Polyethylene Oxide Layer Research Articles

Developing a lithiophilic, solvent-phobic dual-functionality film for dendrite-free Li metal anodes

Li metal anodes (LMAs) are promising candidate for advanced batteries that encounters significant challenges, including electrolyte corrosion and uneven deposition. These issues not only reduce battery lifespan but also pose safety risks due to the uncontrolled growth of dendrites. Herein, we introduce a lithiophilic, solvent-phobic dual-functionality film (LSDF) designed to tackle these problems. The LSDF features an inner layer of polyethylene oxide directly applied to the LMAs and an outer layer of poly(vinylidene fluoride-co-hexafluoropropylene) facing the electrolyte. Both layers contain N-ethyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide, which enhances the rapid transport of Li ions. The inner layer promotes high interfacial stability, while the outer layer offers solvent resistance and Li affinity, thereby inhibiting dendrite growth and reducing side reactions. Consequently, Li||Li symmetric cells achieve stable cycling for 1650 h with a minimal overpotential of 15 mV at 3 mAh cm−2 and 3 mA cm−2. Additionally, full cells paired with LiFePO4 cathodes maintain 85 % capacity retention over 500 cycles at 1 C and demonstrate excellent rate capability. This study presents a new approach to modulate the interface of LMAs, significantly enhancing its stability for high-energy–density battery applications.

Multilayer electrospun nanofibrous membranes for drug - controlled release

Absorbing exudate and realizing drug - controlled release are considered to be the ideal objectives and effects of wound dressing. Therefore, multi - layer wound dressing is regarded as to be a common means for treating burns and other wounds with more exudate in skin tissue engineering. We report a unique platform based on multilayer nanofiber membrane, which can simultaneously inhibit bacterial breeding and prevent wound infection. An electrospun fiber pad containing tetracycline hydrochloride (TCH) was prepared as the core layer, and a layer of polyethylene oxide (PEO)/sodium alginate (SA) nanofiber membrane was covered on the upper and lower layers. The average diameter of multilayer nanofiber membrane is 440 nm, which has good biocompatibility and excellent antibacterial effect. Due to the regular arrangement of nanofibers and more small voids, it is conducive to cell adhesion and proliferation, and the drug in the core layer of fiber membrane has a relatively long release time. Through the bacteriostatic circle experiment, it has a good effect on inhibiting the growth and invasion of bacteria.

High Current‐Density‐Charging Lithium Metal Batteries Enabled by Double‐Layer Protected Lithium Metal Anode

AbstractThe practical application of lithium (Li) metal anode (LMA) is still hindered by non‐uniformity of solid electrolyte interphase (SEI), formation of “dead” Li, and continuous consumption of electrolyte although LMA has an ultrahigh theoretical specific capacity and a very low electrochemical redox potential. Herein, a facile protection strategy is reported for LMA using a double layer (DL) coating that consists of a polyethylene oxide (PEO)‐based bottom layer that is highly stable with LMA and promotes uniform ion flux, and a cross‐linked polymer‐based top layer that prevents solvation of PEO layer in electrolytes. Li deposited on DL‐coated Li (DL@Li) exhibits a smoother surface and much larger size than that deposited on bare Li. The LiF/Li2O enriched SEI layer generated by the salt decomposition on top of DL@Li further suppresses the side reactions between Li and electrolyte. Driven by the abovementioned advantageous features, the DL@Li||LiNi0.6Mn0.2Co0.2O2 cells demonstrate capacity retention of 92.4% after 220 cycles at a current density of 2.1 mA cm–2 (C/2 rate) and stability at a high charging current density of 6.9 mA cm–2 (1.5 C rate). These results indicate that the DL protection is promising to overcome the rate limitation of LMAs and high energy‐density Li metal batteries.

Coupling Water-Proof Li Anodes with LiOH-Based Cathodes Enables Highly Rechargeable Lithium-Air Batteries Operating in Ambient Air.

