Polyethylene Oxide Polymer Research Articles

Manipulating the Trade‐off Between Quantum Yield and Electrical Conductivity for High‐Brightness Quasi‐2D Perovskite Light‐Emitting Diodes

AbstractQuasi‐two‐dimensional (quasi‐2D) perovskites are attracting much attention due to their impressive luminescence properties. However, the introduction of insulating bulky cations reduces the charge transport property of mixed‐dimensional perovskites and leads to lowered brightness and increased turn‐on voltage. The trade‐off between high photoluminescence quantum yield (PLQY) and electrical conductivity should be well manipulated to obtain high‐performance perovskite light‐emitting diodes (PeLEDs). Herein, quasi‐2D perovskite BA2(CsPbBr3)n‐1PbBr4‐PEO with high PLQY and excellent carrier injection efficiency is demonstrated by incorporating bulky n‐butylammonium bromide (BABr), CsPbBr3, and polyethylene oxide (PEO). BA can intercalate into the three‐dimensional perovskite framework to form a layered (quasi‐2D) perovskite structure. The ion conductive polymer PEO is used to protect quasi‐2D perovskite crystals. Additional BABr is removed by using anhydrous isopropyl alcohol as a washing agent due to its selective dissolubility. By carefully modulating the optical and electrical properties of quasi‐2D perovskite films, the maximum luminance of PeLEDs is dramatically enhanced from 191 to 33533 cd m−2, which is the brightest green quasi‐2D PeLED reported thus far, leading to an increase in external quantum efficiency from 1.81% to 8.42%. This work provides a promising route to control the optical and electrical properties of quasi‐2D perovskite films for high‐performance optoelectronic devices.

Thermopolarization Effect in Linear Polyethylene Oxide upon Crystallization from Melt

The correlation between crystallite structural changes and polarization properties of a linear crystallized [–CH2CH2O–]n polyethylene oxide polymer is studied. The average spherulite radius and polarization of polyethylene oxide are inspected as functions of molecular weight of polymer and crystallization temperature from melt in a nonuniform temperature field.

Quality by design based development and optimization of novel gastroretentive floating osmotic capsules of clopidogrel bisulfate

The aim of the present investigation was to develop and optimize gastroretentive floating osmotic formulation of clopidogrel bisulfate using risk based approach. Risk assessment was carried out using failure mode effect analysis (FMEA) and high risk factors were identified. Preliminary studies highlighted importance of selection of low molecular weight PEO (molecular weight ~ 100,000) as rate controlling polymer and band sealing of coated capsules whereas thermal characterization studies assisted in selection of hydrogenated castor oil as more compatible lubricant. A face centered central composite design (CCD) was deployed to optimize high risk factors i.e. amount of osmogen (sodium chloride), amount of rate controlling polymer (Polyethylene oxide), polymer (Cellulose acetate) to plasticizer (PEG 3350) ratio in semipermeable membrane and weight gain per unit surface area. Optimized formulation was selected using constraint based graphical optimization technique and desirability function. Optimized batch was also found to be stable under selected packaging configurations. Optimized batch exhibited dissolution at 1 h of 4.65%, 4 h of 31.23%, 8 h of 62.80%, 12 h of 94.55% with zero floating lag time and total buoyancy time of more than 12 h. Scanning electron microscopy (SEM) was carried out to characterize semipermeable coating membrane before and after dissolution studies. Capability indices of six reproducible batches illustrated capability of selected process for manufacturing batches as per desired specifications. Overall, present investigation successfully illustrated development and optimization of novel hard gelatin capsule based gastroretentive floating osmotic formulation of clopidogrel bisulfate with zero order drug release profile and improved patient compliance.

Novel electrospun fibers with incorporated commensal bacteria for potential preventive treatment of the diabetic foot.

