Good Solvent Research Articles

Polyurethane toughened covalent adaptive networks epoxy composite based on thermoreversible Diels‐Alder reaction: Self‐healable, shape memory, and recyclable

AbstractCovalent adaptive networks (CANs) epoxy based on the Diels‐Alder (DA) reaction usually are commonly used for self‐healing materials. However, poor toughness greatly limits its application in innovative materials. Herein, based on retaining the excellent dynamic characteristics of DA reactive CANs, we introduced thermoplastic polyurethane (TPU) in situ during crosslinking, improving the composite material's strength and toughness. A multicomponent polymeric system with advanced performance can be produced by the individual components on the condition of the synergistic hybrid effects. Molecular‐level interlocking polymer networks between the chain entanglement of TPU and the reversible covalent crosslink of DFB were formed by the topological reorganization of these two immiscible polymers. As the gelation proceeds, a homogenous structure instead of conventional phase separation is formed. When the mixing ratio of DFB and TPU is 1:1, the tensile strength of the prepared sample reaches 35 MPa, and the elongation at break reaches 110%. At the same time, the composites possess good thermal stability and solvent resistance due to the presence of interlocking polymer networks. Furthermore, these DFB‐TPU composites show excellent shape memory, self‐healing, and closed‐loop recycling properties.

Enhanced Removal of Photoresist Films through Swelling and Dewetting Using Pluronic Surfactants.

Organic photoresist coatings, primarily composed of resins, are commonly used in the electronics industry to protect inorganic underlayers. Conventional photoresist strippers, such as amine-type agents, have shown high removal performance but led to environmental impact and substrate corrosiveness. Therefore, this trade-off must be addressed. In this study, we characterized the removal mechanism of a photoresist film using a nonionic triblock Pluronic surfactant [poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide)] in a ternary mixture of ethylene carbonate (EC), propylene carbonate (PC), and water. In particular, the removal dynamics determined by using a quartz crystal microbalance with dissipation monitoring was compared with those determined by performing confocal laser scanning microscopy and visual observation to analyze the morphology, adsorption mass, and viscoelasticity of the photoresist film. In the absence of the Pluronic surfactant, the photoresist film in the ternary solvent exhibited a three-step process: (i) film swelling caused by the penetration of a good solvent (EC and PC), (ii) formation of photoresist particles through dewetting, and (iii) particle aggregation on the substrate. This result was correlated to the Hansen solubility parameters. The addition of the Pluronic surfactant not only prevented photoresist aggregation in the third step but also promoted desorption from the substrate. This effect was dependent on the concentration of the Pluronic surfactant, which influenced diffusion to the interface between the photoresist and the bulk solution. Finally, we proposed a novel photoresist stripping mechanism based on the synergy between dewetting driven by an EC/PC-to-water mixture and adsorption by the Pluronic surfactant.

Ionic liquids based on metal halide complex salts and their applications in extractive desulfurization of liquid fuel: A review

In this review, different types of sulfur compounds (thiols, sulfides, benzothiophenes, etc.) present in liquid fuel can be conveted by combustion to sulphur dioxide, which is a prevailing source of environmental pollution, so many countries proposed standard S-content to lower than 10 ppm. Although, hydrocracking process produce low-sulfur content, but still needs more desulfurization, researches have done using many technologies, among that were: A: Adsorptive desulfurization (ADS), through adsorptive over such surfaces. B: Oxidative Desulfurization (ODS), using an oxidant agent to convert sulfure into form can be removed. C: Hydrodesulfurization process (HDS), which is most efficient than other methods to remove organo sulfur (aliphatic and aromatic). D: Bio desulfurization (BDS), employed microorganisms to remove sulfur atom from organic S-compounds and can be environmental friendly. E: Extractive desulfurization (EDS), is a prosses using solvent as liquid- liquid extraction. The above technologies faced some disadvenges such as nature of volatile molecular solvent coupled with limitation of loss solvent, difficult of extraction regeneration, environmental pollution and costly, as required industrial unit operation at high temperature and pressure beside the expensive of hydrogen gas and catalysts. Therefore, it has been a challenge research investigation to explore a new deep extractive desulfurization methods. Among these treatments was using ionic liquids (ILS) which composed of heterocyclic organic cation (imidazolium, pyridinium, etc.) and different inorganic anions my be applied to decrease temperature, non-toxic, chemical stability, environmental friendly as green solvent, so, (ILS) used for many applications and deep eutectic desulfurization among that. Recently, studies showed that metal contains ionic liquids for extractive sulphur removal have a high influence and ability for sulphur removal than metal free (ILS) , which may be a good solvent in separation and removal of aromatic sulphur from fuel. The Fe, Co, Ni, Zn, Cu, etc. metals halides were used with organic cation to form complexes salts. The mechanism was investigated that the metal (ILS) have almost good extraction ability explained by the complexation of metal moiety with sulfur compounds.

