Waxy crude oil containing large amounts of paraffins often results in various difficulties in extraction and transportation, especially at low temperature. Comb-type copolymers with phenyl pendants were found to be able to improve the flow ability of waxy oils effectively. To investigate the influence of spacer length between phenyl pendant and polymer backbone in comb copolymers on the flow ability of waxy oil, poly­(α-octadecene-co-maleic acid phenyl alkyl amide)­s with various spacer lengths were synthesized by modification of poly­(α-octadecene-co-maleic anhydride) with aniline, phenethylamine, phentermine, and phenyl-undecanoicamide. Their effects on the morphology and crystallization of model and crude oils were observed by polarized light microscopy and DSC. The flow ability of both oils in the presence of copolymers was studied by means of rheology, including measuring yield stress, viscosity, and thixotropic properties. It is found that the spacer length remarkably affects the rheology and wax crystallization behaviors for both oils. The copolymer with a longer spacer can provide better flexibility of phenyl pendants to disperse asphaltenes more effectively, and the long spacer can cocrystallize with long-chain paraffins.

Limb ischemia/reperfusion (LI/R) injury is associated with high morbidity and mortality. The hypothesis of this study is that hydrogen-rich solution could attenuateacute lung injury and improve mortality via chemerin and NLRP3 after LI/R in rats. A rat model of LI/R was performed by clamping the bilateral femoral arteries for 3 h followed by reperfusion. HRS was administered intraperitoneally (10 mL/kg or 2.5 mL/kg) when the atraumatic micro clips were released. The rats were euthanized at 2 h after reperfusion and then the arterial blood and lung specimens were harvested for further analyses. Meanwhile, survival rate was observed. The results showed that HRS improved the survival rate and attenuated pulmonary edema, injury and apoptosis. HRS also decreased the levels of tumor necrosis factor(TNF)-α, interleukin(IL)-6, myeloperoxidase (MPO) and malondialdehyde (MDA), and increased the activity of superoxide dismutase(SOD) in serum and lung after the LI/R event. HRS downregulated the expression of chemerin and NLRP3 in lung. The study demonstrated that chemerin and NLRP3 could serve as important response factors those were involved in the lung injury following LI/R. HRS could significantly attenuate LI/R-mediated acute lung injury, at least in part, by inhibiting the activated chemerin/NLRP3 signaling pathway.

Resin accounts for over 30% of the composition of Liaohe heavy crude oil and can result in severe difficulties in oil recovery and transportation. To determine the structure of the resin extracted from Liaohe heavy oil, matrix-assisted laser desorption ionization time-of-flight mass spectrometry, elemental analysis, Fourier-transform IR spectroscopy, and NMR spectroscopy were employed to determine the chemical structure of the resin. The results showed that the resin molecule is composed of anthracene, two cycloalkanes, and six alkyl chains grafted on the cyclic-structure core. UV−visible spectroscopy, turbidity measurements, dynamic light scattering, optical microscopy, and scanning electron microscopy were used to observe the resin aggregation behavior upon addition of a poor solvent. The effect of the resin on the rheology of model oils was investigated systematically. The π−π interactions among resin molecules impose a critical impact on the assembly of the resins. The quantum mechanics calculations revealed that there are two low-well depths of interaction energy when two resin molecules approach, which implies that the bending and branching structure of the resin aggregates may originate from the staggered stacking of the resin molecules. These findings can improve our understanding of the resin aggregation behavior and thus enlighten the solution to the flowing problem during recovery and transportation of heavy oil with a high resin content.

This study aimed to investigate the efficacy and safety of echinacoside (ECH) using an osteopenia rat model. Forty-eight 6-month-old female Sprague-Dawley rats were randomly divided into one sham-operated group (SHAM) and five OVX (ovariectomized) subgroups: SHAM with vehicle 0.5% carboxymethylcellulose sodium (0.5% CMC-Na) and OVX with vehicle (OVX), OVX with 17β-estradiol (E2), and OVX with ECH of graded doses (ECH-L, ECH-M, and ECH-H). The effects of ECH and E2 on serum biochemical parameters, bone mineral density (BMD), bone biomechanical properties, bone microarchitecture, and immunohistochemistry were examined, and safety assessments were also evaluated. The results showed that ECH treatments improved total femur BMD, bone microarchitecture, and biomechanical properties and decreased serum marker levels in comparison to OVX group. Moreover, ECH administration significantly increased osteoprotegerin (OPG) level, and decreased receptor activator of nuclear factor-κB ligand (RANKL) level in serum, as well as in proximal femur. Importantly, ECH treatment ameliorated the lipid parameters without the overall incidences of adverse events of uterus and mammary gland compared to OVX and SHAM groups. This study demonstrated that administration of ECH for 12 weeks can effectively and safely prevent OVX-induced osteoporosis in rats via increasing the OPG/RANKL ratio.

Asphaltene precipitation often brings difficulties to the recovery and transportation of heavy crude oil. Poly­(maleic acid amide-co-vinyl acetate) copolymers with various aromatic (phenyl, naphthyl, and benzimidazole) pendants and/or aliphatic (octyl, tetradecyl, and octadecyl) grafts were synthesized and found to be capable of dispersing asphaltenes effectively. To study the influence of aromatic and aliphatic pendants in copolymers on asphaltene precipitation behaviors, the initial precipitation point, turbidity, and size of asphaltene precipitates from model heavy oils in the presence and absence of copolymers were determined by UV–vis spectroscopy, turbidity meter, and dynamic light scattering, respectively. The effect of copolymers on the viscosity of Tahe heavy oil with high asphaltene content was investigated by the rheological approach. The results revealed that the copolymers with both aromatic and aliphatic pendants dispersed asphaltene, reduced its precipitates, and thus improved the flowability of Tahe heavy oil more effectively than those with only aromatic or aliphatic graft. The combination of “π–π delocalized conjugation attraction” from aromatic pendants and “steric blocking” from aliphatic grafts should be the reason.

