Search Results (66)

Background: Chronic subdural hematoma (CSDH) is a common condition in older adults with rising rates of incidence. While burr hole drainage remains the standard treatment, it is associated with significant recurrence and complications. This study assesses MMA embolization with Squid, both as a standalone procedure and as an adjunct to surgery. Methods: Our prospective registry included 101 patients with 134 CSDH cases treated at two tertiary care centers from December 2020 to January 2024. Patients were divided into two groups: embolization alone and embolization combined with surgery. Demographic, clinical, radiological, and procedural data were collected. Follow-up imaging was conducted at 1, 3, and 6 months. Treatment failure was defined as rescue surgery, hematoma thickness ≥ 10 mm, midline shift > 3 mm at 6 months, or procedure-related death. Results: Fifty-two patients (51.5%) underwent combined treatment, and forty-nine (48.5%) received embolization alone. Most were men (68.3%) and the median age was 82 years. Combined-treatment patients had larger hematomas and more symptoms. Procedures were performed under general anesthesia in 72.3% of patients, with radial and femoral access used equally frequently, and 32.7% underwent bilateral embolization. Patients’ hematoma thickness in follow-up imaging showed a significant decrease (p = 0.000), reaching a median of 0 mm at six months, with no significant difference between groups. Complications occurred in 5.9%, and treatment failure in 4%. Mortality was higher in the embolization-only group, likely reflecting greater rates of comorbidities. Conclusions: This study supports the use of MMA embolization with Squid as a safe and effective treatment for CSDH. Comparable procedural and radiological outcomes in both groups suggest embolization alone may suffice in select patients, offering a less invasive alternative. Full article

The rapid growth of industrial activities has significantly increased oil demand, leading to wastewater contamination with oil and causing severe environmental pollution. Traditional oil–water separation techniques, such as gravity separation, filtration, and chemical treatments, are hindered by low efficiency, high energy consumption, and secondary pollution. Membrane separation technology has emerged as a promising solution due to its simplicity, low energy consumption, and high efficiency. In this study, we report the fabrication of a novel polyvinylidene fluoride/ethylene–vinyl alcohol (PVDF/EVOH) nanofibrous membrane (NFM) with a unique balsam-pear-skin-like structure using a one-step electrospinning process. The membrane’s superhydrophobicity and superoleophilicity were achieved via water vapor-induced phase separation (WVIPS), by optimizing the rheological properties and mixing ratio of EVOH and PVDF precursor solutions. The resulting PVDF/EVOH (PE12-3) NFM exhibits exceptional properties, achieving separation efficiencies of 99.4% for heavy oil and 98.9% for light oil, with a heavy oil flux of 18,020 L m⁻² h⁻¹—significantly surpassing previously reported performances. Additionally, the membrane shows excellent recyclability, making it ideal for large-scale oil–water separation in wastewater treatment and environmental remediation. This one-step fabrication strategy offers an efficient and scalable approach for developing high-performance membranes to tackle oil pollution in water. Full article

This study investigates the influence of fabric weave design and adhesive type on the adhesion quality and mechanical properties of Kevlar woven fabric-reinforced laminates (FRLs). Three adhesives (EVA, EVOH, and TPU) and three weave structures (plain, 2/2 twill, and crowfoot) were analyzed while keeping other fabric parameters constant. Both weave structure and adhesive type, as well as their interactions, significantly influenced adhesion and mechanical performance. Combinations like the crowfoot weave with EVOH adhesive enhanced adhesion due to increased surface contact, while the 2/2 twill weave with EVA adhesive improved tear strength but resulted in weaker adhesion, highlighting the trade-offs in material design. A negative correlation between yarn pullout force and tear resistance was observed, particularly for EVA and EVOH adhesives, where improved adhesion often coincided with reduced tear resistance. Tensile strength varied significantly across weaves, with twill exhibiting the highest strength, followed by plain and crowfoot weaves. This study highlights the critical role of weave design and adhesive choice in FRLs, providing valuable insights for optimizing material selection to meet specific industrial performance criteria. Full article

Multi-layer films are one of the most challenging classes of polymer waste for recycling, as they consist of a mixture of constituent materials like polyethylene (PE), polyamide 6 (PA6), and ethylene vinyl alcohol (EVOH). This study investigates the characterization, washing, and mechanical properties of recycled blends derived from such multi-layer films. Raman spectroscopy and Differential Scanning Calorimetry (DSC) were used to characterize the individual components in single- and multi-layer films, and distinct properties of LDPE, LLDPE, PA6, and EVOH were observed. Mechanical properties enhanced by proper shredding, washing procedures, and multiple combinations of polyethylene blends were investigated to optimize the mechanical characteristics of the recycled materials, especially strain at break. Additionally, the shrinkage behavior of the recycled films was compared to commercial shrink films, demonstrating their potential for use in industry packaging applications. These results highlight a more sustainable possibility for multi-layer packaging applications. Full article

