Ethylene Vinyl Alcohol Research Articles

Simultaneous Improvement of Oxygen Barrier and Stiffness in High-Density Polyethylene via Effective Integration of Interface Engineering with in Situ Ethylene-Vinyl Alcohol Copolymer Nanofibrillation.

In this study, we proposed a novel technique to simultaneously enhance the oxygen barrier properties and stiffness of high-density polyethylene (HDPE) while preserving its ductility. By utilizing in situ nanofibrillation, fiber-in-fiber composites of an HDPE matrix and ethylene-vinyl alcohol (EVOH) nanofibers were fabricated. Due to the high interfacial tension between HDPE and EVOH, stemming from their differences in chemical structure and polarity, styrene/ethylene-butylene/styrene copolymer grafted with maleic anhydride (SEBS-g-MA) was used as a compatibilizer to improve the affinity between the two polymers. SEM images revealed that the presence of the compatibilizer resulted in smaller fiber sizes (reduced to 65 ± 27 nm from 147 ± 54 nm for 6 wt % compatibilized EVOH compared to noncompatibilized samples), higher aspect ratios, and better distribution. Increasing the aspect ratio and improving nanofiber distribution reduced HDPE's oxygen permeability by 61% after incorporating 10 wt % compatibilized EVOH nanofibers. Additionally, the nonisothermal and isothermal crystallization indicated that EVOH nanofibers reduced the amount of crystallinity and slowed crystallization kinetics. The alteration in HDPE crystalline structure and its effect on permeability properties were also addressed. Finally, tensile test results indicated that the incorporation of 10 wt % EVOH nanofibers, regardless of the presence of the compatibilizer, increased HDPE Young's modulus by around 50%. However, without the compatibilizer, there was a significant reduction in HDPE elongation at the break. The incorporation of the compatibilizer allowed for increased stiffness while preserving HDPE ductility. These promising findings underscore potential applications across rigid and soft packaging.

Preparation and properties of calcium oxide and calcium peroxide from eggshell waste for enhanced antimicrobial activity

Calcium peroxide (CaO2), which releases hydrogen peroxide (H2O2) upon contact with water, has garnered attention as a potential alternative to liquid H2O2. Researchers have explored various methods to enhance the production of CaO2 with reduced environmental impact. This study focuses on the preparation of two potent antimicrobial agents, calcined calcium oxide (C-CaO) and synthesized calcium peroxide (S-CaO2) from eggshell waste. These agents were then incorporated into ethylene vinyl alcohol (EVOH) composite films for antimicrobial packaging. The synthesized CaO and CaO2 were analyzed using Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), Thermogravimetric analysis (TGA) and Scanning electron microscopy (SEM). The results confirmed the successful synthesis of high-purity CaO and CaO2 from eggshell waste. Compared to CaO (a well-known antimicrobial agent), CaO2 exhibited approximately 1.6 to 2 times higher antimicrobial activity, which is attributed to its release of H2O2. EVOH films containing 3% of CaO2 demonstrated significant microbial growth deactivation, reaching 99.99% and 97.24% for gram-negative and gram-positive bacteria, while EVOH films containing 3% of CaO exhibited relatively low deactivation ability of 79.01% and 48.82, respectively. This study underscores the potential of eggshell waste as a valuable resource for producing high-value materials. Moreover, CaO2 emerges as an effective antimicrobial agent, particularly in antimicrobial packaging applications, showcasing its versatility across various sectors.

One-pot construction of all-in-one flexible asymmetrical supercapacitors for extreme-condition applications

All-in-one flexible energy storage devices hold great application potential in the flexible and wearable electronics by virtue of unique configuration, however, still face severe challenges including complex fabrication steps, single variety of symmetrical supercapacitors and limited scenario application. For the first time, we propose a facile one-pot approach to fabricate all-in-one flexible asymmetrical supercapacitors (AFASCs) through magnetic driving localization of magnetic FeOOH anode away from MnO2 cathode in the electrolyte containing ethylene vinyl alcohol copolymers toward multi-scenario application. Distinctly different from the reported all-in-one approaches, this one-pot approach dramatically simplifies fabrication steps and especially extends more variety of electroactive materials for asymmetrical supercapacitors and even aqueous battery systems. A well-integrated configuration without any interfaces forms in the FeOOH/MnO2 AFASCs with low interfacial resistance, high areal capacitance, good cyclic stability and remarkable energy density. Significantly, the FeOOH/MnO2 AFASCs achieve superhigh capacitance retention not only in long-term bending and twisting deformations, but also under various extreme conditions including cutting, rolling, hammering, puncturing, sewing, soaking and washing in the water, as well as low temperature. Furthermore, the FeOOH/MnO2 AFASCs are demonstrated to power wearable smart bracelet, health monitoring, intelligent positioning system and running pod. Those findings can open up a new approach for one-pot construction of all-in-one flexible energy storage devices to meet future needs of flexible and wearable electronic devices under harsh working conditions.

