Carbonyl Groups Of Poly Research Articles

Insight into Multiple Intermolecular Coordination of Composite Solid Electrolytes via Cryo-Electron Microscopy for High-Voltage All-Solid-State Lithium Metal Batteries.

Polymer/ceramic-based composite solid electrolytes (CSE) are promising candidates for all-solid-state lithium metal batteries (SLBs), benefiting from the combined mechanical robustness of polymeric electrolytes and the high ionic conductivity of ceramic electrolytes. However, the interfacial instability and poorly understood interphases of CSE hinder their application in high-voltage SLBs. Herein, a simple but effective CSE that stabilizes high-voltage SLBs by forming multiple intermolecular coordination interactions between polyester and ceramic electrolytes is discovered. The multiple coordination between the carbonyl groups in poly(ε-caprolactone) and the fluorosulfonyl groups in anions with Li6.5 La3 Zr1.5 Ta0.5 O12 nanoparticles is directly visualized by cryogenic transmission electron microscopy and further confirmed by theoretical calculation. Importantly, the multiple coordination in CSE not only prevents the continuous decomposition of polymer skeleton by shielding the vulnerable carbonyl sites but also establishes stable inorganic-rich interphases through preferential decomposition of anions. The stable CSE and its inorganic-rich interphases enable Li||Li symmetric cells with an exceptional lifespan of over 4800 h without dendritic shorting at 0.1mA cm-2 . Moreover, the high-voltage SLB with LiNi0.5 Co0.2 Mn0.3 O2 cathode displays excellent cycling stability over 1100 cycles at a 1C charge/discharge rate. This work reveals the underlying mechanism behind the excellent stability of coordinating composite electrolytes and interfaces in high-voltage SLBs.

Non-covalently-functionalized CNTs incorporating poly(vinyl alcohol) mixed matrix membranes for pervaporation separation of water-isopropanol mixtures

Poly(vinyl alcohol) (PVA) / modified carbon nanotubes (CNTs) mixed matrix membranes (MMMs) were prepared to study the pervaporation (PV) dehydration of aqueous azeotrope isopropanol mixture. CNTs were modified by wrapping different amount (5–14 wt%) of poly(styrenesulfonate) (PSSA) and poly(vinylpyrrolidone) (PVP) on CNT respectively. ATR, XRD, FESEM, TGA and tensile tests were used to characterize the modified carbon nanotubes and the membranes. For carbon nanotubes wrapped lower amount of poly(styrenesulfonate), the pervaporation results showed that the separation factor remarkably increased and the flux slightly decreased by increasing the content of the modified nanotubes from 0 to 3 wt%, while a reverse trend was observed with further incorporation of the nanotubes up to 5 wt%. Interestingly, increasing poly(styrenesulfonate) density around nanotubes’ sidewalls led to non-ideal effects such as interchain coiling of poly(styrenesulfonate) and formation of rigidified coiled-coil aggregations, so the best PV results were achieved at lower wrapping of poly(styrenesulfonate). However, wrapping nanotubes by poly(vinylpyrrolidone) resulted in fabrication of nanocomposites without evidence of defects or agglomerations and enhanced thermal and mechanical properties. Among all prepared membranes, the best PSI (303) was obtained by embedding 4 wt% of poly(vinylpyrrolidone)-wrapped-nanotubes into poly (vinyl alcohol) that could be attributed to good compatibility and interactions between the fillers and the matrix. Hydrogen bonding between carbonyl groups of poly(vinylpyrrolidone) and hydroxyl groups of poly(vinyl alcohol), formation of hydrophilic channels and helical wrapping of poly(vinylpyrrolidone) chains instead of interchain coiling were responsible for the observed improvement in separation performance of the membranes containing PVP-wrapped-CNTs.