The present study introduces an innovative blown coextrusion die technology designed to address a critical gap in the production of multilayer films. Unlike conventional systems, this novel die allows for the creation of films with a high number of layers, ensuring layer integrity even in the micro-nano scale. A key advancement of this die is its ability to increase the number of layers without extending the residence time since it does not require an additional multiplier element. The risk of thermal degradation can, thus be, minimized. The die can easily be combined with existing cast coextrusion technologies, making it very versatile. Stability maps were developed to define processability and, in association with rheological analysis, optimal processing windows were determined. This study highlights the potential of enhancing material efficiency by increasing the number of layers while reducing the need for high percentages of EVOH. The produced multilayer films exhibited strong layer adhesion without the use of tie layers, thus improving recyclability and supporting sustainability goals. Full article

The valorization of potato peel side streams for food packaging applications, especially for the substitution of current petrochemical-based oxygen barrier solutions such as EVOH, is becoming increasingly important. Therefore, potato peel-based films and coatings (on PLA) were developed containing 10–50% (w/w potato peel) citric acid (CA). To determine the impact of CA concentration on the structure and physicochemical properties of cast films and coatings, ATR-FTIR spectroscopy, moisture adsorption isotherms, tensile properties, light transmittance, oxygen permeability, carbon dioxide transmission rate, and water vapor transmission rate measurements were performed. The results indicate that an increase in CA concentration from 10% to 30% increased esterification/cross-linking and resulted in minimal values for the oxygen permeability (0.08 cm³ m⁻² d⁻¹ bar⁻¹) at 50% RH and water vapor transmission rate (1.6 g m⁻² d⁻¹) at 50% → 0% RH, whereas an increase from 30% to 50% increased free CA concentration and resulted in increased flexibility, indicating that CA functioned as a plasticizer within the film/coating at higher concentrations. Overall, potato peel-based coatings containing CA showed comparable barrier properties to EVOH. We assume that an extensive industrial purification or fractionation of potato peel, which was not carried out in this study, could lead to even lower transmission rates. Full article

Storing ground beef at frozen temperatures prior to refrigerated display when using thermoforming vacuum packaging is not a common manufacturing practice. However, limited data on thermoforming packaging film and its interaction with meat quality suggests that more information is needed. The current study aimed to identify the influences of thermoforming packaging on the surface color and lipid oxidation of ground beef. Ground beef was portioned into 454 g bricks and packaged into one of three thermoforming films: T1 (150 µ polyethylene/EVOH/polyethylene coextrusion), T2 (175 µ polyethylene /EVOH/polyethylene coextrusion), and T3 (200 µ polyethylene/EVOH/polyethylene coextrusion), stored for 21 days at −20.83 °C (±1.50 °C), and displayed for 42 days at 3.0 °C ± 1.5 °C. There were no statistical differences for the packaging treatment of lipid oxidation (p = 0.0744), but oxidation increased throughout storage day (p < 0.0001). The main effects of treatment and day resulted in altered (p < 0.05) surface lightness (L*), redness (a*), yellowness, hue angle (°), red-to-brown (RTB), and relative myoglobin for met-myoglobin (MET), deoxymyoglobin (DMB), and oxymyoglobin (OMB). Surprisingly, there was an interaction between treatment and day for the calculated relative values of chroma (p = 0.0321), Delta E (p = 0.0155), and the ratio of a*:b* (p < 0.0001). These results indicate that thermoforming vacuum packaging can reduce the rate of deterioration that occurs to ground beef color and the rate of oxidation. Full article

A functionalized ethylene–vinyl-alcohol (EVOH) nanofibrous membrane (NFM) was fabricated via co-electrospinning H₄SiW₁₂O₄₀ (SiW₁₂) and EVOH first, and then grafting citric acid (CCA) on the electrospun SiW₁₂@EVOH NFM. Characterization with FT-IR, EDX, and XPS confirmed that CCA was introduced to the surface of SiW₁₂@EVOH NFM and the Keggin structure of SiW₁₂ was maintained well in the composite fibers. Due to a number of carboxyl groups introduced by CCA, the as-prepared SiW₁₂@EVOH-CCA NFM can form a high number of hydrogen bonds with CR, and thus can be used to selectively absorb congo red (CR) in aqueous solutions. More importantly, the CR enriched in the NFM can be rapidly degraded via photocatalysis. SiW₁₂ in the NFM acted as a photocatalyst, and the hydroxyl groups in the NFM acted as an electron donor to accelerate the photodegradation rate of CR. Meanwhile, the SiW₁₂@EVOH-CCA NFM was regenerated and then exhibited a relatively stable adsorption capacity in five cycles of filtration–regeneration. The bifunctional nanofibrous membrane filter showed potential for use in the thorough purification of dye wastewater. Full article

