power, speed, and focus) lead to full control over the H:C ratio, sp 2 concentration, and degree of graphitic stacking order of the products. The broad intertunability of these factors results from a wide distribution of carbon material crystallinity from amorphous to highly graphitic and a broad distribution of electrical conductivity up to 10 3 S/m.
Model compounds were used to provide some chemical boundaries for the eight-fraction SAR-ADTM cha... more Model compounds were used to provide some chemical boundaries for the eight-fraction SAR-ADTM characterization method for heavy oils. It was found that the Saturates fraction consists of linear and highly cyclic alkanes; the Aro-1 fraction consists of molecules with a single aromatic ring; the Aro-2 fraction consists of mostly 2 and 3-ring fused aromatic molecules, the pericondensed 4-ring molecule pyrene, and molecules with 3–5 rings that are not fused; and the Aro-3 fraction consists of 4-membered linear and catacondensed aromatics, larger pericondensed aromatics, and large polycyclic aromatic hydrocarbons. The Resins fraction consists of mostly fused aromatic ring systems containing polar functional groups and metallated polar vanadium oxide porphyrin compounds, and the Asphaltene fraction consists of both island- and archipelago-type structures with a broad range of molecular weight variation, aromaticity, and heteroatom contents. The behavior of the eight SAR-ADTM fractions dur...
Transportation Research Record: Journal of the Transportation Research Board
The current Superpave™ performance grading specifications were developed under the Strategic High... more The current Superpave™ performance grading specifications were developed under the Strategic Highway Research Program during the 1990s. Since the implementation of these specifications, the petroleum industry, and in turn asphalt binder formulation and production processes, have changed to a great extent owing to various factors, including improving yields and margins. Therefore, there is a need to evaluate and characterize evolving asphalt binder technologies through chemical-, rheological-, and performance-based approaches and to understand the relationships between these various aspects. This paper provides a robust method to characterize the effects of the binder crude source, compositional chemistry, crude oil processing, and modification type, as well as the thermal properties, on the low-temperature performance parameters (e.g., glass transition, crystallization properties, Δ Tc, asphalt binder cracking device [ABCD] Tcr, etc.). As a part of the National Cooperative Highway R...
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
A novel method is described that selectively precipitates the least soluble asphaltenic material ... more A novel method is described that selectively precipitates the least soluble asphaltenic material from hydroconverted bottoms (HCB) using a dual immiscible solvent approach. This approach separates asphaltenes from the deasphalted (DAO)/precipitant layer by adding acetonitrile (CH 3 CN) as a second immiscible phase. The three phase system precipitates asphaltenes to the bottom which becomes separated from the top DAO/precipitant layer by a middle CH 3 CN layer. Due to some CH 3 CN dissolving in the DAO/precipitant layer, the solvent parameter (and possibly other chromatographic or specific interactions) of the precipitating medium is increased causing less overall asphaltenes to be precipitated, but more of the least soluble precoke-like asphaltenes are selectively precipitated. This treatment produces DAO that is more thermally stable with regard to coke formation compared to DAO generated using only the aliphatic precipitant which precipitates out more asphaltenes. The immiscible CH 3 CN layer reaches a steady state saturation level of HCB components and can be reused multiple times without additional treatment. HCB components that become dissolved into the CH 3 CN are primarily smaller molecular weight aromatics with very little contamination from Ni and V complexes.
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Abstract Despite the potential to lowering fabrication costs of pitch-based carbon fiber (CF) com... more Abstract Despite the potential to lowering fabrication costs of pitch-based carbon fiber (CF) compared to polyacrylonitrile-based CF, large scale utilization is currently limited by the complexity in manufacturing. This is mainly due to the lack of consistency between the pitch structure/chemistry and CF properties under different processing conditions. Here, we employed full atomistic simulations based on reactive force fields to investigate the conversion of pitch precursors to CFs. It was found that at the carbonization stage, the consumption rates of precursors, gas formations, and solid yields (carbonized CFs) are all dependent on the composition and arrangement of molecular moieties in the precursor. Specifically, precursors with sp3 carbons in the cata-condensed core area have limited decomposition pathways (i.e., limited reaction sites), which leads to the formation of carbonized CFs with similar compositions. Furthermore, carbonized CFs possess distinct structural characteristics, and finally lead to the formation of CFs with different moduli. By analyzing CF crystallinity and elemental composition, general rationales are proposed for the selection of optimal precursors and processing conditions, and thus shed lights on parameter screening during industrial CF synthesis. For instance, inclusion of sp3 carbons in cata-condensed rings can be preferred over the presence of sp3 carbons on side chains.
