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A series of poly(azomethine-phenothiazine)s was synthesized by using the reaction of 10-methyl-phenothiazine-3,7-dicarbaldehyde with diamines containing fluorene chromophore or polyethylene glycol (PEG) flexible spacer. The polymers were structurally characterized by 1 H NMR and FTIR spectral techniques, elemental analysis and wide angle X-ray diffraction. Their thermal properties were monitored by using variable temperature polarized light microscopy whilst their photophysical behaviour was demonstrated by using UV–vis absorption and photoluminescence spectroscopy. All of these polymers were found to emit green light with high quantum yield, in both solution and solid state. The emission efficiency in solid state was further improved by mixing the fluorene containing polymers with the PEG containing one, when continuous films with quantum efficiency of up to 16% were obtained. [ABSTRACT FROM AUTHOR]

[Display omitted] • Fluorescent water-soluble polymer sensors were obtained by RAFT method. • Selective and sensitive recognition of Fe3+ and Fe2+. • Fluorophores could be incorporated as RAFT reagent and/or functional monomer. Fe3+ and Fe2+ are common metal ions in natural water environments and creatures. The development of water-soluble fluorescent sensors for detecting Fe2+/Fe3+ ions was of great significance. In this work, two kinds of boron fluoride dipyrrole (BODIPY) fluorescent small-molecules were synthesized firstly. One of the small molecules contains a thioester bond that can be used as a chain transfer agent to participate in the polymerization process, and the other contains an unsaturated C = C double bond at the meso position. Through the reversible addition-fragmentation chain transfer polymerization (RAFT) polymerization method, methacrylic acid (MAA) and methacrylamide (MAM) were used as the main monomers, and small molecular fluorescent monomers were introduced to the end of the main chain. In this way, fluorescent macromolecules were obtained. The polymers were water soluble owing to the presence of long enough hydrophilic carboxyl and amide chains. These fluorescent probes exhibit high sensitivity to Fe2+/Fe3+, good selectivity, and anti-interference of other ions. The detection limit for Fe2+ was as low as 2.3 × 10−7 M, and the detection limit for Fe3+ can reach up to 4.5 × 10−7 M. The results show that these probes can be used as good sensors to identify Fe2+ and Fe3+. Moreover, the fluorophores could be incorporated into polymer chains as the RAFT reagents and/or functional monomers. [ABSTRACT FROM AUTHOR]

Abstract: The main objective of this paper was to synthesize luminescent thermotropic liquid crystalline polyazomethines containing chromophoric mesogen, which design has been addressed to optoelectronic materials. The investigation of the thermotropic behavior by three complementary methods of analyses, i.e. polarized optical microscopy, differential scanning calorimetry and wide angle X-ray diffraction, indicated a nematic mesophase for the polymers containing oxadiazole units, either alternating or random ones. A mesomorphic state maintaining the degree of order of the semicrystalline state while being viscous fluid was evidenced too. The photoluminescence spectra recorded for both polymer solutions and films exhibited a blue light emission. These results point to the possibility of obtaining monodomain or multidomain ordered thin films without grain boundaries showing good mechanical and luminescent properties. [Copyright &y& Elsevier]

Abstract: A new poly(azomethine-ether) was synthesized by the reaction of bisphenol A with a thermotropic azomethine monomer, namely 4,4′-oxy-bis(4-chlorobenzylideneimino phenylene). In order to understand the influence of the molecular weight on the thermal properties, four fractions were isolated from the initial polymer. They were investigated by elemental analysis and spectroscopic methods (IR, UV, 1H NMR) and their thermal behaviour was studied by differential scanning calorimetry, optical microscopy, thermogravimetrical analysis. An increase of the thermal transition temperatures and mesophase order with increasing molecular weight was noticed. [Copyright &y& Elsevier]