The aim of this study was to analyze the influence of different packaging materials on the composition of the headspace (CO₂ and O₂) of rennet cheeses packed in unit packaging under different modified atmosphere (MAP) conditions during a storage period of 90 days at 2 °C and 8 °C. The packaging materials comprised different combinations of BOPP—biaxially oriented polypropylene; PET—polyester; PE—polyethylene; PP—polypropylene; EVOH—ethylene–vinyl alcohol copolymer; PET—polyethylene terephthalate; and PA—polyamide. As the properties of the packaging material (foil) affect the gas conditions inside the packaging, it is important to study whether the modifications, i.e., properties and thickness, of the foils will result in significant differences in the composition of the headspace of packed cheeses. The CO₂ content in the headspace of Gouda cheese packages ranged from 35% to 45%, while for Maasdamer and Sielski Klasyczny cheese, it varied between 55% and 65%. Throughout the storage period, the O₂ content in the headspace of cheeses packaged in tested foils (1–5) did not exceed 0.5%. The type of foil used did not influence the modified atmosphere packaging (MAP) conditions. Full article

The development of active food packaging is desirable for food safety and to avoid food loss and waste. In this work, we developed antioxidant bilayer films combining extrusion and electrospinning techniques. These films consisted of a first layer of thermoplastic cornstarch (TPS), incorporated with microcrystalline cellulose (MCC). The second layer consisted of gallic acid (GA) encapsulated at different concentrations in 1:1 chitosan/poly(ethylene-co-vinyl alcohol) (CS/EVOH) nanofibers. This layer was directly electrospun onto the TPS/MCC film. The morphological, structural, wettability, permeability to oxygen, and antioxidant properties were investigated for the first layer and the bilayer films. Water contact angle measurements revealed the hydrophobic nature of the first layer (θ₀ = 100.6°). The oxygen permeability (OP) was accessed through the peroxide value (PV) of canola oil, kept in containers covered by the films. PV varied from 66.6 meq/kg for the TPS/MCC layer to 60.5 meq/kg for a bilayer film. Intermolecular hydrogen bonds, mediated by GA, contributed slightly to improving the mechanical strength of the bilayer films. The bilayer film incorporated with GA at 15.0% reached a radical scavenging activity against the DPPH radical of (903.8 ± 62.2) μmol.L⁻¹.Eq. Trolox.g⁻¹. This result proved the effectiveness of the GA nanoencapsulation strategy. Full article

Developing high-performance and low-cost protein purification materials is of great importance to meet the demands for highly purified proteins in biotechnological industries. Herein, a facile strategy was developed to design and construct high-efficiency protein absorption and separation media by combining aerogels’ molding techniques and impregnation processes. Poly (ethylene-co-vinyl alcohol) (EVOH) nanofibrous aerogels (NFAs) were modified by grafting butane tetracarboxylic acid (BTCA) over them in situ. This modification was carried out using polyphosphoric acid as a catalyst. The resulting EVOH/BTCA NFAs exhibited favorable comprehensive properties. Benefiting from the highly interconnected porous structure, good underwater compressive properties, and abundant absorption ligands, the obtained EVOH/BTCA NFAs possessed a high static absorption capacity of 1082.13 mg/g to lysozyme and a short absorption equilibrium time of about 6 h. A high saturated dynamic absorption capacity for lysozyme (716.85 mg/g) was also realized solely by gravity. Furthermore, EVOH/BTCA NFAs displayed excellent reusability, good acid and alkaline resistance, and unique absorption selectivity performance. The successful synthesis of such aerogels can provide a potential candidate for next-generation protein absorbents for bio-separation and purification engineering. Full article

