Poly Ethylene Oxide Research Articles

Micellar Solvent Accessibility of Esterified Polyoxyethylene Chains as Crucial Element of Polysorbate Oxidation: A Density Functional Theory, Molecular Dynamics Simulation and Liquid Chromatography/Mass Spectrometry Investigation.

Given that the amphiphilicity of polysorbates represents a key factor in the protection of proteins from particle formation, the loss of this property through degradative processes is a significant concern. Therefore, the present study sought to identify the factors that contribute to the oxidative cleavage of the polysorbate (PS) molecule and to ascertain the preferred sites of degradation. In order to gain insight into the radical susceptibility of the individual polysorbate segments and their accessibility to water, conceptual density functional theory calculations and molecular dynamics simulations were performed. The behavior of monoesters and diesters was examined in both monomer form and within the context of micelles. The theoretical results were corroborated by experimental findings, wherein polysorbate 20 was subjected to 50 ppb Fe2+ and 100,000 lx·h of visible light, and subsequently stored at 25 °C/60% r.h. or 40 °C/75% r.h. for a period of 3 months. Molecular dynamics simulations demonstrated that unesterified polyoxyethylene(POE) chains within a polysorbate 20 molecule exhibited the greatest water accessibility, indicating their heightened susceptibility to oxidation. Nevertheless, the oxidative cleavage of esterified polyoxyethylene chains of a polysorbate 20 molecule is highly detrimental to the protective effect on protein particle formation. This occurs presumably at the oxyethylene (OE) units in the vicinity of the sorbitan ring, leaving a nonamphiphilic molecule in the worst case. Consequently, the critical degradation sites were identified, resulting in the formation of degradation products that indicate a loss of amphiphilicity in PS.

Regulating Interfacial Chemistry to Boost Ionic Transport and Interface Stability of Composite Solid‐State Electrolytes for High‐Performance Solid‐State Lithium Metal Batteries

AbstractComposite solid‐state electrolytes (CSSEs) that combine the benefits of inorganic and polymer electrolytes hold great potential for solid‐state lithium metal batteries (SSLMBs) due to their high ionic conductivity and superior mechanical properties. However, their overall performance is severely hindered by several practical challenges, including inorganic component aggregation, poor interface behavior, and limited Li+ transport. Here, a unique ultrathin coating of triaminopropyl triethoxysilane with a bifunctional structure is introduced that effectively bridges the inorganic fillers (Li1+xAlxTi2‐x(PO4)3, LATP) and the polyvinylidene fluoride hexafluoropropylene /polyethylene oxide polymer matrix, thereby enabling high‐performance CSSEs (referred to as SLPH). This design prevents LATP particle agglomeration, improves interfacial compatibility, and ensures the enrichment and fast transport of Li+ within SLPH. Consequently, the SLPH exhibits a low ionic conduction energy barrier (Ea = 0.462 eV), desirable ionic conductivity (4.19 × 10−4 S cm−1 at 60 °C), and a high Li+ transference number ( = 0.694). As a result, SSLMBs with SLPH, including Li| SLPH |Li symmetric cells, LiFePO4| SLPH |Li coin‐type, and pouch cells, demonstrate superior rate capability and long‐time cycling stability. This work underscores the significance of surface functionalization of inorganic electrolytes to create a stable solid‐solid interface and enhance ionic conduction, paving the way for high‐performance CSSEs in SSLMBs.

Effect of hydroxy-PEO chain density and uremic toxins on plasma protein adsorption

Protein adsorption influences the host response to blood contacting biomaterials. End-tethered polyethylene oxide (PEO) is a gold-standard film for reducing non-specific protein adsorption at the blood-material interface. That said, almost all protein adsorption studies utilize blood from healthy donors, whereas blood composition can vary greatly depending on the disease. Kidney failure leads to the dramatic retention of small molecules (i.e., uremic toxins) within the blood compartment, and their effect on the inhibition of protein adsorption to PEO films is unknown. To understand the effect these uremic toxins have on protein adsorption, surfaces with different chain densities of end-tethered hydroxy-PEO were incubated in platelet-poor plasma laden with uremic toxins. PEO films were characterized using dynamic contact angles and X-ray photoelectron spectroscopy. PEO chain densities were verified using spectroscopic ellipsometry. Eluted proteins were characterized using immunoblot techniques. It was observed that PEO chain density and uremic toxins affected the amount of individually adsorbed proteins and the relative composition of the adsorbed protein corona; especially albumin, complement C3, factor XI, and fibrinogen. This knowledge is considered crucial to the advancement of surfaces for a personalized approach to treating patients with kidney failure.

