Silk fibroin (SF) is a fundamental building block for the development of advanced biomaterials. SF nanofibers are ideal for industrial and biomedical applications due to their excellent biocompatibility, mechanical strength, and tunable biodegradability. However, conventional electrospinning suffers from jet instability, low fiber yield, and poor spinnability, which restricts its performance and scalability. In this study, we present a high-speed, controllable electrospinning process coupled with a simple, environmentally friendly post-treatment using ethanol. SF nanofibers were produced by blending SF with ethyl cellulose (EC), a naturally derived biocompatible polymer. The addition of EC significantly enhanced the viscoelasticity of the spinning solution, enabling the continuous electrospinning of EC-SF composite fibers. This method facilitated the high-yield production of EC-SF composite fibers, offering industrial-level scalability (10 mL per h per needle) and efficiency compared to lab-scale low-SF electrospinning techniques. A key innovation of this approach is the complete removal of EC via simple ethanol washing, which exploits EC's rapid solubility in ethanol to produce large quantities of pristine ultrathin SF nanofibers (average diameter: ∼90 nm) with an ultrahigh surface area (BET: 78.82 m2 g-1). Notably, replacing ethanol with an ethanol-water mixture during post-treatment induced EC-SF microfilm formation, driven by insufficient EC solvation, which triggers gelation and subsequent rearrangement of the SF nanofibers into a network. These results confirm the tunability of our approach for generating a variety of SF-based architectures. As such, this work demonstrates a stable and eco-friendly method for fabricating SF-based composite fibers, EC-SF microfilms, and pure SF nanofibers, thereby eliminating the need for non-biodegradable synthetic polymer carriers or toxic crosslinkers. The simplicity, versatility, and sustainability of this approach offer strong potential for industrial-scale applications in biomedical engineering, filtration, and advanced materials.

Buildings account for nearly one-third of global energy consumption, creating an urgent demand for sustainable, low-conductivity insulation derived from renewable feedstocks. Soft polymeric microtubes are attractive candidates because their hollow, low-density architecture suppresses both conductive and convective heat transfer, yet their fabrication from natural polymers has long been hindered by jet instability, low throughput, and difficulty in controlling wall structures. Here, we report a sheath-assisted triaxial electrospinning strategy that overcomes these limitations and enables the high-throughput, eco-friendly fabrication of ethyl cellulose (EC) microtubes with independently tunable diameter, wall thickness, and porosity. An inner oil core, a middle EC solution, and an outer ethanol sheath are co-extruded through concentric needles; the ethanol sheath stabilizes the multilayer jet at flow rates up to 30 mL h-1 per needle-an order of magnitude higher than typical electrospinning throughputs-while preserving structural integrity. By varying the core oil flow rate and viscosity, tube diameter and wall thickness are continuously tuned from 3.0 +/- 1.2 to 19.2 +/- 7.0 mu m and from 1940 +/- 300 to 120 +/- 30 nm, respectively, with low-viscosity oils favoring the smallest, most uniform tubes. Increasing the EC solution flow rate from 5 to 30 mL h-1 transforms the wall from a dense to a highly porous architecture through accelerated phase separation and solvent evaporation. The resulting hollow, porous EC microtubes deliver low thermal conductivities of 0.130 +/- 0.007 W m-1 K-1 (radial) and 0.060 +/- 0.003 W m-1 K-1 (axial), reduce surface temperatures by more than 30 degrees C against a 70 degrees C heat source, and visibly protect heat-sensitive flowers from thermal damage. Together, these results establish a scalable, solvent-lean platform for converting a renewable polysaccharide into energy-efficient insulation materials for sustainable building applications.

The catalytic hydrogenation of CO2 to light olefins provides a promising route for converting greenhouse gases into value-added chemicals. In this work, a series of carbon nanosphere (CNS)-encapsulated Fe–Co core–shell catalysts with varying Fe/Co molar ratios were synthesized via resorcinol–formaldehyde polymerization followed by carbonization and evaluated for CO2 hydrogenation under atmospheric pressure. Among the catalysts investigated, CNS–Fe1Co2 exhibited comparatively improved catalytic performance, showing higher CO2 conversion and enhanced selectivity toward C2–C4 olefins relative to the monometallic CNS–Fe and CNS–Co catalysts. Structural characterization suggested the formation of a CNS-confined Fe–Co core–shell structure. XRD and XPS analyses indicated progressive transformation of Fe oxide species into carburized Fe-containing phases during reaction, while H2-TPR results suggested strong interaction between Fe and Co species. Raman spectroscopy and TGA results further indicated that the graphitic CNS framework remained largely preserved after reaction. The combined results suggest that Fe–Co interaction together with CNS confinement influences catalyst reducibility, carburization behavior, and structural stability during CO2 hydrogenation.

