Polymer Electrolytes – New Opportunities for the Development of Multivalent Ion Batteries

Batteries, as highly concerned energy conversion system, have a great development prospect in various fields, especially in the field of energy powered vehicles. Multivalent ion batteries are getting more attention due to their low cost, high abundance in earth crust, high capacity and safety compared with Lithium batteries. Despite above advantages, several problems still need to be solved before multivalent ion batteries achieve large-scale application, such as interfacial parasitic reaction, anode passivation, and dendrites. The replacement of liquid electrolytes with gel polymer electrolytes (GPEs) which pose high safety, high mechanical strength and simplified battery system, is an effective strategy to inhibit dendrite growth and improve electrochemical performance. This review mainly discusses the advantages and challenges of multivalent ion batteries including zinc, magnesium, calcium and aluminum batteries. Meanwhile, the major targets of this review are introducing the recent developments and making a summary of the future trends of GPEs in the multivalent ion batteries.     

Polymer Holography – New Theory of Image Growth

Summary: The image forming process in photopolymer holographic film has been studied thoroughly. Many grow-curves, i.e. the curves describing the time dependence of the image grow, have been obtained by the special equipment (described in 1 ) under varying conditions. The varying concerns both the changes in film composition and exposition. The S-type form of the measured grow curves bring out some problem in interpreting them in the framework of the usual diffusion theories of photopolymer image growth. To overcome the problem we add the idea that polymer loses its mobility as it grows to the usual only diffusion theories and put down the more general immobilization-diffusion theory. 2     

Cycloaddition Reactions and Dendritic Polymer Architectures – A Perfect Match

Summery: The potential of cycloaddition (CA) reactions for the synthesis of dendritic polymers is pointed out. The [4 + 2] Diels Alder cycloaddition as well as 1,3-dipolar CA reactions including “click chemistry” are addressed, and the advantages of these reactions like high selectivity, thus high tolerance towards additional functionalities, high yields and synthesis under mild reaction conditions are highlighted. New perfectly branched dendrimers as well as hyperbranched polymers have been prepared and modified using the 1,3-dipolar cycloaddition reaction of azines with alkynes. The 1,3-dipolar CA reaction of bisazine with maleimides results in hyperbranched and thus, irregular and broadly distributed polymers though with a degree of branching of 100% due to special intermediate formation. The [4 + 2] Diels Alder cycloaddition was successfully applied for the synthesis of highly branched polyphenylene structures using the AB₂ + AB and the A₂ + B₃ approach. CA reactions are also very suitable for highly efficient polymer analogous reactions and thus, they can also be used to prepare complex polymer architectures like dendronized polymers.     

Impedance measurements at thin polyaniline films – the influence of film morphology

AC impedance measurements of thin 100-nm polyaniline films electrosynthesized in various acidic electrolyte solutions known to support different film morphologies are reported. By carefully defining experimental parameters obtained data could be satisfactorily explained invoking a simple equivalent circuit assuming a double layer capacity assigned to the polymer/solution interface, a pseudocapacity related to the internal _redox capacity of the film, a film and a solution resistance and could be related to film morphologies. The data can be related to structural/morphological features of PANI films in close agreement with generally accepted changes of PANI films as a function of the degree of oxidation and type of anion present during electropolymerization.     

A Novel Approach for the Surface Modification of Polymeric Membrane with Phospholipid Polymer

A new economic and convenient method to modify the surface of microporous polypropylene (PP) membranes with phospholipid polymer was given. The process included the photo-irradiated graft polymerization of N,N-dimethylaminoethyl methacrylate (DMAEMA) and the ring-opening reaction of the grafted polyDMAEMA with 2-alkyloxy-2-oxide-1,3,2-dioxo-phospholanes (AOP). Four AOPs, whose alkyloxy groups consisted of dodecyl, tetradecyl,hexadecyl and octadecyl moieties, were used to convert the grafted polyDMAEMA to phospholipidpolymers. FT-IR spectra confirmed the chemical change of membrane surface. Platelets adhesion experiment indicated that PP membrane with excellent blood compatible surface could be fabricated by this method.     

A new determination of the structure of water at 25°C

The results of a new neutron diffraction experiment to measure the structure of water are presented. The data, measured at the McMaster Nuclear Reactor, are of a high quality and are analysed to yield the hydrogen-hydrogen pair correlation function using a subtraction procedure which has been used in previous experiments of this kind. This procedure circumvents the necessity of applying inelasticity corrections. The results are in good agreement with earlier work and serve to establish the general correctness of the subtraction procedure when used to determine hydrogen correlations. The data are further analysed to yield separate oxygen-hydrogen and oxygen-oxygen partial structure factors for liquid water. For the second part of the analysis an effective mass model of the dynamic scattering law is used, with the model parameter, the effective mass of the scattering particle, chosen by a least-squares fit to the measured differential cross sections. The final pair correlation functions are obtained using a maximum entropy analysis of the structure functions.     