Electron Delocalization Enables Sulfone‐based Single‐solvent Electrolyte for Lithium Metal Batteries

AbstractLi‐metal batteries (LMB), although providing high energy density, face the grand challenge of identifying good electrolyte solvents for cycling. Common solvents are either only stable against lithium metal anode or only stable against LiNixMnyCo1‐x‐yO2 (NMC) cathode. There is significant effort trying to increase the cathode stability for ether electrolytes, which are in general stable against lithium metal anode. In comparison, there is much less effort trying to increase the anode stability of electrolytes that are stable against NMC cathode. One example is the sulfone‐based electrolyte. It has good cathode stability but is hindered from practical application because of (1) high viscosity and poor wetting capability and (2) poor anode stability. Here, we solve these issues by modifying the sulfone molecules using resonance and electron withdrawing effect. The viscosity is significantly reduced by delocalizing the electrons through introducing additional oxygen on the molecular backbone and applying appropriate fluorination. The resulting molecule 2,2,2‐trifluoroethyl mesylate (TFEM) has decreased Lewis basicity and less reactivity toward Li+. The electrolyte based on TFEM as single solvent enables cycling of LMB under harsh conditions of low N/P ratio (21 mg/cm2 NMC811 and 50 μm Li) with 90 % capacity retention after 160 cycles at C/3 discharge rate.

Electron Delocalization Enables Sulfone-based Single-solvent Electrolyte for Lithium Metal Batteries.

Li-metal batteries (LMB), although providing high energy density, face the grand challenge of identifying good electrolyte solvents for cycling. Common solvents are either stable against lithium metal anode or stable against LiNixMnyCo1-x-yO2 (NMC) cathode. There is significant effort trying to increase the cathode stability for ether electrolytes, which are in general stable against lithium metal anode. In comparison, there is much less effort trying to increase the anode stability of electrolytes that are stable against NMC cathode. An example is the sulfone solvent. It has good cathode stability but is hindered from practical application because of (1) high viscosity and poor wetting capability and (2) poor anode stability. Here, we solve these issues by modifying the sulfone molecules using resonance and electron withdrawing effect. The viscosity is significantly reduced by delocalizing the solvent electrons by introducing additional oxygen on the molecular backbone and applying appropriate fluorination. The resulting molecule 2,2,2-trifluoroethyl mesylate (TFEM) has decreased Lewis basicity and less reactivity toward Li+. The electrolyte based on TFEM as single solvent enables cycling of LMBs under harsh conditions of low N/P ratio (21 mg/cm2 NMC811 and 50 μm Li) with 90% capacity retention after 160 cycles at C/3 discharge rate.

Exploring conformations of comb-like polymers with varying grafting density in dilute solutions.

Comb-like polymers have shown potential as advanced materials for a diverse palette of applications due to the tunability of their polymer architecture. To date, however, it still remains a challenge to understand how the conformational properties of these polymers arise from the interplay of their architectural parameters. In this work, extensive simulations were performed using dissipative particle dynamics to investigate the effect of grafting density, backbone length, and sidechain length on the conformations of comb-like polymers immersed in a good solvent. To quantify the effect of these architectural parameters on polymer conformations, we computed the asphericity, radius of gyration, and backbone and sidechain end-to-end distances. Bond-bond correlation functions and effective Kuhn lengths were computed to quantify the topological stiffness induced by sidechain-sidechain interactions. Simulation results reveal that the effective Kuhn length increases as grafting density and sidechain length increase, in agreement with previous experimental and theoretical studies. This increase in stiffness results in comb-like polymers adopting extended conformations as grafting density and sidechain length increase. Simulation results regarding the radius of gyration of comb-like polymers as a function of grafting density are compared with scaling theory predictions based on a free energy proposed by Morozova and Lodge [ACS Macro Lett. 6, 1274-1279 (2017)] and scaling arguments by Tang et al. [Macromolecules 55, 8668-8675 (2022)].

Highly Solvent Resistant Small-Molecule Hole-Transporting Materials for Efficient Perovskite Quantum Dot Light-Emitting Diodes.

