Polymeric materials with antimicrobial activity

In the same way as electron transport is crucial for information technology, ion transport is a key phenomenon in the context of energy research. To be able to tune ion conduction by light would open up opportunities for a wide realm of new applications, but it has been challenging to provide clear evidence for such an effect. Here we show through various techniques, such as transference-number measurements, permeation studies, stoichiometric variations, Hall effect experiments and the use of blocking electrodes, that light excitation enhances by several orders of magnitude the ionic conductivity of methylammonium lead iodide, the archetypal metal halide photovoltaic material. We provide a rationale for this unexpected phenomenon and show that it straightforwardly leads to a hitherto unconsidered photodecomposition path of the perovskite.

Large tunable photoeffect on ion conduction in halide perovskites and implications for photodecomposition

A facile and versatile approach for the preparation of antifouling and antimicrobial polymer membranes has been developed on the basis of bioinspired polydopamine (PDA) in this work. It is well-known that a tightly adherent PDA layer can be generated over a wide range of material surfaces through a simple dip-coating process in dopamine aqueous solution. The resulting PDA coating is prone to be further surface-tailored and functionalized via secondary treatments because of its robust reactivity. Herein, a typical hydrophobic polypropylene (PP) porous membrane was first coated with a PDA layer and then further modified by poly(N-vinyl pyrrolidone) (PVP) via multiple hydrogen-bonding interactions between PVP and PDA. Data of water contact angle measurements showed that hydrophilicity and wettability of the membranes were significantly improved after introducing PDA and PVP layers. Both permeation fluxes and antifouling properties of the modified membranes were enhanced as evaluated in oil/water emulsion fil...

Antifouling and Antimicrobial Polymer Membranes Based on Bioinspired Polydopamine and Strong Hydrogen-Bonded Poly(N-vinyl pyrrolidone)

A sulfur-polypyrrole composite cathode with a core-shell structure consisting of spherical sulfur particles coated with polypyrrole has been developed. The conductive polypyrrole coating on the sulfur facilitates fast electron transport enabling the material with superior electrochemical stability, rate capability, and cyclability in lithium-sulfur batteries.

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Core-shell structured sulfur-polypyrrole composite cathodes for lithium-sulfur batteries

Emergency water supply: a review of potential technologies and selection criteria.

Periodate oxidized hyaluronic acid-based hydrogel scaffolds for tissue engineering applications

Nanostructures of polypyrrole (PPy) were synthesized in the presence of different dopants including hydrochloric acid (HCl), ferric chloride (FeCl3), p-toluene sulfonic acid (p-TSA), camphor sulfonic acid (CSA), and polystyrene sulfonic acid (PSSA), using a simple interfacial oxidative polymerization method. The method is a reliable non-template approach with relatively simple instrumentation, ease of synthesis, and economic viability for synthesizing PPy nanostructures. Morphology of synthesized PPy structures was investigated using scanning electron microscopy (SEM) and transmission electron microscopy (TEM), which indicate the formation of one-dimensional (1D) nanofibers with average diameter of 75–180 nm. Energy dispersive spectrum (EDS) of the PPy nanofibers indicates the attachment of the dopants to the PPy backbone; the fact is further confirmed by the Fourier transform infrared (FTIR) spectra of PPy nanostructures. Thermal stabilities of the nanostructures explored using thermal gravimetric analysis (TGA) follow the order PPy-p-TSA > CSA > HCl > FeCl3 > PSSA. It is noticed that the electrical conductivity (EC) of PPy nanostructures depends upon the nature of dopant (PPy-p-TSA > CSA > HCl > FeCl3 > PSSA), PPy-p-TSA nanofibers showing the highest EC of 6 × 10−2 Scm−1. Copyright © 2009 John Wiley & Sons, Ltd.

Synthesis and characterization of polypyrrole nanofibers with different dopants

The chemically oxidized gum arabic was prepared and used as a naturally derived nontoxic and pH-responsive cross-linker to develop smart polyvinyl alcohol (PVA)-based hydrogels for the first time. ...

Periodate-Modified Gum Arabic Cross-linked PVA Hydrogels: A Promising Approach toward Photoprotection and Sustained Delivery of Folic Acid.

Injectable, Self-Healing, and Biocompatible N,O-Carboxymethyl Chitosan/Multialdehyde Guar Gum Hydrogels for Sustained Anticancer Drug Delivery.

Nanofibers of poly (indene-co-pyrrole) (CInPy) have been synthesized, using a facile chemical oxidative polymerization reaction. The effect of copolymerization was examined in view of the individually synthesized homopolymer nanostructures of polyindene (PIn) and polypyrrole (PPy). Morphological details of CInPy, studied using scanning electron microscopy (SEM) and transmission electron microscopy, (TEM) reveal the appearance of dense cottony mess, comprising of fine fibers with an average diameter of 5–10 nm. Chemical structural analysis of CInPy, conducted using ultraviolet-visible (UV-Vis), Fourier transform infrared (FTIR), and nuclear magnetic resonance (NMR) spectroscopic techniques, reveals that both PIn and PPy are involved in the formation of copolymer organization. Fluorescence properties of nanosized copolymer are observed in the blue region, with emission λmax placed at 395 nm. Conductivity of copolymer nanofibers (2.4 × 10−3 S/cm) is consistent with the morphology and thermal stability properties of integral homo-polymers. Improved thermal stability and processability along with the enhanced optical and electrical properties of copolymer nanostructures outfit it as a better promising material in optoelectronic and light emitting nanodevices, with reference to nanosized PIn and PPy. Copyright © 2009 John Wiley & Sons, Ltd.

Nasreen Mazumdar

Papers

Periodate oxidized hyaluronic acid-based hydrogel scaffolds for tissue engineering applications

Synthesis and characterization of polypyrrole nanofibers with different dopants

Periodate-Modified Gum Arabic Cross-linked PVA Hydrogels: A Promising Approach toward Photoprotection and Sustained Delivery of Folic Acid.

Injectable, Self-Healing, and Biocompatible N,O-Carboxymethyl Chitosan/Multialdehyde Guar Gum Hydrogels for Sustained Anticancer Drug Delivery.

Synthesis and characterization of poly (indene‐co‐pyrrole) nanofibers