A novel electrospun biocompatible nanofibrous material loaded with commensal bacteria for potential preventive treatment of the diabetic foot was developed. Two biocompatible polymers (carboxymethylcellulose and polyethylene oxide) were combined with a bacterium isolate from the skin located between the toes of a healthy adult (identified using a matrix-assisted laser desorption/ionization mass spectrometry-based method as a strain of Staphylococcus epidermidis). Higher bacteria loads in the material were assured through their encapsulation in polyethylenimine. The nanofibrous material was characterized using scanning electron microscopy, zeta-potential measurements and through evaluation of cell growth and viability. nanometer formation was confirmed using scanning electron microscopy, while the zeta-potential measurements revealed successful bacteria encapsulation. Viable and sufficiently growing cells were confirmed prior and after their incorporation. The prepared materials were proven suitable to deliver viable commensal bacteria in a comparable share to the Staphylococcaceae in the foot microbiome making this approach promising for preventive diabetic foot treatment.

Quercetin-loaded and unloaded electrospun membranes: Synthesis, characterization and in vitro release study

Electrospun fiber membranes have been utilized to delivery hydrophilic/hydrophobic drugs in the drug delivery systems. They offer several features such as high surface area to volume ratio, high porosity and high productivity. In this paper, quercetin (QU)-loaded and unloaded electrospun membranes were prepared via electrospinning of polycaprolactone (PCL) blended with polyethylene oxide (PEO), polylactic acid (PLA), and polylactic-co-glycolic acid (PLGA). The prepared membranes were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and drop shape analysis (DSA). In vitro release of QU from the QU-loaded membranes was examined in simulated physiological condition by ultraviolet–visible spectroscopy. The results of morphological analysis revealed that electrospun membrane prepared by the mixture of PCL and PEO polymers with QU had more smooth, beadless and random morphology. Due to the release study, the highest amount of QU release was obtained within 240 min period. In addition, in vitro cytotoxicity study indicated that the QU-loaded membranes exhibited toxicity on human breast carcinoma cells in 24 h. These results showed that quercetin-loaded PCL and PEO membranes can be used in drug delivery systems as a drug carrier vehicle.

Novel generation systems of gaseous chlorine dioxide for Salmonella inactivation on fresh tomato

Chlorine dioxide (ClO2) is an antimicrobial agent used in fresh produce sanitation to inactivate a board range of pathogens. Compared to its aqueous form, gaseous ClO2 has a stronger penetrating ability and therefore a greater inactivation effect. A novel ClO2(g) generating method utilizes carbon dioxide and moisture naturally released from tomato during respiration to react with NaClO2 for ClO2(g) generation has been proposed in our previous study. This study further developed two novel generation systems (i.e., electrospun fiber and releasing film) for the method applications in reality. In this study, the physical properties (i.e., viscosity, conductivity, pH and surface tension) of different poly-ethylene oxide (PEO) polymer solutions (i.e., 2%, 3%, 4% PEO and 3% PEO with 0.15%, 0.3% NaClO2), the morphology and diameter distribution of electrospun fibers produced as well as the loading efficiency of NaClO2 onto the fibers were investigated. The successful generation of ClO2(g) from the two developed systems were observed. Four log CFU Salmonella/fruit inoculated on the surface were significantly reduced (p < 0.05) to undetectable level (<5 CFU/fruit) within 2 days under both systems and the surface color and firmness of the fruits were not impacted (p > 0.05) during the entire storage period (14 days for 10 °C and 7 days for 22 °C). The information can be utilized for Salmonella safety enhancement on fresh tomato during storage, transportation and retail stages. It also provides insights for the further applications of the generating method on many other fresh produce as well as on many other pathogens.

