Low Temperature Viscosity Research Articles

Viscosity Reduction of Heavy Oil Based on Rice Husk Char-Based Nanocatalysts of NiO/Fe2O3

In recent years, catalytic hydrothermal cracking has gained significant attention as an effective technology for reducing the viscosity of heavy oil in the field of heavy oil recovery. However, the current catalyst temperature window is relatively high, leading to high energy consumption in heavy oil extraction. The development of catalysts that can effectively reduce the viscosity of heavy oil at low temperatures is important to reduce energy consumption in the thermal recovery process of heavy oil. Biochar-based catalysts exhibit good low-temperature activity. Therefore, this study used modified rice husk char as a carrier to develop NiO-RHC, Fe2O3-RHC, and NiO/Fe2O3-RHC catalysts, and investigated their performance in low-temperature catalytic viscosity reduction. Various methods were used to characterize the physical and chemical properties of the catalysts, and the effects of catalyst type and addition amounts on the catalytic viscosity reduction reaction were examined. The results showed that the catalytic performance of the dual-active component catalyst was better than that of NiO-RHC and Fe2O3-RHC. Under the catalysis of NiO/Fe2O3-RHC, the viscosity of heavy oil decreased by 81.81%. As the catalyst addition amounts increased, the viscosity reduction rate of heavy oil also increased. The optimal catalyst addition amount was 1.00wt.%, and the heavy component content in the oil sample was reduced by 4.14% after the catalytic reaction. Finally, the mechanism of heavy oil viscosity reduction was analyzed. It was found that the breaking of C-S bonds was a significant factor in reducing heavy oil viscosity, and the S in H2S mainly came from thioether and sulfoxide sulfur. This study provides valuable references for further research on low-temperature viscosity reduction in heavy oil.

The effect of carbonate assimilation and nanoheterogeneities on the viscosity of phonotephritic melt from Vesuvius

Interaction between magma and carbonate plays a pivotal role in volcanic systems, yet its impact on magma transport properties remains inadequately explored. This study presents novel viscosity data on a leucite-bearing phonotephritic melt from the 472 CE Pollena eruption (Vesuvius, Italy), doped with varying amounts of CaO and CaO + MgO. The compositions match the chemistry of melt inclusions and interstitial glasses from skarns at Vesuvius, which have been interpreted as related to mixing of magma with different amounts of CaO and MgO derived from the host carbonates (limestone and dolostone). Viscosity measurements were conducted at both high (1150–1400 °C) and low temperatures (640–760 °C) by concentric cylinder viscometry, differential scanning calorimetry, and micropenetration methods. Through an integrated approach which combines Brillouin and Raman spectroscopy with the aforementioned techniques, we accurately predict the viscosity changes induced by magma‑carbonate interaction and identify the formation of nanoheterogeneities during low-temperature viscosity measurements. Notably, viscosity models from the literature fail to accurately reproduce our experimental data set at both high and low temperature. In the high-temperature regime, the addition of CaO induces a remarkable viscosity decrease, surpassing that produced by CaO + MgO addition. Furthermore, our findings reveal a significant viscosity/temperature crossover resulting from the addition of CaO and CaO + MgO to the melt phase. Undoped melt exhibits a higher viscosity compared to doped melts above 750 °C, with an inverse trend observed below this temperature threshold. Such rheological constraints may affect the mobility and mixing capability of melts exposed to different levels of carbonate assimilation.

Preparation and characterization of starch carbamate modified natural sodium alginate composite hydrogel blend formulation and its application for slow-release fertilizer