Designing stimuli-responsive carriers that combine the pH-sensitivity of a metal–organic framework (MOF) with the thermal switching of a phase-change material (PCM) requires careful control of the materials process, not only of the materials themselves. Here we report a coaxial-electrospray process that converts a doxorubicin (Dox)-loaded zeolitic imidazolate framework-8 (Dox@ZIF-8) core into a Dox@ZIF-8@PCM core–shell microparticle, using a 4:1 lauric acid/stearic acid (LASA) eutectic with a melting peak near 39 °C as the temperature-triggered shell. Two systematic process studies were carried out. First, the one-pot Dox encapsulation step was tuned across three Dox feed concentrations (0.5, 1.0, and 6.0 mg mL−1), yielding drug loading content of 0.47%, 1.44%, and 3.68%, with particle diameters that decreased from 354 to 210 nm and morphologies that shifted from rhombic dodecahedral toward more spherical as Dox content fell. Second, the outer LASA flow rate of the coaxial electrospray was varied across six set-points from 0.4 to 0.75 mL h−1, identifying 0.65 mL h−1 as the operating point that produces uniform, fiber-free spherical shells of ∼54% PCM content. SEM, XRD, FTIR, DSC, and TGA confirmed that the ZIF-8 framework is retained through encapsulation and that LASA forms a continuous shell with a 38.1 °C melting temperature. In vitro release showed a 76% pH-driven contrast (pH 4.0 vs. 10.0) and a 62% temperature-driven contrast (40 °C vs. 37 °C). The work establishes a process window for transferring this dual-stimuli platform from a model dye to a clinically relevant active pharmaceutical ingredient.

Localized stimuli-responsive delivery systems for chemotherapy drugs have the potential to revolutionize therapeutic outcomes by offering greater selectivity, thereby reducing systemic side effects and bolstering patient benefits. In this work, ethyl cellulose (EC) nanofibers were prepared using electrospinning, encapsulating both doxorubicin HCl (DOX) and Rhodamine B (RhB) as representative hydrophilic chemotherapy and model drugs, respectively, and lauric acid (LA) as a biocompatible phase change material (PCM). In vitro release profiles demonstrated a distinct temperature-dependent release pattern: a noteworthy 27% increase in release for DOX at pH 7.4 at 40°C compared to 37°C after 96 h. Additionally, the release mechanism of DOX showcased pronounced pH sensitivity, evidenced by an increase of 41% in release after 96 h at pH 4 when the temperature was increased from 37°C to 40°C, combined with a noticeable reduction of burst release. Furthermore, cytotoxicity assay indicated the prolonged efficacy of the DOX-embedded nanofibers, underscoring their therapeutic potential. Advanced analytical techniques, such as DSC, XRD, and FTIR, revealed an amorphous state of the drugs and a harmonious PCM integration. Our EC drug delivery system (DDS) demonstrated potential for targeted, stimuli-responsive DOX release, which could revolutionize its traditional administration, particularly in post-surgical scenarios to prevent tumor recurrence.

In this study, the fabrication and multifunctional performance of snowman-shaped particles with integrated amphiphilicity, photocatalytic activity, and magnetic responsiveness are investigated. By utilizing a swellingassisted protrusion strategy on titania-coated polymeric spheres, anisotropic structures with distinct hydrophilic titania and hydrophobic polymer domains are formed. The titania domains serve as photocatalytic sites, while the hydrophobic polymer protrusions promote selective and strong anchoring at oil-water interfaces, thereby allowing the snowman-shaped particles to work as solid surfactants. Crystallization of the titania shell via thermal treatment enhances the photocatalytic degradation efficiency of rhodamine B under UV irradiation. Magnetic responsiveness, which arises from the incorporation of magnetic clusters in the titania domain, allows efficient magnetic recovery and reuse of the snowman-shaped particles. These magnetic snowman-shaped particles exhibit excellent oil removal performance and sustained photocatalytic activity over multiple cycles. The findings highlight the potential of anisotropic particle design and surface engineering in the development of reusable hybrid materials for simultaneously treating multiple contaminants in wastewater.

