Excellent Temperature Resistance Research Articles

Synthesis, investigation of temperature and salt resistant polyacrylamide microspheres used for deep sealing and profile control and function strengthening mechanism

AbstractBased on the requirements of deep sealing and profile control for the excellent temperature and salt resistance on polyacrylamide microspheres, the Poly‐AM/AMPS was prepared depends on aqueous solution polymerization method to improving oil and gas recovery efficiency in low‐permeability and heterogeneous reservoirs resulted by water channeling. The key technical parameters were established through single‐factor experimental methods, and the chemical structure was studied by infrared spectrum analysis (FTIR), energy spectrum analysis, and x‐ray diffraction analysis, and then the thermal stability was investigated depends on the thermogravimetric (TG) and differential thermogravimetric (DTG) distribution curves, moreover, the particle size and distribution, microstructure, and surface morphology were further studied. As a result, the results confirmed that the molecular structure of Poly‐AM/AMPS meets the expected design, and the quality retention rate at 800°C is 17.4%, the median particle size of Poly‐AM/AMPS particles is 35.88 μm, and the particle size distribution range is about 1.94–497.8 μm. Further, the Poly‐AM/AMPS was modified by maleic anhydride, sodium styrenesulfonate, and dimethyl diallyl ammonium chloride through conventional functional strengthening and modification, modified by nano‐SiO2, GO, and S‐CaCO3 through nano‐functional strengthening and modification. Additionally, the functional strengthening and modification mechanism was studied depends on the FTIR, TG, and DTG methods.

Solvent and low temperature resistant natural polyphenolic adhesives

The development of robust and bioinspired adhesives with excellent performances including fast gel time, low cost, good adhesion strength and stability, and excellent solvent and temperature resistance against harsh environment is urgent for practical applications. In this paper, kinds of natural polyphenolic adhesives have been successfully fabricated via the multiple polyphenol-diisocyanate cross-linking (PDC) reactions between natural polyphenols (extracts) and diisocyanate molecules. Under heating, as-prepared adhesives could effectively adhere onto a wide range of substrates (i.e. PTFE, PET, PMMA, Al, Cu, paper, glass, wood) through hierarchical interactions. Moreover, these adhesives exhibited great adhesion stability against complex solvents and low-temperature environments, whose adhesion strength could remain unchanged after soaking solvents after 30 days, which was conducive to their potential applications in industry and chemical fields, including petroleum, wood, metal, glass, plastics, and rubber adhesion. We believed that this work would provide new strategies towards the preparation of robust adhesives with excellent resistant against various solvents and low temperature for many fields by using naturally occurring building blocks.

A strong stability gel foam for water shutoff during oil and gas reservoir development

In view of the short effective period of conventional foam for water shutoff during oil and gas reservoir development, a strong stability gel foam system is proposed in this work. By comparing the foam properties of different foaming systems, the optimized formulation of foam system is “0.3% SDS (sodium dodecyl sulfate) + 0.4% HPAM (partially hydrolyzed polyacrylamide) + 0.3% SD-107 (organic chromium).” At 50 °C and 10 000 mg/l salinities, the volume of foam is basically unchanged after a short time of defoaming and finally remains above 70%, and the drainage half-life can reach 16 days. The polymer and crosslinker form a stable three-dimensional network structure on the Plateau boundary after foaming, which has good viscosity and viscoelasticity. The foam system has excellent temperature and salt resistance. It is appropriate for medium and low temperature shallow reservoirs. The foam system has a good plugging efficiency. It can effectively plug the fracture and improve the sweep volume, which has a good application prospect.

An Environment-Tolerant Ion-Conducting Double-Network Composite Hydrogel for High-Performance Flexible Electronic Devices

HighlightsNovel double-network (DN) ion-conducting hydrogel (ICH) based on a poly(ionic liquid)/MXene/poly(vinyl alcohol) system (named PMP DN ICH) was synthesized using freeze–thawing and ionizing radiation technology.The PMP DN ICH possesses a multiple cross-linking mechanism and exhibits outstanding ionic conductivity (63.89 mS cm−1), excellent temperature resistance (−60–80 °C) and decent mechanical performance.The well-designed PMP DN ICH shows considerable potential in wearable sensing, energy storage, and energy harvesting.