Effect of Polymer and Surfactant‐Polymer Couples on the Acid-Catalyzed Hydrolysis of Phenyl Urea

The mechanism of the hydrolysis decomposition of phenyl urea in acid, polymer, and surfactant‐polymer media was investigated, the addition‐elimination mechanism with rate determining attack of water at N‐protonated substrate having already been studied. This study has introduced the polymer PEG (MW‐400) and (surfactant‐polymer) (ceteyl trimethyl ammonium bromide‐poly ethylene glycol) (CTAB‐PEG), (cetyl pyridinium bromide‐polyethylene glycol) (CPC‐PEG) (sodium dodecyl sulphate‐poly ethylene glycol) (SDS‐PEG), (Triton X‐100‐poly ethylene glycol) (TX‐100‐PEG), and (Brij35‐poly ethylene glycol) (Brij35‐PEG) in acid media. The results indicate that the presence of polymer and surfactant‐polymer enhances the rate of reaction at 80°C in the presence of 0.9 M H₂SO₄. Kinetic studies show that the reaction obeyed first‐order kinetics. The reaction kinetics can be well explained by micellar catalysis models like the PPIE.     

A Metallosupramolecular Coordination Polymer for the ‘Turn-on’ Fluorescence Detection of Hydrogen Sulfide

A coumarin based probe for the efficient detection of hydrogen sulfide in aqueous medium is reported. The investigated coumarine-based derivative forms spherical nanoparticles in aqueous media. In presence of Pd²⁺, a metallosupramolecular coordination polymer is formed, which is accompanied by quenching of the coumarin emission at 390 nm. Its Pd²⁺ complex could be used as a probe for chemoselective detection of monohydrogensulfide (HS⁻). Presence of HS⁻ leads to a'turn-on' fluorescence signal, resulting from decomplexation of Pd²⁺ from the metallosupramolecular probe. The probe was successfully applied for qualitative and quantitative detection of HS⁻ in different sources of water directly collected from sea, river, tap and laboratory drain water, as well as in growth media for aquatic species.     

Adsorption of Bisphenol A by Cross-Linked β-Cyclodextrin Polymer

An insolubilized -cyclodextrin derivative(polyCD) was prepared by polymerizingcyclodextrin with epichlrohydrine. By stirring5 mg/ml of polyCD in 0.2 mM bisphenolA (BPA) solution at pH 7.0 for 2 h, more than98% of BPA was adsorbed on polyCD.The capacity of the adsorption was determinedto be 84 mg-BPA/g-polyCD, meaning 0.65mol-BPA/mol-CD (in polyCD). The effect of pHon the adsorption was studied and foundthat BPA was effectively adsorbed on polyCDat pH between pH 2.2–9.1, but the efficiencydecreased at pH 10.8, suggesting that it didnot adsorb the BPA anion. The polyCD did notadsorb aromatic amino acids, indicating thatBPA could selectively be removed from asolution containing amino acids.     

The Azobenzene Optical Storage Puzzle – Demands on the Polymer Scaffold?

Summary.  The basic mechanism of optical information storage utilizing the azobenzene photoaddressable moiety will briefly be introduced. A synthetically flexible polyester matrix covalently integrating cyanoazobenzene in regularly spaced side chains is particularly well suited for holographic storage. Notable figures of merits of thin film materials of liquid crystalline polyesters are: response time to laser light in the order of ns, storage capacity of 5000 lines/mm, high permanent (more than eight years) diffraction efficiency in the order of 50% or higher, and erasability. The implications of the nature of the main chain on polyester morphology and on the permanency of the induced anisotropy are discussed. Arguments for the design and methods of preparation of other very different polymer scaffolds supporting the cyanoazobenzene are elucidated. Whereas oligopeptides invariably form amorphous materials, both copolymethacrylates and dendritic or hyperbranched polyesters provide some materials that exhibit liquid crystallinity. However, none of these other scaffolds offer materials that allow long-lasting anisotropy to be laser light induced. Received June 23, 2000. Accepted (revised) August 18, 2000     

A New Criterion for Brittle-Ductile Transition of Polymer Blends

The T_c criterion was first used by S. Wu for characterizing the brittleductile (B-D) transition of N6/EPDM blends. But in this paper, a new criterion which is based on the stress analysis of blends is proposed to characterize the B-D transitions of blends, namely, A criterionV_(fc) and d_c are the critical volume fractions and particle size of dispersed particles in blends, respectively. For given blends, A is independent of the morphology of dispersed phase and is only the characteristic parameter of matrix. The B-D transitions of different blends, including polar N6/EPDM blends, nonpolar PP/EPDM blends and PE/CaCO_3 composites, were manipulated with A criterion and satisfactory results were obtained. In addition, a new master curve for the impact strength of PP/EPDM blends versus V_f~2/d was obtained. The results showed that A criterion is more suitable than T_c criterion for characterizing the B-D transition of blends.     