Transparent and Mechanically Robust Janus Nanofiber Membranes for Open Wound Healing and Monitoring.

The electrospun nanofiber membrane has demonstrated great potential for wound management due to its porous structure, large surface area, mechanical strength, and barrier properties. However, there is a need to develop transparent bioactive nanofibers with strong mechanical properties to facilitate the monitoring of the healing process. In this study, we present an electrospinning-based method for creating transparent (∼80-90%), strong (∼11-13 MPa), and Janus nanofiber membranes. The innovative square pattern architecture of the membrane includes a thin hydrophobic polycaprolactone layer on top of a layer of hydrophilic ethylene-vinyl alcohol nanofiber, which enables the absorption of excess biofluid from the wound and exhibits Janus wettability for water. Furthermore, incorporating 5% chitosan into the composition of the nanofibers accelerates the healing process through its antioxidant properties and antimicrobial activity against various bacteria, including drug-resistant strains. The developed membrane also demonstrates skin-repairing function, quick blood clotting (around 145 ± 12 s), and biocompatibility with keratinocyte (≥90%), as well as in vitro quick cell migration (∼24 h). With a tensile strength of 11-13 MPa, the membrane effectively adheres to the knee joint even after running 4 km. These optimal properties of the electrospun nanofiber membrane make it suitable for effective wound management and inspection of the healing process, without the need for frequent dressing changes.

Probing the Thermo-oxidative Degradation of Ethylene Vinyl Alcohol (EVOH) by Time-Resolved Rheology and NMR Spectroscopy

EVOH's excellent gas barrier properties have enabled its continued market growth in numerous applications including food packaging, fuel tanks, and construction. However, EVOH's susceptibility to thermo-oxidation limits its ability to be reprocessed. While it is generally known that EVOH degradation leads to cross-linking, detailed degradation rates and mechanisms are not well established. Understanding EVOH degradation has been elusive because readily accessible thermal and spectroscopy methods do not reveal significant changes. Moreover, gel permeation chromatography requires specialized solvents and columns. We report that measuring changes in viscoelasticity with time-resolved rheology (TRR) is a facile way to monitor the temporal dynamics of EVOH degradation. TRR was performed on EVOH grades with ethylene copolymer contents of 27, 32, 48 mol%. As expected, the grade with the highest ethylene content was the most stable. However, with time, all the EVOH grades transitioned from a Carreau-like fluid to a power law fluid and no longer exhibited terminal behavior. Cole-Cole plots also revealed that EVOH relaxation evolved from rapid process into a long, complex process consistent with network formation. The mechanism of degradation was further elucidated by using 13C distortionless enhancement of polarization transfer (DEPT-135) nuclear magnetic resonance spectroscopy. These results showed that degradation occurred by ring-opening of lactone terminal groups that led to cross-linking. This enhanced understanding provides a foundation for developing methods to probe and mitigate EVOH degradation.

The LAVA Study: A Prospective, Multicenter, Single-arm Study of a Liquid Embolic System for Treatment of Peripheral Arterial Hemorrhage

