Binary Systems Research Articles

Efficient removal of cationic dyes by a bivanadyl capped, highly reduced Keggin polyoxometalate through flocculation

Flocculation is widely applied for dye wastewater treatment, due to its low cost, high efficiency and convenient operation. However, finding novel flocculant with high performance and low cost is still a challenge. Therefore, a fully characterized bivanadyl capped, highly reduced Keggin polyoxometalate (Et3NH)5[PMoV6MoVI6O40(VIVO)2] (PMoV2) was explored as flocculant for the treatment of simulated cationic dye wastewater. The effect of initial pH, PMoV2 dosage, and concentrations of dyes and inorganic salts on the flocculation rate of methylene blue (MB)/ crystal violet (CV)/rhodamine B (RhB) was investigated. Under the optimum conditions, the flocculation rates of MB, CV and RhB were 99.7%, 99.8% and 99.7% in 5min, respectively. In addition, PMoV2 and dyes could be easily recovered from flocs. PMoV2 exhibited high selectivity for CV in the binary systems of CV-MB and CV-MO. Even after five recycling tests, PMoV2 still kept high flocculation rate of MB/CV/RhB. The possible flocculation mechanisms for MB/CV/RhB single system, and MB-CV and MO-CV binary systems were charge neutralization, charge neutralization and π-π interaction, and charge neutralization and electrostatic interaction, respectively. PMoV2 was better than the reported flocculants in the respect of easy availability and operation conditions, reusability and high flocculation rate. The cost effectiveness, eco-friendly nature and excellent flocculation performance in individual and binary dye systems made PMoV2 competitive in the field of water environment remediation and material development. This is the first report about the flocculation activities of bivanadyl capped, highly reduced Keggin polyoxometalate.

Hybrid nano-biocomposite based on polysaccharide and graphene oxide for the practical separation of proteins in a fixed bed adsorption column

Proteins and amino acids are essential to humans and all living beings. Moreover, these compounds are present in the pharmaceutical, food, and cosmetic industries. Proteins need to be purified for use in industry. This work aims to synthesize and apply a nano-biocomposite based on graphene oxide (GO) and agar (polysaccharide) for protein separation and purification. The hydrogel composite was tested for myoglobin (Mb) adsorption, the effect of changing the initial pH in Mb adsorption, and the ionic strength was evaluated. The adsorptive capacity values were higher at pH=5 and 6 and decreased at higher pH values. The increase in NaCl concentration did not affect the adsorptive capacity significantly. The composite exhibited a notorious value of maximum experimental adsorption capacity in the equilibrium of over 790 mg g−1 at pH=5 and 25 °C. As GO interacts with the polymeric agar matrix, resulting in a 3D material, the material developed could adsorb Mb in a fixed bed column and single and binary (BSA+Mb) systems. There are indications that the GO-based composite possibly forms a complex with the peptide ligands of myoglobin, forming a protein corona, making Mb desorption difficult.

Constructing SDBS-intercalated MoS2 nanosheets confined and near-vertically grown on network biochar adsorbent: Insights into highly efficient co-adsorption of ciprofloxacin and lead ions

To overcome the problems of the weak adsorption ability of biochar to heavy metal ions (HMIs) and competitive adsorption between HMIs and antibiotics during co-adsorption, the adsorbent material in which 2D sodium dodecylbenzenesulfonate-intercalated molybdenum disulfide nanosheets confined and growing near-vertically on 3D network biochar (SDBS-MoS2/BC) was synthesized. The SDBS-MoS2/BC demonstrated good adsorption ability for ciprofloxacin (CIP) and lead ions (Pb2+). Notably, the adsorption capacity of SDBS-MoS2/BC for the target in the binary system remains higher than in the single system, even at elevated concentrations of the competing target (Qmax,CIP = 393.701 mg g−1, Pb2+: 100 mg/L; Qmax,Pb = 264.550 mg g−1, CIP: 100 mg/L). This may be due to the improvement in the utilization of edge/interlayer adsorption sites by the near-vertical SDBS interlayer expansion of MoS2 as a heavy metal ion anchor. Furthermore, the spatial difference between the upper edge site of near-vertical SDBS-MoS2 and the BC plane, that is, the “longitudinal steric effect”, can separate the CIP and Pb2+ adsorptions in a different horizontal plane to avoid competitive adsorption. The underlying adsorption mechanism was elucidated through a series of experiments and the analysis of characterization results. Furthermore, the load of the SDBS-MoS2/BC sponge-packed column can continuously remove contaminants from water. The rapid, anti-interference, multifunctional and reusable properties make SDBS-MoS2/BC promising for excellent environmental treatment.