In situ high-valued transformation of nonmetals in waste printed circuit boards into supercapacitor electrodes with excellent performance.

Nonmetals in waste printed circuit boards after metal separation containing brominated resin and fiberglass are considered hazardous and low-recoveryvalue e-waste. However, if these nonmetals are not treated or are improperly treated, they can cause serious environmental pollution. Therefore, there is an urgent and significant need to develop an efficient recycling process for these nonmetals. Based on the concept of high-valued recycling of waste, this study in situ utilized such nonmetals to prepare a porous supercapacitor electrode through a facile carbonization, activation, and carbon thermal reduction process. The results indicated that the activation was a key role in constructing a porous structure. The optimal parameters for activation were a temperature of 800 °C, mass ratio of KOH to pyrolytic residues of 2, and an activation time of 1 h. The electrode materials exhibited a surface area of 589 m2 g-1 and hierarchical porous structures. In addition, the supercapacitors exhibited a capacitance of 77.14 mF cm-2 (62.5 mF cm-2) at 0.5 mA cm-2 (100 mV s-1). Moreover, the supercapacitors had excellent temperature resistance and adaptability. The capacitance retention was 89.36% and 90% at -50 °C and 100 °C after 10 000 cycles, respectively. This study provides a high-valued recycling strategy to utilize the nonmetals in e-waste as energy materials.

Constructing self-healing flexible supercapacitors using a graphene oxide synergistic multi-network polymer-supramolecular hydrogel electrolyte

The prepared PAM/CMCS/PEG/GO hydrogels have excellent self-healing and temperature resistance, and the FSC has good electrochemical properties.

Compound Anionic–Nonionic Surfactant System with Excellent Temperature and Salt Resistance for Enhanced Oil Recovery

Compound Anionic–Nonionic Surfactant System with Excellent Temperature and Salt Resistance for Enhanced Oil Recovery

High performance MOF UiO-66 membranes for MeOH/MTBE separation

The preparation of high-performance polycrystalline MOF membranes for MeOH/MTBE separation poses a challenge. In this study, intact 400 nm thick UiO-66 membranes with well-controlled structures were successfully fabricated using a novel formulation. The high ligand/metal ratios and the new zirconium sources provide ideas for designing UiO-66 membranes with effective pore structures. Consequently, the membranes exhibited an exceptional pervaporation performance, achieving a flux of 5.68 kg m−2 h−1 and a separation factor of 28000 for MeOH/MTBE (5/95 wt/wt.%) at 40 °C. Further, the UiO-66 membranes have excellent temperature and concentration resistance and remain stable during 120 h of operation. The high pervaporation performance, along with this stability, demonstrates that this UiO-66 membrane is a competitive candidate for MeOH/MTBE separation.

An Amphiphilic Multiblock Polymer as a High-Temperature Gelling Agent for Oil-Based Drilling Fluids and Its Mechanism of Action.

Oil-based drilling fluids are widely used in challenging wells such as those with large displacements, deepwater and ultra-deepwater wells, deep wells, and ultra-deep wells due to their excellent temperature resistance, inhibition properties, and lubrication. However, there is a challenging issue of rheological deterioration of drilling fluids under high-temperature conditions. In this study, a dual-amphiphilic segmented high-temperature-resistant gelling agent (HTR-GA) was synthesized using poly fatty acids and polyether amines as raw materials. Experimental results showed that the initial decomposition temperature of HTR-GA was 374 °C, indicating good thermal stability. After adding HTR-GA, the emulsion coalescence voltage increased for emulsions with different oil-to-water ratios. HTR-GA could construct a weak gel structure in oil-based drilling fluids, significantly enhancing the shear-thinning and thixotropic properties of oil-based drilling fluids under high-temperature conditions. Using HTR-GA as the core, a set of oil-based drilling fluid systems with good rheological properties, a density of 2.2 g/cm3, and temperature resistance up to 220 °C were constructed. After aging for 24 h at 220 °C, the dynamic shear force exceeded 10 Pa, and G' exceeded 7 Pa, while after aging for 96 h at 220 °C, the dynamic shear force exceeded 4 Pa, and G″ reached 7 Pa. The synthesized compound HTR-GA has been empirically validated to significantly augment the rheological properties of oil-based drilling fluids, particularly under high-temperature conditions, showcasing impressive thermal stability with a resistance threshold of up to 220 °C. This notable enhancement provides critical technical reinforcement for progressive exploration endeavors in deep and ultra-deep well formations, specifically employing oil-based drilling fluids.

