Gap Distance Research Articles

Au-coated quartz fabric by plasma treatment as a flexible SERS substrate for rapid detection of harmful substances

Food safety remains a global concern and there is always demanded to advance methods to ensure that toxic substances and contamination do not pose safety concerns. This study discusses the development of a rapid, low-cost, portable, in situ method for the detection of harmful substances on the surface of fruits and vegetables to ensure safety for human consumption. Gold nanoparticles (Au NPs) are deposited onto quartz fabric by using a magnetron sputtering system. The argon flow rate and sputtering time are both controlled to produce Au NPs of different sizes on the quartz fabric with different gap distances. Scanning electron microscope images, X-ray diffraction spectra, and Raman intensity are used to evaluate the produced substrates. With an average grain size of about 32.35 nm, the Au particles with a thickness of 70 nm deposited onto the quartz fabric (i.e., Qt-70) provide the best surface-enhanced Raman scattering (SERS) performance of 65,639 counts towards a 10−3 M methylene blue (MB) solution. The results show that the Qt-70 SERS substrate is highly sensitive, reproducible, and stable, and demonstrates good reusability. Images of “hotspots” that form between two Au nanoparticles based on electric field distribution are simulated by using the finite-difference time-domain (FDTD) method to explain for the signal enhancement. In addition, Qt-70 can be used for the direct collection of pesticides, such as Rhodamine B (RhB), Rhodamine 6G (R6G), and Malachite green (MG), from food surfaces. This novel flexible SERS (FSERS) substrate has good potential for the rapid detection of harmful substances on food.

Exploring effect of charge dissipation in charged powder space on electric field distribution in silo

The electric field distribution is important for understanding the underlying mechanism of electrostatic discharge in silos and for developing anti-static strategies. However, the charge dissipation of charged powder usually is not well modeled in the existing electric field simulation, resulting in inaccurate estimation of the electric field in silos. This paper studied the electric field distribution in a cylindrical silo based on the space charge density distribution created by the charged particles. The influences of the normalized filling time, gap distance, and the silo height-to-diameter ratio on the electric field were explored. The results indicate that the area with a larger space charge density shrinks from the heap bottom to the heap surface, leading to a decline in the electric field and suggesting a lower probability of electrostatic discharge at the larger normalized filling time. Continuous decrease of the gap distance when the heap surface is close to the silo ceiling will lead to a sharp increase in the electric field, regardless of the charge dissipation. The silos with a height-to-diameter ratio greater than 2 are demonstrated to have a lower probability of electrostatic discharge and a space higher utilization ratio.

Proximity and cross-border acquisitions of technology assets by firms in latecomer economies: a study of Chinese firms, 2001-2018

ABSTRACT We propose an analytical framework to examine how various dimensions of proximity between home and host countries could account for the trajectories and specificities of cross-border acquisitions of technology assets (CATAs) conducted by acquirer firms in latecomer economies. As Chinese firms have been increasingly using CATAs as a mean to catch up with their counterparts in advanced economies, we referred to their acquisition records to illustrate the applicability of the proposed framework. Based on a compiled dataset of the number of CATA transactions from 2001 to 2018, this paper examines the effects of various dimensions of proximity on the spatio-temporal patterns of Chinese CATAs using negative binomial regression models. Our findings demonstrate that the difference in governance between China and host countries (institutional proximity), the size of overseas Chinese population in host countries (social proximity), and the value of import from host countries (economic proximity) have significant effects on the propensity of Chinese firms to engage in CATAs. Physical distance and cultural gap between China and host countries, however, have no significant impact on CATAs. Further examination of the results reveals that Chinese firms tend to acquire target firms outright in culturally distant host countries to reduce the risk of their overseas acquisition in CATAs. In addition, we also found that there is a dynamic relationship between different dimensions of proximity and CATAs: from the relative importance of economic proximity between 2001 and 2012 to the rising influence of social and institutional proximity between 2013 and 2018 on CATAs.