A Universal Double‐Side Passivation for High Open‐Circuit Voltage in Perovskite Solar Cells: Role of Carbonyl Groups in Poly(methyl methacrylate)

AbstractThe performance of state‐of‐the‐art perovskite solar cells is currently limited by defect‐induced recombination at interfaces between the perovskite and the electron and hole transport layers. These defects, most likely undercoordinated Pb and halide ions, must either be removed or passivated if cell efficiencies are to approach their theoretical limit. In this work, a universal double‐side polymer passivation approach is introduced using ultrathin poly(methyl methacrylate) (PMMA) films. Very high‐efficiency (≈20.8%) perovskite cells with some of the highest open circuit voltages (1.22 V) reported for the same 1.6 eV bandgap are demonstrated. Photoluminescence imaging and transient spectroscopic measurements confirm a significant reduction in nonradiative recombination in the passivated cells, consistent with the voltage increase. Analysis of the molecular interactions between perovskite and PMMA reveals that the carbonyl (CO) groups on the PMMA are responsible for the excellent passivation via Lewis‐base electronic passivation of Pb2+ ions. This work provides new insights and a compelling explanation of how PMMA passivation works, and suggests future directions for developing improved passivation layers.

Blends of biodegradable poly(butylene adipate-co-terephthalate) with poly(hydroxi amino ether) for packaging applications: Miscibility, rheology and transport properties

The improvement of the properties of biodegradable poly(butylene adipate-co-terephthalate) (PBAT) through the addition of poly(hydroxi amino ether) (PHAE) is investigated. Analysis by means of DSC, DMTA, FTIR and TEM reveals that blends are partially miscible, with finely dispersed droplet/matrix morphology. Besides of morphology, hydrogen bonds between both, hydroxyl groups and tertiary amines in neat poly(hydroxi amino ether), and with carbonyl groups of poly(butylene adipate-co-terephthalate) in the blends, work out the linear viscoelastic properties and the time relaxation spectrum. Blends rich in poly(hydroxi amino ether) show the highest relaxation times and consequent strain hardening behaviour, which facilitates film elaboration for packaging.Permeability to water vapour, limonene and carbon dioxide is measured obtaining a great reduction on PBAT permeability with the addition of poly(hydroxi amino ether), specially for carbon dioxide. The mechanical properties of the blends are similar to the polymer that forms the matrix. Overall, this work aims to shed light on the effect of a second component on the properties of a biodegradable polymer in order to design suitable materials for packaging applications.

Highly Stretchable and Waterproof Electroluminescence Device Based on Superstable Stretchable Transparent Electrode.

Realization of devices with enhanced stretchability and waterproof properties will significantly expand the reach of electronics. To this end, we herein fabricate an elastic transparent conductor that comprises silver nanowires (AgNWs) on a hydroxylated polydimethylsiloxane (PDMS) substrate covered by polyurethane urea (PUU), which is fully compatible with both materials. Carboxylic acid groups of PUU was designed to form hydrogen bonds with the carbonyl groups of poly(vinylpyrrolidone) on the AgNW surface, resulting in an enhanced affinity of AgNWs for PUU. Exceptionally strong hydrogen bonds between PUU and the hydroxylated PDMS thus facilitate the achievement of water sealable, mechanically stable, and stretchable transparent electrodes. To fabricate stretchable electroluminescence (EL) devices, ZnS particles were mixed with PUU, and the mixture was coated onto the AgNWs/hydroxylated PDMS, followed by a face-to-face lamination with another identical electrode. The devices could be stretched up to 150% without a severe reduction in the emission intensity, and they survived 5000 cycles of 100% stretch-release testing. The high adhesion between PUU and PDMS even in water is responsible for the good waterproof characteristics of the EL devices. These results pave the way for realization of fully stretchable and waterproof electronic devices.

Cytotoxicity and Compatibility of Polymeric Blend: Evaluation of the Cytotoxicity in Fibroblast Bovine Cells and Compatibility of Poly(ɛ-Caprolactone)/Poly(Methyl Methacrylate-co-Butyl Methacrylate) Blend Films

ABSTRACTBlends between poly(ϵ-caprolactone) and poly(methyl methacrylate-co-butyl methacrylate) were prepared by solution blending in the presence of dichloromethane as solvent. The compatibility of the blends was studied by Fourier-transform infrared spectroscopy, Raman spectroscopy, micro-Raman imaging, and thermogravimetric analysis. Cytotoxicity assays were also performed to assess the feasibility of using such materials in veterinary devices. Based on results, we conclude that poly(ϵ-caprolactone) and poly(methyl methacrylate-co-butyl methacrylate)-form compatible blends owing to specific interactions between carbonyl groups of poly(methyl methacrylate-co-butyl methacrylate) and hydrogens present in the polymeric chain of poly(ϵ-caprolactone). Furthermore, these materials were not toxic to bovine fibroblasts, which supports their possible use in cattle veterinary devices.