PurposeTo present the results of the Liquid Embolization of Arterial Hemorrhages in Peripheral Vasculature (LAVA) study evaluating safety and efficacy of Lava Liquid Embolic System (Lava LES), an ethylene vinyl alcohol (EVOH), for peripheral arterial hemorrhage (PAH). Materials and MethodsLAVA was a pivotal, prospective, multicenter, single-group, centrally adjudicated study of adults with active PAH. Patients received EVOH at one of two viscosities, administered by experienced physicians. Primary safety endpoint was freedom from 30-day major adverse events (MAE) defined as ischemia/infarction of target territory, non-target embolization, allergic reaction, and catheter breakage/entrapment. Primary efficacy endpoint was 30-day clinical success defined as absence of bleeding from target lesion after embolization without need for emergency surgery, re-embolization, or other target lesion re-interventions. Secondary endpoints included serious adverse events and mortality. Results113 patients (mean age 57.4 years [SD 18.0; range 18.0-93.0]; 63.7% male) with 148 lesions were enrolled at 19 US centers. Targeted areas included non-gastrointestinal (GI) visceral arteries (31.1%), kidneys (26.3%), upper GI (11.5%), lower GI (6.8%) and extremities (6.1%). Empiric embolization was performed for 20.9% of lesions. The primary efficacy endpoint was achieved in 94.3% of lesions (95.3% patients), exceeding the performance goal of 72%. Two target lesions treated with EVOH required subsequent re-embolization. No surgeries were performed for bleeding or ischemia. There were no MAEs reported per study definition. All-cause mortality rate at 30 days was 8.3%. ConclusionsThe LAVA study suggests that EVOH is effective and can be safely used as an embolic agent for treatment of PAH.

Enhancing Shelf‐Life of Bael Beverage Through Various Pasteurization Techniques: A Comparative Study at 25°C and 4°C With Thermal, Pulsed Light, and Microwave Treatments

ABSTRACTThe influence of thermal (95°C, 5 min), pulsed light (PL, 1.64 kJ/cm2 available fluence) and microwave (MW, 2 kW, and 16 min ≈ 90°C final temperature) treatment on various quality attributes and shelf‐life of bael (Aegle marmelos) beverage was investigated. The quality parameters under consideration included microbial growth, enzyme activity, bioactive components, sensory quality, and physicochemical properties. Effects of different packaging materials (ethyl vinyl alcohol (EVOH) and multilayered (ML) pouches) and storage temperatures (25°C and 4°C) were also explored. The rate of sample deterioration, loss of bioactive components, and sensory qualities increased with higher storage temperature. MW and thermal processing showed better storage stability based on the minimum microbial counts, enzyme activities, and minimal changes in soluble solids. Least sedimentation was seen in thermally treated samples. MW treatment was better in preventing alterations in pH and titratable acidity (at 25°C), reducing sugars, browning, and sensory acceptance. On 50th day at 4°C, higher total phenolic content (59%–64%), antioxidant capacity (69%–72%), and total carotenoid content (136%–139%) were obtained with the PL treatment. For both packaging materials, a shelf‐life of 40–50 days (as per aerobic mesophile count ≤ 4.0 log CFU/mL) and 30 days (as per overall sensory acceptability > 5) at 4°C was obtained for thermal and microwave. As per AM count, shelf‐life of PL irradiated beverages was 40 days, and according to sensory acceptability, it was 30 days. Overall, MW processed beverages stored in ML‐pouches and at 4°C exhibited better shelf life and storage quality.

Comparison of embolization using coil versus coil and ethylene vinyl alcohol copolymer in pelvic venous disorders

Endovascular treatments are frequently applied in pelvic venous disorders(PeVDs) with guidelines recommendations. There is no clear answer as to which of the embolization methods applied with endovascular treatments is superior. In this study, we aimed to compare the outcomes and symptom relief of patients with PeVDs treated using coils alone versus those treated with both coils and ethylene vinyl alcohol copolymer, as well as to evaluate the material usage and safety and efficacy of these treatments. Patients with PeVDs who underwent embolization of ovarian veins with coil and/or ethylene vinyl alcohol copolymer between January 2022 and April 2024 were included in the study. These patients were divided into two groups: patients who underwent coil embolization only (Group I) and patients who used ethylene vinyl alcohol copolymer together with coils (Group II). These patients were followed up at 1st ,3rd 6st and 12st months postoperatively. Symptoms were evaluated with an examination and a visual analog scale (VAS). Between January 2022 and April 2024, 90 patients with PeVDs who underwent endovascular treatment of their ovarian and pelvic veins were included in our study. 31 patients underwent coil embolization only (Group I), while 59 received both coil embolization and a ethylene vinyl alcohol copolymer (Group II). The mean age was 37.5 ± 7.9 and 40.4 ± 7.9 for Groups I and II, respectively. In group I, When pelvic pain was evaluated with VAS, there was a significant decrease in VAS scores between the preoperative period and at the 1st(VAS: 5.3±0.9) , 3rd(VAS:3.9±1.2), 6th(VAS: 3.5±1.5) , and 12th(VAS: 3.6±1.5) months postoperatively (p = 0.011, <0.001, <0.001, <0.001, respectively). In Group II, When pelvic pain was evaluated with VAS, there was a similarly significant decrease in VAS scores between the preoperative period and the 1st(VAS: 5.3±1.4), 3rd(VAS: 3.3±1.7) , 6th(VAS: 2.8±1.8) , and 12th(VAS:2.5±2.1) months postoperatively (p = 0.002, <0.001, <0.001, <0.001, respectively). Group II demonstrated significantly lower VAS scores at the 3rd, 6th, and 12th months compared to Group I. When examining the clinical symptoms of the patients individually, no significant differences were observed between the preoperative and 1st-month VAS scores for any specific symptom. However, at the 3rd, 6th, and 12th months, while there were no significant differences between Group I and Group II in terms of menstrual pain, Group II exhibited significantly lower scores for standing abdominal pain, sitting abdominal pain, and dyspareunia. In our study, The use of ethylene vinyl alcohol copolymer and coils in the embolization of PeVDs is considered an effective and safe procedure with a higher clinical efficacy rate compared to other embolization techniques. Additionally, the use of ethylene vinyl alcohol copolymer reduces the need for coils, providing a cost-effective advantage.

