The fabrication of functional nanofibrous composites by one-step electrospinning relies on the assumption that incorporated particles remain accessible after fiber formation. In practice, however, particle positioning within the fibers is strongly governed by the spinning process. In this work, we compare needle-based and needleless wire electrospinning to evaluate how processing conditions influence the distribution and functional accessibility of UiO-66 and NH2-UiO-66 particles embedded in polyacrylonitrile (PAN) nanofibers. Although the crystalline structure of the metal organic frameworsks (MOFs) is preserved after electrospinning, X-Ray Photoelectron Spectroscopy (XPS), specific surface area analysis, and CO2 sorption measurements show that their porosity remains largely inaccessible due to encapsulation within the polymer matrix. Needle-spun composites exhibit the strongest loss of accessible surface area and no measurable enhancement in CO2 uptake, while wire-spun fibers show slightly higher porosity and a modest sorption increase, indicating reduced but still significant pore obstruction. These results demonstrate that electrospinning technology critically determines particle accessibility and, consequently, the functional performance of MOF/polymer composites. The findings highlight an inherent limitation of the one-step blending approach and underscore the need for surface-directed spinning strategies when accessible active sites are required for sorption or catalytic applications.

The urgent demand for efficient carbon capture technologies has sparked the search for simple, scalable materials with tailored sorption properties. In this study, we demonstrate that unmodified cellulose acetate (CA) nanofiber membranes can serve as effective CO2 sorbents at room temperature, offering a low-cost and environmentally friendly alternative to chemically modified polymeric systems. The distinct wrinkled morphology of the CA nanofibers achieved through targeted electrospinning conditions (solvent selection and high humidity) enhances the surface area and contributes to a CO2 sorption capacity of up to 2.14 mmol/g, comparable to that of more complex porous materials. Beyond single-material systems, we emphasize the often-overlooked role of matrix–additive compatibility in composite membranes. Using a CA/β-zeolite system as a case study, we show that specific interactions between the polymer matrix and active phase–β- ammonium zeolite can entirely suppress CO2 sorption instead of the assumed synergy of sorption properties for both components. The cellulose-based support was chosen for its biodegradability and biocompatibility, further supporting its use in sustainable technologies. To address the stability of modifying agents, we introduce a sandwich-type nanofiber membrane architecture (CA/Zeolite/CA) in which active nanocrystals–β-zeolites are embedded and fixed within layered structures. However, the sandwich structure of the membrane in this case indicated a negative effect of the mutual interaction of the CA carrier and β-ammonium zeolites on the sorption capacity of the composite membrane. Overall, the combination of simplicity, performance, and green chemistry makes CA nanofiber membranes a promising candidate for scalable and sustainable CO2 capture.

The increasing concentration of atmospheric carbon dioxide (CO2) demands innovative solutions for its capture and sequestration. Composite and nanocomposite materials have gained attention for their high surface area, adjustable properties, and improved adsorption capabilities. This manuscript explores the preparation, characterization, and performance assessment of a novel composite material consisting of polyamide 6 nanofibers combined with two types of zeolites, designed for CO2 capture. We detail the fabrication process, as well as the structural, chemical, and morphological characterization of the composites. The results confirmed the successful modification of polyamide 6 nanofibers with both types of zeolites. CO2 sorption measurements revealed that the composite with zeolite Y exhibited a notably high sorption capacity, with a maximum of 35.8 cm³/g, significantly surpassing the performance of amine-modified nanofibers, which demonstrated sorption capacities approximately three times lower. These findings highlight the potential of this composite for efficient CO2 capture, providing valuable insights into its practical application for reducing greenhouse gas emissions. While the CO2 sorption capacities of the composite are lower than those of pure zeolites, the composite offers practical advantages, such as easier handling and simplified application.

A graphic representation of applied electrospinning technology and methods of one-step and multi-step modification of nanofibrous membranes for targeted hydrogen sorption.