Intermolecular Hydrogen Bonding of Poly(Imino Imino Ketone Ketone)

Molecular dynamics calculations were made of the distance from the hydrogen atom of the imino group to the distance of the oxygen atom of the carbonyl group of poly(imino imino ketone ketone) (PIIKK). The results showed that theoretically there was hydrogen bond formation between the hydroxyl group and the carbonyl group of PIIKK. The existence of the hydrogen bonding between the polymer chains of PIIKK was confirmed by infrared spectrum analysis. Due to the existence of the hydrogen bonding, the glass transition temperature increased to 273°C from 143°C for poly(ether ether ketone) (PEEK).

Synthesis of poly(1-oxodimethylene) via oxidation of poly(vinyl alcohol) with a hydrogen peroxide/hydrobromic acid system and metal complexation behavior of poly(1-oxodimethylene)

Poly(1-oxodimethylene) was synthesized via oxidation of poly(vinyl alcohol) with a hydrogen peroxide/hydrobromic acid system. The content of the carbonyl groups in poly(1-oxodimethylene) depended on the amount of water added, and lower amounts of water were suitable for efficient oxidation due to higher acidity of the reaction system. The highest content of carbonyl groups was estimated to be above 88% by the titration with hydrazine that reacted with the carbonyl groups in poly(1-oxodimethylene). The obtained poly(1-oxodimethylene) complexed with Cu and Ni ions under basic conditions. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 2598–2605

Organic-inorganic hybrid hydrogels based on linear poly(N-vinylpyrrolidone) and products of hydrolytic polycondensation of tetramethoxysilane

The initial stage of gelation of organic-inorganic hybrid hydrogels based on poly(N-vinylpyrrolidone) and the products of hydrolytic polycondensation of tetramethoxysilane has been studied by capillary viscometry. The development of strong bonds between polymer molecules and silica particles in aqueous solutions is proved by the electrokinetic sonic amplitude method. The molecular mass of poly(N-vinylpyrrolidone), the concentration of starting components, and their total amount affect the onset time of gelation in poly(N-vinylpyrrolidone)—water—tetramethoxysilane systems. The general scheme of formation of three-dimensional networks in such systems under the conditions of mutual penetration of poly(N-vinylpyrrolidone) coils is suggested. According to this scheme, nanoparticles of the general formula SiOx(OH)y(OR)z linking poly(N-vinylpyrrolidone) macromolecules serve as junctions of the gel network due to the formation of hydrogen bonds between hydrogens of silanol groups of organosilanes and oxygens of carbonyl groups of poly(N-vinylpyrrolidone).

Investigation of the interaction of CO2 with poly (L‐lactide), poly(DL‐lactide) and poly(ε‐caprolactone) using FTIR spectroscopy

AbstractFourier transform infrared (FTIR) spectroscopy was used to reveal intermolecular interactions between carbon dioxide (CO2) and the carbonyl groups of poly(L‐lactide) (PLLA), poly(D,L‐lactide) (PDLLA), and poly(ε‐caprolactone) (PCL). After exposing polymer films to high pressure CO2, the wave number of the absorption maxima of the polymer carbonyl groups shifted to higher values. Also, due to the interaction between CO2 and the carbonyl groups of the polymers, a new broad peak in the bending mode region of CO2 appeared. To distinguish between polymer‐associated and nonassociated CO2, and to quantify these contributions, the bending mode peaks were deconvoluted. From these contributions, it was found that in the case of PCL more CO2 is interacting with the polymer carbonyl groups than in the case of PDLLA and PLLA. Under our experimental conditions, 40°C and pressures up to 8 MPa, a significant depression of the PCL melting temperature was observed. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

The molecular basis of CO 2 interaction with polymers containing fluorinated groups: computational chemistry of model compounds and molecular simulation of poly[bis(2,2,2-trifluoroethoxy)phosphazene