Realizing an energy‐dense, highly rechargeable nonaqueous lithium–oxygen battery in ambient air remains a big challenge because the active materials of the typical high‐capacity cathode (Li2O2) and anode (Li metal) are unstable in air. Herein, a novel lithium–oxygen full cell coupling a lithium anode protected by a composite layer of polyethylene oxide (PEO)/lithium aluminum titanium phosphate (LATP)/wax to a LiOH‐based cathode is constructed. The protected lithium is stable in air and water, and permits reversible, dendrite‐free lithium stripping/plating in a wet nonaqueous electrolyte under ambient air. The LiOH‐based full cell reaction is immune to moisture (up to 99% humidity) in air and exhibits a much better resistance to CO2 contamination than Li2O2, resulting in a more consistent electrochemistry in the long term. The current approach of coupling a protected lithium anode with a LiOH‐based cathode holds promise for developing a long‐life, high‐energy lithium–air battery capable of operating in the ambient atmosphere.

Highly Efficient Vacuum-Evaporated CsPbBr3 Perovskite Light-Emitting Diodes with an Electrical Conductivity Enhanced Polymer-Assisted Passivation Layer.

Highly efficient vacuum-deposited CsPbBr3 perovskite light-emitting diodes (PeLEDs) are demonstrated by introducing a separate polyethylene oxide (PEO) passivation layer. A CsPbBr3 film deposited on the PEO layer via thermal co-evaporation of CsBr and PbBr2 exhibits an almost 50-fold increase in photoluminescence quantum yield intensity compared to a reference sample without PEO. This enhancement is attributed to the passivation of interfacial defects of the perovskite, as evidenced by temperature-dependent photoluminescence measurements. However, direct application of PEO to an LED device is challenging because of the electrically insulating nature of PEO. This issue is solved by doping PEO layers with MgCl2. This strategy results in an enhanced luminance and external quantum efficiency (EQE) of up to 6887 cd m-2 and 7.6%, respectively. To the best of our knowledge, this is the highest EQE reported to date among vacuum-deposited PeLEDs.

Enhancement of patterned triboelectric output performance by an interfacial polymer layer for energy harvesting application.

Efficaciously scavenging waste mechanical energy from the environment is an emerging field in the self-powered and self-governing electronics systems which solves battery limitations. It demonstrates enormous potential in various fields such as wireless devices, vesture, and portable electronic devices. Different surface textured PET triboelectric nanogenerators (TENGs) were developed by the laser pattern method in the previous work, with the line textured TENG device showing improved performance due to a larger surface contact area. Here, a polyethylene oxide (PEO) and polyvinyl alcohol (PVA) coated line patterned PET-based TENG was developed for the conversion of mechanical energy into useful electric energy. The PEO layer boosted the TENG output to 4 times higher than that of the PA6-laser patterned PET TENG device (our previous report) and 2-fold higher than that of a pristine line patterned TENG. It generated an open-circuit voltage, short circuit current, and instantaneous power density of 131 V, 2.32 μA, and 41.6 μW cm-2, respectively. The as-fabricated device was tested for 10 000 cycles for reliability evaluation, which shows no significant performance degradation. In addition, the device was deployed to power 10 LEDs with high intensity. Thus, this device can be used for ambient mechanical energy conversion and to power micro and nano-electronic devices.

Asymmetric double-layer composite electrolyte with enhanced ionic conductivity and interface stability for all-solid-state lithium metal batteries

All-solid-state Li metal battery has been regarded as a promising battery technology due to its high energy density based on the high capacity of lithium metal anode and high safety based on the all solid state electrolyte without inflammable solvent. However, challenges still exist mainly in the poor contact and unstable interface between electrolyte and electrodes. Herein, we demonstrate an asymmetric design of the composite polymer electrolyte with two different layers to overcome the interface issues at both the cathode and the anode side simultaneously. At the cathode side, the polypropylene carbonate layer has enough viscosity and flexibility to reduce the inter-facial resistance, while at the Li anode side, the polyethylene oxide layer modified with hexagonal boron nitride has high mechanical strength to suppress the Li dendrite growth. Owing to the synergetic effect between different components, the as-prepared double layer composite polymer electrolyte demonstrates a large electrochemical window of 5.17 V, a high ionic conductivity of 6.1 × 10−4 S/cm, and a transference number of 0.56, featuring excellent ion transport kinetics and good chemical stability. All-solid-state Li metal battery assembled with LiFePO4 cathode and Li anode delivers a high capacity of 150.9 mAh/g at 25 °C and 0.1 C-rate, showing great potential for practical applications.