Fluorocarbon-based (CF) nanofibrous membrane has been prepared by electrospinning of a source polyvinylidene fluoride and its surface was modified by CeOx nanoparticles by immersion in a water colloidal solution with CeOx nanoparticles (CeOx NPs). Two ways of the deposition of CeOx nanoparticles on the CF nanofiber membrane were used: (1) deposition of CeOx NPs on the pristine electrospun membrane and (2) the immediate deposition CeOx NPs on the plasma treated electrospun membrane. We investigated the effect of plasma treatment on the amount of CeOx NPs deposited on CF nanofiber surfaces and on the Ce3+/Ce4+ ratio in CeOx NPs deposited on CF. The amount of CeOx on nanofiber surfaces was determined by XPS (X-ray photoelectron spectroscopy) and SEM analysis. Results showed a significant increase of CeOx NPs amount on the plasma treated CF membrane, accompanied by slight decrease of Ce3+/Ce4+ ratio in CeOx NPs adherent on plasma treated CF surface in comparison with pristine CF surface. Detailed analysis of XPS spectra - C1s, O1s, and Ce3d indicated a possibility of the chemical bonding of CeOx NPs on the plasma treated CF surface.

Manufacturing of membranes for carbon dioxide (CO 2 ) capture is a significant research topic. Achieving maximum CO 2 sorption capacity while maintaining air permeability with a minimum number of technological steps was the main motivation of this work. The greatest advantages of this approach are its simplicity, low cost and easy transition to industrial scale. Electrospun nanofibrous membranes polyacrylonitrile (PAN)/triethylenetetramine (TETA) and polyacrylonitrile (PAN)/tetraethylenepentamine (TEPA) were prepared by one-step technology (modifying amines TETA, TEPA in different weight concentrations dissolved directly in spinning solution) using two different spinning conditions: needle spinning (electric field attached to a hollow needle through which a polymer solution is extruded under pressure) and wire spinning (electric field connected to a thin wire that is coated with a layer of polymer solution, and the spinning thus takes place from the free surface). Wire electrospinning turns out to be more suitable for a one-step technology with a modifying substance in the spinning solution. The best result as to the CO 2 sorption capacity has been obtained for wire spinning PAN_TEPA_2% 11.7 ± 1.3 cm 3 /g with air permeability 53 ± 5 L/m 2 /s, which gives a good chance for the design of a sandwich functional unit for practical use. In addition to studies of CO 2 adsorption, the article also deals with the comparison of both spinning methods for the PAN polymer, which have not yet been compared for this polymer in the literature, not only from the point of view of the possibility of preparing PAN nanofibers, but also their functional use precisely for CO 2 capture.

Layered crystal structures tend to form flat platelet-like crystallites, and nanofibers having such a structure exhibit strip-like morphology. Crystallographic plane forming the dominant flat surface of the nanofibers can be used for surface modification with catalytically active nanoparticles capable of anchoring to the dominant flat surface. In this study, polyvinylidene fluoride (PVDF) nanofibers exhibiting strip-like morphology and longitudinal folding were prepared using wire electrospinning, and surface modified with CeO2 nanoparticles. Experimental characterization of the CeO2/PVDF membrane using (high-resolution) scanning electron microscopy and X-ray photoelectron spectroscopy was supplemented by a force field-based molecular modeling. The modeling has shown that the dominant PVDF(100) plane is suitable for anchoring the CeO2 nanoparticles. In this respect, the PVDF(100) plane is comparable to the less exposed fluorine-oriented PVDF(010) plane, and both planes show stronger interaction with CeO2 compared to hydrogen-oriented PVDF(010) plane. Molecular modeling also revealed preferred crystallographic orientations of anchored CeO2 nanoparticles: these are the catalytically active planes (100), (110), and (111). The successful surface modification and the finding that CeO2 nanoparticles on the dominant PVDF(100) surface can preferentially exhibit these crystallographic orientations thus provides the possibility of various practical applications of the CeO2/PVDF membrane.