The exploration of environmentally friendly slow-release fertilizer (SRF) based on natural bio-polymers is of great importance in the development of modern agriculture and horticulture. Herein, a novel starch carbamate (SC) modified sodium alginate (SA) hydrogel (SC/SAH) was prepared utilizing as-synthesized SC and natural SA through the cationic ions crosslinking method and ultimately the corresponding slow-release fertilizer (SC/SAH-SRF) was successfully developed by immersing the dried SC/SAH matrix into saturated urea solution. Due to the low gelation temperature and high viscosity of the synthesized SC, the formed SC/SAH exhibits significantly enhanced properties including excellent water absorbency up to 8.02 g/g with considerable repeatability, abundant pore structure and high hydrophilicity compared with the neat SAH and natural starch based hydrogel (NS/SAH). Accordingly, the SC/SAH leads to higher urea loading amount ∼ 1.28 g/g. Importantly, the resultant SC/SAH-SRF also shows superior slow-release performance, yielding a cumulative urea release of only 61.6 % within 10 h and almost completely release >16 h in water, what's more, only 58.5 % of the urea releases within 25 days and exceeding 50 days for complete release in soil column assays. The slow-release of urea from SC/SAH-SRF well complies for the first-order kinetics and accomplishes via a non-Fickian diffusion process. Moreover, the pot experiment demonstrates that the SC/SAH-SRF has higher growth promotion role for the maize seedlings than those of others. Consequently, this work provides a novel strategy for preparing environmentally friendly SRF by blending modified starch and hydrogel.

Effect of Ce2O3 content on structure, viscosity, and melting properties of CaO-Al2O3-MgO-SiO2-Ce2O3 slag

To ensure the reliable operation of high aluminum steel smelting, it is common practice to employ low-reactivity CaO-Al2O3-based slag. Various analytical methods, including scanning electron microscopy with energy-dispersive X-ray spectroscopy, X-ray diffraction, Raman spectroscopy, and so on, are employed to investigate the impact of Ce2O3 content on the crystalline phase and structure within the CaO-Al2O3-MgO-SiO2 slag. Concurrently, the slag properties of viscosity and melting temperature are assessed. The findings reveal that the principal crystalline phases in the CaO-Al2O3-MgO-SiO2 slag include Ca3Al4MgO10, Ca3Al2O6, and MgO. Additionally, the introduction of Ce2O3 leads to the formation of the high melting temperature CaCeAlO4 phase, whose abundance correlates positively with the Ce2O3 content. Ce2O3 demonstrates efficient bridging oxygen bond disruption, causing the transformation of network former [AlO4]-tetrahedron into network modifier [AlO6]-octahedron. Simultaneously, Q4Al shifts to Q2Al and Q3Al in [AlO4]-tetrahedron, resulting in a marked reduction in degree of polymerization of slag. This reduction is evident in decreased viscosity and melting temperature, reaching the minimum value of 0.153 Pa·s and 1331 °C, respectively. However, the Ce2O3 content is beyond 15 wt%, Q2Al and Q3Al transform into Q4Al, which lead to an upward trend in high-temperature viscosity. Furthermore, as the temperature decreases, the precipitation of the CaCeAlO4 phase from the slag occurs. The content and precipitation temperature of CaCeAlO4 increase with rising Ce2O3 content, representing the primary factor behind the elevation of low-temperature viscosity and melting temperature.

Low-temperature rheological properties and viscosity equation of Al/HTPB suspension system

The rheological behavior of propellant slurries is crucial for ensuring the feasibility of the 3D printing process, controlling print quality, regulating performance, and simulating predictions. However, there have been relatively few prior studies on the rheological properties of composite solid propellant slurries at low temperatures, which hinders the application of 3D printing propellant technology under extreme temperature conditions. In addition, the use of 3D printing technology to manufacture propellants at low temperatures is advantageous for improving safety. This paper investigates the rheological properties of monodisperse systems with aluminum powder as a solid filler and end-hydroxy polybutadiene (HTPB) as the dispersed phase at low temperatures (−15∼10 °C). It explores the effects of solid content, temperature, and particle size on their rheological properties. Results show that the viscosity of the system in the range of −15∼10 °C increases exponentially with the decrease in temperature, and the viscosity at −15 °C increases by 616.90 % compared with that at 10 °C when the volume fraction (φ) of Al-1 is 35.8 %; the larger size of the particles the larger the viscosity is when the temperature and φ are the same, which is interpretes in terms of interfacial properties between the systems. The low-temperature correction factor is introduced into the Einstein-Roscoe equation to obtain the modified viscosity-volume fraction equation, and the correction factor is 0.0173, as evidenced by its excellent agreement with the experimental data.