Perovskite quantum dot light-emitting diodes (Pe-QLEDs) have been shown as promising candidates for next-generation displays and lightings due to their unique feature of wide color gamut and high color saturation. Hole-transporting materials (HTMs) play crucial roles in the device performance and stability of Pe-QLEDs. However, small-molecule HTMs have been less studied in Pe-QLEDs due to their poor solvent resistance and low hole mobility. In this work, three novel small-molecule HTMs employing benzimidazole as the center core, named X4, X5, and X6, were designed and synthesized for application in Pe-QLEDs. One of the tailored HTM-X6 exhibits excellent solvent resistant ability to the perovskite quantum dot (QD) inks due to its proper solubility and low surface energy. Our result clearly demonstrated that the synergistic effect of poor solubility and low surface energy facilitates the achievement of good solvent resistance to perovskite QD inks. As a result, a promising maximal external quantum efficiency (EQE) of 14.1% is achieved in X6-based CsPbBr3 Pe-QLEDs, which is much higher than that of X4 (9.16%) and X5 (6.60%)-based devices, which is comparable to the PTAA reference (EQE ∼ 15.8%) under the same conditions. To the best of our knowledge, this is the first example that a benzimidazole-based small-molecule HTM demonstrated a good application in Pe-QLEDs. Our work provides new guidance for the rational design of small-molecule HTMs with high solvent resistance for efficient Pe-QLEDs and other photoelectronic devices.

A novel thin layer chromatography-flame ionization detection method for saturated, asphaltenes, resins, and asphaltenes group-type composition analysis with reverse order of chromatogram development.

The methodologies of asphaltenes-containing petroleum materials: saturated, aromatics, resins, asphaltenes group-type composition analysis are performed with the use of column adsorption-desorption or thin layer chromatography (TLC)-flame ionization detection under normal phase conditions with silica gel as the adsorbent. In a three-step procedure, the TLC chromatogram is developed within a decreasing distance by the mobile phase with increasing elution strength (polarity). The n-alkane used in the first step does not dissolve asphaltenes, which leads to the occlusion effect and an underestimation of the percentage of saturated hydrocarbons. In this article, the reverse order of the subsequent elution steps was proposed: the solvent polarity is simultaneously reduced and the chromatogram development distance is increased in the order dichloromethane:methanol 95:5 v/v, 3cm; toluene, 6cm; and n-hexane, 10cm. It was also intentional to reduce the weight of the applied sample to 5μg for bitumen and 2μg for asphaltene purity testing. It should be the rule that in stepwise TLC chromatogram development, the first mobile phase is a good solvent for all testing components. The IP 469 procedure should be corrected.

Molecular conformations of dumbbell-shaped polymers in good solvent.

We study conformational properties of diluted dumbbell polymers composed of two rings attached to both ends of a linear spacer segment. Our investigation involves analytical methods of field theory and bead-spring coarse-grained molecular dynamics simulations. We focus on the influence of the relative length of the spacer segment to the length of side rings on the shape and the relative size of dumbbells as compared to linear polymers of equal mass. We find that dumbbells with short spacers exhibit a significantly more compact structure than linear polymers. Conversely, as the spacer length increases, the influence of the side rings on the size of the dumbbells becomes negligible. Consequently, dumbbell molecules with long spacers attain a size comparable to corresponding linear chains. Our analytical theory accurately predicts a quantitative conformational crossover between the behaviors of short-spacer and long-spacer dumbbells, which is further confirmed by our numerical simulations.

Effectiveness of DPD Simulations to Predict the Dynamics of Polymer Chains in Solutions at Equilibrium and Steady Shear Flows

AbstractThe suitability of dissipative particle dynamics simulations is investigated to predict the dynamics of polymer chains in dilute polymer solutions. The authors find that the predictions depend on the value of the repulsive parameter for bead‐bead pairwise interactions used in the DPD simulations (aij). For all systems, the chain sizes and the relaxation time spectrum are analyzed. For aij = 0, theta solvent behaviour is obtained, whereas the dynamics at equilibrium agrees well with the predictions of the Zimm model. For higher values of aij, the static properties of the chain show good solvent behaviour. However, the scaling laws for the chain dynamics at equilibrium show wide variations, with consistent results obtained only at an intermediate value of aij = 25. At higher values of the repulsive parameter (aij ⩾ 25), the simulations are also able to predict the abrupt cut‐off in the relaxation spectrum, which has been observed earlier in experiments of dilute solutions. To verify further, the chain dynamics in shear flow using DPD simulations is studied. Specifically, the variation of the chain is analysed stretch and end‐over‐end tumbling with shear rates. Overall, the trends obtained from DPD simulations agree well with those observed in earlier BD simulations.