Effects of the ground-electrode temperature on electrical and optical characteristics of a coaxial dielectric barrier discharge in atmospheric pressure air

The applied power and electron energy are believed to play important roles in plasma applications, which can be significantly altered by controlling the ground-electrode temperature in a coaxial dielectric barrier discharge (DBD). The effects of the ground-electrode temperature on the electrical and optical characteristics of the DBD were investigated in atmospheric pressure air. The results show that the breakdown voltage decreases, and the number of discharge pulses, the transferred charges, and the applied power increase with the electrode temperature, while the peak current tends to decrease when the electrode temperature is below −35 °C and above 25 °C, respectively. When the electrode temperature remains constant, the breakdown voltage increases and the applied power decreases with the gap distance. The applied power increases with the applied voltage. The dielectric capacitance, the total capacitance, and the gap capacitance at the electrode temperature below −35 °C are generally higher than those at the electrode temperature above 25 °C. Moreover, they change in the same trend when the electrode temperature and the applied voltage increase. The dielectric and total capacitances increase while the gap capacitance decreases. The relative intensities of the spectral lines increase with the electrode temperature. The electron, vibrational, and rotational temperatures increase with the electrode temperature above 25 °C. However, the electron and vibrational temperatures increase and decrease with the electrode temperature below −35 °C. The secondary emission coefficients and electron energy distributions with the electrode temperature were discussed.

Fabrication of high-flux defect-free hollow fiber membranes derived from a phenolphthalein-based copolyimide for gas separation

In the realm of gas purifications, hollow fiber membranes have gained significant prominence due to their unique advantages. However, achieving defect-free membranes poses a considerable challenge. In this study, we addressed this challenge with a novel copolymer, 6FDA-DAM:DAP(2:1), comprising 4,4′-(hexafluoroisopropylidene) diphthalic anhydride (6FDA), 2,4.6-Trimethy-m-phenylenediamine (DAM), and a phenolphthalein-derived diamine of 3,3′-diaminophenolphthalein (DAP). We found that defect-free hollow fiber membranes could be prepared when 20 wt% or more ethanol was added in the polymer dope solution, but this led to the formation of oval hollow fibers that would be flattened under high pressure. We solved this limitation by lowering ethanol content to 15 wt%, adding 2 wt% LiNO3, and increasing the air–gap distance. These measures reduced the difference in phase inversion rates between the surface region and the bulk phase of the nascent hollow fiber. The CO2 permeance of this defect-free hollow fiber membrane reached 282 GPU with a CO2/CH4 selectivity of 50.2. Highly permeable defective hollow fiber membranes were also developed using a polymer dope without LiNO3 and a low THF content of 5 wt%. After coated by silicone rubber, CO2 permeance of the membrane reached 554 GPU with a CO2/CH4 selectivity of 45.0. In mixed gas tests, the two membranes exhibited O2 permeances of approximately 43.3 and 75.3 GPU, with O2/N2 selectivities of 5.5 and 5.4, respectively. Their CO2 permeances were 281 and 465 GPU, with CO2/CH4 selectivities of 45 and 41, CO2/N2 selectivities of 35.7 and 33.3, respectively. These separation performances were among the best of state-of-art polymeric hollow fiber membranes and demonstrated great potential for gas separation applications such as natural gas sweetening, flue gas treatment, and air separation.

Effectiveness of multi-junction cells in near-field thermophotovoltaic devices considering additional losses

Abstract Thermophotovoltaic (TPV) energy converters hold substantial potential in converting thermal radiation from high-temperature emitters into electrical energy through photovoltaic (PV) cells, offering applications ranging from solar energy harvesting to waste heat recovery. Near-field TPV (NF-TPV) devices, focused on enhancing power output density (POD), exhibit unique potential by harnessing photon tunneling. However, this potential can be mitigated by additional losses arising from high photocurrent densities and corresponding scalability issues. This study comprehensively investigates the effectiveness of multi-junction-based NF-TPV devices, accounting for additional losses. We propose two approximative expressions to quantify the impact of additional losses and characterize current density-voltage curves. Verification against rigorously optimized results establishes a criterion for effective performance. Our method provides precise POD estimations even for devices with 10 or more subcells, facilitating performance analysis across parameters like vacuum gap distance, cell width, emitter temperature, and the number of subcells compared to far-field counterparts. This research outlines a roadmap for the scalable design of NF-TPV devices, emphasizing the role of multi-junction PV cells. The analytical framework we developed will provide vital insights for future high-performance TPV devices.