Hybrid polycaprolactone/polyethylene oxide scaffolds with tunable fiber surface morphology, improved hydrophilicity and biodegradability for bone tissue engineering applications

In the present study, we attempt to modify Polycaprolactone (PCL) by blending it with a water soluble polymer Polyethyleneoxide (PEO) having two different molecular weights (Mv ~1,00,000 and 6,00,000) using electrospinning technique. The effect of PEO molecular weight and blend ratio on fiber morphology, porosity, surface wettability, static and dynamic mechanical properties of PCL was investigated. In vitro degradation studies in phosphate buffer saline (PBS) at 37 °C demonstrated formation of pores on fiber surface especially in blend scaffolds with 50:50 ratios. In vitro studies using human osteoblast sarcoma (hOS) cell lines on blend scaffolds showed improved cellular response with good cell adhesion, viability and proliferation. The study revealed that incorporation of PEO on PCL scaffolds complemented the properties of PCL and facilitated fabrication of scaffolds with improved hydrophilicity, mechanical property and tunable degradation profile with better cell viability which makes it an ideal candidate for bone tissue engineering applications.

Identification of relaxation processes in pure polyethylene oxide (PEO) films by the dielectric permittivity and electric modulus formalisms

The ac‐impedance of bulk‐like films of pure polyethylene oxide (PEO) polymer was measured as a function of frequency f in the range 0.1 to 107 Hz at various constant temperatures T (155 − 330 K). The as‐measured data were analyzed by electric permittivity and modulus formalisms to unveil which dielectric and conductive relaxation processes were responsible for their relaxation behavior below/above glass transition temperature Tg of pure PEO polymer. At T &gt; Tg, none of the α‐, β‐, or γ‐relaxations could be inferred for studied pure PEO films from frequency variation of measured imaginary part ε′′(f, T) of complex dielectric permittivity , as low‐frequency losses masked real dielectric contribution to the measured ε′′(f, T) at low frequencies and high temperatures. However, at T &lt; Tg, a broad, relaxation process has been observed in the high‐frequency part of their isothermal ε′′(f, T) − f spectra, which can be related to the β‐ or γ‐dielectric relaxation process. Nonlinear regressions of the measured ε′′(f, T) − f data for T &lt; Tg yielded moral fits to a simple addition of a Havriliak‐Negami function, and a Bergman‐loss Kohlrausch‐Williams‐Watts‐type function, with the relaxation time τmax(T) obtained from Havriliak‐Negami‐fitting parameters, was found to follow a thermally activated Arrhenius‐like relaxation behavior. Conversely, representation of the imaginary part M′′(f, T &gt; Tg) − f spectra of complex electric modulus was found to depict 2 overlapped relaxation processes, which were detached well by a nonlinear regression of a simple superposition of 2 different M′′(f) expressions having the form of the universal Bergman loss function, where it was found that the relaxation time is also thermally activated.

Performance of EMIMFSI ionic liquid based gel polymer electrolyte in rechargeable lithium metal batteries

Flexible gel polymer electrolytes based on polymer polyethylene oxide, salt lithium bis(fluorosulfonyl)imide and ionic liquid 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide are synthesized. Prepared samples show high thermal stability, high ionic conductivity at room temperature and an electrochemical stability window of ∼3.51V vs. Li/Li+. Lithium deposition-striping voltage profiles show the formation of a stable solid electrolyte interface. A Li/GPE/LiFePO4 cell was assembled by low cost thermal lamination technique. This cell can deliver 143mAhg−1 capacity at room temperature at C/20 rate with good discharge efficiency. Use of micro grid mesh type Al current collector in cathode exhibits significant improvement in capacity retention.

Electrochemical study of Ionic Liquid based polymer electrolyte with graphene oxide coated LiFePO4 cathode for Li battery

Ionic Liquid (IL) based polymer electrolytes using polymer poly ethylene oxide (PEO), salt lithium bis(fluoromethylsulfonyl)imide and IL N-propyl-N-methylpyrrolidinium-bisfluorosulfonylimide (PYR13FSI) are synthesized by solution cast method. Using different experimental techniques, good thermal stability and wide electrochemical window are observed for synthesized polymer electrolytes. Maximum Li+ conductivity is found for 10% IL containing polymer electrolyte so, it is used in Li cell preparation. LiFePO4 (LFP) cathode and graphene oxide wrapped LFP cathode (GO-LFP) are also prepared to observe the effect of graphene oxide coating in electrochemical performance of the Li cell. From charge –discharge process, high specific discharge capacity (~163 mAh g−1 at 0.1 C) is found for GO-LFP as compared to LFP cathode. GO-LFP cathode shows good cyclability and Coulombic efficiency up to 100 cycles. High charge-discharge capacity of GO-LFP is noticed even at higher current rate.