Characterisation of locust bean gum with asymmetric flow field-flow fractionation (AF4) and light scattering

We present a detailed characterisation of locust bean gum (LBG), an industrially significant galactomannan, utilising asymmetric flow field-flow fractionation (AF4) and light scattering. Molecular weight and size determination of galactomannans is complicated by their tendency to aggregate, even in dilute solutions; AF4 allows us to confirm the presence of aggregates, separate these from well-dispersed polymer, and characterise both fractions. For the dispersed polymer, we find Mw=9.2×105 g mol−1 and Rg,z=82.1 nm; the distribution follows Flory scaling (Rg∼Mν) with ν∼ 0.63, indicating good solvent conditions. The aggregate fraction exhibited radii of up to 1000 nm and masses of up to 3×1010 g mol−1. Furthermore, we demonstrate how both fractions are influenced by changes to filtration procedure and solvent conditions. Notably, a 200 nm nylon membrane effectively removes the aggregated fraction; we present a concentration-dependent investigation of solutions following this protocol, using static and dynamic light scattering, which reveals additional weak aggregation in these unfractionated samples. Overall, we demonstrate that AF4 is highly suited to LBG characterisation, providing structural information for both well-dispersed and aggregated fractions, and expect the methods employed to apply similarly to other galactomannans and associating polymer systems.

Compression and Ordering of Hollow Microgels in Monolayers Formed at Liquid-Liquid Interfaces.

Monolayers of polymer microgels with a spherical cavity adsorbed at the liquid-liquid interface were studied using mesoscopic computer simulations. One liquid, named water, was always considered as a good solvent, while the microgel solubility in the second liquid, named oil, was varied. The symmetric and asymmetric cases of vanishing and the strong differences in solubility between the network particles and the liquids were considered. The simulations provided us with an insight into the shape and volume changes of the microgels upon compression, making it possible to relate the response of the individual network with the collective order and structure of the monolayer. Similar to regular microgels, the compression of the monolayer of hollow particles led to a decrease in lateral sizes accompanied by shape transformation from a flattened to a nearly spherical shape. However, the presence of a cavity filled with solvent caused some unique differences in the behavior of the system. The adsorption pathway of hollow microgels at the liquid interface predefines: (a) the position of the particles with respect to the interface and (b) the structure of the monolayer. A striking discovery is that in the symmetric case of similar solubility of the microgel in both liquids, it is possible to produce a monolayer in which one part of the network faces the aqueous phase and the other part faces the oil phase. The polymer concentration profiles plotted along the normal to the interface reveal a redistribution of polymeric mass of the microgels relative to the interface, distinguishing between the microgels whose cavities are filled with water and oil, respectively. Moreover, the ratio between the microgels faced in water and oil does not change upon compression and predetermines the response and order of the monolayer.

Nicotinamide-based agglomerates of ibuprofen: formulation, solid state characterization and evaluation of tableting performance with in-silico investigation

BackgroundThe objective of the present investigation was to obtain directly compressible agglomerates of ibuprofen with nicotinamide by a quasi-emulsification solvent diffusion technique. Ibuprofen-nicotinamide agglomerates were prepared by quasi-emulsification solvent diffusion technique using ethanol (good solvent), water (poor solvent), and chloroform (bridging liquid). The prepared agglomerates were characterized by ATR-FTIR, powder X-ray diffraction, differential scanning calorimetry, and scanning electron microscopy and were evaluated for tableting performance and in vitro drug release. To appropriately identify the hydrogen bonding sites, a thorough understanding of the structures of API and coformer is necessary, hence molecular docking approach was implemented to depict the interaction between the proposed coformer and COX-2 protein (PDB Id:4PH9).ResultsThe percent yield of agglomerates was in the range of 85–98 w/w%, and drug content for all batches was in the range of 96–99%. The microphotographs showed irregular circularly shaped agglomerates. ATR-FTIR study showed a strong possibility of hydrogen bonding between ibuprofen and nicotinamide. The crystallinity of ibuprofen was slightly reduced and confirmed by P-XRD and DSC. Crushing strength and friability studies showed good handling qualities of ibuprofen agglomerates. Heckel plot studies showed low mean yield pressure and high tensile strength, indicating excellent compressibility and compactibility of ibuprofen agglomerates. More than 90% drug release was obtained within 60 min in PBS (pH 7.4). The docking studies revealed that nicotinamide individually has –CDOCKER energy 16.8109 where coformer showed 29.0584, which indicates coformer has a better binding affinity to target as compared to nicotinamide individual.ConclusionsIt can be concluded that the agglomerates improved the dissolution, tableting performance, and solid-state properties of ibuprofen and hence can be useful to improve the therapeutic performance of ibuprofen.Graphic