Determination of Wax Deposition Rate Model of Blended Oils with Different Blending Ratios

Blending with light oil is a commonly used and reliable method of crude oil transportation, and the blending ratio is a crucial operating parameter in determining the safe and efficient operation of the pipeline. In this paper, in-house flow and deposition experiments are used to evaluate the flow and deposition characteristics of crude oils with varying blending ratios. The results show that (1) blending with light oil basically does not affect the shape of the DSC curve of crude oil; (2) blending with light oil will not eliminate the thermal treatment effect, and the mixed oil flowability still remains highly dependent on the thermal treatment temperature; (3) blending with light oil can greatly decrease the abnormal point and oil viscosity, in which the low-temperature viscosity decreases more significantly; and (4) a wax deposition model of mixed oil is obtained through the fitting of Huang’s model, where the blending ratio is a crucial factor in the determination of the model parameters k, m, and n.

TDA/rGO@WS with Joule heat and photothermal synergistic effect: A promising adsorption material for all–weather recovery of viscous oil spills at sea

Oil spills are a global environmental protection challenge, and traditional adsorption materials have poor effect on low temperature and high viscosity marine oil spills. This article reports composite adsorption materials TDA/rGO@WS for viscous oil spills: loaded with rGO/TDA coating on a commercial biomass wood pulp sponge (WS), achieving Joule heating, photothermal effect and hydrophobic modification. The results showed that the TDA/rGO@WS has good photothermal conversion ability and Joule heating ability, and the temperature increased to 83.7 °C and 148 °C, respectively, under simulated solar irradiation and additional voltage at room temperature. The efficiency of adsorption at a low temperature of 5 °C increased by 22.41% at 1 sun and by 51.53% at 10 V. Temperature effectively reduced the viscosity of the offshore oil spill and ensures the efficient adsorption of oil spills at low temperatures promoted. The TDA/rGO@WS also showed good hydrophobicity (WCA=129°), excellent efficiency of water–oil separation (99.53%) and good adsorption capacity (9.4–13.68 g/g) for marine fuel oils. TDA/rGO@WS effectively solves the problem of cleaning up high–viscosity oil spills from ships in winter and polar waters, and proposes a new strategy for all–weather efficient treatment of oil spills at sea.

Thermal properties and thermodynamic model of lithium doped 45S5 bioglass

AbstractShakhmatkin and Vedishcheva thermodynamic model (SV TDM) of the 45S5 Bioglass® doped with three different amounts of Li2O (4.1, 9.9, and 12.3 mol%) was evaluated at T = 800 K. The 55 components of SV TDM were considered, among them 12 lithium containing compounds. Different number of components with not negligible equilibrium molar amount was found for different glass compositions (9 or 10). In all glass compositions containing nonzero amount of Li2O, the four lithium compounds with not negligible equilibrium amount were identified, i.e., Li2O·SiO2, 3Li2O·P2O5, Li2O·2CaO·2SiO2, and 2Li2O·SiO2. In the 45S5 glass composition four phosphate compounds with not negligible abundance were identified: 9Na2O·6SiO2·2P2O5, Na2O·2CaO·P2O5, 5Na2O·4SiO2·P2O5, and Na2O·CaO·P2O5. In all other glasses the 3Li2O.P2O5 was found with not negligible abundance. Moreover, in the glass with 4.1 mol% Li2O the Na2O·2CaO·P2O5 and 3Li2O·P2O5 compounds were found with not negligible abundance. For each studied glass the glass transition temperature, coefficient of thermal expansion of glass and metastable melt were measured by thermodilatometry. The low temperature viscosity was measured by thermomechanical analysis. The viscous flow activation energy was evaluated from the viscosity temperature dependence. The compositional dependence of measured thermal properties was analyzed by correlation analysis with the Q-distribution of silicate and phosphate units.