Ab initio molecular orbital calculations of CO 2 and model compounds have been used to identify the nature of specific interactions between CO 2 and the fluorinated substituent groups of polymers such as poly(trifluoropropyl methyl siloxane) and poly[bis(2,2,2-trifluoroethoxy)phosphazene] (PTFEP) that exhibits high CO 2 permeability and permselectivity. Second-order Møller–Plesset (MP2) perturbation calculations (6-311++G ∗∗ basis set) were used to obtain energies, dipole and quadrupole moments, and polarizabilities of CO 2, three alkanes (CH 4, CH 3CH 3, and CH 3CH 2CH 3), and three fluoroalkanes (CF 4, CH 3CF 3, and CH 3CH 2CF 3). Results of energy calculations of three CO 2–alkane and three CO 2–fluoroalkane dimers indicate that CO 2 forms a favorable quadrupole–dipole interaction with the fluoroalkyl groups. The maximum quadrupole–dipole interaction energy obtained was −11.5 kJ mol −1 for CO 2–CF 3CH 2CH 3. This value is less than interaction energies typical for hydrogen bonding but greater than the London dispersion values reported for the interaction of CO 2 with the carbonyl group of poly(methyl methacrylate) (PMMA). Electrostatic potential distributions indicate a small redistribution of electron density to the fluorine atoms of the trifluoroalkanes and to the oxygen atoms of CO 2 in the CO 2–CF 3CH 3 and CO 2–CF 3CH 2CH 3 dimers. Sorption and molecular association of CO 2 with PTFEP has been investigated by molecular simulation of an amorphous cell using the COMPASS molecular mechanics force field. CO 2 sorption isotherms obtained by Grand Canonical Monte Carlo (GCMC) simulation indicate an upward deviation from the linear relationship between log S and the Lennard–Jones potential well depth parameter, ε/ k, in agreement with reported permeability data. Pair-correlation analysis obtained from molecular dynamics simulation show strong correlation of CO 2 with the trifluoromethyl group of PTFEP in agreement with the MP2 results showing an association of CO 2 with both CH 3CF 3 and CH 3CH 2CF 3.

Spectral–Luminescence Properties of Molecular Complexes of Photoconductive Polymers with Neutral Organic Acceptors

It has been found that in films of aryl– and alkyl–substituted polysilanes -- poly(methylphenylsilane) and poly(dihexylsilanes) -- the molecules of electron acceptors of tetracyanoquinodimethane, dinitrofluorenone, and trinitrofluorenone form weak complexes with charge transfer from the longest segments of the polymeric chain. The absorption and luminescence spectra of these complexes are similar to the spectra of complexes formed by the carbonyl groups of poly–N–epoxypropyl carbazole with the above acceptors and consist of wide bands situated in the visible range of wavelengths.

Detection of Polymer Miscibility by 1H/13C/14N Triple Resonance Solid State Nuclear Magnetic Resonance

1 H/ 13 C/ 14 N triple resonance has been used to verify the existence of a template complex formed by poly(methacrylic acid) and poly(N-vinylimidazole). The proximity of the imidazole ring and the carbonyl group of poly(methacrylic acid) leads to a significant loss of carbon-13 spin-echo intensity when 14 N is irradiated. This means that the internuclear distances in this template complex between the carbons of poly(methacrylic acid) and the nitrogen of poly(N-vinylimidazole) are less than 5 A, as confirmed by a numerical model. Such an intimate mixing of the two components can also be concluded from proton T 1ρ measurements.

Relationship between reduction of ceric ion with poly(vinyl alcohol) and graft copolymerization

AbstractVarious poly(vinyl alcohol) samples were preliminarily subjected to oxidation treatment with sodium hypochlorite, and the reduction of ceric ion and subsequently initiation in the graft copolymerization in the system containing methyl methacrylate were investigated. The reduction behavior of ceric ion could be subdivided into three parts, each of different reaction rate. In the initial stage of the reaction, there was observed rapid cleavage of the backbone chain of poly(vinyl alcohol) with ceric salts. The amount A of cleavage was proportional to the amount of ceric ion reduced at the initial fastest rate for various samples of different extents of oxidation; cleavage of 1 mole required ca. 10 moles of reduction of ceric ion. Higher carbonyl contents of the sample caused increased A. Graft polymerization was carried out in the same system with the addition of the monomer. The amounts of grafted chains produced were determined, and approximately one mole of grafted chains was obtained for per mole of cleavage. The copolymer is concluded to be blocklike in structure. The contribution of the carbonyl groups in poly(vinyl alcohol) sample to the initiation of the polymerization should be emphasized.