Study of triamcinolone release and mucoadhesive properties of macroporous hybrid films for oral disease treatment

The aim of this study was to develop macroporous mucoadhesive films from ureasil–polyether materials for future application in oral disease treatment. The films were prepared via the sol–gel route by using polyethylene oxide (PEO) and polypropylene oxide (PPO) polymers; triamcinolone was used as a model drug for in vitro release testing. The in vitro drug release assay revealed that Ureasil-PEO500 films containing 3% and 6% of the model drug released 56% and 33% of the initial mass, respectively. This difference in release is probably due to a higher amount of the drug, making relaxation of polymer chains difficult, causing reduced swelling. For Ureasil-PPO400 films the amount of the drug did not influence the release; the rate of release was 5.1% after 12 hours and this lower release can be explained by the hydrophobic character of Ureasil-PPO400 polymeric chains. These results are in agreement with the swelling results. The swollen behavior of the films was monitored by small-angle x-ray scattering measurements (SAXS). Atomic force microscopy demonstrated that all the films are macroporous (pores around 400 nm) but the Ureasil-PEO500 film possesses more pores than Ureasil-PPO400. Mucoadhesion force assessment revealed that all ureasil–polyether films with or without a model drug have higher mucoadhesion values than the commercial product. These results indicate that macroporous ureasil–polyether mucoadhesive films are promising candidates for oral disease treatment considering their cost, biocompatibility, drug release and ease of handling, and they have more adhesion force to oral mucosa than the commercial product.

An in vitro - in silico approach for the formulation and characterization of ranitidine gastroretentive delivery systems

Contemporary trends in the pharmaceutical development emphasize the utility of advanced computer tools to facilitate formulation of new medicines. A special attention has been given to the formulation and characterization of dosage forms for targeted drug delivery that can improve therapeutic outcome. The objective of this study was to apply the combined in vitro-in silico approach to optimize the design of gastroretentive floating system for sustained release of ranitidine hydrochloride. Formulation of the floating systems was based on the effervescent effect of sodium-bicarbonate, whereas prolonged release of ranitidine hydrochloride was provided by the hydrophilic polyethylene oxide polymers which swell and form a gel layer on the surface of the floating tablets. Dosage form floating characteristics and drug dissolution were investigated under biorelevant conditions simulating stomach environment. The obtained dissolution data were used as inputs in ranitidine-specific physiologically-based pharmacokinetic model within GastroPlus™ software to predict the expected pharmacokinetic profiles following oral administration of the designed formulations. The predictive power of the designed model was tested by comparing the simulation outcomes with literature values on drug plasma concentration-time profiles following intravenous and oral administration of different ranitidine doses. In addition, simulation results demonstrated increased extent of drug absorption with prolonged gastric residence times.

Electrochemical investigations of Na0.7CoO2 cathode with PEO-NaTFSI-BMIMTFSI electrolyte as promising material for Na-rechargeable battery

We report herein the development of a sodium polymer battery consisting of solid polymer electrolyte (SPE) system (polymer + ionic liquid and salt) as an electrolyte and sodium cobalt oxide as cathode material. Solid polymeric membranes (SPMs) were synthesized using polymer polyethyleneoxide (PEO), ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (BMIMTFSI) (10–40 wt.%), and sodium bis(trifluoromethylsulfonyl)imide (NaTFSI) salt. Na0.7CoO2 cathode material was prepared using solid-state reaction route. These solid polymeric membranes were optimized using various experimental techniques such as thermogravimetric analysis, differential scanning calorimetry, and electrochemical impedance spectroscopy (EIS). It was found that the membrane containing 40 wt.% of IL has high room temperature (~ 30 °C), ionic conductivity (~ 4.1 × 10−4 S cm−1), Na+ transference number (~ 0.39), and good thermal stability. The optimized polymeric membrane shows high electrochemical potential window (~ 3.6 V) vs. Na/Na+, a specific discharge capacity of ~ 138 mAhg−1 (at 0.1 C rate) and maximum coulombic efficiency (~ 99%) for the prepared cell Na | SPE | Na0.7CoO2. Thus, the membrane containing 40 wt.% IL polymer electrolyte and Na0.7CoO2 as cathode is promising material for the formation of sodium rechargeable battery.