Extended fuel properties of sustainable aviation fuel blends derived from linalool and isoprene

Seven different sustainable aviation fuel blends were prepared with hydrocarbons derived from terpenoid precursors. The first, designated as L-Jet, was formulated with various molecules produced from linalool (a terpene alcohol) including hydrogenated methylcyclopentadiene dimers, p-menthane, 2,6-dimethyloctane, and hydrogenated isobutylene trimers. L-Jet was also blended with a synthetic paraffinic kerosene derived from fatty acids and esters (HEFA-Jet) as well as Jet-A. The other four sustainable aviation fuel blends consisted of either Jet-A or HEFA-Jet mixed with cyclic hydrogenated isoprene dimers that can be readily produced from the bio-based hemiterpene, isoprene. To determine the suitability of these blends as surrogates for conventional jet fuel, a number of properties including density, low temperature viscosity, heat of combustion, flashpoint, corrosion, smoke point, conductivity, simulated distillation, existent gum, lubricity, thermal stability, and derived cetane number were measured. The 100 % SAF blends exhibited higher gravimetric heats of combustion and higher smoke points (less soot) compared to the blends with Jet-A. Several of the blends met American Society of Testing and Materials (ASTM) requirements, suggesting that they are promising candidates for certification as next generation aviation fuels.

NMR based experiment of fluid invasion to natural gas hydrate reservoir and hydrate dissociation inhibition mechanism

Hydrate dissociation inhibition has an important bearing on drilling safety for natural gas hydrate exploitation. A low-field NMR-based experimental method is developed for characterizing the hydrate dissociation inhibition effect during fluid invasion to hydrate-bearing sediment. The hydrate core sample is prepared by excess-gas method, and deionized water or hydrate dissociation inhibitor solution was injected at constant flow rate. In the presence of hydrate dissociation inhibitor, the invasion area is significantly reduced, and invasion fluid saturation was kept at 30 % instead of 80 % compared to water. Experimental techniques were used to reveal hydrate dissociation inhibition mechanism. Hydrate dissociation inhibitor at 1 % can reduce the thermal conductivity of aqueous solution from 0.5870 W·m−1·K−1 to 0.5710 W·m−1·K−1 at 4 °C, and increase the low-temperature apparent viscosity from 1 mPa·s to 10 mPa·s, reducing the heat and mass transfer ability of drilling fluid with hydrate reservoirs. The surface tension of water was decreased from 72.8 mN·m−1 to 59.94 mN·m−1, which is conducive to the multi-point adsorption of inhibitors at the hydrate interface. The water activity was reduced from 1.000 to 0.985, showing little effect on the equilibrium temperature of hydrate phase. This work showcases the significance of hydrate dissociation inhibition during fluid invasion to hydrate-bearing sediment.

Synthesis and characterization of high-density biosynthetic fuels from myrtenal

Apopinene was synthesized from myrtenal by catalytic decarbonylation followed by either hydrogenation to generate dihydroapopinene or Simmons-Smith cyclopropanation to generate exo-(1R,2R)-7,7-dimethyltricyclo[4.1.1.02,4]octane (cyclopropanated apopinene, CPA). Key fuel properties of apopinene and the two derivative fuels were evaluated including density, heat of combustion, and low temperature viscosity. CPA exhibited a density of 0.918 g mL−1 and a volumetric net heat of combustion (NHOC) 20 % higher than the lower limit for conventional jet fuel. This exceptional NHOC is a result of the high density of the tricyclic compound and the ring strain of the bridging cyclobutane and fused cyclopropane groups. Dihydroapopinene exhibited a high freezing point that will limit its applications as a jet fuel blendstock. In contrast, no freezing point down to −80 °C was observed for CPA via differential scanning calorimetry (DSC). In addition, CPA exhibited a moderate kinematic viscosity of 10.11 mm2 s−1 at −20 °C and 22.76 mm2 s−1 at −40 °C. This work demonstrates that fuels with both high energy densities and excellent low temperature properties can be generated from bio-based substrates through cyclopropanation reactions.