The Simulation of Dielectric Barrier Discharge for Breakdown Voltage in Starch Modification

This paper presents the simulation results for dielectric barrier discharge (DBD) at atmospheric pressure in argon gas for different relative permittivity, granule shape, thickness layer, and granule diameter measurements for starch on the breakdown voltage. DBD is commonly utilized to generate cold plasma for starch modification. The electric field was computed using COMSOL Multiphysics 5.3a software. The breakdown voltage was calculated employing Paschen’s law for this electric field. The voltage was found according to the breakdown criterion for gap distance 0.2–1.0 cm, and then the Paschen curve could be plotted. The results show that the top electrode of the plasma system may be replaced with the parallel plate electrode by a mesh electrode with a bigger mesh size to achieve a lower breakdown voltage. In addition, increasing the relative permittivity and decreasing the thickness layer can reduce the applied voltage for plasma formation. When compared to the sphere and ellipsoid shapes, starch with a polyhedral granule shape requires a significantly lower voltage for breakdown. The starch granule diameter does not affect the breakdown voltage. These findings can be utilized to determine the optimal breakdown voltage for each type of starch modification, contributing to the construction of a high-efficiency plasma production system for starch modification.

Near-field radiative heat transfer between nanoporous GaN films

Photon tunneling effects give rise to surface waves, amplifying radiative heat transfer in the near-field regime. Recent research has highlighted that the introduction of nanopores into materials creates additional pathways for heat transfer, leading to a substantial enhancement of near-field radiative heat transfer (NFRHT). Being a direct bandgap semiconductor, GaN has high thermal conductivity and stable resistance at high temperatures, and holds significant potential for applications in optoelectronic devices. Indeed, study of NFRHT between nanoporous GaN films is currently lacking, hence the physical mechanism for adding nanopores to GaN films remains to be discussed in the field of NFRHT. In this work, we delve into the NFRHT of GaN nanoporous films in terms of gap distance, GaN film thickness and the vacuum filling ratio. The results demonstrate a 27.2% increase in heat flux for a 10 nm gap when the nanoporous filling ratio is 0.5. Moreover, the spectral heat flux exhibits redshift with increase in the vacuum filling ratio. To be more precise, the peak of spectral heat flux moves from ω = 1.31 × 1014 rad⋅s−1 to ω = 1.23 × 1014 rad⋅s−1 when the vacuum filling ratio changes from f = 0.1 to f = 0.5; this can be attributed to the excitation of surface phonon polaritons. The introduction of graphene into these configurations can highly enhance the NFRHT, and the spectral heat flux exhibits a blueshift with increase in the vacuum filling ratio, which can be explained by the excitation of surface plasmon polaritons. These findings offer theoretical insights that can guide the extensive utilization of porous structures in thermal control, management and thermal modulation.

Heat transfer analysis and thermo-mechanical property of M-shape metal-rubber at high-temperature

Particular attention is given to the M-shape metal-rubber (MMR), which is a porous material with cushioning characteristics and excellent heat resistance coated in pipelines. The heat transfer characteristics and thermo-mechanical property of MMR has not been clear due to its complicated micro-porous structures and the coupling effect between structure and performance. In this work, the influence of different parameters (emissivity, density and gap distance) on the equivalent thermal conductivity of MMR were considered at the mesoscopic model level. In addition, thermal stress at different temperatures was used as predefined fields for thermal-mechanical coupling to analyze the transformations of performance. The results indicate that surface emissivity and cavity emissivity during heat transfer exhibit an inverse relationship with MMR thermal conductivity. Furthermore, it is observed that natural convection has the most significant impact on thermal conductivity. And, the thermal conductivity is negative correlation with density and gap distances. Under cyclic loading, stress concentration and plastic strain occur in MMR, and residual thermal stress is generated. The secant stiffness exhibits a positive correlation with temperature, while the loss factor demonstrates a negative correlation, primarily due to thermal expansion.

Breakdown characteristics of nitrogen at different pressures in alternating non-uniform electric fields

Abstract AC breakdown characteristics of nitrogen at different pressures in electric fields with different degrees of non-uniformity provided by a sphere-plane electrode system have been investigated. It is found that the measured breakdown voltages obey Paschen’s law at the values of the field factor (the ration of the maximum field strength between electrodes to the average field strength) below ∼2. Deviations start to appear and increase gradually if the field factor increases above this threshold. Respectively, the dependence of the breakdown voltage U b on the product of pressure p and gap distance d changes from been linear U b ∼ p ×d to a more complex relationship of type U b ∼ p ×ln(d). It is found that the maximum field strength corresponding to the breakdown increases with increasing gas pressure and decreasing electrode radius but it is independent on the gap distance. The breakdown voltages predicted by the streamer criterion agree well with the experimental data. The results obtained for nitrogen were compared with the breakdown characteristics of air and it was found that at the values of the field factor below 9, the breakdown strength of nitrogen was higher than that of ambient air.