Sudden death following dystocia and peritoneal contamination with a polyethylene polymer‐based obstetrical lubricant in an alpaca

A four‐year‐old alpaca suffered muscle tremors, weakness and rear limb paresis following transvaginal correction of dystocia with the aid of a polyethylene oxide polymer (PEP) obstetrical lubricant. A large volume of serosanguinous fluid containing a viscous substance consistent with the PEP lubricant was found in the abdomen. The alpaca died 5.5 hours after dystocia and postmortem examination confirmed multiple uterine tears and presence of a large volume of PEP in the abdomen. The onset of clinical signs and death are consistent with that reported after intraperitoneal instillation of PEP‐based lubricants in horses and cows. Veterinarians should exercise caution when using PEP‐based lubricants based on the risk of death if intra‐abdominal contamination with PEP occurs.

Термополяризационный эффект в линейном полиэтиленоксиде при кристаллизации из расплава

AbstractThe correlation between crystallite structural changes and polarization properties of a linear crystallized [–CH_2CH_2O–]_ n polyethylene oxide polymer is studied. The average spherulite radius and polarization of polyethylene oxide are inspected as functions of molecular weight of polymer and crystallization temperature from melt in a nonuniform temperature field.

Investigating the improvement of Degradation Resistant with the Addition of SDBS Anionic Surfactant to PEO polymer

Polyethylene Oxide (PEO) is one of the most common drag reduction agents. However, its ability to reduce drag in turbulent flow decreases with the time due to the degradation of its molecules. Thus, the enhancement of its degradation resistance by the addition of Anionic surfactant is presented. The Polyethylene oxide (PEO) was used in different concentration ranges from 10 to 60 ppm and with addition of sodium dodecyl benzene sulfonate (SDBS) as the anionic surfactant with five concentrations between 100 to 500 ppm. The degradation measurements were done using rotating disk apparatus (RDA). The RDA results have shown a considerable improvement in the degradation resistance of PEO with the addition of surfactant to the polymer solution. The interaction between the polymer and the surfactant results in transferring the polymer chain from coil to straight-like body. Thus, enhance the polymer degradation resistant ability.

Solid polymer electrolytes incorporating cubic Li7La3Zr2O12 for all-solid-state lithium rechargeable batteries

The advantages of all-solid-state batteries in terms of high energy density and improved safety have accelerated the research into durable and reliable solid electrolytes and into scale up of their processing technology. High lithium-ion-conducting Li7La3Zr2O12 (LLZO) ceramic-based solid electrolytes have been intensively studied recently, but their widespread commercial deployment has been constrained due to their fragility and brittleness. In the present study, LLZO ceramic powders have been successfully incorporated into the polyethylene oxide (PEO) polymer by tape casting. The ionic conductivity of the PEO/LLZO composite electrolyte membranes is significantly enhanced at the optimal LLZO concentration of 7.5 wt.% at which the materials exhibits maximum ionic conductivity of 5.5 × 10−4 S·cm−1 at 30 °C. The ionic conductivity enhancement mechanism of the composite electrolyte is revealed by differential scanning calorimetry (DSC), which shows that the LLZO filler represses crystallinity in PEO. Furthermore, as evidence of the advantageous electrochemical properties of the composite electrolyte an all-solid-state battery of LiFePO4/Li fabricated herein delivered a maximum discharge capacity of 150.1 mAh·g−1 at 0.1C, good cycling performance, and excellent rate capability under 60 °C.