Effect of nanocomposite pour point depressant EVAL/CNT on flow properties of waxy crude oil

The nanocomposite EVAL-CNT was produced by chemical grafting in the solution system through the esterification of ethylene-vinyl alcohol copolymer (EVAL) and carboxylated multi-walled carbon nanotubes (O-MWCNT), and its structural properties were characterized. The improvement of the rheological properties of the waxy oil system by the novel pour point depressant was investigated using macroscopic rheological measurements and microscopic observations. The results showed that EVAL-CNT nanocomposite pour point depressant (PPD) could significantly reduce the pour point and improve the low temperature fluidity of crude oil and had better performance than EVAL-GO at the same addition level. The best effect was achieved at the dosing concentration of 400 ppm, which reduced the pour point by 13 °C and the low-temperature viscosity by 85.4%. The nanocomposites dispersed in the oil phase influenced the precipitation and crystallization of wax molecules through heterogeneous crystallization templates, which led to the increase of wax crystal size and compact structure and changed the wax crystal morphology, which had a better effect on the rheological properties of waxy oil.

Key melt properties for controlled synthesis of glass beads by aerodynamic levitation coupled to laser heating

AbstractBinary alkali silicate glasses were synthesized as beads by aerodynamic levitation coupled to laser heating to test the applicability of the method to this compositional range. While bubble‐free lithium disilicate beads could be easily obtained, sodium and potassium silicates proved more challenging to melt without significant alkali evaporation: the final samples contained bubbles and exhibited compositional drifts compared to the starting stoichiometry, especially at high SiO2content. The risk of volatilization from the melts was evaluated empirically: the volatility of each oxide component scaled to the ratio between its melting temperatureTmand theTmof the target composition (revap), while the difference between such ratios (Δevap) provided a qualitative estimation of the risk of differential evaporation. The formulated approach enables to evaluate the suitability of aerodynamic levitation synthesis for a given target glass composition: while low melting temperature and low liquidus viscosity (η < 100 Pa s) represent the primary optimal conditions, more viscous materials can still be prepared without major compositional drifts using a more careful melting procedure, especially ifrevapandΔevapare minimized.

Comparative Study between a Copolymer Based on Oleic Acid and Its Nanohybrid for Improving the Cold Flow Properties of Diesel Fuel.

The as-synthesized copolymer based on the prepared monomers and its nanohybrid were used for improving the cold flow of diesel fuel that has a vital role in meeting energy needs. The copolymer (AE) was created using the prepared monomers, by free radical solution polymerization of the prepared hexadecylmaleamide and octyloleate ester, and the polymer nanohybrid (NH) was created by emulsion polymerization of the same monomers with 1% nano-SiO2. The chemical structures of the copolymer and its nanohybrid were proved by Fourier transform infrared spectroscopy (FTIR), 1H NMR, dynamic light scattering (DLS), and transmission electron microscopy (TEM). Through exploring the effect of the nanohybrid, before and after adding the dosage of the additives to the diesel fuel, the pour point temperature (PPT), rheological characteristics, and viscosity index were measured. The data were the best for the nanohybrid; the PPT decreased from -3 to -36 °C upon adding 10,000 ppm nanohybrid but decreased from -3 to -30 °C for 10,000 ppm copolymer. In addition, the efficiency of the additives was proved by viscosity-shear rate and shear rate-shear stress curves to give the apparent viscosity, which decreased from 124 cP for the blank to 15.74 and 12.8 cP for AE and NH, respectively; also, the yield stress decreased from 576 D/Cm2 for the blank to 541.44 and 477.9 D/Cm2 for AE and NH, respectively, at room temperature. The viscosity index increased from 116 for the blank to 119 and 121 for the copolymer and the nanohybrid, respectively. Polarizing optical microscopy was performed to show more tiny and separated wax upon adding the additives. The findings showed that delayed crystal precipitation and altered crystal shape with the NH and AE greatly reduced low-temperature viscosity and enhanced the cold flow characteristics of the diesel fuel.

