Novel polymeric aromatic lithium sulfonylimides as salts for polymer electrolytes

Three new polymeric aromatic lithium sulfonylimides were used as salts in high molecular weight poly(ethylene oxide) (PEO) electrolytes. Their conductivity and electrochemical stability behaviors were investigated. The electrolytes with lithium poly[4,4′‐(hexafluoroisopropylidene)diphenoxy]sulfonylimide (LiPHFIPSI) showed a better conductive performance compared with the other two lithium salts. The best conductivity was obtained for PEO/LiPHFIPSI EO/Li = 16 (1.90 × 10^?4 S/cm at 60°C). Thermal analysis indicated that the salts effectively decreased the crystallinity of PEO. Moreover, the electrolytes also had good electrochemical stability and their oxidative potential was to 5.5 V versus Li/Li⁺. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1802–1805, 2002     

Organoiron Polyelectrolytes: Synthesis and Characterization of Cationic Cyclopentadienyliron Complexes of Polyarylether-Imines

The synthesis of an aromatic ether complex of cyclopentadienyliron containing two terminal aldehyde groups was achieved via metal-mediated nucleophilic aromatic substitution reactions. This dialdehyde monomer was subsequently reacted with a variety of aliphatic and aromatic diamines to produce the corresponding soluble cationic organoiron polyether-imines. These cationic organometallic polymers were characterized using IR, ¹H, and ¹³C NMR, viscosity and thermogravimetric analysis. Viscosity measurements showed that these polymers exhibited polyelectrolyte effects in DMSO solutions. Thermogravimetric analysis showed that decoordination of the iron moieties occurred at about 300°C for polymers with aliphatic spacers in their backbones, while the cyclopentadienyliron moieties were cleaved from the polymers with aromatic spacers in their backbones at about 200°C. Photolytic demetallation of the organoiron polymers resulted in the removal of the pendent cyclopentadienyliron moieties and allowed for the isolation of their organic analogs. While the organoiron polymers were soluble in polar organic solvents, the corresponding organic polymers exhibited very limited solubilities or were insoluble. The organic polymers had glass transition temperatures between 101 and 120°C     

Synthesis and characterisation of fluorescent pyrene‐end‐capped polylactide fibres

Fluorescent markers are critical for tracking the position and movement of molecules both in vivo and in vitro. Conventionally, synthetic dyes are non‐covalently added to polymers for fluorescent tracking, but often diffuse away. Here we demonstrate, for the first time, a facile method for the synthesis of fluorescent poly(lactic acid) nano‐/microfibres for biomedical applications using solution spin blowing. Pyrene‐end‐capped poly(l ‐lactide) (PLLA) derivatives were synthesised using the ring‐opening polymerisation of l ‐lactide and they were characterised using spectroscopic and thermal analyses. Submicrometre‐sized fluorescent fibres were produced from these PLLA derivatives using solution blow spinning techniques generating polymer blends and core–shell fibres. Such system could be further exploited to incorporate electrically conductive carbon allotropes via the pyrene aromaticity, producing fluorescent and electrically active fibres for in vitro monitoring and electrical stimulation. © 2018 Society of Chemical Industry     

Main and Interactive Effects of Polyaromatic Sulfur Heterocyclic Compounds on Growth and Biodegradation Efficiencies of Bacillus sphaericus HN1: Modeling and Statistical Analysis

Bioremediation is an effective technique to remediate soil and water contaminated with a mixture of recalcitrant polyaromatic sulfur heterocyclic (PASH) compounds. Based on two levels of full factorial design, a statistical design of experiments was used in this study to investigate the interactive effects of three PASHs; thiophene (Th), benzothiophene (BT), and dibenzothiophene (DBT) on their biodegradation in multisubstrate batch process using Bacillus sphaericus HN1. Kinetic modeling was performed to estimate the rate of biodegradation of each PASH in single-, binary-, and tertiary-substrate systems. Biodegradation of BT, DBT, and total PASHs follows the first order kinetic reaction in the single- and multisubstrate batch systems, while biodegradation of Th follows the first-order kinetic reaction, in single-substrate system, but second-order kinetic reaction in multisubstrate batch system. Four linear interaction regression models were estimated and validated to describe the interactive effect of the three PASHs on their biodegradation. Statistical analysis of the results in the form of analysis of variance and Student t test indicated significant role played by the main effects of Th, BT and DBT on their biodegradation (p < 0.01). Th and the interactive effect between Th and DBT has statistically significant negative effect on DBT removal (p = 0.0665). However, DBT expresses higher statistically significant positive effect on total PASHs removal than that of Th (p = 0.0178 and p = 0.026, respectively), but their interaction has a significantly negative effect (p = 0.0143).     