Understanding the Influence of Surface Oxygen Groups on the Electrochemical Behavior of Porous Carbons as Anodes for Lithium-Ion Batteries.

The present study elucidates the role of surface oxygen functional groups on the electrochemical behavior of porous carbons when used as anodes for Li-ion batteries. To achieve this objective, a carbon xerogel (CX) obtained by pyrolysis of a resorcinol-formaldehyde gel, was modified by different postsynthesis treatments in order to modulate its surface chemistry while maintaining its external surface constant. Various surface modifications were obtained by oxidation in air, in situ polymerization of dopamine, and finally by grafting of a polyethylene oxide layer on the polydopamine coating. While oxidation in air did not affect the pore texture of the CX, modifications by coating techniques substantially decreased the micropore fraction. Detailed electrochemical characterizations of the materials processed as electrodes were performed by capacitance measurements and galvanostatic cycling. Surface chemistry results, from X-ray photoelectron spectroscopy, show that the accessibility and the capacity increase when carbonyl (R-C═O) groups are formed on the CX, but not with oxides and hydroxyls. The amount of surface carbonyls, and in particular, aldehyde (O═CH) groups, is found to be the key parameter because it is directly correlated with the modified CX electrochemical behavior. Overall, the explored surface coatings tend to reduce the micropore volume and add mainly hydroxyl functional groups but hardly change the Li+ insertion/deinsertion capacities, while oxidation in air adds carbonyl groups, increasing the Li+ ion storage capacity, thanks to an improved accessibility to the carbon network, which is not caused by any textural change.

Synergistic Effect of Polyethylene Oxide Layer on TiO2/TiO2-Graphene based Perovskite Solar Cell

This article reports the influence of titania (TiO2) and TiO2-graphene (TGr) as electron transport layer (ETL) on the performance of polyethylene oxide (PEO) based perovskite solar cell (PSC). Compared to most commonly used ETLs, graphene based ETLs showed immense promise towards scalable fabrication and higher carrier injection of PSC. Driven by this idea, PEO layer was introduced in TiO2 and TGr based PSC to inspect the feasibility of achieving notably high fill factor. As-grown nanocomposites were analyzed using varied analytical tools to determine the effect of graphene inclusion on their morphology, optical and electrical properties. An increase in the absorption bandwidth and red-shift in the absorption peak was observed from UV-VIS spectra indicating band gap narrowing. By exploiting TGr nanocomposite in perovskite solar cells as electron collection layer, a remarkable fill factor of 44% has been achieved. In short, present disclosure may contribute towards the development of ETL in high performing PEO based perovskite solar cell (PSC).

Efficient Inverted Polymer Solar Cells with ITO Cathode Modified by Zinc Oxide and Polyethylene Oxide Bilayers

For inverted polymer solar cells (PSCs), zinc oxide (ZnO) with various advantages are typically used as cathode buffer layer, but the existing surface traps/detects of ZnO layer obviously restrict device performance. In this work, the authors introduce polyethylene oxide (PEO) with high molecular weight of 300 thousands to modify the surface of ZnO layer on ITO cathode for inverted PSCs, where PEO possesses the particular advantages of easy accessibility and low cost. Compared with the ITO modified by pure ZnO and PEO layer, the ITO modified by ZnO/PEO bilayers shows the similarly good transparency, the lowest work function, the best surface morphology, and contact property. ZnO/PEO bilayers can provide the optimal energy alignment and interface contact between ITO and active layer, and efficiently eliminate the surface defects of ZnO layer. Therefore, the ITO/ZnO/PEO-based device exhibits the best photovoltaic performance with the PCE of 9.57% compared to the ITO/ZnO-based device (8.42%) and the ITO/PEO-based device (8.16%). The impressive results suggest that ZnO/PEO bilayers should be promising cathode buffer layer for high-performance inverted PSCs.