This study introduces a novel temperature-responsive drug delivery system using ethyl cellulose (EC) nanofibers encapsulating a eutectic mixture of lauric acid/stearic acid (LA/SA) as phase change materials (PCMs) and Rhodamine B (RhB) as a model drug. Employing blend electrospinning, the nanofibers achieved controlled drug release responsive to temperature changes. The peak shift of the carbonyl group in FTIR analysis confirmed drug-polymer compatibility, while the absence of RhB peaks in the XRD and DSC assessments revealed RhB's amorphous distribution within the fibers. Our findings demonstrate that RhB release is dependent on its loading, with a slow initial release (<2 %) for 1 % and 5 % RhB loadings and a burst release (similar to 12 %) for 10 % loading. Notably, the release rate was tunable at 37 degrees C by adjusting LA/SA concentration. The optimal LA/SA loading for temperature-responsive release is identified as 10 %. Over 240 h, there is a 32 % increase in RhB release at 37 degrees C, and an additional 8 % increase at 40 degrees C, compared to 25 degrees C. This research illustrates the potential of PCM-integrated nanofibers in smart drug delivery, particularly for chemotherapy, antibiotics, and anti-inflammatory drugs, showcasing an innovative approach to improving therapeutic efficiency while reducing side effects.

In this study, we explored an innovative application of heat-assisted solution electrospinning, a technique that significantly advances the control of phase separation in polystyrene (PS) fibers. Our experimental approach involved the use of direct heating and a convection air sheath applied through a coaxial needle, focusing on solvents with varying vapor pressures. This method enabled a detailed investigation into how solvent evaporation rates affect the morphology of the electrospun fibers. SEM and AFM measurements revealed that the application of direct heating and a heated air sheath offered precise control over the fiber morphology, significantly influencing both the surface and internal structure of the fibers. Additionally, we observed notable changes in fiber diameter, indicating that heat-assisted electrospinning can be effectively utilized to tailor fiber dimensions according to specific application requirements. Moreover, our research demonstrated the critical role of solvent properties, particularly vapor pressure, in determining the final characteristics of the electrospun fibers. By comparing fibers produced with different solvents, we gained insights into the complex interplay between solvent dynamics and heat application in fiber formation. The implications of these findings are far-reaching, offering new possibilities for the fabrication of nanofibers with customized properties. Furthermore, this could have profound impacts on various applications, from biomedical to environmental, where specific fiber characteristics are crucial. This study not only contributes to the understanding of phase separation in electrospinning but also opens avenues for further research on the optimization of fiber properties for diverse industrial and scientific applications.

Amid growing concerns about climate change and energy sustainability, the need to create potent catalysts for the sequestration and conversion of CO2 to value-added chemicals is more critical than ever. This work describes the successful synthesis and profound potential of high-performance nanofiber catalysts, integrating earth-abundant iron (Fe) and cobalt (Co) as well as their alloy counterpart, FeCo, achieved through electrospinning and judicious thermal treatments. Systematic characterization using an array of advanced techniques, including SEM, TGA-DSC, ICP-MS, XRF, EDS, FTIR-ATR, XRD, and Raman spectroscopy, confirmed the integration and homogeneous distribution of Fe/Co elements in nanofibers and provided insights into their catalytic nuance. Impressively, the bimetallic FeCo nanofiber catalyst, thermally treated at 1050 degree celsius, set a benchmark with an unparalleled CO2 conversion rate of 46.47% at atmospheric pressure and a consistent performance over a 55 h testing period at 500 degree celsius. Additionally, this catalyst exhibited prowess in producing high-value hydrocarbons, comprising 8.01% of total products and a significant 31.37% of C2+ species. Our work offers a comprehensive and layered understanding of nanofiber catalysts, delving into their transformations, compositions, and structures under different calcination temperatures. The central themes of metal-carbon interactions, the potential advantages of bimetallic synergies, and the importance of structural defects all converge to define the catalytic performance of these nanofibers. These revelations not only deepen our understanding but also set the stage for future endeavors in designing advanced nanofiber catalysts with bespoke properties tailored for specific applications.