Evaluation of the effect of sodium alginate, hydroxyethyl cellulose, aspartame, and poly(ethylene oxide)-b-poly(propylene oxide) copolymer on the in-vitro corrosion of AZ31 Mg alloy in simulated body fluid.

Research on Mg-based implants has increased recently because of their compatibility and biodegradability. Despite this promise, challenges related to high corrosion rates hampered wide-scale deployment. This paper explores the inhibiting properties of biomacromolecules, sodium alginate (ALG), hydroxyethyl cellulose (HEC), aspartame (ASP), and poly(ethylene oxide)-b-poly(propylene oxide) copolymer (PEO-b-PPO) on AZ31 Mg alloy in simulated body fluid at 37 °C. Results revealed that PEO-b-PPO accelerated, ALG insignificantly inhibited, while ASP and HEC showed moderate inhibition. At 2000 ppm, ASP and HEC offered 54 % and 53 % protection after 48 h and over 65 % if blended. Mechanistic insights were gained via XPS, FTIR, and distribution of relaxation times (DRT) analysis. Three corrosion mechanisms, Cl- transport, charge transfer, and ion transport across inherent MgO lattice are revealed by DRT and occurred at f = 5 Hz, f = 21 Hz and 832 Hz, and f = 100,000 Hz. Inhibitors' presence prolonged the relaxation time or changed the frequency of occurrence. Carbonates (Mg, Ca), hydroxides (Mg), and phosphates are the main corrosion products. Adsorbed ASP and HEC molecules are mixed with these products to protect the alloy. These findings offer a better understanding of the underlying mechanisms that could facilitate the development of target-oriented corrosion inhibitors for Mg.

Selective acceleration and inhibition of crystal growth of glass carbamazepine by low-concentration poly(ethylene oxide):effects of drug polymorph.

Drug polymorphism attracts considerable interest within the pharmaceutical field. Herein, we investigate the impact of low-concentration poly(ethylene oxide) (PEO) on the crystal growth of carbamazepine (CBZ) polymorphs in the glassy state. The addition of 3%(w/w) PEO increases 5.3-fold the bulk crystal growth rates of CBZ form III and 36.7-fold of form IV at 40°C (Tg -11°C). However, the same content of PEO exhibits a negligible effect on the bulk crystal growth of form I. In addition, the effects of PEO on the crystal growth of the CBZ polymorph at the free surface are also explored. In the presence of 3%(w/w) PEO, surface growth rates of forms III and IV of CBZ are accelerated by 4.7-fold and 3.1-fold, respectively. For comparison, the same content of PEO exhibits an unexpected inhibitory effect on the surface growth rates of form I. Molecular-dynamic simulations attribute these polymorph-dependent effects of PEO mainly to the polymer enrichment at the interface and different crystal surface polymer interactions. This study is relevant for understanding the crystallization of amorphous pharmaceutical solids containing polymorphic drugs.

Enhanced Biodegradation and Biocompatibility of Vascular Grafts Through Oriented Core-Shell Fibrous Structure and Incorporation of Sodium Tanshinone IIA Sulfonate.

Microstructure and biological activity have been pivotal factors in the modification of vascular grafts. Equally crucial, however, are degradation behavior and mechanical stability, both of which are key to long-term success of grafts. To optimize these properties, we prepared oriented fiber membranes with core-shell structures through coaxial electrospinning, incorporating varying concentrations of sodium tanshinone IIA sulfonate (STS). In this design, poly-ethylene oxide (PEO)/STS served as the core layer, while poly-L-lactide-co-caprolactone (PLCL) formed the shell. Our findings revealed that both random and oriented fiber membranes exhibited excellent mechanical properties. Notably, compared to random fiber membranes, the oriented counterparts showed enhanced hydrophilicity and a tunable degradation rate. Furthermore, the sustained release of STS from the membranes inhibited platelet adhesion and significantly promote cell diffusion, growth, and proliferation. Importantly, the oriented fiber membranes loaded with STS were able to induce a highly organized cell arrangement and upregulate the expression of CD144 and vWF in endothelial cells. These promising findings suggest that oriented core-shell fiber membranes loaded with PEO/STS could offer valuable insights into vascular graft design and hold potential for further exploration in animal studies.