Performance enhancement of poly (vinylidene fluoride-co-hexafluoro propylene)/polyethylene oxide based nanocomposite polymer electrolyte with ZnO nanofiller for dye-sensitized solar cell

Nanocomposite polymer electrolytes (NCPEs) were prepared by blending poly (vinylidene fluoride-co-hexafluoro propylene) copolymer (PVdF-HFP) and polyethylene oxide (PEO) polymers and incorporation of ZnO inorganic nanofiller (PVdF-HFP:PEO:EC:PC:NaI:I2:ZnO). The highest ionic conductivity value of 8.36 mS cm−1 was recorded when 3 wt.% of ZnO inorganic nanofiller was incorporated into the NCPE system. Temperature-dependant ionic conductivity behaviour of NCPEs was analysed and proven to follow the Arrhenius thermal activated model. Structural studies of NCPEs were carried out using X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy analysis. NCPEs were used to fabricate Dye-sensitized solar cells (DSSCs). Enhancements in the solar light to electricity conversion efficiency (η) of DSSCs were observed in the presence of ZnO inorganic nanofiller in the NCPE system and NCPE with 3 wt.% ZnO represented the highest η of 7.33% under full sun irradiation.

N991/MWCNTs/PEO composite films with nano SiO2 particles as filler for advanced flexible electric heating elements

Carbon/polymer based flexible electrothermal films due to the excellent formability, flexibility, light weight and cost-effectiveness are recognized as a promising alternative material compared to traditional metal based materials. In this work, a series of flexible electrothermal films were synthesized by incorporating pyrolysis N991 and multi-walled carbon nanotubes (MWCNTs) in polyethylene oxide (PEO) matrix with adding non-conductive SiO2 filler. The influences of SiO2 on morphology, microstructure and electrothermal performance of electrothermal films were systematically investigated. SiO2 filler guarantees the homogeneous dispersion of N991 and MWCNTs in PEO polymer matrix, which could prevent the unceasing migration of N991 and MWCNTs during the repeating heating-cooling cycles. The result shows that adding 5wt.% SiO2 can achieve a stable electrical resistivity and excellent electrothermal reproducibility. Bending tests were employed to evaluate its superior mechanical flexibility. A new application was further developed to fabricate a flexible electrothermal film with a reversible thermochromic temperature-indicating function.

Solid polymer electrolytes based on Li+/ionic liquid for lithium secondary batteries

Ionic liquid (IL)-based solid polymer electrolytes (SPEs) were synthesized by solution cast technique using polymer polyethylene oxide (PEO), lithium bis(trifluoromethane sulfonyl) imide (LiTFSI) salt, and IL 1-butyl-3-methylimidazolium bis(trifluoromethane sulfonyl) imide (BMIMTFSI). The obtained polymer electrolytes (PEO + 20 wt.% LiTFSI) + x wt.% BMIMTFSI where x = 0, 5, 10, 15, and 20 were characterized by DSC, TGA, SEM, XRD, FTIR, electrochemical impedance spectroscopy (EIS), cyclic voltammetry, chronoamperometry, and chronocharge-discharge. Ionic conductivity of optimized composition SPE (PEO + 20 wt.% LiTFSI) + 20 wt.% BMIMTFSI is ∼1.5 × 10−4 S cm−1 at 30 °C and follows Arrhenius-type thermally activated behavior. The prepared SPEs are free-standing and flexible with excellent thermal and mechanical stabilities. SEM, XRD, and DSC studies show that the amorphicity of SPEs increases on increasing IL content due to the plasticization effect of IL. The assembled cell exhibits good electrochemical stability and cationic transference number $$ {t}_{{\mathrm{Li}}^{+}}\sim 0.27 $$ . The capacity of cell, Li | PEO + 20 wt.% LiTFSI + 20 wt.% BMIMTFSI | LiMn2O4, shows a stable cyclic performance and high Coulombic efficiency.