Heavy metal sensors and sequestrating agents based on polyaromatic copolymers and hydrogels

A series of readily available, amphiphilic pyrene‐ and perylene‐containing fluorescent materials, derived from the co‐polymerisation of 2‐acrylamido‐2‐methyl‐1‐propanesulfonic acid with acrylate esters, can be used to detect heavy metal ions in the micromolar concentration range in aqueous solutions. The incorporation of these amphiphilic copolymers into semi‐interpenetrating hydrogels also resulted in the irreversible removal of divalent Co²⁺, Ni²⁺, Cu²⁺ and Pb²⁺ ions from aqueous solutions at neutral pH.     

Contaminated Land Remediation in the UK with Reference to Risk Assessment: Two Case Studies

The approach to land reclamation in the UK has traditionally relied upon the use of cover and concealment, which can leave a legacy of problems below the ground. Alternatively, the bulk export of materials to licensed landfill has often been used, but this (a) simply transfers a problem, (b) can cause considerable disruption, and (c) is becoming increasingly expensive. Remedial strategies involving the use of barrier systems or off-site removal both have their place in the efficient and economic development of contaminated sites. However, there is now increasing interest in the use of on-site technology which can provide cost savings and by treating, destroying or stabilizing contamination, can serve to minimize future liabilities. The design, costing and application of treatment, as opposed to cover or disposal, depends fundamentally on understanding the problem and evaluating the capabilities and availability of appropriate technologies. With reference to UK case studies, this paper highlights some of the options available and routes taken in order to achieve site-specific, commercially-acceptable, remedial responses.     

六溴三聚吲哚在不同溶剂中的可控自组装结构

研究了六溴三聚吲哚在不同溶剂中的自组装行为,并通过改变溶剂的极性和沸点调控自组装结构。结果表明,通过向六溴三聚吲哚的N,N′-二甲基甲酰胺(DMF)溶液中添加不同极性的第2种溶剂(添加后六溴三聚吲哚为1×10-3 mol·L-1),其自组装结构可以进行调控。降低六溴三聚吲哚溶液的浓度(0.5×10-3 mol·L-1)发现,分子可自组装成岛状结构。表明分子自身间相互作用较强,分子首先堆积成较小的核,然后以此为中心向四周生长。添加极性较强的溶剂有利于分子的重组,形成较长的纳米线;添加非极性溶剂时分子容易团聚,生长的纳米线的长度较短。     

Polyaromatics

The polyaromatics are an important group of industrial polymers. For the highest performance applications the polyaryletherketones and polyarylethersulphones have proved very effective and have been successfully commercialised. Both polymer types, but mainly polyetheretherketone (Victrex PEEK), have been subjected to intense academic and industrial research in respect of their physical and chemical properties, thermal stability, irradiation resistance and their application in engineering and composite matrices. The synthesis of these polyaromatics has been widely studied but the nucleophilic polycondensation route is proving to be the only commercially viable one. Block copolymers have been synthesised, using transetherification to randomise polyaryletherketone-co-sulphone backbones as well as by utilising the reactive polymer end-groups, and studied in considerable detail to establish structure–property relationships. Such end-groups on arylethersulphone-type polymers have also been used effectively in the development of tough, solvent-resistant and easily processable thermoset–thermoplastic blends for use, in particular, as composite matrices. Pendant functionality has been studied as a route to improved properties and solvent resistance and is used commercially in the manufacture of polymers for membranes.