Operando tribo-Raman spectroscopic observation for wear processes of superlow frictional concentrated polymer brushes at frictional interface

Concentrated polymer brushes (CPBs) synthesized by advanced surface-initiated controlled radical polymerization have received increasing attention in the tribological field because CPBs in good solvents exhibit superlow friction phenomena under macroscopic severe sliding conditions. To realize tribological applications of CPBs, an understanding of the wear mechanisms of CPBs is required to develop a method to enhance their durability. In this study, an operando tribo-Raman spectroscopic experiment, which is an effective approach for revealing the wear mechanisms of tribo-materials, was conducted on the frictional interface between a polymethyl methacrylate (PMMA)-CPB and a bearing steel ball immersed in an ionic liquid (IL), which is a good solvent for PMMA-CPBs. From the operando tribo-Raman results, the concentrations and molecular structures of the PMMA-CPBs and IL at the frictional interface were found to be constantly changing with the sliding cycles during operation. Moreover, their time-dependent changes strongly affected the wear process and superlow friction phenomena of the PMMA-CPB lubricated with the IL. Consequently, our results suggest that controlling the degree of swelling of CPBs at frictional interface is an effective approach for realizing a durable-superlow frictional tribo-system of CPBs.

Arabinoxylan in Water through SANS: Single-Chain Conformation, Chain Overlap, and Clustering.

Using small-angle neutron scattering (SANS), we examine the structure and conformational behavior of wheat arabinoxylan (AX) prepared at various concentrations in a sodium phosphate aqueous buffer. As for another major hemicellulose, xyloglucan, we observe a small number of large clusters surrounded by AX chains that behave exactly as a polymer in good solvent with a Flory exponent ν = 0.588. The fit of the data at high q-values to a standard worm-like chain model gives the persistence length lp = 45 Å and cross section of the chains 2Rc = 11-12 Å. In addition, using a dedicated modeling approach, we extract from the SANS data at the intermediate q-range the correlation length ξ of the solutions in the semidilute regime. The decay of ξ with concentration follows a scaling law that further confirms the self-avoiding statistical behavior of the AX chains. This first comprehensive study about the properties of water-soluble AX at different length scales may help in the development of products and processes involving AX as a substitute for fossil carbon molecules.

Effect of Different Stabilizers on Spherical Agglomerates of Montelukast Sodium by Quasi Emulsion Solvent Diffusion (QESD)

Abstract: The present study was focused on the spherical crystallization of an asthmatic drug, Montelukast Sodium (MLS) using quasi emulsion solvent diffusion (QESD) technique in which distilled water was an external phase and the internal phase consisted of Ethanol which acts as good solvent and Ethyl acetate as a bridging liquid for recrystallization and agglomeration process. Apart from being poorly water soluble, MLS exhibits poor flow and compressibility. The spherical agglomeration was carried out in the presence of different stabilizers like acacia, PEG 4000, sodium lauryl sulphate, span 40 and tween 80. The prepared agglomerates were characterized in terms of production yield, drug content, solubility, in-vitro release profile, Xray diffraction (XRD), and Fourier transform infra red spectroscopy (FT-IR).The optimized spherical agglomerates exhibited excellent physicochemical and micromeritic properties, solubility and dissolution rate when compared with pure drug .The XRD also revealed a characteristic decrease in crystallinity. The dissolution studies demonstrated a marked increase in the dissolution rate. FTIR study reveals there are no chemical changes in prepared recrystallized agglomerates. The considerable improvement in the dissolution rate of MLS from optimized crystal formulation was attributed to the wetting effect of polymers, decreased drug crystallinity, altered surface morphology and micronization. If this process can be scaled-up to manufacturing level, this technology has the potential to provide the directly compressed spherical agglomerates with improving the physicochemical and micromeritic properties

A Stretchable Polymer Conductor Through the Mutual Plasticization Effect.