Synthesis and properties of self‐healing hydrogel plugging agent

AbstractThe P(AM‐co‐AMPS)/SA DN hydrogel was synthesized through aqueous polymerization in this study. It formed a crosslinking network with hydrophobic associations between acrylamide (AM) and lauryl methacrylate (LMA), as well as an ionic bond network involving sodium alginate and Ca2+. To enhance its high‐temperature resistance, 2‐acrylamide‐2‐methylpropane sulfonic acid (AMPS) was incorporated into the hydrogel formulation. The structure of the hydrogel was characterized using Fourier transform infrared spectrometer (FTIR), thermogravimetric analyzer (TGA), and scanning electron microscopy (SEM) techniques. Results demonstrated that the hydrogel exhibited excellent temperature resistance and possessed a porous structure. Mechanical testing revealed a high tensile strength of 110 kPa, elongation at break of 995.31%, along with good fatigue resistance and self‐recovery performance during multiple cyclic stretching. Healing experiments indicated that the healing strength of the hydrogel was influenced by temperature variations. Furthermore, pressure plugging tests were conducted on steel models with crack widths of 0.5 and 1 mm, respectively; it was found that the 0.8%P(AM‐co‐AMPS)/SA DN hydrogel could withstand pressures up to 4.5 MPa at a temperature of 70°C. This novel hydrogel material exhibits remarkable mechanical properties along with certain self‐healing capabilities, making it suitable for leak control applications.

Preparation of carbon-based active nanofluids with temperature and salt resistance for enhanced oil recovery

The abundant hydrophilic surface groups endow carbon-based nanoparticles (CDs) with intrinsic great dispersibility, however, the strong hydrophilicity limits the oil–water interface activity, restraining the performance in enhanced oil recovery. Developing CDs with simultaneously ultra-small sizes, high temperature and salt tolerance, as well as superior interfacial activity is of great significance. In this work, CDs with the size of 3.3 nm and excellent temperature and salt resistance were prepared by hydrothermal reaction, using citric acid (CA) and ethylenediamine (EDA) as precursors. Carboxyl ether carboxylate-6Na (APEC-6Na) was selected as the compound agent to construct carbon-based active nanofluids (CANs) with excellent oil–water and oil-solid interfacial activities. CANs can reduce the oil–water interfacial tension to 8.9 × 10-4 mN m−1, withstand a temperature up to 90°C and a salinity up to 6.3 × 104 mg·L-1. Even at the highest tolerant salinity, the underwater oil contact angle of 155° can be achieved, demonstrating excellent wettability control capability, which could be attributed to the synergistic effect of the compound CANs system. The increase of the contact angle of underwater oil droplets facilitates the coalescence of oil film on the lipophilic surface to form oil droplets. The electrostatic repulsion generated by the adsorption of CDs and APEC-6Na at the oil–water interface and rock surface makes the coalesced oil droplets more easily detached from the rock surface, and the oil film reduction rate exceeds 97.7 % within 24 h. The excellent oil–water and oil-solid interface properties and the structural separation pressure endows CANs with remarkable performance in core displacement experiments. Compared with simulated formation water, CANs can improve the recovery rate by 26.3 %, exhibiting important application value for improving the recovery rate of ultra-low permeability reservoirs.

Enhancing structural and magnetic properties of BaFe12O19 nanoparticles through co-substitution (Co-Mn): A promising approach for permanent magnet applications

In-depth study into the creation and improvement of rare-earth free permanent magnets, particularly ferrites, has been sparked by recent economic and environmental concerns. M-type barium hexaferrites (BaFe12O19, pure BHF) are a class of low-cost permanent magnets with an excellent curie temperature and good resistance to oxidation and corrosion that are significant from a technological perspective. In the current study, the experimental conditions are optimized to obtain barium hexaferrite (BaFe12O19) co-substituted with transition elements (Co and Mn) (BaFe12–2xCoxMnxO19) via the chemical co-precipitation method. In this framework, different substitution possibilities will be investigated. The structure, morphology, vibrational spectrum, and thermal stability of the generated nanoparticles were revealed using powder x-ray diffraction (XRD), transmission electron microscope (TEM), Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). Rietveld refinement was used to estimate the average bond length and bond angle in order to determine the impact of superexchange interaction. Based on more precise structural characteristics, the atomic occupation and distribution of bonds are depicted from their charge density graph. For all the synthesized materials, the maximum energy product (BH)max and magnetic characteristics (VSM) were also investigated. The potential causes of this phenomenon were examined and discussed at length.