Electrospun Fibers for Controlled Release of Nanoparticle-Assisted Phage Therapy Treatment of Topical Wounds

ABSTRACTBacterial cultures exposed to iron-doped apatite nanoparticles (IDANPs) prior to the introduction of antagonistic viruses experience up to 2.3 times the bacterial destruction observed in control cultures. Maximum antibacterial activity of these bacteria-specific viruses, or phage, occurs after bacterial cultures have been exposed to IDANPs for 1 hr prior to phage introduction, demonstrating that IDANP-assisted phage therapy would not be straight forward, but would instead require controlled time release of IDANPs and phage. These findings motivated the design of an electrospun nanofiber mesh treatment delivery system that allows burst release of IDANPs, followed by slow, consistent release of phage for treatment of topical bacterial infections. IDANPs resemble hydroxyapatite, a biocompatible mineral analogous to the inorganic constituent of mammalian bone, which has been approved by the Food and Drug Administration for many biomedical purposes. The composite nanofiber mesh was designed for IDANP-assisted phage therapy treatment of topical wounds and consists of a superficial, rapid release layer of polyethylene oxide (PEO) fibers doped with IDANPs, followed by inner, coaxial polycaprolactone / polyethylene glycol (PCL/PEG) blended polymer fiber layer for slower phage delivery. Our investigations have established that IDANP-doped PEO fibers are effective vehicles for dissemination of IDANPs for bacterial exposure and resultant increased bacterial death by phage. In this work, slower delivery of the phage behind IDANPs was accomplished using coaxial, electrospun fibers composed of PCL/PEG polymer blend.

Enhanced oral absorption and anticancer efficacy of cabazitaxel by overcoming intestinal mucus and epithelium barriers using surface polyethylene oxide (PEO) decorated positively charged polymer-lipid hybrid nanoparticles

Polymer-lipid hybrid nanoparticles, PMONPs, were developed to improve the oral absorption of cabazitaxel (CTX), a semi-synthetic taxane derivative, by overcoming multiple gastrointestinal barriers. The nano-carrier is comprised of a poly(ε-caprolactone) (PCL) and chain triglyceride (MCT) hybrid core for drug loading, and a positively charged surface while slightly concealed with a polyethylene oxide (PEO) shell by insertion of poloxamer 188, with the aim of improving the intestinal mucus permeation and epithelial cell uptake. The CTX-loaded PMONPs (CTX-PMONPs) were optimized with 10% MCT content in the core, and characterization showed they were on the nanoscale with a size of 170.2±5.7nm, zeta potential of +40.90±3.05mV, drug loading of 11.5%, and sustained release property. Enhanced mucus permeation of PMONPs were confirmed in a bulk permeation test, in situ SPIP and intestinal distribution study, and is likely attributed to the combined effect of positive charge and hydrophilic PEO layer on the surface. Meanwhile, promoted cellular uptake was found in mucus-secreting cells evaluation, in which potential adsorptive transcytosis, caused by positively charged surface, played a key role. Furthermore, lymphatic transport was positively demonstrated, contributing to the high oral absorption of CTX-PMONPs. The oral bioavailability of CTX was elevated from 7.7% (CTX solution (CTX-Sol)) to 56.6% after oral administration of CTX-PMONPs, approximately 7.3 times higher than that of CTX-Sol. An in vivo anticancer efficiency study showed that CTX-PMONPs orally exhibited a good tumor inhibition effect, and reduced the CTX-caused systemic toxicity compared with intravenous CTX-Sol. In conclusion, PMONPs are able to efficiently orally deliver the anticancer drug, CTX, into systemic circulation, and can achieve the desired oral anticancer effect. This surface modified polymer-lipid hybrid nanoparticle is likely to be a promising carrier for oral delivery of small molecule anticancer drugs.