Characterization of thin oxide layers formed by Ti-Nb Alloy anodization

Ti-Nb alloys are gaining more prominence in the industrial and scientific environment due to their high biocompatibility, mechanical strength/weight ratio, and exceptional corrosion resistance compared to other metallic materials. Metals exhibiting this passivation characteristic are known as metal valves and may exhibit semiconductive or insulating oxides. Controlling the growth of distinct thickness layer films is possible through tunning anodization conditions. In this work, a Ti-Nb binary system is anodized, and the grown oxide layer is comprehensively characterized using ellipsometry based on its optical properties and thickness at different applied potentials. Confocal Microscopy assessed their surface roughness, and SEM/EDS probed the surface material's elemental composition. CF-LIBS successfully confirmed the 70/30 composition of the Ti-Nb alloy. Raman spectra have detected the presence of amorphous TiO2 and Nb2O5 at potentials higher than 80V, 100V, and 120V. Finally, a linear dependence of the oxide thickness with the applied potential was observed.

Characteristics of Solidification Cracking for Ni-P Coated Cu-Al5052 Single-Mode Fiber Laser Welds

This study fundamentally examines the characteristics of solidification cracking in Cu-Al5052 single-mode fiber laser welding by utilizing uncoated and Ni-P coated Cu plates for the high durability busbar welding of pouch-type lithium-ion battery packs. Weld solidification cracking was confirmed regardless of Ni-P coating for both weld materials. However, there were differences in the regions of crack occurrence. Unlike the uncoated Cu-Al5052 welds where cracks occurred randomly within the fusion zone, for the Ni-P coated Cu-Al5052 welds, solidification cracks were concentrated near the faying surface of the upper and lower materials, particularly near the fusion line. The effect of the Ni and P components on the solidification cracking susceptibility, i.e., the welding solidification temperature range, was considered. Diffusion-controlled Scheil’s solidification calculations revealed that the mushy zone range enlarged with the use of a Ni coating layer. It was confirmed that an extremely wide mushy zone range of 1060 K was calculated at the solidification cracking region. Furthermore, P was also identified as an element that expands the solidification temperature range based on the Cu-P binary system. Consequently, during the laser welding of Cu-Al5052 dissimilar materials, the behavior of solidification cracking in the welds is influenced by the composition of the coating material and the incorporated composition within the weld fusion zone. Hence, it is necessary to select the optimal coating material and layer thickness considering weld solidification cracking susceptibility.

Influence of Arsenate Competition on Tungstate Sorption by Soil

The green and digital transitions toward sustainable development will drive an increased demand for critical raw materials, among which tungsten plays a crucial role in emerging sustainable technologies. Understanding the sorption processes of tungsten in soils is essential for assessing its bioavailability and potential toxicity to living organisms. In many soils, tungsten may co-exist with other contaminants, such as arsenic. Investigating the competitive sorption between these two anions helps clarify how they interact within the soil matrix. Batch experiments were conducted on three Mediterranean soils to evaluate the sorption behavior of tungstate and arsenate, both individually and in combination, using a “Langmuir-type” model. Both anions exhibited the highest sorption in acidic soils and the lowest in alkaline soils. While the shapes of the isotherms were similar in both single and binary systems, the maximum sorption values decreased when a co-occurring anion was present. These reductions can be attributed to competition for soil sorption sites, which have a high affinity for both anions. In all tested soils, the percentage decrease in arsenate sorption in the presence of tungstate was greater than the decrease observed for tungstate in the presence of arsenate. Gaining a deeper understanding of tungsten’s sorption mechanisms is critical, not only for advancing environmental research but also for informing regulations that currently give limited attention to the presence of tungsten in soils.