The advancement of EVA polymerization kinetics and development of high-performance EVOH polymerization process

Ethylene-vinyl alcohol copolymer (EVOH) is a material with excellent barrier properties, produced via the radical copolymerization of ethylene and vinyl acetate in solution, followed by alcoholysis in methanol with NaOH as a catalyst. It is widely used in packaging and medical materials. However, balancing the barrier properties and processability remains challenging. Currently, multi-scale research methods using density functional theory (DFT) to explore polymerization mechanisms and obtain kinetic data, combined with process simulation methods to develop high-performance EVOH polymerization process, are gaining attention. Therefore, this study employs DFT and transition state theory (TST) methods to study the kinetics of chain growth and chain transfer reactions of radicals at first, yielding the average chain growth and chain transfer rate constants for copolymerization reactions. Then, based on these rate constants, process simulations were used to model the ethylene–vinyl acetate solution copolymerization reactor, developing polymerization process for EVOH with high barrier properties as well as EVOH with both high barrier properties and good processability. These findings provide suggestions and guidance for EVOH production and application.

Polymer-Based Room-Temperature Phosphorescence Materials Exhibiting Emission Lifetimes up to 4.6 s Under Ambient Conditions.

The long-emission-lifetime nature of room-temperature phosphorescence (RTP) materials lays the foundation of their applications in diverse areas. Despite the advantage of mechanical property, processability and solvent dispersity, the emission lifetimes of polymer-based room-temperature phosphorescence materials remain not particularly long because of the labile nature of organic triplet excited states under ambient conditions. Specifically, ambient phosphorescence lifetime (τP) longer than 2 s and even 4 s have rarely been reported in polymer systems. Here, luminescent compounds with small phosphorescence rate on the order of approximately 10-1 s-1 are designed, ethylene-vinyl alcohol copolymer (EVOH) as polymer matrix and antioxidant 1010 to protect organic triplets are employed, and ultralong phosphorescence lifetime up to 4.6 s under ambient conditions by short-term and low-power excitation are achieved. The resultant materials exhibit high afterglow brightness, long afterglow duration, excellent processability into large area thin films, high transparency and thermal stability, which display promising anticounterfeiting and data encryption functions.

From multilayer LDPE/EVOH flexible film scraps to new multilayer films

This study explores the mechanical and optical properties of multilayer films incorporating recycled materials, mimicking the structure of industrial films. Using a coextrusion blown film line with a three-layer ABC configuration extrusion head, films were produced using two different recycled multilayer films, from post-industrial scraps, in layers A and B and virgin low-density polyethylene (LDPE) in one of the external layers (C). These recycles result from multilayer films mainly constituted of LDPE; one has also linear-LDPE (LLDPE) Metallocene, and the other has Ethylene Vinyl Alcohol (EVOH). Both recycled materials enabled to maintain blown film extrusion process stability during film production. The multilayer films produced with the incorporation of recycles were characterized using scanning electron microscopy (SEM), haze and gloss measurements, and tensile tests. Films with Recycled EVOH presented haze values much higher than those obtained for the Recycled Metallocene. However, all films presented good mechanical properties when compared to single layer virgin LDPE film. Anisotropic behaviour was observed, emphasizing the directional dependence of mechanical properties. The findings provide insights into the behaviour of multilayer films with recycled content, offering valuable information for the development of sustainable packaging solutions.