In the wake of a growing bitumen binder variability resulting from economic and geopolitical cons... more In the wake of a growing bitumen binder variability resulting from economic and geopolitical constraints leading to changes in crude oils and refining processes, the asphalt industry is facing challenges of quality, consistency and early pavement failures in the form of cracking and raveling in particular. New, innovative and relevant analytical tools and approaches are being developed particularly at the Western Research Institute (WRI) to address the challenges and advance from trials and errors to modelling and predictions. Studies launched by WRI have demonstrated the proof of concept, and the validation of chemometric correlations; linking chemical composition of bitumen binders to their physical properties and their performance in mixes. Relevant strong correlations were obtained for compositional fractions, chemical functionalities, and thermal parameters with binder rheological properties, specification parameters, as well as asphalt mix properties, through a study with a road contractor. Hence, the binder impacts mixture stiffness and fatigue resistance, but less prominently in mixture resistance to moisture-induced damaged, rutting resistance and compaction properties, where aggregates become more prominent. Other important results confirmed some performance indicators from binder to mixes, such as the stiffness modulus, fatigue parameters, thermal cracking parameters (relaxation and cracking temperature), and rutting resistance. New possible indicators were detected like the binder glass transition and crossover temperatures as well as their difference, named temperature of intermediate region (TIR) with respect to cracking resistance and healing propensity. The effect of long term aging, particularly with respect to cracking, was also evaluated. Many of these results have been obtained through two major projects: the Asphalt Industry Research Consortium launched by WRI which is ongoing on a very wide binder range aiming to chemically fingerprint binders to predict their mechanical properties as well as their aging susceptibility and their compatibility with various modifiers or recycled materials. The second project is the ongoing National Cooperative Highway Research Program 09-60 project. This involves studying the impact of binder resistance to internal restraint damage mechanism on mixture cracking, and the influence of other thermal cracking factors such as, long-term aging and reversible time-dependent physical hardening. The ultimate goal of this project is to develop and propose new and more relevant specification parameters to avoid age-induced surface damage in the form of transverse cracking, block cracking, and raveling.
Two-dimensional covalent organic frameworks (2D-COFs) have been of increasing interest in the pas... more Two-dimensional covalent organic frameworks (2D-COFs) have been of increasing interest in the past decade due to their porous structures that ideally can be highly ordered. One of the most common routes to these polymers relies on Schiff-base chemistry, i.e., the condensation reaction between a carbonyl and an amine. In this report, we elaborate on the condensation of 3,6-dibromobenzene-1,2,4,5-tetraamine with hexaketocyclohexane (HKH) and the subsequent carbonylation of the resulting COF, along with the possibility that the condensation reaction on HKH can result in a trans configuration resulting in the formation of a disordered 2D-COF. This strategy enables modification of COFs via bromine substitution reactions to place functional groups within the pores of the materials. Ion-sieving measurements using membranes from this COF, reaction of small molecules with unreacted keto groups along with modeling studies indicate disorder in the COF polymerization process. We also present a ...
The automated Asphaltene Determinator coupled with saturates, aromatics, and resins (SAR-AD TM) s... more The automated Asphaltene Determinator coupled with saturates, aromatics, and resins (SAR-AD TM) separation is a powerful characterization tool initially designed for the rapid and repeatable analysis of asphalt bitumen and petroleum residua. By virtue of the evaporative light scattering detector (ELSD)-and the fact that saturates and a portion of aromatics do not contain chromophores making them undetectable in the 500 or 700 nm detectors-the complete quantification of petroleum fractions by this method is somewhat restricted to samples that do not contain a significant amount of volatiles. Crude oils can contain more than 70% of volatile material which is not detected by the ELSD. To overcome the SAR-AD volatiles limitation, a quantitative vacuum distillation method was developed to capture the volatiles and produce unaltered residua that do not lose volatiles in the ELSD. To complete the characterization, the volatiles are analyzed for their saturate, aromatic, and reactive olefin content by proton nuclear magnetic resonance spectroscopy (1 H NMR). The data from these two methods are combined in the form of a modified colloidal instability index to give a more complete profile of the original whole crude oils.