Outflow from the very massive Wolf-Rayet binary Melnick 34

Melnick 34 (Mk\,34) is one of the most massive binary systems known and is one of the brightest X-ray point sources in the 30 Doradus region. We investigated the impact of this massive system on the surrounding interstellar medium (ISM) using the optical spectroscopic capabilities of the narrow-field mode (NFM) of the Multi-Unit Spectroscopic Explorer (MUSE). MUSE-NFM spatially resolved the ISM in the vicinity of Mk\,34 with a resolution comparable to that of the HST. The analysis of the N ii \,lambda \,6583 and S ii \,lambda \,6717 emission lines reveals a cone-like structure apparently originating from Mk\,34 and extending southeast. Electron density maps and radial velocity measurements of the ISM lines further support an outflow scenario traced by these emissions. While no clear northwestern counterpart to this outflow was observed, we note increased extinction in that direction, towards the R136 cluster. The ISM material along the projected diagonal of the outflow on both sides of Mk\,34 shows similar properties in terms of the emission line ratios seen in the Baldwin-Phillips-Terlevich diagram. These results are consistent across two observational epochs. Additionally, we examined the residual maps within a 0.5" radius of Mk\,34 after modeling and subtracting the point spread function. The observed variations in the residuals could potentially be linked to Mk\,34's known periodic behavior. However, further observations with appropriate cadence are needed to fully monitor the 155\,day periodicity of Mk\,34's X-ray emissions.

Triple trouble with PSR J1618−3921: Mass measurements and orbital dynamics of an eccentric millisecond pulsar

Context. PSR J1618−3921 is one of five known millisecond pulsars (MSPs) in eccentric orbits (eMPSs) located in the Galactic plane, whose formation is poorly understood. Earlier studies of these objects revealed significant discrepancies between observations and predictions from standard binary evolution scenarios of pulsar-helium white dwarf (HeWD) binaries, especially in the case of PSR J0955−6150, for which mass measurements ruled out most eMSP formation models. Aims. We aim to measure the masses of the pulsar and its companion, and constrain the orbital configuration of PSR J1618−3921. This facilitates understanding similarities among eMSPs and could offer hints as to their formation mechanism. Methods. We conducted observations with the L-band receiver of the MeerKAT radio telescope and the UWL receiver of the Parkes Murriyang radio telescope between 2019 and 2021. These data were added to archival Parkes and Nançay observations. We performed a full analysis on this joint data set with a timing baseline of 23 years. We also used the data from recent observations to give a brief account of the emission properties of J1618−3921, including a rotating vector model (RVM) fit of the linear polarisation position angle of the pulsar. Results. From the timing analysis, we measure a small but significant proper motion of the pulsar. The long timing baseline allowed for a highly significant measurement of the rate of advance of periastron of ω̇ = (0.00145±0.00010)°yr−1. Despite the tenfold improvement in timing precision from MeerKAT observations, we can only report a low-significance detection of the orthometric Shapiro delay parameters, h3 = 2.70−1.47+2.07 μs and ς = 0.68−0.09+0.13. Under the assumption of the validity of general relativity (GR), the self-consistent combination of these three parameters leads to mass estimates of the total and individual masses in the binary of Mtot = 1.42−0.19+0.20 M⊙, Mc = 0.20−0.03+0.11 M⊙, and Mp = 1.20−0.20+0.19 M⊙. We detect an unexpected change in the orbital period of Ṗb = −2.26−0.33+0.35 × 10−12, that is an order of magnitude larger and carries an opposite sign to what is expected from the Galactic acceleration and the Shklovskii effect, which are a priori the only non-negligible contributions expected for Ṗb. We also detect a significant second derivative of the spin frequency, f̈. The RVM fit reveals a viewing angle of ζ = (111 ± 1)°. Furthermore, we report an unexpected, abrupt change in the mean pulse profile in June 2021 of unknown origin. Conclusions. We propose that the anomalous Ṗb and f̈ we measure for J1618−3921 indicate an additional varying acceleration due to a nearby mass. The J1618−3921 binary system is likely part of a hierarchical triple, but with the third component much farther away than the outer component of the MSP in a triple star system, PSR J0337+1715. This finding suggests that at least some eMSPs might have formed in triple star systems. Although the uncertainties are large, the binary companion mass is consistent with the Pb − MWD relation, which has been verified for circular HeWD binaries and also for the two HeWDs in the PSR J0337+1715 system. Future regular observations with the MeerKAT telescope will, due to the further extension of the timing baseline, improve the measurement of Ṗb and f̈. This will help us further understand the nature of this system, and perhaps improve our understanding of eMSPs in general.