Synthesis, characterization, and antimicrobial properties of novel double layer nanocomposite electrospun fibers for wound dressing applications.

Herein, novel hybrid nanomaterials were developed for wound dressing applications with antimicrobial properties. Electrospinning was used to fabricate a double layer nanocomposite nanofibrous mat consisting of an upper layer of poly(vinyl alcohol) and chitosan loaded with silver nanoparticles (AgNPs) and a lower layer of polyethylene oxide (PEO) or polyvinylpyrrolidone (PVP) nanofibers loaded with chlorhexidine (as an antiseptic). The top layer containing AgNPs, whose purpose was to protect the wound site against environmental germ invasion, was prepared by reducing silver nitrate to its nanoparticulate form through interaction with chitosan. The lower layer, which would be in direct contact with the injured site, contained the antibiotic drug needed to avoid wound infections which would otherwise interfere with the healing process. Initially, the upper layer was electrospun, followed sequentially by electrospinning the second layer, creating a bilayer nanofibrous mat. The morphology of the nanofibrous mats was studied by scanning electron microscopy and transmission electron microscopy, showing successful nanofiber production. X-ray diffraction confirmed the reduction of silver nitrate to AgNPs. Fourier transform infrared spectroscopy showed a successful incorporation of the material used in the produced nanofibrous mats. Thermal studies carried out by thermogravimetric analysis indicated that the PVP–drug-loaded layer had the highest thermal stability in comparison to other fabricated nanofibrous mats. Antimicrobial activities of the as-synthesized nanofibrous mats against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Candida albicans were determined using disk diffusion method. The results indicated that the PEO–drug-loaded mat had the highest antibacterial activity, warranting further attention for numerous wound-healing applications.

Dielectric and Mechanical Investigations on the Hydrophilicity and Hydrophobicity of Polyethylene Oxide Modified on a Silicon Surface

Polyethylene oxide (PEO) has been widely used in biomedical fields. The antibiofouling property of the PEO-modified surface has been extensively investigated but is far from being fully understood. A series of PEOs with narrowly distributed molecular weight (Mw), synthesized with the technique of high vacuum anionic polymerization, have been successfully grafted onto the surface of silicon wafers. The power-law relationship between the thickness of the monolayer versus the Mw of the grafted PEO shows a scaling of 0.3, indicating compact condensing of the chains. The static contact angles show higher hydrophobicity for the layer of PEO with higher Mw, which can be attributed to the closely packed conformation of the chains with high density. The frequency shift of the contact resonance indicates that the Young's modulus decreases and the loss factor increases with the increase in the Mw of PEO and the thickness of the PEO layers. Dielectric spectroscopy of bare or PEO-grafted wafers in the aqueous solutions reveals an interfacial polarization, which results from compositional and structural changes in the interface layer and depends on temperatures and salt concentrations. At a given grafting density, the PEO chains are swollen in pure water, demonstrating hydrophilic behavior, whereas they collapse in salt solutions, showing hydrophobic characteristics.

Electrochemical performance of an all-solid-state lithium–oxygen battery under humidified oxygen

The electrochemical performance of an all-solid-state lithium–oxygen battery was examined using a platinum patterned electrode with a lithium conducting solid electrolyte under a humidified O2 atmosphere. The cell consisted of a lithium metal anode, a protective layer of polyethylene oxide with Li(CF3SO2)2N, a lithium-conducting solid electrolyte of Li1+x+yAlx(Ge,Ti)2−xSiyP3−yO12, and a sputtered platinum stripe-patterned air electrode. The open circuit voltage (OCV) of the virgin cell was 3.5V under humidified O2 and decreased to 3.2V after slight discharge, which is comparable with that under dry O2 (2.4V). The cell was successfully discharged and charged at 0.1mAcm−2 and 60°C. A reaction product was observed on the platinum electrode; however, it could not be identified by X-ray diffraction analysis or Raman spectroscopy, which indicated it was amorphous. Nano-secondary ion mass spectrometry (SIMS) analysis suggested that the reaction product contains Li, H, and O.