Production of xylo-oligosaccharides with degree of polymerization 3–5 from wheat straw xylan by a xylanase derived from rumen metagenome and utilization by probiotics

In this study, a new xylanase gene (RuXyn) was obtained from a rumen metagenome and heterologously expressed in Escherichia coli to produce xylo-oligosaccharides (XOS) as a prebiotic. RuXyn, which belongs to the glycosyl hydrolase 10 (GH10) family, exhibited maximum activity at pH 6.0 and 50 °C, with excellent temperature resistance at 30–50 °C. RuXyn showed preferential hydrolysis of xylan, especially rice straw xylan. RuXyn activity was significantly increased in the presence of 5 mM dithiothreitol, 0.5% Tween-20, and 0.5% Triton X-100 (31%, 37%, and 43%, respectively). Reaction time (10, 15, 30, and 45 min) and dosage (0.15, 0.31, and 0.62 U) of RuXyn affected XOS yield and composition, with a maximum yield at 0.62 U and 30 min. The primary degradation products of wheat straw xylan, resulting from RuXyn activity, were xylotetraose, xylotriose, and xylopentose, which accounted for 33.4%, 33.0%, and 26.4% of the total sugar yield, respectively. The prebiotic effects of XOS were evaluated by in vitro fermentation of XOS using known probiotic Bifidobacterium bifidum and Levilactobacillus brevis strains. Results showed that regardless of incubation time and XOS concentration, XOS stimulated the growth and xylanolytic enzyme secretion of the two probiotics compared to the controls. Supplementation with XOS significantly enhanced lactate production in B. bifidum and L. brevis. Thus, these results indicate that RuXyn is capable of hydrolyzing wheat xylan to produce XOS with a degree of polymerization 3 and 5 and to subsequently promote the growth of probiotics.

Multicomponent Si–Zr-based lightweight nanofiber films with a hollow structure exhibiting excellent thermal insulation properties

Hollow-structured ceramic fibers with multiple components are ideal as lightweight insulation materials. In this study, tetraethyl orthosilicate, boric acid, and zirconia octahydrate were used as raw materials for fabricating SiZrBOC hollow ceramic fibers through coaxial electrospinning. These ceramic fibers exhibit a low thermal conductivity and an excellent temperature resistance. The electrospun SiZrBOC hollow ceramic fibers display a clean and compact morphology with internal folds. Fourier-transform infrared spectroscopy and thermogravimetric analysis (TGA) were used to assess the transformation process and thermal behavior of the hollow ceramic fibers. The results suggest that the incorporation of B promotes the formation of Si–O–B bonds within the system, leading to a maximum yield of 75.49 wt% for the production of the SiZrBOC hollow ceramic fibers. The phase composition and microstructure of the SiZrBOC hollow ceramic fibers were analyzed via X-ray diffraction (XRD) measurements. The pyrolysis at 1000 °C resulted in the appearance of diffraction peaks corresponding to SiO2 and SiC in the XRD patterns of the SiZrBOC hollow ceramic fibers. Laser thermal conductivity measurements reveal that the SiZrBOC hollow ceramic fibers exhibit a thermal conductivity of only 0.06 W‧m−1K−1 at 25 °C and 0.124 W‧m−1K−1 at 500 °C, indicating a significantly superior thermal insulation performance compared with conventional solid SiZrBOC ceramic fibers.