Critical Evaluation and Thermodynamic CALPHAD Reassessment of the Gallium–Germanium Binary System

Critical Evaluation and Thermodynamic CALPHAD Reassessment of the Gallium–Germanium Binary System

Microstructural Insights and Composition Analysis of a Fractured Brass Alloy of Unknown Composition Using Advanced Characterization Techniques

This study aims to investigate the microstructural and compositional characteristics of a fractured brass alloy using energy-dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM), and X-ray diffraction (XRD). The brass alloy, initially of unknown composition, was determined to consist of 63.65 at% Cu, and 36.35 at% Zn through EDS analysis. Microstructural analysis via SEM revealed a typical ductile fracture pattern with necking and dimple formation, indicative of significant plastic deformation prior to failure. The alloy exhibited a grain size ranging from 10 µm to 80 µm and displayed both α-phase (FCC structure) and possible traces of β-phase, though XRD detected only the α-phase due to the low concentration of β-phase (<5%). A comparison between EDS and XRD results for analyzing chemical composition showed that good assumptions could be made from the lattice parameters of the binary alloy following Nelson-Relay function to predict an approximate composition in binary alloy systems, which was found to be 34 at% Zn in our analysis. Furthermore, the sample’s crystal structure was confirmed as FCC, which supported its observed ductility and plastic deformation prior to fracture. The SEM analysis also confirmed that the material went through an annealing process. The fracture morphology further showed that the FCC structure and the annealing process both contributed to the material’s increased ductility. The analysis further confirms that EDS is more reliable for chemical composition determination in an alloy system. Evidence of annealing twinning in the SEM images suggests the sample underwent an annealing process, contributing to its enhanced ductility.

Probing the Propeller Regime With Wide Neutron Star Binaries

ABSTRACTWe model the duration of the propeller stage in wide binary systems with neutron stars and calculate the time of accretion onset for various propeller models. We apply our modeling to the symbiotic X‐ray binary SWIFT J0850.8‐4219. Unless a propeller with a very slow spin‐down is operating, it is very improbable to find a system similar to SWIFT J0850.8‐4219 at the propeller stage. Then we model the evolution of a neutron star in a binary with a solar‐like companion. We calculate for which orbital separations and magnetic fields a neutron star can start to accrete while the companion is still on the Main sequence. We demonstrate that for the magnetic field G neutron stars at the orbital separation AU do not reach the propeller stage. In the case of a slow propeller spin‐down, neutron stars never start to accrete. For the more rapid propeller spin‐down, a neutron star can start to accrete or spend a long time at the propeller stage depending on the parameters.

Covalent organic framework membranes with vertically aligned nanorods for efficient separation of rare metal ions

Covalent organic frameworks (COFs) have emerged as promising platforms for membrane separations, while remaining challenging for separating ions in a fast and selective way. Here, we propose a concept of COF membranes with vertically aligned nanorods for efficient separation of rare metal ions. A quaternary ammonium-functionalized monomer is rationally designed to synthesize COF layers on porous substrates via interfacial synthesis. The COF layers possess an asymmetric structure, in which the upper part displays vertically aligned nanorods, while the lower part exhibits an ultrathin dense layer. The vertically aligned nanorods enlarge contact areas to harvest water and monovalent ions, and the ultrathin dense layer enables both high permeability and selectivity. The resulting membranes exhibit exceptional separation performances, for instance, a Cs+ permeation rate of 0.33 mol m−2 h−1, close to the value in porous substrates, and selectivities with Cs+/La3+ up to 75.9 and 69.8 in single and binary systems, highlighting the great potentials in the separation of rare metal ions.

Ca(Mo,W)O4 Solid Solutions Formation in CaMoO4‐CaWO4 System

AbstractThe formation of solid solutions in the CaMoO4‐CaWO4 binary system is investigated by X‐ray diffraction, Raman spectroscopy, and scanning electron microscopy methods. The intermixtures of CaMoO4 and CaWO4 components are sintered in 600—1200 °C temperature range (in 100 °C increments). The solidus of the CaMoxW(1‐x)O4 system is studied by the differential scanning calorimetry method in the x = 0.3 … 1.0 range. CaMoO4‐CaWO4 phase diagram is constructed up to 1550 °C. The minimal sintering temperature in order to get CaMoxW(1‐x)O4 solid solution is shown to be 800 °C. Cathodoluminescence study of CaMoxW(1‐x)O4 compounds showed higher intensity of molybdate luminescence type.