Polycyclic heavy hydrocarbons (HHs) such as coal, tar, and pitch are a family of materials with e... more Polycyclic heavy hydrocarbons (HHs) such as coal, tar, and pitch are a family of materials with extremely rich and complex chemistry, representing a massive opportunity for their use in a range of potential applications. The present work shows that optimal selection of initial HHs based on molecular constituents is essential in tuning the material for a particular and targeted electronic application. Combining the selection of feedstock chemistry (H:C and aromatic content) and controlling variable laser treatment parameters (laser power, speed, and focus) lead to full control over the H:C ratio, sp 2 concentration, and degree of graphitic stacking order of the products. The broad intertunability of these factors results from a wide distribution of carbon material crystallinity from amorphous to highly graphitic and a broad distribution of electrical conductivity up to 10 3 S/m.
Model compounds were used to provide some chemical boundaries for the eight-fraction SAR-ADTM cha... more Model compounds were used to provide some chemical boundaries for the eight-fraction SAR-ADTM characterization method for heavy oils. It was found that the Saturates fraction consists of linear and highly cyclic alkanes; the Aro-1 fraction consists of molecules with a single aromatic ring; the Aro-2 fraction consists of mostly 2 and 3-ring fused aromatic molecules, the pericondensed 4-ring molecule pyrene, and molecules with 3–5 rings that are not fused; and the Aro-3 fraction consists of 4-membered linear and catacondensed aromatics, larger pericondensed aromatics, and large polycyclic aromatic hydrocarbons. The Resins fraction consists of mostly fused aromatic ring systems containing polar functional groups and metallated polar vanadium oxide porphyrin compounds, and the Asphaltene fraction consists of both island- and archipelago-type structures with a broad range of molecular weight variation, aromaticity, and heteroatom contents. The behavior of the eight SAR-ADTM fractions dur...
Transportation Research Record: Journal of the Transportation Research Board
The current Superpave™ performance grading specifications were developed under the Strategic High... more The current Superpave™ performance grading specifications were developed under the Strategic Highway Research Program during the 1990s. Since the implementation of these specifications, the petroleum industry, and in turn asphalt binder formulation and production processes, have changed to a great extent owing to various factors, including improving yields and margins. Therefore, there is a need to evaluate and characterize evolving asphalt binder technologies through chemical-, rheological-, and performance-based approaches and to understand the relationships between these various aspects. This paper provides a robust method to characterize the effects of the binder crude source, compositional chemistry, crude oil processing, and modification type, as well as the thermal properties, on the low-temperature performance parameters (e.g., glass transition, crystallization properties, Δ Tc, asphalt binder cracking device [ABCD] Tcr, etc.). As a part of the National Cooperative Highway R...
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
A novel method is described that selectively precipitates the least soluble asphaltenic material ... more A novel method is described that selectively precipitates the least soluble asphaltenic material from hydroconverted bottoms (HCB) using a dual immiscible solvent approach. This approach separates asphaltenes from the deasphalted (DAO)/precipitant layer by adding acetonitrile (CH 3 CN) as a second immiscible phase. The three phase system precipitates asphaltenes to the bottom which becomes separated from the top DAO/precipitant layer by a middle CH 3 CN layer. Due to some CH 3 CN dissolving in the DAO/precipitant layer, the solvent parameter (and possibly other chromatographic or specific interactions) of the precipitating medium is increased causing less overall asphaltenes to be precipitated, but more of the least soluble precoke-like asphaltenes are selectively precipitated. This treatment produces DAO that is more thermally stable with regard to coke formation compared to DAO generated using only the aliphatic precipitant which precipitates out more asphaltenes. The immiscible CH 3 CN layer reaches a steady state saturation level of HCB components and can be reused multiple times without additional treatment. HCB components that become dissolved into the CH 3 CN are primarily smaller molecular weight aromatics with very little contamination from Ni and V complexes.