Defective MOF-supported Poly(ethylene oxide) composite polymer electrolytes for high-performance all-solid-state lithium ion batteries

Defective MOF-supported Poly(ethylene oxide) composite polymer electrolytes for high-performance all-solid-state lithium ion batteries

Contact ion-pair SN2 reactions activated by Lewis Base Phase transfer catalysts

We present experimental probes of contact ion-pair (CIP) SN2 reactions for simplest prototype systems by 19F-NMR spectroscopy. This study provides crucial evidences for the reactions of CIP metal salts facilitated by Lewis base phase transfer catalysts (PTCs) [2,2,2]-cryptand, 18-crown-6, pentaethylene glycols (pentaEGs) and BINOL–based pentaEG. The 19F-NMR spectra of MF (M = K, Cs) ion-pairs in various solvents are used as fingerprinting tools to identify the CIP CsF/PTC/substrate complexes in SN2 reactions. Examination of the prototype reactions demonstrates that the novel CIP mechanism, which is in sharp contrast to the conventional perspectives, may account for the observed phenomenal efficiency of the SN2 processes using the alkali metal salts under the influence of various PTCs. In this extremely efficient and selective protocol of wide applicability, the CIP MF is activated by the Lewis base PTCs acting on the counter-cation M+ to drastically mitigate the latter’s retarding Coulomb forces on the adjacent nucleophile F-, with or without the participation of hydrogen bonds.

Unveiling the Li/Electrolyte Interface Behavior for Dendrite-Free All-Solid-State Lithium Metal Batteries by Operando Nano-Focus WAXS.

Poly(ethylene oxide) (PEO)-based solid composite electrolytes suffer from poor conductivity and lithium dendrite growth, especially toward the metallic lithium metal anode. In this study, succinonitrile (SN) is incorporated into a PEO composite electrolyte to fabricate an electrode-compatible electrolyte with good electrochemical performance. The SN-doped electrolyte successfully inhibits the lithium dendrite growth and facilitates the SEI layer formation, as determined by the operando nanofocus wide-angle X-ray scattering (nWAXS), meanwhile, stably cycled over 500 h in Li/SN-PEO/Li cell. Apart from the observation of lithium dendrite, the robust SEI layer formation mechanism in the first cycle is investigated in the SN-enhanced composite electrolyte by nWAXS. The inorganic electrochemical reaction products, LiF and Li3N, are found to initially deposit on the electrolyte side, progressively extending toward the lithium metal anode. This growth process effectively protected the metallic lithium, inhibited electron transfer, and facilitated Li⁺ transport. The study not only demonstrates a high-performance interfacial-stable lithium metal battery with composite electrolyte but also introduces a novel strategy for real-time visualizing dendrite formation and SEI growth directing at the interface area of electrolyte and metallic lithium.

Enhancing the Interfacial Stability of Thin Solid Polymer Electrolyte with Fluorinated Covalent Organic Framework Nanosheets.

Thin poly(ethylene oxide) (PEO)-based electrolytes with higher energy density face challenges such as low ionic conductivity, deterioration of lithium dendrites, and severe side reactions. To address these issues, a surface modification strategy was developed to enhance the electrode-electrolyte interfacial stability by introducing fluorinated covalent organic framework nanosheets (CONs) to construct a thin PEO-based electrolyte with a mere 14 μm thickness. Characterization and DFT calculation indicated that the CON layer promotes concentration enrichment and averaging of free Li+ and mitigates side reactions at the interface. The electrode/electrolyte interface stability is significantly improved compared to the unmodified group (Li symmetric cells stabilized for more than 1000 h, and the full cell of LiFePO4∥Li exhibited a satisfactory capacity retention of 97.3% at 0.5 C after 150 cycles at 60 °C. This interface modification strategy provides a valuable reference for applying thin polymer electrolytes in high-energy solid-state lithium metal batteries.