Investigation of the influence of opening speed on vacuum arc under transverse magnetic field

The objective of this paper is to investigate the vacuum arc characteristics on transverse magnetic field (TMF) contacts at different opening speeds. Experiments are carried out at different opening speeds. The experimental current ranges from 7 to 16 kA (peak current) at approximately 50 Hz. The contact material is CuCr30. The results show that increasing the opening speed increases the expansion speed of the arc after ignition. A higher opening speed increases the gap distance at which an anode spot occurs and reduces the duration of the instability stage, and it also reduces the duration of the motion stage. The arc motion can be optimized by adjusting the opening speed. The moment of contacts separation has no obvious influence on the gap distance at the transition of the arc mode. When the arc ignites between the arms, it expands slowly. This phenomenon is analyzed by a finite element method. The simulation results show that the ignition position influences the current direction, which influences electromagnetic force of the arc. The radial electromagnetic force is smaller when the arc ignites between the arms, causing a stagnation of the arc.

Effects of Circular Hydraulic Jump on the Material Removal Characteristics of Jet Electrochemical Machining

Jet electrochemical machining (Jet-ECM) is a potential precision machining method. Due to the advantages of non-stress-free machining and high flexibility, it is widely used in surface finishing and complex structural machining. However, the “w” shaped removal profile and wide removal range caused by inappropriate process parameters reduce the stability and localizability of Jet-ECM. In this paper, the material removal characteristics of Jet-ECM were investigated both theoretically and experimentally. A multi-physics field simulation model for Jet-ECM was established, and the overall shape of the circular hydraulic jump (CHJ), current density distribution and workpiece deformation were calculated. The effects of CHJ on the material removal characteristics were investigated by experiments with jet flow rate and inter-electrode gap (IEG) distance. The results reveal the qualitative relationship between CHJ states and process parameters and give the range of parameters that can form a stable CHJ and ensure a Gaussian shaped removal profile and a narrower removal range. This study provides theoretical guidance on the process parameters of Jet-ECM to improve its processing stability and localizability, which is significant for the accuracy of surface finishing and the controllability of complex structural machining, promoting the further application of Jet-ECM.

Data-driven design of multilayer hyperbolic metamaterials for near-field thermal radiative modulator with high modulation contrast

The thermal modulator based on the near-field radiative heat transfer has wide applications in thermoelectric diodes, thermoelectric transistors, and thermal storage. However, the design of optimal near-field thermal radiation structure is a complex and challenging problem due to the tremendous number of degrees of freedom. In this work, we have proposed a data-driven machine learning workflow to efficiently design multilayer hyperbolic metamaterials composed of α-MoO3 for near-field thermal radiative modulator with high modulation contrast. By combining the multilayer perceptron and Bayesian optimization, the rotation angle, layer thickness and gap distance of the multilayer metamaterials are optimized to achieve a maximum thermal modulation contrast ratio of 6.29. This represents a 97 % improvement compared to previous single layer structure. The large thermal modulation contrast is mainly attributed to the alignment and misalignment of hyperbolic plasmon polaritons and hyperbolic surface phonon polaritons of each layer controlled by the rotation. The results provide a promising way for accelerating the designing and manipulating of near-field radiative heat transfer by anisotropic hyperbolic materials through the data-driven style.

Exploiting Surface Plasmon with Dielectric Coating in Copper Wires Waveguide for the Propagation of Terahertz Waves

Recently, metallic wires have gained popularity for utilization as waveguides in propagating sub-THz and THz waves through surface plasmonic polaritons (SPPs). Single and double metallic wire waveguides have demonstrated the ability to propagate these high frequencies with minimal loss and nearly zero dispersion. However, wires typically installed commercially are often coated with dielectric material. Therefore, this paper investigated the effects of using two and four metallic copper wires, both with and without dielectric coating. The impact of various gap distances on different propagation characteristics was also analyzed. Computer Simulation Technology (CST) Microwave Studio was employed in this study for electromagnetic simulations of both uncoated and coated configurations of two and four wires. The introduction of a dielectric coating led to an enhancement in reducing conductor losses and improving energy confinement, with the goal of enhancing the overall efficiency of waveguide signal propagation.