The influence of Al/Ti and Al/Cr ratios on the structural, mechanical and tribological properties of AlTiSiN and AlCrSiN coatings, deposited by the cathodic arc evaporation PVD method at a temperature of 400°C, was investigated. The remains of the original AlSiN hexagonal phase were observed in the obtained coatings as well as the crystallites of cubic TiN and CrN, respectively. XPS analysis assumes the presence of a substoichiometric SiN. The addition of 11 at.% Ti or 13 at.% Cr in AlSiN led to an increase in both the coating’s resistance to plastic deformation and the plasticity index. The addition of 13 at.% and 24 at.% Cr to the AlSiN coating structure resulted in a decrease in the average coefficient of friction with 18% and 36% against a counterpart of Al2O3, respectively, and with 36% for both concentration against steel ball counterpart. The addition of Ti have no influence on the values of the coefficient of friction at using ceramic counterpart, while at steel counterpart decreased it up to 30%. Both element change the abrasion effect of the coating.Keywords:AlCrSiN; AlTiSiN;Cathodic Arc Deposition; Tribological Behaviour; Abrasion Resistance; Nanoindentation

A simple one-step technology of wire electrospinning is presented for the manufacturing of air-permeable CO2-capturing membranes, easily transferable to industrial production lines. The design of the chemically-modified polyurethane nanofiber membranes for CO2 capture was based on a combination of molecular modeling and technological experiments using one-step electrospinning (i.e., a modifying agent dissolved directly in a spinning solution). Polyurethane (PUR Larithane), chemically modified by TETA/TEPA amines, was used in the present study for the membrane design. Special attention was paid to two key parameters significant for the design of the functional unit, i.e., the CO2 sorption capacity and air permeability which depended on the amine concentration. The optimal combination of these parameters was found for the PUR/TEPA membrane (5 wt.% of TEPA in spinning solution): the sorption capacity was 13.97 cm(3)/g with an air permeability of 0.020 m/s. Molecular modeling proved to be a valuable tool that helped to clarify, at the molecular level, the structure of chemically-modified nanofibrous membranes.

Electrospun nanofiber membranes for filtration and medical applications are still under rapid development. The common example of membranes - polyamide 6 (PA6) with hydrophilic properties was selected for the conversion to hydrophobic membranes. The fiber diameter in the membrane is about 100 nm. To reach the hydrophobic properties, the hydrophilic PA6 membrane was plasma coated by CF film from Argon/C4F8 = 2:1 gas mixture in radio frequency (RF) 20 W plasma in total pressure about 0.7 Pa for 5 min. The membranes are by this process coated deeply inside the structure up to underlying spunbond substrate used for the membrane production as a collector substrate. The contact angle measured on CF functionalized membrane is about 120 degrees and it is higher than the contact angle measured on the reference flat CF coating on Si sample with same chemical bonding. Chemical structure was studied by XPS where identical CFx components were identified on flat samples and on the top of functionalized membrane. The zeta potential decreased significantly if PA6 membrane is functionalized by CF groups. The coating process did not damage the nanofibers in the membrane and the diameters of the fibers were not significantly increased.

Polyvinylidene fluoride (PVDF) polymeric nanofibers deposited by roller electrospinning on polypropylene nonwoven fabric were treated with atmospheric pressure plasma to hydrophilize its surface. Diffuse coplanar surface barrier discharge (DCSBD) was employed to generate low-temperature atmospheric plasma in ambient air. Changes in wettability were determined by evaluating water contact angles before and after plasma treatment for various treatment times. The effect of aging of plasma-treated surfaces stored in laboratory conditions was studied in the course of storage time. The chemical composition of the surfaces was determined by X-ray photoelectron spectroscopy (XPS) which showed a decrease in carbon and an increase in oxygen atomic concentrations. Subsequently, significant differences in loading of iron oxide nanoparticles between treated and untreated PVDF samples were observed by scanning electron microscopy.

Present paper shows special benefits of low energy plasma treatment on PVDF electrospun nanofiber membrane, where the plasma power 120W has been applied between two flat electrodes creating homogeneous electric field. This experimental arrangement was crucial for two specific effects: (1) Surface activation took place by the scission of C-H bonds without defluorination (preserving the stronger C-F bonds) and consequently preserving the chains ordering and (2) Homogeneous electric field by low plasma power led to better chains ordering, higher degree of crystallinity and increase in the proportion of electroactive beta phase to almost the entire sample volume. This is a major difference from previous publications using higher plasma energies (240-500W) that report successful surface activation, but accompanied by defluorination, chain breaks and a decrease in the electroactive beta phase fraction.