Characterization of Luffa-reinforced Polyaniline Films

Herein, Polyaniline (PANI)/polyethylene oxide (PEO) - luffa cylindrica bio-composite films of various mass fractions (%) have been prepared via casting solution of emeraldine base polyaniline and cellulose extracted from luffa. The biopolymer films were structurally and thermally characterized using X-ray diffraction (XRD), Fournier Transform-InfraRed (FT-IR) spectroscopy, and differential scanning calorimetry analysis (DSC). Moreover, the electrical properties of conductive biopolymer solutions were measured by using the conductivity meter. According to the obtained results, treated luffa increases the conductivity of biopolymers. XRD results reveal that luffa increases the crystallinity of bio-composite films in comparison to PANI/PEO films. FTIR analysis proved the presence of functional groups of PANI, PEO, and luffa in the film structure. Also, an increase in the weight of luffa in the bio-composite film brings about an increase in the peak intensities of the O-H group. It is determined that luffa enhances the thermal stability of composites via the results of DSC analysis.

3D Porous Polycaprolactone with Chitosan-Graft-PCL Modified Surface for In Situ Tissue Engineering

Tissue engineering has emerged as a promising approach for improved regeneration of native tissue and could increase the quality of life of many patients. However, the treatment of injured tissue transitions is still in its early stages, relying primarily on a purely physical approach in medical surgery. A biodegradable implant with a modified surface that is capable of biological active protein delivery via a nanoparticulate release system could advance the field of musculoskeletal disorder treatments enormously. In this study, interconnected 3D macroporous scaffolds based on Polycaprolactone (PCL) were fabricated in a successive process of blending, annealing and leaching. Blending with varying parts of Polyethylene oxide (PEO), NaCl and (powdered) sucrose and altering processing conditions yielded scaffolds with a huge variety of morphologies. The resulting unmodified hydrophobic scaffolds were modified using two graft polymers (CS-g-PCLx) with x = 29 and 56 (x = PCL units per chitosan unit). Due to the chitosan backbone hydrophilicity was increased and a platform for a versatile nanoparticulate release system was introduced. The graft polymers were synthesized via ring opening polymerization (ROP) of ε-Caprolactone using hydroxy groups of the chitosan backbone as initiators (grafting from). The suspected impact on biocompatibility of the modification was investigated by in vitro cell testing. In addition, the CS-g-PCL modification opened up the possibility of Layer by Layer (LbL) coating with alginate (ALG) and TGF-β3-loaded chitosan tripolyphosphate (CS-TGF-β3-TPP) nanoparticles. The subsequent release study showed promising amounts of growth factor released regarding successful in vitro cell differentiation and therefore could have a possible therapeutic impact.

Nanocrystals with Aggregate Anionic Structure Enable Ion Transport Decoupling of Chain Segment Movement in Poly(ethylene oxide) Electrolytes

All‐solid‐state polymer electrolytes are promising for lithium batteries, but Li+ transport in these electrolytes relies on amorphous chain segment movement, leading to low Li+ mobility and poor mechanical strength. Here we propose a novel Li+ transport mechanism mediated by PEO3:LiBF4 nanocrystals (NCPB) with the aggregate (AGG) anionic structure, which enables a change from amorphous to crystalline phase dominated ion transport in all‐solid‐state PEO/LiBF4 electrolyte. Experiments and simulations reveal that the interaction between Li+ and F in NCPB with AGG anionic structure simultaneously restricts anion transport and reorients anions within the free volume of NCPB, resulting in a three‐coordination intermediate to facilitate Li+ transport. The unique Li+ transport mechanism through NCPB makes the PEO/LiBF4 electrolyte with a high Li+ transference number (0.73) and remarkably increased mechanical strength (Young's modulus > 100 MPa) at 45 °C. As a result, the Li|LiFePO4 batteries with the ultrathin self‐supported PEO/LiBF4 electrolyte (10 μm) exhibit significantly improved cycle life (92% @ 500 cycles) compared to those with PEO/LiTFSI electrolyte (failed @ 68 cycles). This work demonstrates a novel ion transport mechanism for achieving selective and rapid Li+ transport.

Nanocrystals with Aggregate Anionic Structure Enable Ion Transport Decoupling of Chain Segment Movement in Poly(ethylene oxide) Electrolytes.