Encapsulation of Volatile Compounds in Silk Microparticles.

Various techniques have been employed to entrap fragrant oils within microcapsules or microparticles in the food, pharmaceutical, and chemical industries for improved stability and delivery. In the present work we describe the use of silk protein microparticles for encapsulating fragrant oils using ambient processing conditions to form an all-natural biocompatible matrix. These microparticles are stabilized via physical crosslinking, requiring no chemical agents, and are prepared with aqueous and ambient processing conditions using polyvinyl alcohol-silk emulsions. The particles were loaded with fragrant oils via direct immersion of the silk particles within an oil bath. The oil-containing microparticles were coated using alternating silk and polyethylene oxide layers to control the release of the oil from the microspheres. Particle morphology and size, oil loading capacity, release rates as well as silk-oil interactions and coating treatments were characterized. Thermal analysis demonstrated that the silk coatings can be tuned to alter both retention and release profiles of the encapsulated fragrance. These oil containing particles demonstrate the ability to adsorb and controllably release oils, suggesting a range of potential applications including cosmetic and fragrance utility.

Activity Retention after Nisin Entrapment in a Polyethylene Oxide Brush Layer

The cationic, amphiphilic peptide nisin is an effective inhibitor of gram-positive bacteria whose mode of action does not encourage pathogenic resistance, and its proper incorporation into food packaging could enhance food stability, safety, and quality in a number of circumstances. Sufficiently small peptides have been shown to integrate into otherwise nonfouling polyethylene oxide (PEO) brush layers in accordance with their amphiphilicity and ordered structure, including nisin, and we have recently shown that nisin entrapment within a PEO layer does not compromise the nonfouling character of that layer. In this work we test the hypothesis that surface-bound, pendant PEO chains will inhibit displacement of entrapped nisin by competing proteins and, in this way, prolong retention of nisin activity at the interface. For this purpose, the antimicrobial activity of nisinloaded, PEO-coated surfaces was evaluated against the gram-positive indicator strain, Pediococcus pentosaceous. The retained antimicrobial activity of nisin layers was evaluated on uncoated and PEO-coated surfaces after incubation in the presence of bovine serum albumin for contact periods up to 1 week. Nisin-loaded, uncoated and PEO-coated samples were withdrawn at selected times and were incubated on plates inoculated with P. pentosaceous to quantify nisin activity by determination of kill zone radii. Our results indicate that nisin activity is retained at a higher level for a longer period of time after entrapment within PEO than after direct adsorption in the absence of PEO, owing to inhibition of nisin exchange with dissolved protein afforded by the pendant PEO chains.