Polyacrylonitrile (PAN) membranes have been prepared using needleless electrospinning with wire electrode and characterized by a series of methods HRSEM, XRD, air permeability and area weight measurements in dependence of high voltage and electrode distance. HRSEM analysis revealed the tendency to longitudinal rolling of strip-shaped PAN fibers forming hollow fibers. Combination of XRD analysis and molecular modeling explains this phenomenon as the consequence of the specific crystal structure of PAN fibers, where the isotactic PAN chains are arranged in layers forming belt shaped nanofibers with the strong tendency to roll up longitudinally forming hollow fibers. This effect offers the possibility to create hollow nanofibers by electrospinning with the appropriate choice of structure of polymer chains.

Krystalizace polymerních nanovláken pøi elektrostatickém zvláknìní probíhá v silném elektrickém poli (napìtí mezi elektrodami desítky kV). Na krystalovou strukturu a mor fo logii polymerních nanovláken má silný vliv nejen intenzita elektrického pole, ale i celá øada dalších faktorù. Kromì vlastností zvlákòujících roztokù jako je viskozita a elektrická vodivost je pro krystalizaci dùležitý i charakter zvlákòující aparatury (jehlové zvláknìní, resp. nanospider se strunovou nebo válcovou elektrodou) a uspoøádání zvlák òující aparatury (vzdálenost a tvar elektrod). Tato technologie vede pøirozenì k pøednostní orientaci krysta litù, kdy krystalový smìr pøednostní orientace leží v ose vlákna. O typu textury tzn. o její symetrii rozhoduje cha rak ter polymerních øetìzcù daný jejich molekulární struk turou. Polymerní øetìzce bez postranních funkèních skupin tvoøí krystalové struktury s pseudohexagonálním uspoøá dáním polymerních øetìzcù pøibližnì válcového tvaru. Polymerní øetìzce s výraznì asymetrickou struk turou s pos tran ními funkèními skupinami tvoøí složitìjší vrstev naté struktury s texturou, jejíž distribuèní funkce nemá válcovou symetrii. To se projeví samozøejmì výraznì na morfologii nanovláken a následnì na užitných vlastnos tech nanovlákenné membrány pokud jde o vzdušnou a kapalinovou propustnost.

Antimicrobial polyvinylidene fluoride (PVDF) membrane modified by dodecyltrimethyl ammonium bromide (DTAB) has been electrospun using simple one-step technology, where the modifying agent DTAB is dissolved in spinning solution. X-ray photoelectron spectroscopy and electrokinetic analysis confirm reliably the presence of DTAB on the nanofibers surfaces; electrokinetic analysis shows the changes of zeta potential due to modification by DTAB. X-ray diffraction shows that electrospinning converts the part of phase (approximate to 40%) present in PVDF powder into phase with all trans (TTT) zigzag chains conformation in PVDF electrospun membrane. Surface modification does not affect the phase composition of PVDF nanofibers, just only leads to lower crystallinity (smaller size of crystallites) in PVDF nanofibers. DTAB causes the curling of fibers and their aggregation, what completely changed the membrane structure. DTAB-modified membrane exhibits antibacterial properties against Staphylococcus aureus subsp. Aureus. Concentration of 0.5 wt% DTAB in spinning solution causes partial inhibition of bacterial growth only, while 1.0 wt% concentration leads to complete inhibition.

TiCN thin coatings with various different carbon contents were deposited using cathode arc evaporation of pure titanium in a mixture of N-2 and C2H2 gasses at a constant pressure of 1.5 Pa. The analyses show a transition from a stoichiometric to a non-stoichiometric coating structure with an increasing C2H2 content. Moreover, the increase in the acetylene in the gas mixture leads to a decrease in the crystal phase from pure polycrystalline to pure amorphous. Nanohardness changes from 30.4 to 4.4 GPa and the cohesive failure of the coatings is in the range of 61 - 72 N. The tribology is estimated by the Ball-on-Disc method and an Si3N4 ball as the counterpart. The measured coefficient of friction is in the range of 0.2 - 0.56.

