Antimicrobial N-halamine polymers and coatings have been studied extensively over the past decade thanks to their numerous qualities such as effectiveness toward a broad spectrum of microorganisms, long-term stability, regenerability, safety to humans and environment and low cost. In this review, recent developments are described by emphasizing the synthesis of polymers and/or coatings having N-halamine moieties. Actually, three main approaches of preparation are given in detail: polymerization, generation by electrochemical route with proteins as monomers and grafting with precursor monomers. Identification and characterization of the formation of the N-halamine bonds (>N-X with X = Cl or Br or I) by physical techniques such as Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance spectroscopy (NMR), energy-dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), and by chemical reactions are described. In order to check the antimicrobial activity of the N-halamine compounds, bacterial tests are also described. Finally, some examples of application of these N-halamines in the water treatment, paints, healthcare equipment, and textile industries are presented and discussed.

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The interface [BuMeIm][Tf2N]/electrode, where [BuMeIm][Tf2N] stands for the ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, was characterized by electrochemical impedance spectroscopy at different temperatures and for different electrode materials: platinum (Pt, metallic), glassy carbon (GC, high conductivity), carbon nitride (a-CNx, mean conductivity), and boron-doped diamond (BDD, semiconducting with a quasimetallic character). For Pt, GC, and a-CNx, the behavior of the interface could be described by the same equivalent electrical circuit. In the case of BDD, a parallel combination of Rsc and Csc was introduced into the circuit to take into account the potential drop due to the development of a space charge region within the material. The Mott-Schottky plots have confirmed the polycrystalline semiconductor character of the BDD material, and the boron concentration estimated is fully consistent with the B amount introduced for the synthesis. The variations of the double-layer capacitance as a function of potential were found to be camel shaped for all electrode materials at the highest studied temperature. This is consistent with the prediction of Kornyshev's theory as low values of the packing parameter γ were estimated by simulation (lower than 0.33). An increase of the double-layer capacitance is found with the temperature similarly to most of the results obtained for molten salts.

Fast ionic transfer and transport properties continue to be one of the main pressing research concerns regarding energy storage materials (batteries, supercapacitors). Accompanying this search for optimal materials, appropriate characterization tools to assess key parameters of newly developed materials are required. In spite of its great relevance, fast electrogravimetric methods, i.e., coupling fast quartz crystal microbalance (QCM) and electrochemical impedance spectroscopy (EIS) (ac-electrogravimetry), have not yet been used for studying transfer and transport phenomena in materials for charge storage (except for the use of QCM along with cyclic voltammetry experiments (EQCM)). This coupled method, socalled ac-electrogravimetry, differs from classical EQCM and measures the usual electrochemical impedance, ΔE/ΔI (ω), and the mass variations of the film under a sinusoidal potential perturbation, Δm/ΔE (ω), simultaneously. This coupling has the ability to detect the contribution of the charged or uncharged species and to separate the anionic, cationic, and free solvent contributions during the various (pseudo)capacitive processes. The Li-birnessite type MnO 2 thin films were studied in two different media, LiClO 4 and NaClO 4 , by ac-electrogravimetry. The Li + ions, Na + ions, and their respective hydrated ionic species are detected to be involved in the pseudocapacitive charge storage of Li-birnessite type MnO 2 thin films. The kinetics (fc i ) and resistance (Rt i ) of charged and noncharged species transferred at the electrode/electrolyte interfaces and the number of water molecules in the hydration shell of the ions are estimated considering integer values. The opposite flux direction of free water molecules was also detected by ac-electrogravimetry. This indicates that there is a population of hydrated Li + or hydrated Na + ions losing their hydration shell before being transferred at the electrode/electrolyte interfaces. Therefore, the effect of desolvation is clearly and experimentally demonstrated. The ac-electrogravimetry responses of the electrodeposited Li-birnessite type MnO 2 thin films can serve as a gravimetric probe for studying the charge-storage mechanisms and extracting subtleties unreachable with classical tools.

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A kinetic study of the ZnO precipitation reaction from supersaturated zincate solutions is made by conductometric and nephelometric measurements and by complexometric titration of the zinc remaining in the solution. The precipitation occurs following a homogeneous and a heterogeneous reaction, the second one being catalyzed by ZnO, formed either during the decomposition or intentionally added. Addition of potassium silicate inhibits the heterogeneous reaction but not the homogeneous one. Both reactions are of the second order vs. the species at the origin of supersaturation, and it is proposed that supersaturation is due to either the presence of partially dehydrated tetrahydroxozincate, the oxodihydroand the dioxozincate ([ZnO(OH)2] 2-and [ZnO2] 2-or to a polymeric species like [(OH)3Zn-O-Zn(OH)~] 4 ) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 138.251.14.35 Downloaded on 2015-03-29 to IP ) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 138.251.14.35 Downloaded on 2015-03-29 to IP

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Different superhydrophilic polypyrrole nanostructures can be electrosynthezised in the presence of anions of weak acid (monohydrogenophosphate) and non-acidic anions (perchlorate) without the need for templates. Actually the type of nanostructures formed depends both on the concentration of anions at the electrode and on the interfacial pH. Depending on the anion composition of the pyrrole aqueous solution the film electrogenerated under a given applied potential is either a very thin membrane (10-20 nm) consisting of overoxidized polypyrrole or a tridimensional film with oriented nanowire array or a network of more or less interconnected nanofibers. The formation of such nanostructures is explained by a side reaction which is water oxidation. Since this reaction is pH-dependent, the pH of the pyrrole solution is one of the key parameter for the synthesis of such nanostructures. The reaction mechanism is discussed and compared to those proposed in the literature for nanofiber network electrosynthesis.Actually in the monomer solution, the role of the anions of weak acid is twofold. On the one hand they allow to limit the decrease of the interfacial pH during pyrrole oxidation and on the other hand to decrease the interfacial anion concentration, so that water oxidation takes place with formation of hydroxyl radicals and dioxygen nanobubbles.