Intrinsically stretchable conductors play key roles in the dynamic interfacing of electronic devices with soft human tissues. However, it is difficult to simultaneously achieve high electrical conductivity and mechanical stretchability. Here, we prepared highly stretchable and conductive thin film electrodes by combining PEDOT:PSS and a mutually plasticized polymer dopant. Notably, harsh acid treatment for conductivity enhancement was avoided, and good solvent tolerance and high optical transparency were realized, all of which are essential to device fabrication. We further developed a transparent electrochromic display that can bear stretching up to 80% strain, demonstrating its promising application in next-generation optoelectronics. This article is protected by copyright. All rights reserved.

Polybenzimidazole: a novel, fluorocarbon-free, SPME sorbent binder with good thermal and solvent resistance properties for GC and LC analysis.

A novel solid-phase microextraction (SPME) coating is presentedthat uses polybenzimidazole (PBI) as a binder to immobilize micro-size sorbent particles onto a support. An evaluation of the developed binder's thermal and solvent desorption capabilities demonstrated its compatibility with both gas and liquid chromatography (GC and LC). The incorporation of hydrophilic-lipophilic balanced (HLB) particles provided optimal extraction coverage for an array of chemically diverse analytes possessing a range of hydrophobicities and molecular weights. The developed binder's performance was assessed by comparing it to a selection of binders commonly used in the literature, including polydimethylsiloxane (PDMS) and polyacrylonitrile (PAN), as well as the more recently developed polyvinylidene fluoride (PVDF) and polytetrafluoroethylene amorphous fluoroplastic (PTFE AF 2400). The results revealed that PBI provides better performance compared to PVDF and PTFE AF 2400 in terms of its environmental impact, while also being convenient for use in coating preparation and offering good matrix compatibility. The thermal analysis revealed that PBI exhibited more than 93% weight retention at 550°C, which is superior to PVDF's 80.07% weight retention at 393.78°C. To the best of our knowledge, this work is the first to use PBI as a particle binder in SPME coatings. The PBI coating maintained high extraction efficiencies under extreme conditions with pH values of 3 and 12. The performance of PBI in combination with HLB was assessed by employing it to extract several drugs of abuse and McReynolds compounds for LC and GC analysis, respectively. The results indicated that PBI performs similarly to PAN for LC but is outperformed by PDMS in GC applications with respect to extraction and desorption kinetics. Nonetheless, the thermal and solvent desorption results indicated that PBI can be used for both applications, as it remains stable at temperatures over 350°C and isstable when solvent desorption is applied.

Thermally Reversible Cross-Linking of Recyclable Polyamide Materials Based on Schiff Base and Diels-Alder Reactions.

Recyclability of cross-link polymer materials is essential to alleviate environmental pollution caused by discarded or damaged polymers. Herein, a facile method for producing recyclable polyamide materials is developed. Linear polymer chains are constructed by Schiff base reaction between glutaraldehyde (GD) and furandiamine (FD). The linear polymer chains are crosslinked by bismaleimide (BM) to give rise to polyamide material, named GF-BMs. The resulting GF-BMs polyamide material possesses strong tensile strength (78MPa) and good solvent resistance from room temperature to 135 °C. Especially, the thermally reversible Diels-Alder covalent bonds and dynamic imine bonds in the polymer network have a synergistic effect on fast-reprocessing, self-healing, and recyclability, which provides a new idea for recyclable materials.

Macroporous fibers electrospun from dual‐good solvent system

AbstractThe polymer/solvent/nonsolvent ternary solutions have been previously used for fabricating electrospun macroporous fibers, in which the nonsolvent was expected to induce a liquid–liquid phase separation that leads to formation of pores after drying. In this study, we demonstrate that the poly(styrene‐co‐acrylonitrile) (SAN)/chlorobenzene (CB)/dimethyl sulfoxide (DMSO) system can be successfully electrospun into highly uniform macroporous fibers with pore size >50 nm at CB/DMSO volume ratio ~7/3 though both CB and DMSO are good solvents to SAN. The results imply that a premixed nonsolvent is not necessary for the formation of macropores. We find that it is the water droplets condensed from the atmosphere that work as the nucleation sites to trigger the phase separation while water‐miscible DMSO plays a supporting role to expand the solvent‐rich phase and the resultant pore size. Instead of solvent quality, the distinct volatilities and water miscibilities of the solvents are the keys. The macropores throughout the fibers provide high surface areas and large openings on surface such that the fibers show a significant improvement in oil adsorption capacity in comparison to the smooth and mesoporous ones.