All-solid-state polymer electrolytes are promising for lithium batteries, but Li+ transport in these electrolytes relies on amorphous chain segment movement, leading to low Li+ mobility and poor mechanical strength. Here we propose a novel Li+ transport mechanism mediated by PEO3:LiBF4 nanocrystals (NCPB) with the aggregate (AGG) anionic structure, which enables a change from amorphous to crystalline phase dominated ion transport in all-solid-state PEO/LiBF4 electrolyte. Experiments and simulations reveal that the interaction between Li+ and F in NCPB with AGG anionic structure simultaneously restricts anion transport and reorients anions within the free volume of NCPB, resulting in a three-coordination intermediate to facilitate Li+ transport. The unique Li+ transport mechanism through NCPB makes the PEO/LiBF4 electrolyte with a high Li+ transference number (0.73) and remarkably increased mechanical strength (storage modulus >100 MPa) at 45 °C. As a result, the Li|LiFePO4 batteries with the ultrathin self-supported PEO/LiBF4 electrolyte (10 μm) exhibit significantly improved cycle life (97 % @ 468 cycles) compared to those with PEO/LiTFSI electrolyte (failed @ 68 cycles). This work demonstrates a novel ion transport mechanism for achieving selective and rapid Li+ transport.

Internalization of Ionic Transport Ability of Polymer Semiconductors via Photochemical Cross-Linking.

In the field of organic electronics and optics, there is rapidly growing interest in enhancing both charge transport and the ion transport properties of semiconductors, particularly in light of recent emerging technologies such as organic electrochemical transistors (OECTs) and switchable organic nanoantennas. Herein, we propose a universal method for internalizing the ionic transport properties of conventional polymer semiconductors. The incorporation of a tetrafluorophenyl azide-based photochemical cross-linker with a tetraethylene glycol bridge into poly(3-hexylthiophene) (P3HT) significantly enhances the performance and operational stability of ion-gating devices. Changes in the characteristics of the OECTs with cross-linked P3HT are minimal even after 100 cycles of operation; moreover, the cross-linked OECTs exhibit faster switching properties. In addition, the enhanced doping efficiency allows for the clear observation of plasmon resonances in nanostructured, highly doped P3HT. We believe that the proposed technique for internalizing ionic transport abilities can be applied to various ion-based semiconductor applications.

Ameliorating and Tailoring the Features of Silica-Silicon Carbide Nanoceramic Doped Polyethylene Oxide for Promising Optoelectronics Applications

Ameliorating and Tailoring the Features of Silica-Silicon Carbide Nanoceramic Doped Polyethylene Oxide for Promising Optoelectronics Applications

Surface-Confined Disordered Hydrogen Bonds Enable Efficient Lithium Transport in All-Solid-State PEO-Based Lithium Battery.

Polyethylene oxide (PEO)-based electrolytes are essential to advance all-solid-state lithium batteries (ASSLBs) with high safety/energy density due to their inherent flexibility and scalability. However, the inefficient Li+ transport in PEO often leads to poor rate performance and diminished stability of the ASSLBs. The regulation of intermolecular H-bonds is regarded as one of the most effective approaches to enable efficient Li+ transport, while the practical performances are hindered by the electrochemical instability of free H-bond donors and the constrained mobility of highly ordered H-bonding structures. To overcome these challenges, we develop a surface-confined disordered H-bond system with stable donor-acceptor interactions to construct a loosened chain segments/ions arrangement in the bulk phase of PEO-based electrolytes, realizing the crystallization inhibition of PEO, weak coordination of Li+ and entrapment of anions, which are conducive to efficient Li+ transport and stable Li+ deposition. The rationally designed LiFePO4-based ASSLB demonstrates a long cycle-life of over 400 cycles at 1.0 C and 65 °C with a capacity retention rate of 87.5%, surpassing most of the currently reported polymer-based ASSLBs. This work highlights the importance of confined disordered H-bonds on Li+ transport in an all-solid-state battery system, paving the way for the future design of polymer-based ASSLBs.