The precipitation and deposition of asphaltenes often cause great troubles to the recovery and transportation of crude oil. Adding polymer inhibitors is an effective approach to prevent asphaltenes from clogging. In this study, maleic anhydrideco-octadecene copolymers with imidazolyl, phenyl, and pyridyl pendants were synthesized. The inhibition behaviors of two extracted asphaltenes in the presence of these copolymers were investigated, which were also identified by the rheological tests of the heavy crude oil sample. The chemical structure of both asphaltenes was analyzed by Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), elemental analysis, and time-of-flight (TOF) spectrometry. Both asphaltenes A and B have a high aromaticity and low H/C. However, asphaltene B has a much higher aromaticity and polarity than that of asphaltene A. Ultraviolet−visible spectroscopy, turbidity meter, and dynamic light scattering (DLS) were employed to determine the precipitation behaviors of asphaltenes in the absence and presence of copolymers. The influence of intrinsic properties of asphaltenes, polymer concentration, and aromatic group grafting ratio on asphaltene precipitation were also compared. It is found that the initial precipitation point (IPP) of both asphaltenes is increased most by the copolymer containing 2-aminopyridine (PMO-2-P), while the copolymer containing N-(3-aminopropyl)imidazole (PMO-I) shows the worst inhibition performance. It is because that pyridine group has a stronger adsorption capacity with asphaltene than the imidazole group. The effect of various functional groups in copolymers on inhibiting asphaltene precipitation conforms to the following sequence: 2-aminopyridine > aniline > 4aminopyridine > N-(3-aminopropyl)imidazole. It is also found that high polymer concentration and grafting ratio are beneficial to inhibit the asphaltene precipitation. As a result of the π−π conjugation and hydrogen-bonding attractions between the aromatic groups in the copolymers and the asphaltenes, the polymers can be stably adsorbed onto the surface of the asphaltenes and prevent their aggregation.

In this work, a pressure responsive poly­(α-octadecene-co-maleic acid azobenzene amide) (Azo-MAC) was synthesized and able to enhance the flowability of waxy crude oil with asphaltenes significantly under high pressure. High-pressure UV–vis spectrometer was used to characterize its pressure response under pressures. The onset temperature and enthalpy during wax crystallization of Liaohe waxy crude oil under various pressures were determined by using high-pressure differential scanning calorimeter. The viscosity and yield stress were measured by high-pressure rheometer. On the basis of our experimental data, a mechanism was propounded that the conformation transformation from cis to trans of azobenzene groups in Azo-MAC at enhanced pressure may destroy the assembly of asphaltenes, disturb the crystallization of paraffins and thus improve the flowability of oils. Azo-MAC should be an ideal additive for exploitation and transportation of oils under high pressure.

Catalytic aquathermolysis in situ upgrading and reducing the viscosity of heavy oil in the reservoir remarkably enhances the recovery and is considered as a promising technology. However, the low catalytic efficiency and inferior dispersity in both water and oil limit its applications. In the present work, spherical polymer brush nanocatalysts were synthesized, in which nano-TiO2 is the core and poly­(vinyl imidazole) (PVI)-loading nickel cations are polymer brushes. The chemical characteristics, polymer-grafting content, nickel-loading content, and morphology of as-prepared catalysts were characterized by infrared (IR) spectroscopy, thermogravimetric analysis, inductively coupled plasma optical emission spectrometry, scanning electron microscopy, and transmission electron microscopy. The polymerization degree of PVI was analyzed by proton nuclear magnetic resonance (1H NMR) spectra. The effects of the nickel-loading content, catalytic conditions, and hydrogen donor on the viscosity of heavy oil were studied. The results show that the heavy oil is catalytically cracked by the synthesized catalysts, which leads to the reduction of oil viscosity. The viscosity reduction is enhanced by the increase of the nickel-loading content, catalytic temperature, dosage of catalyst, and hydrogen donor. The rheological behaviors in terms of flow curve, thixotropy, viscoelasticity, and time dependence of cracked oil were studied. To explore the cracking mechanism, the four compositions of heavy oil before and after aquathermolysis were compared. The extracted asphaltenes and resins were further analyzed by elemental analysis, 1H NMR spectra, and IR spectroscopy. The organic compounds in reacted water were characterized by gas chromatography–mass spectrometry. It is found that the content of light saturates is much increased after aquathermolysis, along with the distinct decrease of resins. From the structure change of resins, such as the decrease of hydrogen/carbon and methylene/methyl ratios and increase of aromaticity and aromaticity condensation, the increased light saturates are due to the dissociation of alkyl side chains in resins. In addition, the aromaticity and aromaticity condensation in asphaltenes are found decreased, which is because of the fragmentation and depolymerization of large aromatics. Meanwhile, the loss of oxygen in both asphaltenes and resins is connected with the phenols found in the reacted water, indicating the breakage of the C–O bond and heteroaromatic ring-open reaction in both asphaltenes and resins during aquathermolysis.