Flow regimes in a melting system composed of binary fluid: transition from penetrative convection to diffusion

In a horizontally heated melting system, where a solid substance is subject to melting by a warmer liquid beneath, the presence of solute in the liquid introduces a complex interplay between temperature and concentration dynamics. Employing a recently developed sharp interface method (Xue et al., J. Comput. Phys., vol. 491, 2023), we conduct direct numerical simulations to investigate the transient behaviour of the system across a broad range of Rayleigh numbers and solute concentrations. Our observations reveal distinct flow regimes: at low concentrations, the system resembles a temperature-driven melting problem, characterized by vortex rolls beneath the melting interface. As the solute concentration increases, a stably stratified layer emerges beneath the interface, leading to the transition from thermal convection to penetrative convection, which resembles those flow characteristics observed in the double-diffusive convection. This shift results from the competition between the stabilizing effect induced by solute concentration gradient and the destabilizing effect caused by temperature gradient. Otherwise in the diffusion regime, characterized by very high solute concentrations, the flow becomes static due to the complete suppression of convection by the stably stratified layer. This regime further exhibits two distinct patterns: ‘melting’ and ‘dissolution’. Beyond characterizing diverse flow patterns, our study conducts a quantitative analysis, examining heat/mass transfer, melting rates, and the evolution of temperature and concentration at the interface. These insights contribute to a better understanding of the intricate interplay between temperature and solute concentration during phase change, with implications for accurately estimating melting rates in binary fluid systems.

A Comprehensive Study of Thermonuclear X-Ray Bursts from 4U 1820–30 with NICER: Accretion Disk Interactions and a Candidate Burst Oscillation

We present the results obtained from timing and spectral studies of 15 thermonuclear X-ray bursts from 4U 1820–30 observed with the Neutron Star Interior Composition Explorer (NICER) during its 5 yr of observations between 2017 and 2022. All bursts showed clear signs of photospheric radius expansion (PRE), where the neutron star (NS) photosphere expanded more than 50 km above the surface. One of the bursts produced a superexpansion with a blackbody emission radius of 902 km for the first time with NICER. We searched for burst oscillations in all 15 bursts and found evidence of a coherent oscillation at 716 Hz in a burst, with a 2.9σ detection level based on Monte Carlo simulations. If confirmed with future observations, 4U 1820–30 would become the fastest-spinning NS known in X-ray binary systems. The fractional rms amplitude of the candidate burst oscillation was found to be 5.8% in the energy range of 3–10 keV. Following the variable persistent model from burst time-resolved spectroscopy, an anticorrelation is seen between the maximum scaling factor value and the (preburst) persistent flux. We detected a low value of ionization at the peak of each burst based on reflection modeling of burst spectra. A partially interacting inner accretion disk or a weakly ionized outer disk may cause the observed ionization dip during the PRE phase.

Revisiting the Period Change and Frequency Analysis of a Variable Star SZ Lyncis

This study aims to investigate the period change of the variable star SZ Lyncis. The observations were conducted at the Regional Observatory for the Public, Nakhon Ratchasima (ROP-NMA), operated by the National Astronomical Research Institute of Thailand (NARIT), on January 8th-9th and February 19th-20th 2024. The data was acquired using the CCD camera with a B-filter mount on the 0.7-m reflecting telescope. We report the period change of 1.37(±0.08)´10-12 day cycle-1. Analysis of the O-C diagram revealed the presence of a binary companion with a semi-amplitude of 0.0052(±0.0002) days, the projected semi-major axis of 0.90(±0.04) AU, the eccentricity of 0.25(±0.09), and the orbital period of 1184.1(±1.5) days and the mass function of 0.07(±0.01) M⨀. We also identified the time-series light curve data using the Discrete Fourier transform (DFT) in the Period04 package and obtained results of four frequencies. The main frequency of 8.29630(±0.00002) cycle day-1 corresponds to a period of 0.1205357(±0.0000003) days. These results contribute to our understanding of the pulsation properties of SZ Lyncis and its binary system.