Multilayer Separator for Lithium Batteries

Lithium metal provides the highest specific energy density and would be a perfect anode material for a lithium ion battery [1]. But so far only polymer batteries based on PEO show a stable interaction with lithium metal [2-3]. However, these electrolytes feature only a low ionic conductivity (up to 10-3 S cm-1) at room temperature. To use lithium metal in combination with liquid electrolytes, a thin layer (10 μm) of polyethylene oxide (PEO) was coated on conventional separators. A simple, solvent free technique was used to combine the polymer electrolyte to the separator (patent pending). To enhance the mechanical stability during the swelling with electrolyte, the polymer was cross-linked after the coating step [4].An application of the polymer/separator system is possible with established positive electrode materials like lithium iron phosphate (LFP) or lithium nickel manganese cobalt oxide (NMC) to enhance the energy density of the system. Even more promising is the use in next generation battery systems like lithium air and lithium-sulfur. The thin layer of PEO optimizes the lithium-electrolyte interface and therefore acts as a protective layer against parasitic reactions like electrolyte decomposition [5]. In Li-O2and Li-S batteries, the PEO could additionally act as a barrier against, respectively, oxygen or polysulfide diffusion to the lithium anode.The PEO layer was found to be mechanically stable during cell assembling and electrolyte application. Due to the cross-linking, even an excess of electrolyte does not dissolve the polymer. By chemical bonding between the PEO and polyethylene (PE) or polypropylene (PP) a loss of connection between the two separator layers is prevented. Partly impregnation of PEO into porous ceramic separators during the coating process shows the same effect after cross-linking. Differential scanning calorimetry (DSC) tests show that PEO and ionic liquids form an amorphous layer on the lithium surface, similar to ternary polymer electrolytes [6].To verify the electrochemical stability of the PEO on the lithium metal surface, stripping-plating tests in symmetrical lithium cells were performed with a broad range of electrolytes. For established cathode materials, carbonate-based solvents like ethylene carbonate (EC) and dimethyl carbonate (DMC) with lithium hexafluorophosphate (LiPF6) were investigated. For next generation batteries or cycling at higher temperatures, tests with tetraethylene glycol dimethyl ether (TEGDME), 1,3-dioxolane and ionic liquids like 1-butyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide (Pyr14TFSI) with lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) were performed. Finally, cycling tests with NMC and sulfur cathodes were performed.1. Bruce, P.G., et al., Li-O2 and Li-S batteries with high energy storage. Nat Mater, 2012. 11(02): p. 172-172.2. Li, Z., et al., A review of lithium deposition in lithium-ion and lithium metal secondary batteries.Journal of Power Sources, (0).3. Kim, G.T., et al., UV cross-linked, lithium-conducting ternary polymer electrolytes containing ionic liquids. Journal of Power Sources, 2010. 195(18): p. 6130-6137.4. Rupp, B., et al., Polymer electrolyte for lithium batteries based on photochemically crosslinked poly(ethylene oxide) and ionic liquid. European Polymer Journal, 2008. 44(9): p. 2986-2990.5. Peled, E., et al., The sei model—application to lithium-polymer electrolyte batteries. Electrochimica Acta, 1995. 40(13–14): p. 2197-2204.6. Joost, M., et al., Phase stability of Li-ion conductive, ternary solid polymer electrolytes. Electrochimica Acta, 2013. 113(0): p. 181-185.

Conductive-bridging random-access memory cell fabricated with a top Ag electrode, a polyethylene oxide layer, and a bottom Pt electrode

We developed a conductive-bridging random-access memory cell with a sandwiched structure of an Ag top electrode, an electrolyte (polyethylene oxide: PEO), and a Pt bottom electrode on a 250-nm hole pattern. The cell demonstrated the bipolar switching behavior of resistive randomaccess memory. The nonvolatile characteristics of the cell strongly depended on the wt% (PEO thickness): i.e., maximum memory characteristics, such as a retention-time of > 1 × 105 s with a memory margin of 1 × 104 and program/erase cycles of > 103 with a memory margin of 1.3 × 104, which are very close to thereof a commercial memory cell, were observed at a specific wt% of PEO (0.4 wt%)

Blood protein repulsion after peptide entrapment in pendant polyethylene oxide layers

A number of sufficiently small peptides have been shown to integrate into polyethylene oxide (PEO) brush layers in accordance with their amphiphilicity and ordered structure. Those results have suggested that responsive drug delivery systems based on peptide-loaded PEO layers can be controlled by modulation of solution conditions and peptide amphiphilicity. However, the presence of entrapped peptide may compromise the protein repulsive character of the PEO layer, and in this way reduce the viability of a medical device coating based on such an approach. Nisin is a cationic, amphiphilic, and antimicrobial peptide that has been shown to integrate into PEO brush layers. In this work, the preferential location of fibrinogen at PEO-coated, nisin-loaded layers was investigated in nisin-fibrinogen sequential adsorption experiments using detection of fluorescein isothiocyanate labeled fibrinogen, detection of changes in zeta potential, and measurement of adsorption and elution kinetics by optical waveguide lightmode spectroscopy. Results from each technique indicate that the presence of entrapped nisin does not affect fibrinogen interaction with the PEO layer. In addition, entrapment of blood solutes within PEO layers contacted with 25% equine plasma in phosphate-buffered saline was reduced by the prior entrapment of nisin within the layer.