Toward mechanical recyclability of high barrier food packaging films through filler incorporation on the EVOH layer

AbstractTo preserve food from moisture and oxygen, polymers, such as ethylene vinyl alcohol (EVOH) are used in multilayer structures to provide oxygen barrier, while low‐density polyethylene (LDPE) is used for a water vapor barrier. While this material combination is functionally ideal, it may not comply with the new packaging recycling guidelines. Some European markets have implemented rules that limit the weight percentage of EVOH in LDPE films. One way to increase recyclability is by reducing the amount of EVOH in the film structure while maintaining the packaging's oxygen barrier properties. To achieve this, it is necessary to improve the barrier properties of EVOH. With this objective in mind, this study evaluated the incorporation of nanoclays (NC), cellulose microcrystals (MCC), silicon dioxide nanoparticles (SiO2), and cellulose nanocrystals (CNC) into an EVOH matrix. The results indicate that NC and MCC facilitate a stable blown film extrusion process and have a better dispersion in the EVOH matrix. Based on this finding, three‐layer films (with an ABA configuration) consisting of LDPE (A) and EVOH (7 μm layer) with 0.5 or 1 wt.% MCC or NC (B) were produced to protect the EVOH from moisture and enable blown film processing. The oxygen transmission rate (OTR) values were lowest for 0.5 wt.% NC and 1 wt.% MCC incorporation. Although the films with micro and nanoparticles had increased haze, this did not affect the visibility of the packaged food.

Angiographic and Histopathological Characteristics of a Novel Polyacrylate Liquid Embolic Agent Compared with Ethylene Vinyl Alcohol Copolymer in a Large Animal Model

PurposeTo study the in vivo safety and effectiveness of a novel radiopaque nonadhesive polyacrylate (PA) peripheral liquid embolic system (AMBER SEL-P) relative to ethylene vinyl alcohol copolymer (EVOH, Onyx) in a healthy swine endovascular model. Materials and MethodsTwenty-five swine underwent rete mirabile and bilateral kidney embolization with PA or EVOH and were followed up for 24 hours (n = 5) and 30 days (n = 10), and 3 (n = 10) months. Angiographic features (penetrability, radiopacity, catheter entrapment, fragmentation, occlusion, and vasospasm) were evaluated. Necropsy and histology were used to evaluate the nontarget embolization, safety, and target embolization effectiveness by recanalization and analyze the vascular response. ResultsNo adverse events occurred during the embolization process or study period. The angiographic performance confirmed a significant positive effect of PA compared with that of EVOH in terms of penetrability (P = .007), catheter entrapment (P = .007), fragmentation (P = .007), vascular occlusion (P = .038), vasospasm (P = .038), and follow-up vascular occlusion (P = .038). Prenecropsy angiography found no vascular recanalization in the organs treated with PA, whereas it was detected at 3 months in 2 samples treated with EVOH. Histologically, PA was classified as nonirritant compared with EVOH under the study conditions according to ISO 10993-6:2016 as modified. No systemic effects during necropsy were detected in the animals treated with these agents. ConclusionsThis in vivo study concludes that the angiographic behavior of PA has advantages compared with EVOH. The embolization and biocompatibility of PA are similar to those of EVOH. PA is safe and effective for transarterial embolization in an acute, subacute, and chronic endovascular embolization models.

Innovating a EVOH composite coating towards outstanding H2 barrier and anti-corrosion properties

Concerning the mitigating leakage and hydrogen-induced embrittlement during the conveyance of hydrogen (H2), we have developed an innovative dual-layer composite coating that exhibits exceptional hydrogen gas barrier properties and good resistance to corrosion. Using a bottom-top approach combining hot pressing with spin-coating techniques, the bottom Ethylene-vinyl alcohol copolymer (EVOH) layer with glass flakes (GF) serves as an effective hydrogen gas barrier and the top fluorosilicone resin (FSR) layer with composite nanofiller possesses good corrosion resistance, ensuring the functional integrity of the EVOH layer. The composite coating shows an exemplary low hydrogen gas transmission rate (H2 GTR) value of 2.858 cm3/(m2·24 h·0.1 MPa), representing a substantial decrease of 99.98 % compared to the FSR coating and 15 times more effective than commercial gas barrier films. Moreover, even after a 90-day immersion in 3.5 wt% NaCl solution, the coating maintains an impressive impedance at 0.01 Hz (|Z|0.01 Hz) of 1.0 × 1011 Ω·cm2. The composite coating is exposed to 2 MPa hydrogen for 7 days, and we find that it still sustains outstanding hydrogen gas barrier and anti-corrosion properties.