Full Abundance Study of Two Newly Discovered Barium Giants

Barium (Ba) stars are chemically peculiar stars that show enhanced surface abundances of heavy elements produced by the slow-neutron-capture process, the so-called s-process. These stars are not sufficiently evolved to undergo the s-process in their interiors, so they are considered products of binary interactions. Ba stars form when a former Asymptotic Giant Branch (AGB) companion, which is now a white dwarf, pollutes them with s-process-rich material through mass transfer. This paper presents a detailed chemical characterization of two newly discovered Ba giants. Our main goal is to confirm their status as extrinsic s-process stars and explore potential binarity and white dwarf companions. We obtained high-resolution spectra with UVES on the Very Large Telescope to determine the chemical properties of the targets. We perform line-by-line analyses and measure 22 elements with an internal precision up to 0.04 dex. The binary nature of the targets is investigated through radial velocity variability and spectral energy distribution fitting. We found that both targets are enhanced in all the measured s-process elements, classifying our targets as Ba giants. This is the first time they are classified as such in the literature. Additionally, both stars present a mild enhancement in Eu, but less than in pure s-process elements, suggesting that the sources that polluted them were pure s-process sources. Finally, we confirmed that the two targets are RV variable and likely binary systems. The abundances in these two newly discovered polluted binaries align with classical Ba giants, providing observational constraints to better understand the s-process in AGB stars.

State uncertainty propagation and sensitivity analysis of the post-impact binary asteroid system

State uncertainty propagation and sensitivity analysis of the post-impact binary asteroid system

Performance and economic analysis of various geothermal power plant systems: Case study for the Chingshui geothermal field in Taiwan

Geothermal power plants are a source of sustainable energy. However, their performance is influenced by various factors, including production temperature and well locations, and few studies have investigated the relationships between these factors. To address this research gap, the present study developed integrated models of a geothermal reservoir and a variety of power plant systems. By using COMSOL and MATLAB, we conducted simulations for the Chingshui geothermal field in Taiwan to investigate the performance and economic feasibility of five common types of geothermal power plant systems over their operational lifetime under different well configurations. The key findings of this investigation are as follows. First, the locations of production wells are a primary factor influencing production temperature. Constructing wells in low-permeability zones results in considerable increases in the pressure differential in the injection pump; thus, wells should not be constructed in such zones. Second, as system flow rate and well depth decrease, production temperature remains relatively stable, net power output decreases, and system efficiency increases. This efficiency increase is caused by decreases in pumping power requirements at lower flow rates and shallower well depths. Finally, among the investigated systems, the organic Rankine cycle system had the lowest electricity production cost and shortest payback period within the enthalpy range of 500–1000 kJ/kg. Double-flash (DF) and DF–binary systems are also viable options when the mass flow rate is 10–20 kg/s and the enthalpy is 700–800 kJ/kg. Overall, the results of this study offer valuable insights for the design of geothermal power plants, thereby contributing to the optimization of renewable energy systems.

Construction and Properties Evaluation of the Binary Flooding System Based on Lipid Peptide.

To enhance crude oil recovery under complex reservoir conditions and reduce the environmental impact of the oil displacement system, a biosurfactant lipid peptide (TH) was combined with four chemical surfactants. From these combinations, those capable of achieving an ultralow interfacial tension region (<10-2 mN/m) were selected. The selected surfactant mixtures were then combined with polyacrylamide (HPAM) to construct a surfactant-polymer binary oil displacement system. The results showed that TH/OAB(2:1), TH/OAB(3:1), and TH/EAO(3:1) could reduce IFT to the ultralow interfacial tension region. Compound surfactants are easier to form mixed micelles than single surfactants, and the EACN of TH/OAB(2:1) and TH/EAO(3:1) is consistent with EACNOil, which can achieve higher surface activity at lower concentrations. The three compound surfactants have a wide range of ultralow interfacial tension concentrations and excellent antidilution performance. TH/OAB(2:1) and TH/EAO(3:1) have better antiformation adsorption performance than TH/OAB(3:1), and the oil washing rate of TH/OAB(2:1) is up to 80.30%. TH and OAB have spatial complementarity, which can increase the molecular packing density at the oil-water interface and reduce the IFT. In CaCl2 and NaCl solutions, the IFT of the two binary flooding systems constructed by TH/OAB(2:1) and TH/EAO(3:1) and HPAM remained in the ultralow interfacial tension region, with excellent salt resistance. When aged in the reservoir for 90 days, the IFT slightly increased but the viscosity decreased significantly. Adding a viscosity retaining agent (JW) was required to maintain the viscosity of the system. In the simulated oil displacement experiment, the recovery improvement of the two binary oil displacement systems was higher than those of surfactant and polymer alone. This study provides a new idea for the alkali-free surfactant-polymer binary oil flooding system and provides theoretical support for the practical application of TH in tertiary oil recovery.