The rheological properties of nanocellulose aqueous suspensions play a critical role in the development of nanocellulose-based bulk materials. High-crystalline, high-aspect ratio, and slender nanofibrillated cellulose (NFC) were extracted from four biomass resources. The cellulose nanofibrils and nanofibril bundles formed inter-connected networks in the NFC aqueous suspensions. The storage moduli of the suspensions with different concentrations were higher than their corresponding loss moduli. As the concentration increased, the storage and loss modulus of NFC dispersion increased. When the shear rate increased to a certain value, there were differences in the changing trend of the rheological behavior of NFC aqueous suspensions derived from different biomass resources and the suspensions with different solid concentrations. NFC dispersion’s storage and loss modulus increased when the temperature rose to nearly 80°C. We hope this study can deepen the understanding of the rheological properties of NFC colloids derived from different biomass resources.

In this study, the effect of surface modification and the resulting surface charge of colloidal silica seeds on the growth of silica rods during an emulsion droplet-based process is investigated. Through electrostatic interactions between negatively charged poly(vinylpyrrolidone) (PVP) and seed surfaces, significant PVP adsorption occurs as the seed surfaces are modified with positively charged cationic substances and then aged with PVP. This surface charge-enhanced PVP adsorption promotes the anchoring of water emulsion droplets, serving as the starting point for the growth of silica rods on the seed surfaces and leading to a high yield of silica rod-decorated particles during emulsion droplet-based growth. The surface properties, including surface charge and hydrophobicity, can be further modified by applying different cationic modifiers, which influence the morphology, structural architecture, and yield of the final product. We further demonstrated the versatility of this approach by successfully generating silica rod-decorated magnetic core (Fe3O4)–multishell (silica/polystyrene/titania) particles. The findings of this study highlight the critical role of surface charge engineering in controlling the structure and morphology of silica rod-decorated silica particles as well as their integration into complex multicomponent systems.

Stimuli-responsive drug delivery systems (DDSs) offer precise control over drug release, enhancing therapeutic efficacy and minimizing side effects. This review focuses on DDSs that leverage the unique capabilities of phase change materials (PCMs) and metal-organic frameworks (MOFs) to achieve controlled drug release in response to pH and temperature changes. Specifically, this review highlights the use of a combination of lauric and stearic acids as PCMs that melt slightly above body temperature, providing a thermally responsive mechanism for drug release. Additionally, this review delves into the properties of zeolitic imidazolate framework-8 (ZIF-8), a stable MOF under physiological conditions that decomposes in acidic environments, thus offering pH-sensitive drug release capabilities. The integration of these materials enables the fabrication of complex structures that encapsulate drugs within ZIF-8 or are enveloped by PCM layers, ensuring that drug release is tightly controlled by either temperature or pH levels, or both. This review provides comprehensive insights into the core design principles, material selections, and potential biomedical applications of dual-stimuli responsive DDSs, highlighting the future directions and challenges in this innovative field.

This study reports the successful synthesis of core-shell microparticles utilizing coaxial electrospray techniques, with zeolitic imidazolate framework-8 (ZIF-8) encapsulating rhodamine B (RhB) in the core and a phase change material (PCM) shell composed of a eutectic mixture of lauric acid (LA) and stearic acid (SA). ZIF-8 is well-recognized for its pH-responsive degradation and biocompatibility, making it an ideal candidate for targeted drug delivery. The LA-SA PCM mixture, with a melting point near physiological temperature (39 °C), enables temperature-triggered drug release, enhancing therapeutic precision. The structural properties of the microparticles were extensively characterized through scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). Drug release studies revealed a dual-stimuli response, where the release of RhB was significantly influenced by both temperature and pH. Under mildly acidic conditions (pH 4.0) at 40 °C, a rapid and complete release of RhB was observed within 120 h, while at 37 °C, the release rate was notably slower. Specifically, the release at 40 °C was 79% higher than at 37 °C, confirming the temperature sensitivity of the system. Moreover, at physiological pH (7.4), minimal drug release occurred, demonstrating the system’s potential for minimizing premature drug release under neutral conditions. This dual-stimuli approach holds promise for improving therapeutic outcomes in cancer treatment by enabling precise control over drug release in response to both pH and localized hyperthermia, reducing off-target effects and improving patient compliance.