Stable antimicrobial nanofibrous membrane for air filtration based on polyamide 6 (hereafter PA6) modified by 1-dodecyltrimethylammonium bromide (DTAB) has been prepared by electrospinning using one-step technology, i.e. with modifying antimicrobial agent dissolved in spinning solution. Stability of antibacterial membrane function has been tested by air-blowing test to prove the permanency of chemical composition and antibacterial activity. X-ray diffraction, high-resolution scanning electron microscopy (HRSEM) revealed the effect of modifying agent on structure and morphology of PA6 nanofibres. X-ray photoelectron spectroscopy, electrokinetic analysis and antibacterial tests proved the stability of chemical composition and antibacterial activity after air-blowing tests. Special air-blowing device has been constructed for this purpose. The results prove the applicability so prepared membrane for a long-term air-conditioning.

Antibacterial nylon 6 (PA6) nanofibers have been prepared in one-step procedure using Nanospider technology. Chlorhexidine (CHX), 1-dodecyltrimethylamonium bromide (DTAB) and benzyltrimethylamonium bromide (BTAB) have been used as antibacterial agents. Samples were characterized by a series of analytical and testing methods to investigate the surface chemistry, zeta potential, structure, morphology, phase composition, mechanical properties and antibacterial activity. Experimental characterization has been combined with molecular modeling to analyze the interaction of nanofibers with modifying molecules for better understanding the effect of nanofibers modification on their properties. Antibacterial modification of PA6 led to significant changes of zeta potential (from -31 mV for PA 6 up to -49 mV for PA6/BTAB), changes in phase composition (decrease of alpha phase content and increase of gamma phase content for PA6/BTAB and PA6/CHX) and to significant increase of fiber diameter for PA6/BTAB. Antibacterial modification resulted in the straightening of nanofibers and to higher permeability of nanofiber textile for all investigated samples. Tensile tests showed the the increase of Young modulus for all the investigated samples. All the modified samples: PA6/DTAB, PA6/BTAB and PA6/CHX exhibit good antibacterial activity.

AlSiN coatings were prepared by the cathodic arc deposition method at a temperature of 400 degrees C and pressure of 2.6 Pa. The chemical composition, determined by SEM/EDS analysis, shows that the AlSiN coating presented here has a stoichiometry structure (Al40Si9N51). XPS and XRD analyses indicated AlN in both cubic and hexagonal modifications in the coating, and that the coating has a not fully completed nanocomposite structure. Nano-indentation measurements indicate nanohardness and elastic modulus of 39 GPa and 389 GPa, iespectively. The coating has a very good adhesion strength with an average critical load of 28.3N (first cohesive failure) and 62.3N (first adhesion failure). The estimated wear rate and coefficient of friction of the coating are 27.2 x 10(-6) mm(3) N-1 m(-1) and 0.7, respectively (using the friction pair AISiN/Al2O3). (C) 2017 Elsevier Ltd. All rights reserved.

The polypropylene (PP) powder is used for various purposes. However, its good mechanical properties are accompanied by poor wettability. The PP powder was therefore modified by air plasma in fluidized bed reactor (FBR). Several techniques were employed to characterize the treated samples - XPS for the surface chemistry, electrokinetic analysis for zeta potential determination, contact angle measurement for the wettability characterization and SEM for morphology observations. The wettability was enhanced by the plasma treatment and the contact angle of water decreased from 139 to 83 after the plasma treatment. The XPS showed over 20% of oxygen on the surface after the plasma modification. SEM confirmed that only chemistry is responsible for the wettability improvement. No morphological changes were induced by the plasma. The wettability measurements were done also with polyethylene (PE) powder and some similarities between PP and PE were observed. (C) 2016 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.