Lysozyme, a common antimicrobial agent, is widely used in the food, biopharmaceutical, chemical, and medicine fields. Rapid and effective isolation of lysozymes is an everlasting topic. In this work, ethylene vinyl alcohol (EVOH) copolymer nanofibrous membranes with a gradient porous structure used for lysozyme adsorption were prepared through layer-by-layer nanofiber wet-laying and a cost-efficient ultraviolet (UV)-assisted graft-modification method, where benzophenone was used as an initiator and 2-acrylamide-2-methylpropanesulfonic acid as a modifying monomer. As indicated in the Fourier Transform Infrared (FTIR) and X-ray photoelectric energy spectrometer (XPS) investigation, sulfonic acid groups were introduced on the surface of the modified nanofibrous membrane, which possessed the ability to adsorb lysozyme. Compared with membranes with homogenous porous structures, membranes with a gradient porous structure present higher static (335 mg/g) and dynamic adsorption capacities (216.3 mg/g). Meanwhile, the adsorption capacity remained high after five cycles of the adsorption–desorption process. The results can be attributed to the gradient porous structure rather than the highest porosity and specific surface area. This suggests that the membrane with comprehensive separation performance can be designed from the view of the transmembrane porous structure, which is of significance for the development of next-generation advanced chromatographic membranes. Full article

This study investigates the rheological, morphological, and mechanical properties of melt-processed polylactide/ethylene vinyl alcohol (70PLA/30EVOH) blend composites containing 0.25, 0.5, and 1 wt.% of graphene oxide (GO) nanoplates. Thermodynamic-based suggested the localization of nanoparticles in EVOH, SEM studies showed that the introduction of GO to the blend increased dispersed droplet size, which was attributed to the localization of GO within EVOH, as confirmed by TEM. The rheology results indicated a decrease in the elasticity for the composite containing 0.25 wt.% of GO compared to the neat blend, which was attributed to the sliding effect of the added GO nanoplatelets. However, samples containing higher amounts of GO nanoplatelets exhibited more excellent elasticity than the neat blend. The increased elasticity was suggestively attributed to the dominance of hydrodynamic interactions, the physical network of added nanoplatelets, and polymer/GO interactions over the sliding role of the GO nanoplatelets at higher loadings. In addition, the effect of the order of mixing was investigated, and the premixing of PLA and GO exhibited a decrease in the droplet radius compared to the neat blend. It was ascribed to the localization of GO nanosheets in the PLA and interface, which was confirmed by rheological results and mechanical assessments. Full article

This research aimed to provide an understanding of the selection and safe application of pipeline liner materials for hydrogen transport by examining the permeation properties and mechanisms of hydrogen within polymers commonly used for this purpose, such as high-density polyethylene (HDPE) and ethylene-vinyl alcohol copolymer (EVOH), through molecular simulation. The study was carried out within defined operational parameters of temperature (ranging from room temperature to 80 °C) and pressure (from 2.5 to 10 MPa) that are pertinent to hydrogen pipeline infrastructures. The results reveal that with an increase in temperature from 30 °C to 80 °C, the solubility, diffusion, and permeability coefficients of hydrogen in HDPE increase by 18.7%, 92.9%, and 129.0%, respectively. Similarly, in EVOH, these coefficients experience increments of 15.9%, 81.6%, and 112.7%. Conversely, pressure variations have a negligible effect on permeability in both polymers. HDPE exhibits significantly higher hydrogen permeability compared to EVOH. The unique chain segment configuration of EVOH leads to the formation of robust hydrogen bonds among the hydroxyl groups, thereby impeding the permeation of hydrogen. The process by which hydrogen is adsorbed in polymers involves aggregation at low potential energy levels. During diffusion, the hydrogen molecule primarily vibrates within a limited range, with intermittent occurrences of significant hole-to-hole transitions over larger distances. Hydrogen exhibits a stronger interaction with HDPE compared to EVOH, leading to a higher number of adsorption sites and increased hydrogen adsorption capacity in HDPE. Hydrogen molecules move more actively in HDPE than in EVOH, exhibiting greater hole amplitude and more holes in transition during the diffusion process. Full article

In this work, the EVOH/Ti₃C₂ composite fibers were prepared via electrospinning and the effect of added Ti₃C₂ on the structure and properties of electrospun EVOH fibrous membranes was further investigated. The morphology, crystal structure, thermal properties, wettability, tensile properties, as well as air permeability and water vapor permeability of as-prepared EVOH/Ti₃C₂ composite fibers were studied. The Ti₃C₂ is uniformly loaded onto the surface and inside the composite fiber and affects the fiber diameters. Furthermore, The Ti₃C₂ self-orients along the fiber axis and does not change the crystal structure of the electrospun EVOH fibers, improving the crystallinity and thermal stability of the electrospun EVOH/Ti₃C₂ fibrous membranes. With the increase in the Ti₃C₂ concentration in the electrospinning polymer solution, the addition of Ti₃C₂ not only rapidly improves the wettability of the fibrous membranes, but also enhances their air permeability, compared with the pristine electrospun EVOH fibrous membranes. The experimental results provide theoretical guidance for the preparation of Ti₃C₂ composite fibers, and also expand the application of electrospun EVOH and EVOH/Ti₃C₂ fibrous membranes. Full article