For this work, we investigated the promotor effect (M = Na+, K+, Ce3+, Zn2+, Mn2+) on carbon nanosphere-encapsulated bimetallic Fe-Co core–shell catalysts for CO2 hydrogenation, promising selectivity for converting CO2 to light olefins. The fresh and spent catalysts were characterized using a combination of experimental techniques such as scanning electron microscopy (SEM), X-ray diffraction (XRD), thermogravimetric analysis and differential scanning calorimetry (TGA–DSC), and Raman spectroscopy, and our results reveal that the addition of the promotor M enhanced the formation of graphitic carbon and metal carbides in the promoted catalysts when compared with the unpromoted catalysts. The metal carbides were determined to be the active sites for the production of light olefins.

Electrospun nanofibers for drug delivery systems (DDS) introduce a revolutionary means of administering pharmaceuticals, holding promise for both improved drug efficacy and reduced side effects. These biopolymer nanofiber membranes, distinguished by their high surface area-to-volume ratio, biocompatibility, and biodegradability, are ideally suited for pharmaceutical and biomedical applications. One of their standout attributes is the capability to offer the controlled release of the active pharmaceutical ingredient (API), allowing custom-tailored release profiles to address specific diseases and administration routes. Moreover, stimuli-responsive electrospun DDS can adapt to conditions at the drug target, enhancing the precision and selectivity of drug delivery. Such localized API delivery paves the way for superior therapeutic efficiency while diminishing the risk of side effects and systemic toxicity. Electrospun nanofibers can foster better patient compliance and enhanced clinical outcomes by amplifying the therapeutic efficiency of routinely prescribed medications. This review delves into the design principles and techniques central to achieving controlled API release using electrospun membranes. The advanced drug release mechanisms of electrospun DDS highlighted in this review illustrate their versatility and potential to improve the efficacy of medical treatments.

Drug-releasing contact lenses are emerging therapeutic systems for treating ocular diseases. However, their applicability is limited by the burst release of drugs during lens wear and premature drug leakage during packaging, rendering the precise control of release duration or dose difficult. Here, we introduce a pH-sensitive contact lens exhibiting on-demand drug release only during lens wear and negligible premature drug leakage during packaging and transportation, which is accomplished by incorporating drug-loaded mesoporous silica nanoparticles (MSNs) coated with a pH-sensitive polymer into the contact lens. The compositionally optimized pH-sensitive polymer has a lower critical solution temperature (LCST) at >45 °C at pH 7.4, whereas its LCST decreases to <35 °C under acidic conditions (pH ∼ 6.5). Consequently, the MSN-incorporated contact lens sustainably releases the loaded drugs only in the acidic state at 35 °C, which corresponds to lens-wear conditions, through the MSN pores that open because of the shrinkage of polymer chains. Conversely, negligible drug leakage is observed from the contact lens under low-temperature or neutral-pH conditions corresponding to packaging and transportation. Furthermore, compared with the plain contact lens, the pH-sensitive contact lens exhibits good biocompatibility and unchanged bulk characteristics, such as optical (transmittance in the visible-light region), mechanical (elastic modulus and tensile strength), and physical (surface roughness, oxygen permeability, and water content) properties. These findings suggest that the pH-sensitive contact lens can be potentially applied in ocular disease treatment.

In this study, we explored the influence of molecular interactions and solvent evaporation kinetics on the formation of porous structures in electrospun nanofibers, utilizing polyacrylonitrile (PAN) and polystyrene (PS) as model polymers. The coaxial electrospinning technique was employed to control the injection of water and ethylene glycol (EG) as nonsolvents into polymer jets, demonstrating its potential as a powerful tool for manipulating phase separation processes and fabricating nanofibers with tailored properties. Our findings highlighted the critical role of intermolecular interactions between nonsolvents and polymers in governing phase separation and porous structure formation. Additionally, we observed that the size and polarity of nonsolvent molecules affected the phase separation process. Furthermore, solvent evaporation kinetics were found to significantly impact phase separation, as evidenced by less distinct porous structures when using a rapidly evaporating solvent like tetrahydrofuran (THF) instead of dimethylformamide (DMF). This work offers valuable insights into the intricate relationship between molecular interactions and solvent evaporation kinetics during electrospinning, providing guidance for researchers developing porous nanofibers with specific characteristics for various applications, including filtration, drug delivery, and tissue engineering.