Solvent Welding-Based Methods Gently and Effectively Enhance the Conductivity of a Silver Nanowire Network

To enhance the conductivity of a silver nanowire (Ag NW) network, a facile solvent welding method was developed. Soaking a Ag NW network in ethylene glycol (EG) or alcohol for less than 15 min decreased the resistance about 70%. Further combined solvent processing via a plasmonic welding approach decreased the resistance about 85%. This was achieved by simply exposing the EG-soaked Ag NW network to a low-power blue light (60 mW/cm2). Research results suggest that poly(vinylpyrrolidone) (PVP) dissolution by solvent brings nanowires into closer contact, and this reduced gap distance between nanowires enhances the plasmonic welding effect, hence further decreasing resistance. Aside from this dual combination of methods, a triple combination with Joule heating welding induced by applying a current to the Ag NW network decreased the resistance about 96%. Although conductivity was significantly enhanced, our results showed that the melting at Ag NW junctions was relatively negligible, which indicates that the enhancement in conductivity could be attributed to the removal of PVP layers. Moreover, the approaches were quite gentle so any potential damage to Ag NWs or polymer substrates by overheating (e.g., excessive Joule heating) was avoided entirely, making the approaches suitable for application in devices using heat-sensitive materials.

Studi Permukaan Produk Berbahan PLA Hasil Fabrikasi Menggunakan Mesin 3D Printer Jenis Fused Deposition Modelling (FDM) dengan Variasi Kecepatan Printing

<p><em>A study of the surface of the fabrication process using the fused deposition modeling (FDM) technique is needed to determine the suitability of the process parameters with the use of the product to be made. Products that have special characteristics that take advantage of the surface properties of fabricated using FDM are often encountered in technical applications involving fluids. This research is a preliminary study of the Water Contat Angle (WCA) study on polymer filaments made of PLA. In this study, the effect of printing speed on the width of polymer deposition and the gap distance between one deposit and another polymer deposit on the sample surface was observed and analyzed using image processing techniques. The printing speed is made to vary from 30 mm/s, 60 mm/s, and 90 mm/s. The relationship between printing speed and polymer deposition width produces a linear equation y = 0.0008 x + 0.28 and the gap width between filament deposition on the sample surface shows a linear equation relationship y = -0.0002 x + 0.0833</em></p><p> </p><p><em><br /></em></p>

Following car reduces motorcycles’ size-arrival effect: A study using online experiments

Many fatal motorcycle accidents occur because car drivers infringe on motorcycle riders' right-of-way. The size-arrival effect refers to observers' tendency to judge larger objects as arriving sooner than smaller objects when estimating an approaching object's arrival time, which is one cause of right-of-way motorcycle accidents. Previous research has focused on a single vehicle that approaches the driver. However, it is also possible that a motorcycle approaches a driver along with other vehicles driving on multiple-lane roads. This paper presents the results of two online experiments; Experiment 1 validated the size-arrival effect when either a car or a motorcycle approached a driver waiting to turn across an intersection; and Experiment 2 investigated the size-arrival effect when a motorcycle and a parallelly driven car simultaneously approached the driver. Participants (n = 1723) in Experiment 1 and (n = 986) in Experiment 2 took part in the study. The results (1) validated the size-arrival effect; drivers accepted a smaller gap for approaching motorcycles than cars; (2) in the present settings drivers made turn decisions based on the distance gap rather than the time-to-arrival gap; (3) driver's acceptance of the gap when facing a motorcycle and a car was comparable to when facing only the car and significantly larger than facing only a motorcycle. These findings indicate that a car driving parallelly or behind a motorcycle reduces the size-arrival effect. These findings provide implications to suggest a safe riding strategy for motorcycle riders. We also suggest that such online experiments would facilitate studying large samples with less effort.