Designer Biosynthetic Jet Fuels Derived from Isoprene and α-Olefins

Isoprene was hydrovinylated with a series of α-olefins (1-pentene, 1-hexene, 1-heptene, 1-octene) to produce acyclic branched C10–C13 alkenes. The process utilized CoBr2(DPPE) as the precatalyst in loadings as low as 0.1 mol % and zinc as the reducing agent. Use of the cobalt catalyst resulted in primarily 1,4-addition, with carbon coupling at the 4-position of isoprene. A significant amount (∼20%) of the coupling products at the 1-position of isoprene was also observed. Each of the discrete C10, C11, C12, and C13 products were then hydrogenated with 10% Pd/C (200 °C; 650 psi H2) to yield jet fuel blendstocks. In addition to the reactions with pure α-olefins, an equimolar mixture of the C5–C8 α-olefins was used to mimic a stream of olefins produced from ethanol dehydration/oligomerization or Fischer–Tropsch catalysis. The different fuel blends exhibited densities ranging from 0.73 to 0.76 g mL–1, gravimetric net heats of combustion (NHOC) from 43.91 to 44.13 MJ kg–1, and −20 °C kinematic viscosities from 2.4 to 6.3 mm2 s–1. The NHOC values were ∼2.9% higher than the lower limit for Jet-A, while the low-temperature viscosities were up to 70% lower than the upper limit for Jet-A. In addition to studying the suitability of the lightly branched hydrocarbons generated in this process as jet fuel blendstocks, it was of interest to explore their potential as diesel fuels. The equimolar C10–C13 fuel mixture exhibited a derived cetane number (DCN) of 56, which is 16 units higher than that required for Diesel #2 (40). The outstanding fuel properties of the isoprene-derived fuels suggest that they have applications as replacements for both petroleum-derived Jet-A and Diesel #2.

Monomethyl branched-chain fatty acids enriched bacterial oil production by furan aldehydes tolerant halophile Lentibacillus salarius strain BPIITR using non-detoxified sugarcane bagasse

The structural diversity of monomethyl branched-chain fatty acids (mBCFAs) expanded their application in biolubricants, biofuels for enhancing cold flow and thermo-oxidative properties. Current study focuses on mBCFAs production from sugarcane bagasse hydrolysate in biorefinery approach with halophilic Lentibacillus salarius BPIITR. Halophilic bacterium exhibited tolerance towards furan aldehydes up to 150 mM in minimal medium and produced 3.40 ± 0.13 and 2.47 ± 0.15 gL−1 lipid rich in mBCFAs, in xylose and glucose rich non-detoxified hydrolysate, respectively at bench-scale bioreactor. In addition, 2,5-furandicarboxylic acid and 2-furancarboxylic acids were co-produced as value-added products up to 41.34 ± 4.73 and 59.84 ± 5.17 mM, respectively. The biosynthesized bacterial oil exhibited onset oxidation temperature of 319.5 °C and low temperature viscosity ratio of 2.92. The accumulated lipid was rich in triacylglycerol content more than 67 % with 12-methyl tetradecanoic acid as major fatty acid.

Synthesis and fuel properties of high-density and low-freezing-point asymmetric cycloalkyl adamantane

The exploration to increase the fuel energy density is stimulated by the payload and cruising range concerns in aerospace industry. The high-density fuels are always rationally designed for the advanced volume-limited aircrafts to fulfill more complicated missions. Alkyl adamantanes gradually become a prospective class of high-energy-density fuels. Herein, in this work, we reported an approach to synthesize asymmetric cyclopentyl adamantane via AlCl3-catalyzed alkylation of adamantane and cyclopentene with an attractive combination of a high density of 0.990 g/mL as well as a low freezing point of −30 °C. The obtained 1-cyclopentyl-adamantane was well designed with the cyclic substituent (enhance the density) and asymmetric structure (lower the freezing temperature). Subsequently, the comprehensive fuel performance of cyclopentyl adamantane, i.e., density, freezing point, low-temperature viscosity, heating value, and combustion properties were evaluated. It was shown that both density and combustion properties of cycloalkyl adamantane were superior to the typical high-density JP-10 fuel. In addition, the properties of binary fuel mixture (1-cyclopentyl-adamantane and JP-10) demonstrated that cyclopentyl adamantane could be used as a promising blendstock with conventional jet fuel to enhance the energy density and promote the combustion performance of the final fuel blends.