In an epoch dominated by escalating concerns over climate change and looming energy crises, the imperative to design highly efficient catalysts that can facilitate the sequestration and transformation of carbon dioxide (CO2) into beneficial chemicals is paramount. This research presents the successful synthesis of nanofiber catalysts, incorporating monometallic nickel (Ni) and cobalt (Co) and their bimetallic blend, NiCo, via a facile electrospinning technique, with precise control over the Ni/Co molar ratios. Application of an array of advanced analytical methods, including SEM, TGA–DSC, FTIR-ATR, XRD, Raman, XRF, and ICP-MS, validated the effective integration and homogeneous distribution of active Ni/Co catalysts within the nanofibers. The catalytic performance of these mono- and bimetallic Ni/Co nanofiber catalysts was systematically examined under ambient pressure conditions for CO2 hydrogenation reactions. The bimetallic NiCo nanofiber catalysts, specifically with a Ni/Co molar ratio of 1:2, and thermally treated at 1050 °C, demonstrated a high CO selectivity (98.5%) and a marked increase in CO2 conversion rate—up to 16.7 times that of monometallic Ni nanofiber catalyst and 10.8 times that of the monometallic Co nanofiber catalyst. This significant enhancement in catalytic performance is attributed to the improved accessibility of active sites, minimized particle size, and the strong Ni–Co–C interactions within these nanofiber structures. These nanofiber catalysts offer a unique model system that illuminates the fundamental aspects of supported catalysis and accentuates its crucial role in addressing pressing environmental challenges.

In this study, we present an ecofriendly technique for encapsulating lauric acid (LA), a natural phase change material, within polystyrene (PS) nanofibers through coaxial electrospinning. The resulting LAPS core-sheath nanofibers exhibited a melting enthalpy of up to 136.6 J/g, representing 75.8% of the heat storage capacity of pristine LA (180.2 J/g), a value surpassing all previously reported core-sheath fibers. Scanning electron microscopy revealed uniform LAPS nanofibers free of surface LA until the core LA feed rate reached 1.3 mL/h. As the core LA feed rate increased, the fiber diameter shrank from 2.24 ± 0.31 to 0.58 ± 0.45 μm. Infrared spectra demonstrated a proportional increase in the LA content with rising core LA injection rates. Thermogravimetric analysis found the maximum core LA content in core-sheath nanofibers to be 75.0%. Differential scanning calorimetry thermograms displayed a trend line shift upon LA leakage for LA1.3PS nanofibers. LAPS fibers containing 75.0% LA effectively maintained consistent cycling stability and reusability across 100 heating-cooling cycles (20-60 °C) without heat storage deterioration. The core LA remained securely within the PS sheath after 100 cycles, and the LAPS nanofibers retained an excellent structural integrity without rupture. The energy-dense and form-stable LAPS core-sheath nanofibers have great potential for various thermal energy storage applications, such as building insulation, smart textiles, and electronic cooling systems, providing efficient temperature regulation and energy conservation.

Electrospinning is a straightforward technique for the fabrication of nanofibers with the potential for various applications. Thermal energy storage systems using electrospun nanofibers have gained researchers’ attention due to its desirable properties such as nanoscale diameter, large surface area, excellent thermal conductivity, and high loading and thermal energy storage capacity. The encapsulation of phase change materials (PCMs) in electrospun nanofibers for storing renewable thermal energy can be achieved by uniaxial electrospinning of a blend of PCM and polymer, coaxial electrospinning of a PCM core and a polymer sheath, or post-electrospinning absorption. The PCM content and thermal energy storage capacity of different PCM composite nanofibers are compared in this chapter. The drawbacks of traditional electrospinning PCM encapsulation techniques and benefits of post-electrospinning encapsulation methods are discussed.