Online Modules Discussion Forums: A Pedagogical Platform Facilitating Learning in DE Environments

Student support in an open distance e-learning (ODeL) institution takes different forms and shapes. These forms and shapes are used in defining the nature of ODeL institutions. Bridging the distance gap between students in ODeL institutions, different platforms to facilitate interaction among students, students and their instructors are developed and made available. These interactions assist students by reducing the feeling of loneliness in the learning process. Loneliness is one of the experiences associated with dropout rates that negatively impact students’ success rate. The question is, are students making use of these platforms as they were designed for, which is to facilitate the process of learning by interacting with other stakeholders such as with fellow students, students and instructors, students and content? The other question, given that students are from diverse backgrounds, is whether the platform is equally usable and accessible to all students. Are the other social challenges, such as poverty, low technological skills, inequality, network coverage, and loadshedding among factors, considered when introducing and rolling out these platforms to students? Leading the pack in these platforms is the online discussion forum, which is embedded in learning management systems (LMS), available on each online or blended or hybrid module registered for. For example, if a student has registered for two modules, each module has its own discussion forum. There is a concern whether participation in online discussion forums is related to students’ success. The study determines whether participation in online discussion forums is related to a student’s success in the module. Two modules were conveniently selected and used for meeting the purpose of study. The modules were offered using the blended or online pedagogy. The students’ posting on the discussion forum was extracted and statistically analysed to determine whether it relates to success or performance in the modules. The study reported mixed results, where either participation or non-participation is related to student success. Student success comprises a variety of activities, for which participation by posting in online discussion forums forms part, however, it is not the only solution.

Evaluation of anti‐wetting nano‐fumed silica/PVDF hollow‐fiber membrane by central composite design optimization towards efficient desalination performance via membrane distillation

AbstractBACKGROUNDMembrane distillation (MD) is considered a viable technology to overcome the issue of water scarcity by desalination of seawater. However, the application of MD has been severely restricted by membrane‐wetting phenomena. This study aims to optimize the desired mixed‐matrix hollow‐fiber (HF) membrane conditions that have anti‐wetting characteristics for efficient desalination. Response surface methodology based on central composite design was used to predict and optimize the permeate flux and salt rejection (SR). The combined effects of polymer (polyvinylidene fluoride, PVDF) concentration, nano‐fumed silica (NFS) particle loading, coagulation bath temperature (CBT) and air gap distance (AG), as well as their interactions in terms of desalination performance, have been investigated.RESULTSThe linear factors (NFS, CBT), the quadratic effects of all variables, as well as the interacting terms between (PVDF, NFS), (PVDF, CBT) and (NFS, CBT) had significant effects for both pure water and permeate fluxes. For SR, only PVDF presented a linear effect, while a quadratic effect was obtained in (NFS, AG) and an interaction effect was obtained between PVDF and NFS. Under optimal conditions of PVDF (15.03 wt%), NFS (1.21 wt%), CBT (54.85 °C) and AG (9.9 cm), the optimal mixed‐matrix HF membrane demonstrated higher experimental average values for pure water and permeate fluxes, which reached up to 11.95 and 11.61 kg m−2 h−1 respectively, and an SR of 99.96% as compared to the pristine membrane.CONCLUSIONOur research provides an efficient anti‐wetting NFS/PVDF mixed‐matrix HF membrane, indicating that the optimal membrane possesses high potential for the direct contact membrane distillation (DCMD) process. © 2023 Society of Chemical Industry (SCI).

Fabrication of highly selective hollow fiber membranes based on P84/PES blends for CO2/CH4 separation

AbstractIn this study, the aim was to purify CH4, an efficient and renewable clean energy source, which often contains CO2 that needs to be removed to improve its combustion efficiency. To achieve this, hybrid hollow fiber membranes were developed using BTDA‐TDI/MDI (P84) and polyethersulfone (PES) through a dry jet‐wet spinning process. The effects of different parameters, including core liquid composition, solidification bath composition and temperature, spinneret temperature, and air gap distance, were studied to optimize membrane structure, morphology, and CO2/CH4 separation performance. The P84/PES hollow fiber membrane obtained through this process demonstrated good CO2/CH4 separation performance, with CO2 permeation of 2.12 GPU and a selectivity of 51.23. To further improve the membrane's performance, a coating of poly(ether block‐amide) (PEBA) was applied to the P84/PES hollow fiber membrane. This modification resulted in a P84/PES‐PEBA hollow fiber membrane with increased CO2 affinity due to the polar poly(ethylene oxide) groups of PEBA. The P84/PES‐PEBA hollow fiber membrane exhibited high selectivity of 56.5 and CO2 permeance of 1.42 GPU at 25°C.