Manufacturing and Biological Potential of Saliva‐Loaded Core‐Sheath Pressure‐Spun Polymeric Fibers

AbstractThe rich array of antimicrobial components in saliva offers alternative treatments for drug‐resistant bacteria. One therapeutic challenge associated with the effective delivery of salivary components is the quick degradation of salivary proteins outside the oral environment. In this study, polyethylene oxide (sheath) and polycaprolactone (core) based fibers are successfully synthesized using the pressurized gyration technique. Six different pressure‐spun fibers are produced. These fibers are created by varying the quantity of artificial saliva in the sheath layer. This unique and effective methodology of embedding saliva within the sheath of the fiber exhibits enhanced bacterial inhibition against Escherichia coli and Staphylococcus aureus with 80% and 78% inhibition efficiency, respectively. This study showcases a novel technique for promoting wound healing, utilizing core‐sheath fibers, which have tremendous potential because of their superior antimicrobial properties, while also aiding in the process of epithelialization. In vitro, cytotoxicity test results showed that there is no cytotoxic effect on the fibroblast cell line. As a result, it is evaluated that the produced fiber meshes can be ideal wound dressing material, considering their lack of toxic effects and high antibacterial activity levels.

Improved interfacial li-ion transport in composite polymer electrolytes via surface modification of LLZO

Composite polymer electrolytes that incorporate ceramic fillers in a polymer matrix offer mechanical strength and flexibility as solid electrolytes for lithium metal batteries. However, fast Li+ transport between polymer and Li+-conductive filler phases is not a simple achievement due to high barriers for Li+ exchange across the interphase. This study demonstrates how modification of Li7La3Zr2O12 (LLZO) nanofiller surfaces with silane chemistries influences Li+ transport at local and global electrolyte scales. Anhydrous reactions covalently link amine-functionalized silanes [(3-aminopropyl)triethoxysilane (APTES)] to LLZO nanoparticles, which protects LLZO in air. APTES functionalization lowers the poly (ethylene oxide) (PEO)-LLZO interphase resistance to half that of unmodified LLZO and increases effective Li+ transference number, while insulating Al2O3 completely blocks ion exchange and lowers transference number and conductivity in PEO-lithium bis(trifluoromethanesulfonyl)imide (LiTFSI)-LLZO composites. Modeling an inner resistive interphase between LLZO and PEO surrounded by an outer conductive interphase explains non-linear conductivity trends. Solid-state 7Li & 6Li nuclear magnetic resonance shows Li+ only exchanges between PEO-LiTFSI and some LLZO interphase, with no appreciable Li+ transport through bulk LLZO. Surface functionalization is a promising path toward lowering the polymer-ceramic interphase resistance. This work demonstrates that local changes in Li+ transport affect macroscopic performance, highlighting the intricate relationships between all interfaces in inherently heterogeneous composite polymer electrolytes.

Unraveling the Role of Polyoxometalates-Based Superchaotropes on the Photophysics of Organic Molecules and Modulation of Water Dynamics in a Hydrophilic Block Copolymer Solution.

Polyoxometalates (POMs) are composed of nanometric metal-oxide anions and have rich solution chemistry. In this class, Keggin POMs have been identified as the most influential inorganic additives for aqueous nonionic soft matter systems. POMs being at the borderline of classical ions and charged colloids possess fascinating solution properties; the present work aims to delve deeper into the interactions between nanoions and nonionic soft matters from a spectroscopic point of view. Our studies reveal that although of the same structural makeup, silicotungstic acid hydrate (SiW) and phosphotungstic acid hydrate (PW) affect the photophysics of Coumarin-480 (C-480) in poly(ethylene oxide)-block-poly(propylene oxide)-block-poly(ethylene oxide) ((PEO)76-(PPO)30-(PEO)76, F-68) copolymeric media in a dissimilar manner. From time-resolved studies, we find a preference for SiW toward the intramolecular charge transfer state of C-480, whereas PW favors the locally emissive state of the probe. Further, from rotational relaxation studies, it appears that SiW renders a rigid environment around the probe molecule, while PW relaxes the copolymeric environment. Finally, the dynamic quenching mechanism of the added nanoions was unraveled, which showed a straightforward Förster mechanism for SiW but a short-range interaction was operative for PW. From Fourier transform infrared and 1H NMR, it can be concluded that both the nanoions interacted with the PPO moiety of the copolymer; yet, their contrasting effect on the photophysics has been rationalized as a consequence of charge density on the ions.