Capsulated phase-change materials containing paraffin core/polymethyl methacrylate shell: Thermoregulation modifier for asphalt binder

The paraffin/polymethyl methacrylate capsulated phase-change material (CPCM) with 55–56 °C phase transition temperature was synthesized via in-situ polymerization, and its applicability in asphalt binder was investigated by conducting various experiments. The CPCM possesses spheric morphology, with an initial decomposition temperature as high as 185.2 °C, with melting enthalpy of 128.13 J·g−1, exhibiting remarkable thermal stability. Therefore, the thermoregulation efficiency of CPCM for asphalt and the impact of CPCM on the physical properties, storage stability and rheological performance of asphalt binder were further investigated. The thermoregulation result shows that the maximum temperature difference between matrix asphalt and modified asphalt can reach 7.5 °C during the heating process. The heating rate of modified asphalt remarkably reduced at the temperature range of 47–55 °C due to the phase transition of CPCM. Additionally, the addition of CPCM slightly affected the softening point and penetration of asphalt while reducing the low-temperature ductility and viscosity. Furthermore, the softening point difference and rheological segregation index can be reached at 1.7 and 1.43, respectively, when the content of CPCM was 9 %, indicating poor compatibility between CPCM and matrix asphalt. Dynamic shear rheometer (DSR) results reveal that the addition of CPCM increased the elastic components in asphalt. Besides, the G*/sin δ of all the modified asphalt was higher than matrix asphalt during the phase transition temperature range, demonstrating the dramatic improvement in the rutting resistance of the asphalt binder.

Study on low-temperature plasma γ-Al2O3 catalytic viscosity reduction of polyacrylamide solution.

The wide use of polyacrylamide (PAM) in enhanced oil recovery generates a large amount of polymer-bearing wastewater featuring high viscosity and difficult viscosity reduction, making the treatment of wastewater increasingly difficult. In this paper, the experimental study on reducing the viscosity of wastewater containing polyacrylamide by using the plasma generated by dielectric barrier discharge (DBD) and the synergistic effect of catalyst γ-Al2O3 is carried out. The law of plasma reducing the viscosity of wastewater containing polyacrylamide is studied under the different conditions of amounts of γ-Al2O3 catalyst, discharge voltages, and initial concentrations of polyacrylamide-containing wastewater. The mechanism of viscosity reduction of polyacrylamide is studied through environmental scanning electron microscope (ESEM), Fourier transform infrared (FTIR) spectrometer, and X-ray photoelectron spectroscopy (XPS). The results show that the catalytic viscosity reduction is the best when the discharge voltage is 18kV and the discharge time is 15min. With the increase in the input of the γ-Al2O3 catalyst, the viscosity of the PAM solution decreases gradually. When the amount of γ-Al2O3 is 375mg, the shear rate changes from 0.5 1/sec to 28 1/sec, and the viscosity of the solution containing polyacrylamide changes from 434.5mPa·s to 40.2mPa·s. The viscosity reduction rate of the PAM solution is 90.7%. After the catalytic viscosity reduction, the functional groups of polyacrylamide do not change much. The elemental composition of the catalyst has not changed, which is still Al, C, and O.

Micro-Raman spectroscopy for a comprehensive understanding of the structural evolution of Basaltic-Andesite and Trachybasalt multiphase systems

The liquid viscosity of multiphase systems is usually retrieved by the use of combined chemical analysis and empirical chemistry-based models. Here we present an alternative approach to study the glassy pools in highly crystallized basaltic-andesite and trachybasalt samples obtained from isothermal crystallization experiment at different shear rates. Polarized micro-Raman spectra were collected at room temperature on the glassy portions. Results of residual glass structures from the high frequency region of Raman spectra show an increasing polymerization degree. The fragility, derived from the evolution of the boson peak, decreases according to the experimental time evolution. Also, the presence of nanolites in residual glasses adds a further degree of complexity that needs to be considered in the frame of melts polymerization and rheological behavior of volcanic systems. On this concern, the MYEGA formalism approach allows to retrieve the residual melt viscosity of the partly crystallized samples, avoiding its direct measurement and reducing the errors induced when general viscosity models, based only on chemical data, are used. We validated our prediction by determining the low-temperature viscosity data converting, through known shift factors, the thermograms obtained by differential scanning calorimetry. This study provides a further route in characterizing multiphase systems, also including the effect of nanosized crystals, and offers the possibility of increasing the spatial resolution through microscopy and ridding viscosity parametrizations of invasive and time-consuming operations.