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Abstract Despite the potential to lowering fabrication costs of pitch-based carbon fiber (CF) com... more Abstract Despite the potential to lowering fabrication costs of pitch-based carbon fiber (CF) compared to polyacrylonitrile-based CF, large scale utilization is currently limited by the complexity in manufacturing. This is mainly due to the lack of consistency between the pitch structure/chemistry and CF properties under different processing conditions. Here, we employed full atomistic simulations based on reactive force fields to investigate the conversion of pitch precursors to CFs. It was found that at the carbonization stage, the consumption rates of precursors, gas formations, and solid yields (carbonized CFs) are all dependent on the composition and arrangement of molecular moieties in the precursor. Specifically, precursors with sp3 carbons in the cata-condensed core area have limited decomposition pathways (i.e., limited reaction sites), which leads to the formation of carbonized CFs with similar compositions. Furthermore, carbonized CFs possess distinct structural characteristics, and finally lead to the formation of CFs with different moduli. By analyzing CF crystallinity and elemental composition, general rationales are proposed for the selection of optimal precursors and processing conditions, and thus shed lights on parameter screening during industrial CF synthesis. For instance, inclusion of sp3 carbons in cata-condensed rings can be preferred over the presence of sp3 carbons on side chains.
In the wake of a growing bitumen binder variability resulting from economic and geopolitical cons... more In the wake of a growing bitumen binder variability resulting from economic and geopolitical constraints leading to changes in crude oils and refining processes, the asphalt industry is facing challenges of quality, consistency and early pavement failures in the form of cracking and raveling in particular. New, innovative and relevant analytical tools and approaches are being developed particularly at the Western Research Institute (WRI) to address the challenges and advance from trials and errors to modelling and predictions. Studies launched by WRI have demonstrated the proof of concept, and the validation of chemometric correlations; linking chemical composition of bitumen binders to their physical properties and their performance in mixes. Relevant strong correlations were obtained for compositional fractions, chemical functionalities, and thermal parameters with binder rheological properties, specification parameters, as well as asphalt mix properties, through a study with a road contractor. Hence, the binder impacts mixture stiffness and fatigue resistance, but less prominently in mixture resistance to moisture-induced damaged, rutting resistance and compaction properties, where aggregates become more prominent. Other important results confirmed some performance indicators from binder to mixes, such as the stiffness modulus, fatigue parameters, thermal cracking parameters (relaxation and cracking temperature), and rutting resistance. New possible indicators were detected like the binder glass transition and crossover temperatures as well as their difference, named temperature of intermediate region (TIR) with respect to cracking resistance and healing propensity. The effect of long term aging, particularly with respect to cracking, was also evaluated. Many of these results have been obtained through two major projects: the Asphalt Industry Research Consortium launched by WRI which is ongoing on a very wide binder range aiming to chemically fingerprint binders to predict their mechanical properties as well as their aging susceptibility and their compatibility with various modifiers or recycled materials. The second project is the ongoing National Cooperative Highway Research Program 09-60 project. This involves studying the impact of binder resistance to internal restraint damage mechanism on mixture cracking, and the influence of other thermal cracking factors such as, long-term aging and reversible time-dependent physical hardening. The ultimate goal of this project is to develop and propose new and more relevant specification parameters to avoid age-induced surface damage in the form of transverse cracking, block cracking, and raveling.
Two-dimensional covalent organic frameworks (2D-COFs) have been of increasing interest in the pas... more Two-dimensional covalent organic frameworks (2D-COFs) have been of increasing interest in the past decade due to their porous structures that ideally can be highly ordered. One of the most common routes to these polymers relies on Schiff-base chemistry, i.e., the condensation reaction between a carbonyl and an amine. In this report, we elaborate on the condensation of 3,6-dibromobenzene-1,2,4,5-tetraamine with hexaketocyclohexane (HKH) and the subsequent carbonylation of the resulting COF, along with the possibility that the condensation reaction on HKH can result in a trans configuration resulting in the formation of a disordered 2D-COF. This strategy enables modification of COFs via bromine substitution reactions to place functional groups within the pores of the materials. Ion-sieving measurements using membranes from this COF, reaction of small molecules with unreacted keto groups along with modeling studies indicate disorder in the COF polymerization process. We also present a ...
Uploads
Papers by Jeramie Adams