Effect of Oxygen and Bacteria on the Property of Polymer Gel

The viscosity property of Cr~(3 ),Al~(3 ),and compound ion cross-linked polymer gel solution in the anaerobic and aerobic environment was investigated aiming at meeting the practical demand of the oil field.The viscosity reserving effect after adding the biocide and the gelation in the anaerobic and aerobic environments was also studied in the paper.The results indicate that the viscosity of the cross-linked polymer gel solution caused by the water produced in aerobic environment is higher than that in anaerobic environment,and that the viscosity value of the cross-linked polymer gel solutions after adding biocides has improved to some extent and polymer gel has gelated well in anaerobic environment.     

Modeling the Chain-Length Differentiated Polymer Microstructure of α-Olefins

Summary: Due to a complex polymerization scheme, incorporating besides propagation, termination and transfer to monomer and chain transfer agents in addition intra- and inter-molecular transfer to polymer as well as β-scission, α-olefin (co)polymers feature a quite complex polymeric microstructure. It is demanding to design a kinetic model that describes these in a predictive manner in order to have a tool for computer-aided product design. The molecular weight distribution and branching indices together with the composition are the subjects of interest in this case. The latter quantities are often provided as being averaged over the molecular weight distribution. Modern coupled analytical techniques of size exclusion chromatography provide even more insight. The combination of size exclusion chromatography with fractionation techniques provide under adequate processing of the data branching indices and co-polymer composition differentiated with respect to chain-lengths. This contribution will inspect how good a model for predicting the chain-length differentiated co-polymer composition in high-pressure high-temperature ethene – vinyl acetate-co-polymerizations will coincide with analytical results of technical products.     

Imaging of Activity of Horseradish Peroxidase at β-Cyclodextrin Polymer by Scanning Electrochemical Microscopy

The activity of horseradish peroxidase at β-cyclodextrin polymer was imaged by scanning electrochemical microscopy using 3, 3′, 5, 5′-tetramethylbenzide and H2O2 as the substrates.     

Electrochemical Polymerization of Brilliant Cresyl Blue and Properties of the Polymer

ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅｄｉｓｃｏｖｅｒｙｏｆｔｈｅｃｏｎｄｕｃｔｉｖｉｔｙｏｆｐｏｌｙａｃｅｔｙｌｅｎｅｈａｓｏｐｅｎｅｄａｎｅｗｒｅｓｅａｒｃｈｆｉｅｌｄｆｏｒｔｈｅｓｙｎｔｈｅｓｉｓｏｆｎｅｗｍａｔｅｒｉａｌｓ .Ｃｏｎｄｕｃｔｉｎｇｐｏｌｙｍｅｒｓｃａｎｂｅｓｙｎｔｈｅｓｉｚｅｄｂｙｔｈｅｃｈｅｍｉｃａｌｐｏｌｙｍｅｒｉｚａｔｉｏｎａｎｄｅｌｅｃｔｒｏｃｈｅｍｉｃａｌｐｏｌｙｍｅｒｉｚａ ｔｉｏｎ .1 7Ｔｈｅｅｌｅｃｔｒｏｃｈｅｍｉｃａｌｐｏｌｙｍｅｒｉｚａｔｉｏｎｐｒｏｖｉｄｅｓａｓ…     

A Study on the Optically Active Polymer Poly‐β‐pinene

Poly‐β‐pinene (PBP) was obtained by radiation‐induced polymerization of monomer with γ radiation. The polymerizations were conducted both in vacuum and in the presence of air at different radiation doses up to 1–3 MGy. It was found that the presence of oxygen retards the polymerization rate and reduces the polymer yields and the radiation chemical yield suggesting that the polymerization mechanism involves free radicals. It is shown that PBP can also be obtained in low yields from β‐(‐)pinene polymerization with a free radical initiator. The chemical structures of the PBP radiopolymer and PBP obtained by a free radical initiator were studied by FT‐IR and ¹³C CP‐MAS NMR spectroscopy. The data shows that the PBP obtained have highly ordered structures, which is manifested also by the very high specific optical rotation which is about 3 times that of the starting monomer in the case of the radiopolymer and about 5 times in the case of the PBP prepared with the free radical initiator. In contrast, PBP obtained in high yields by cationic polymerization shows a very low specific optical rotation, much lower than that of the starting monomer and low regularity in chemical structure has been attributed to this polymer by FT‐IR and ¹³C CP‐MAS NMR spectroscopy. It is shown that PBP with high optical activity racemizes over an acidic catalyst.