• Chitosan fibers were prepared by electrospinning. • They were functionalized by imination reaction with furfural. • The as prepared furfuryl-imine-chitosan fibers showed nanoporous morphology. • They revealed high adsorption capacity for CO 2. The goal of the paper was to design a new pathway towards eco-materials suitable for CO 2 capture, by functionalization of nanoporous chitosan fibers with monoaldehydes via imination. To this end, nanoporous chitosan fibers were prepared by electrospinning and further reacted with furfural. Their morphology was investigated by SEM and AFM microscopies and revealed the formation of a network of nanoporous submicrometric fibers. The successful imination was proved by FTIR, XPS, and NMR spectroscopies. As a proof of concept, the CO 2 adsorption isotherms displayed enhanced CO 2 adsorption of the furfuryl-imine-chitosan fibers compared to pristine ones, indicating the imination of porous chitosan fibers as a feasible method to new eco-materials for CO 2 adsorption. [ABSTRACT FROM AUTHOR]

[Display omitted] Over time, functionalized polysulfones have been obtained through various synthetic routes, aiming at the preparation of high-performance materials with targeted functions for specific applications. The successful use of polysulfones and chemically functionalized polysulfones in the fabrication of membranes with applicability in clinical dialyzers, separation of water/organic solvent mixtures, wastewater treatment, gas separation, fuel cells or as a support for composite membranes encourages the study of chemical modification methods of these polymers that lead to the improvement of the properties and the broadening of the applications field. This review summarizes the research progress on the development, investigation, and application of functionalized polysulfones and analyzes why some of their properties, especially surface and morphological ones, should be considered for their extensive use in industrial and environmental scope, membranes for electro-electrodialysis, separation of enantiomer mixtures, ultrafiltration and direct osmosis processes, removal of metals, anion or proton exchange membranes for fuel cells, but also in the biomedical field as hemodialysis membranes, immune response modulators, materials with antimicrobial activity. In addition, the present review highlights the challenges and recent advances achieved through various synthetic approaches that overcome the existing problems and improve the performance of these polymers in medical and industrial fields. [ABSTRACT FROM AUTHOR]

[Display omitted] • BODIPY based fluorescent small molecules were synthesized. • BODIPY monomers are copolymerized mathacrylic acid to prepare fully-water soluble polymer sensors. • The as-prepared polymers sensors exhibit high sensitivity and selectivity to Fe3+ ion. The development of water-soluble polymer dyes is of great practical and scientific significance. In this article, small fluorescent molecule boron-dipyrromethene (BODIPY) bearing C=C bond was synthesized first. And then, via Suzuki reaction, recognition groups were introduced into the 2, 6 positions of BODIPY. Thus polymerizable fluorescent monomers were prepared. Finally, methacrylic acid (MAA) was copolymerized with the as-prepared small molecular fluorescent monomers via reversible addition-fragmentation chain transfer (RAFT) polymerization methodology. Four fully-water-soluble polymer sensors with BODIPY moieties in the end of the polymer chain were obtained eventually. In the presence of long PMAA chain, and by the assistance of it, BODIPY could be dissolved totally in water. These polymer sensors exhibited sensitive and selective recognition ability to Fe3+. Even the content rate of BODIPY was as low as 0.5% of the polymer (calculated from element analysis), the detection limit could reach 1.2 μM. The sensors with two recognition groups in one BODIPY unit were more sensitive than that with one recognition groups in each BODIPY unit. The sensing mechanism was investigated as well. By endowing the water solubility to organic sensors, the application scope could be greatly enlarged in sensing metal ions in aqueous environments. This work provides a method to develop water soluble high performance polymer sensors. [ABSTRACT FROM AUTHOR]

The quaternary ammonium salts of chitosan are water soluble derivatives which keep the promise for real life applications in a large realm of biomedical fields, such as antimicrobial products, gene therapy, drug delivery, wound healing, tissue engineering and cosmetics. The increased potential for such applications is gained by a beneficial combination of the intrinsic properties of chitosan with those of the quaternary ammonium units. Since the first report of the synthesis of the quaternary ammonium salts of chitosan, many synthetic routes were developed, each of them with advantages and disadvantages which influence the product's properties. The aim of this review was to systemize these synthetic procedures and the properties of the resulted products, highlighting these advantages and disadvantages, in the desire to help the researchers working in this productive domain to choose the most suitable synthetic pathway when specific properties are targeted. [ABSTRACT FROM AUTHOR]