Correlations between adhesion and molecular interactions at buried interfaces of model polymer systems and in commercial multilayer barrier films.

Sum frequency generation vibrational spectroscopy (SFG) was applied to characterize the interfacial adhesion chemistry at several buried polymer interfaces in both model systems and blown multilayer films. Anhydride/acid modified polyolefins are used as tie layers to bond dissimilar polymers in multilayer barrier structures. In these films, the interfacial reactions between the barrier polymers, such as ethylene vinyl alcohol (EVOH) or nylon, and the grafted anhydrides/acids provide covalent linkages that enhance adhesion. However, the bonding strengths vary for different polymer-tie layer combinations. Here, using SFG, we aim to provide a systematic study on four common polymer-tie interfaces, including EVOH/polypropylene-tie, EVOH/polyethylene-tie, nylon/polypropylene-tie, and nylon/polyethylene-tie, to understand how the adhesion chemistry varies and its impact on the measured adhesion. Our SFG studies suggest that adhesion enhancement is driven by a combination of reaction kinetics and the interfacial enrichment of the anhydride/acid, resulting in stronger adhesion in the case of nylon. This observation matches well with the higher adhesion observed in the nylon/tie systems in both lap shear and peel test measurements. In addition, in the polypropylene-tie systems, grafted oligomers due to chain scission may migrate to the interface, affecting the adhesion. These by-products can react or interfere with the barrier-tie chemistry, resulting in reduced adhesion strength in the polypropylene-tie system.

Controlled localization of graphene oxide to improve barrier, biodegradation and mechanical properties of PBAT/EVOH

AbstractIncorporating graphene oxide (GO) with controlled localization into poly(butylene adipate‐co‐terephthalate) (PBAT) blends with poly(ethylene vinyl alcohol) (EVOH) aimed to improve barrier properties, biodegradability, and mechanical strength of PBAT. The PBAT/EVOH/GO nanocomposites containing 0 to 1 wt% of GO were prepared by a reactive mixing process in internal mixer. Microscopic images confirmed that the GO nanoplatelets are mainly localized in PBAT phase and then at the interface, contrary to the thermodynamic affinity of GO toward EVOH. The reactive nature of PBAT/EVOH/GO nanocomposites was confirmed via time‐sweep rheological studies where specific changes were observed in melt viscosity over time. The results of microscopic studies, rheometry, tensile test, and dynamic mechanical thermal analysis (DMTA) confirmed that localizing GO at the interface establishes strong interactions between PBAT and EVOH. By the addition of 0.75 wt% GO, tensile and yield strength were improved by 19% and 45%, respectively. Increasing GO significantly increased the hydrolysis degradation rate of the nanocomposites. Furthermore, the addition of GO considerably decreased the oxygen and water vapor permeability of the blends by up to 40% at 1 wt% GO.

Impact of pulsed light treatment on achieving microbial safety, enzymatic stability, and shelf life extension of dragon fruit juice

AbstractDue to microbial and enzymatic spoilage, dragon fruit juice has a limited shelf life. This study examines the shelf life of dragon fruit juice treated with thermal and pulsed light (PL) processing and stored at 4°C. The thermal treatment at 95°C/3 min and PL treatment at 1.4 J cm−2 produce a microbially safe juice. Both thermal and PL‐treated juice samples were packed in ethylene vinyl alcohol pouches and stored at refrigerated conditions (4°C). The juice's microbial, enzymatic, and biochemical attributes were analyzed over 30 days of refrigerated storage. There is no significant influence (p &lt; 0.05) on total soluble solids, pH, and titratable acidity. The thermally treated juice loses 36% of the total phenols and 22% of antioxidants. The loss of bioactive compounds is higher in thermal than in PL treatment. The shelf life of PL‐treated juice is 25 days, and thermal treatment juice is 30 days, based on the microbial analysis (6 log10 CFU mL−1). The study affirms the potential of PL treatment as an alternative technique for preserving dragon fruit juice.