Machine Learning Technique to Predict Flashover Voltage of Nanocomposite Materials

Epoxy resin is frequently employed in medium- and high- voltage transmission insulation, because of its low dielectric losses and excellent temperature resistance. At low temperatures, epoxy resin has high chemical resistance. Epoxy resin insulated types have largely superseded the conventional, paper-insulated varieties in numerous cable sectors owing to several advantages. Numerous studies have been conducted to enhance the properties of epoxy resin. With the addition of silicon dioxide (SiO2) nanofiller, the electrical and physical properties of epoxy resin are intended to be improved in this research. Epoxy resin composites with SiO2 filler were created with lengths of 5, 10, 15, and 20 mm and concentrated at 7wt%. Subsequently the key findings of this research are outlined, highlighting the significance of this study's focus on polymer utilized in the highly competitive and technologically advanced power industry, which is used globally.

Polymeric ultralong organic phosphorescence with excellent humidity and temperature resistance via hydrophobic effect

AbstractPolymeric ultralong organic phosphorescence (UOP) with persistent emission is of great importance in practical applications. However, achieving good water‐resistance for long‐term environmental stability is a formidable challenge. In this contribution, through tailoring the alkyl‐chain length of the hardeners and emitters, polymeric UOPs with varying crosslinking density and hydrophobic effect were obtained. Notably, all the polymers show no obvious decrease in UOP emission after high temperature‐humidity test (85°C/85% relative humidity for 7 days). Detailed investigations demonstrate that the rigid covalent crosslinking networks suppress the quenching of triplet excitons while the hydrophobic microenvironment affords good water/moisture‐resistance ability. Moreover, the polymers with superior processability are successfully applied as optical coatings, prepreg, and afterglow displays. With this work, we provide a new strategy to promote the long‐term stability of polymeric UOP materials in high‐temperature‐humidity conditions.

Investigation on flame‐retardant, thermal and mechanical properties of glass fiber reinforced polyimide composites

AbstractComposites with excellent flame retardant and mechanical properties are in high demand in the aerospace and various industrial fields. Glass fiber (GF) reinforced polyimide (PI) composites (GFRPCs) were fabricated using a simple ball milling and hot pressing technique. The effect of GF content on the thermal stability, mechanical and flame retardant properties of composites has been systematically studied. The Rockwell hardness of GFRPCs increase with increasing GF content, while the compressive strength, impact strength and flexural strength initially show an increase followed by a decrease due to the excellent dispersibility of the fillers and the strong interfacial interaction between the one‐dimensional GF and PI matrix. Thermogravimetric analysis results show that the addition of GF with very low thermal conductivity and excellent temperature resistance can effectively improve the thermal stability of PI. Adding GF into PI can obviously improve the limiting oxygen index value. Moreover, as the GF content increased, the time to ignition of the composites prolonged while total heat release decreased. These findings suggest a viable solution for enhancing both the flame retardance and mechanical properties of PI‐based composites.Highlights GFRPCs with high GF content fabricated via ball milling‐hot pressing method. Silane modified GF obviously improves the thermal stability of PI matrix. GFRPCs‐28 exhibits superior mechanical properties. An increases in time to ignition (TTI) and mass residual rate (MRR) of the GFRPCs was observed on adding GF.

Evaluation of Supramolecular Gel Properties and Its Application in Drilling Fluid Plugging

Supramolecular gels are physically cross-linked hydrogels formed by non-covalent interactions. The synthesis, structure optimization, property regulation, and application expansion of supramolecular gels has gradually become the research hotspot in the field of gel materials. According to the non-covalent interactions such as hydrophobic association and hydrogen bonding, the supramolecular gel prepared in this study has excellent rheological properties and adaptive filling and plugging properties, and can be used in the field of drilling fluid plugging. In this paper, the microstructure, rheological properties, temperature resistance, and plugging properties of supramolecular gels were studied and characterized in detail. The experimental findings demonstrated that when the strain was less than 10%, the supramolecular gel displayed an excellent linear viscoelastic region. The increase in strain weakens the rheological properties of supramolecular gel and reduces the elastic modulus of supramolecular gel to a certain extent. The supramolecular gel still had a neat three-dimensional reticular structure after curing at high temperatures, and the network of each layer was closely connected. Its extensibility and tensile properties were good, and it had excellent temperature resistance and mechanical strength. The supramolecular gel had excellent tensile and compressive properties and good deformation recovery properties. When the elongation of the supramolecular gel reached 300%, the tensile stress was 2.33 MPa. When the compression ratio of supramolecular gel was 91.2%, the compressive stress could reach 4.78 MPa. The supramolecular gel could show an excellent plugging effect on complex loss layers with different fracture pore sizes, the plugging success rate could reach more than 90%, and the plugging layer could withstand 6.3 MPa external pressure. The smart plugging fluid prepared with supramolecular gel material could quickly form a fine barrier layer on the rock surface of the reservoir. It could effectively isolate drilling fluid from entering the reservoir and reduce the adverse effects, such as permeability reduction caused by drilling fluid entering the reservoir, so as to achieve the purpose of reservoir protection.

Synthesis of a network‐structured polymer with low viscosity effect and its use as filtrate reducer for water‐based drilling fluids

AbstractWith the development of deep formations, high temperature and high salinity seriously affect the rheology and filtration performance of water‐based drilling fluids. Therefore, in this study, a network‐structured polymer (DSD‐β‐CD) with low viscosity effect was synthesized using β‐cyclodextrin (β‐CD) as the backbone and N,N‐dimethylacrylamide (DMAA), sodium p‐styrene sulfonate (SSS), and dimethyl diallyl ammonium chloride (DMDAAC) as monomers. The polymer was analyzed by transmission electron microscope, Fourier transform infrared spectrum, nuclear magnetic resonance, and thermogravimetric analysis. The filtrate reducer in this study showed excellent temperature and salt resistance, the filtration loss of the water‐based drilling fluid containing 3.5% DSD‐β‐CD and 18% NaCl was 5.1 mL after hot rolling at 220°C for 16 h. Additionally, its viscosity was 0.2 mPa s higher than that of the water‐based drilling fluid with 18% NaCl, showing an excellent low viscosity effect. The filtration loss reduction mechanism of DSD‐β‐CD was investigated by viscosity analysis, mud cake analysis, particle size distribution, hydration swelling of bentonite, and Zeta potential. The results showed that DSD‐β‐CD could be adsorbed on the surface of bentonite particles through hydrogen bonds and ionic bonds, which increased the dispersion of bentonite particle and the compactness of the mud cake, thus reducing the filtration loss.

Research and performance optimization of carbon dioxide foam fracturing fluid suitable for shale reservoir

Compared to conventional fracturing techniques, foam fracturing has numerous advantages, including good shear resistance, strong sand carrying capacity, low fluid loss, low damage, and fast return rates. It is particularly suitable for stimulation in low pressure, low permeability, and water-sensitive formations. Specifically, CO2 foam fracturing is crucial in energy savings and emission reductions, controlling the expansion of reservoir clay minerals, reducing crude oil viscosity, and improving the production of water-locked reservoirs. In this paper, we investigate the foam fracturing fluid and evaluate its performance. We selected thickeners with good foaming stability and foaming agents with excellent performance at low dosage levels, based on experimental evaluation. We finally determined the formulation of the foam fracturing fluid by analyzing the experimental data, such as foam half-life, foam mass, and viscosity. We experimentally evaluated the viscosity, static sand settling properties, and rheological properties of the fluid. After being tested on the reservoir core, the foam fracturing fluid has a viscosity of 2 mPas. Moreover, the residue content is 1.1 mg/L, the surface tension is 24.5 mN/m, and the interfacial tension is 1.5 mN/m. The fluid-carrying sand experiment of 40–70 mesh ceramic particles, commonly used in shale gas fracking, was evaluated. The sand-to-liquid ratio was set at 40% for the static sand-carrying experiment. The flow of the fluid-carrying sand was good, and the settling property was satisfactory for 3 h. We used shale reservoir cores from well W-1 to assess the rate of foam fracture, which was less than 19%. Under the experimental conditions of a shear rate of 170 S−1 and a temperature of 90°C, the viscosity of fracturing fluid was measured to be greater than 50 mPas, 90 min after shear, demonstrating the excellent temperature and shear resistance of the foam fracturing fluid. Using CO2 foam fracturing fluid can significantly improve the reconstruction effect of low permeability hydrocarbon reservoirs (especially unconventional reservoirs) and solve problems related to water resources and environmental protection during the process of oil and gas reservoir development. It will be a major factor in improving construction impacts and addressing water and environmental concerns for low permeability hydrocarbon reservoirs, particularly unconventional ones that utilize CO2 foam fracturing fluids.