Under Water Superelastic Porous Nanofibrous Sponge for Efficient RNA Separation and Purification.

Developing monolithic materials for chromatography columns with a novel interconnected porous structure is vital for the enhancement of the separation efficiency of RNA purification processes. Herein, a porous nanofibrous sponge (PNFS) is constructed by freeze molding and freeze-drying a nanofiber dispersion with ethylene vinyl alcohol copolymer nanofibers as the skeleton, chitosan (CS) and polyethylenimine (PEI) as the binders, and glutaraldehyde (GA) as the crosslinking agent. The results show that when the CS content of the dispersion is 1.5 wt %, PNFS demonstrates a high static adsorption capacity of 406.5 mg/g (30.7 mg/m2) and a dynamic adsorption capacity of 382.6 mg/g (28.9 mg/m2) at a flow rate of 1 mm/min. Moreover, PNFS shows a high specific adsorption performance toward RNA in the presence of bovine serum albumin, lecithin, or DNA by adjusting the solution pH value and the method of gradient elution. Besides, PNFS presents exceptional performance in the rapid separation of RNA from HT22 cells without degradation. This result can be attributed to optimized morphology, pore structure, and comprehensive performance of PNFS, benefiting from the synergistic effect of the highly oriented porous structure and CS-PEI interaction derived from the high-density adsorption ligands on the channel walls of PNFS. This work provided an efficient strategy to handle the permeability/adsorptivity trade-off for ion-exchange chromatographic materials.

Pioneering high barrier packaging for pressure assisted thermal sterilization of low-acid food products

Pressure-assisted thermal sterilization (PATS) utilizes flexible packaging with low oxygen and water vapor transmission rates (OTRs, WVTRs). In this study, pouches made from metal oxide (MO)-coated (A–D) and ethylene vinyl alcohol (EVOH)-containing (E, F) multilayer films were filled with water and mashed potatoes (MP), preheated at 98 ± 0.5 °C for 10 min, and processed using a pilot-scale high-pressure processing machine (HPP) at 600 ± 5 MPa for 300 s. The initial vessel temperature and the fluid medium were 90 °C, and during processing, the temperature of the fluid medium increased to approximately 120 °C. After processing, the water-filled pouches were emptied, refilled with a novel oxygen indicator, and stored at 40 ± 0.2 °C for 80 days. The MP-filled pouches were stored at 49 ± 1 °C for 60 days. MO-coated film D contained fewer defects, had ultra-low OTRs and WVTRs, showed insignificant (p > 0.05) moisture absorption and changes in crystallinity after PATS processing, and exhibited minimal color change in both the oxygen indicator and the packaged MP during the 60 days of storage. The ultra-high barrier of film D could be attributed to the presence of multiple AlOx-coated PET layers that successfully prevented oxygen ingress, even after exposure to high temperature and pressure conditions during PATS processing. Among the EVOH-based structures, the Film F showed a 22.3 % lower OTR than Film E (p < 0.05), due to a 16.7 % greater EVOH-layer thickness, despite having a lower overall thickness than Film E. Overall, this study can assist packaging manufacturers in designing and developing high-barrier flexible packaging suitable for in-package, shelf-stable food products.

Synergistic effect of modified ethylene-vinyl acetate and asphaltenes on improving the flow properties of model oil

The effect of alcoholic polyethylene-vinyl acetate (EVA) product ethylene-vinyl alcohol copolymer (EVAL) on the low-temperature flow properties of model oil containing asphaltene (ASP) was investigated. The change of wax crystal microscopic morphology of model oil before and after modification were examined, and the influence of asphaltene mass fraction on the rheological improvement effect of EVAL was analyzed. The composite system of EVAL and asphaltene significantly reduced the pour point, gel point, apparent viscosity, storage modulus and loss modulus of waxy oil at low temperatures. When the EVAL concentration is 400 ppm and the asphaltene mass fraction is 0.5 wt%, the synergistic effect of the two is optimal, which can reduce the pour point by 17 °C and the modulus value by more than 98%. The introduction of EVAL strengthens the interaction between asphaltenes and wax crystals, forming EVAL-ASP aggregates, which promote the adsorption of wax crystals on asphaltenes to form composite particles, and the polar groups prevent the aggregation of wax crystals and reduce the size of wax crystals, thus greatly improving the fluidity of waxy oils.