Basic chemistry of copper is responsible for its Janus-faced feature: on one hand, copper is an essential trace element required to interact efficiently with molecular oxygen. On the other hand, interaction with reactive oxygen species in undesired Fenton-like reactions leads to the production of hydroxyl radicals, which rapidly damage cellular macromolecules. Moreover, copper cations strongly bind to thiol compounds disturbing redox-homeostasis and may also remove cations of other transition metals from their native binding sites in enzymes. Nature has learned during evolution to deal with the dangerous yet important copper cations. Bacterial cells use different efflux systems to detoxify the metal from the cytoplasm or periplasm. Despite this ability, bacteria are rapidly killed on dry metallic copper surfaces. The mode of killing likely involves copper cations being released from the metallic copper and reactive oxygen species. With all this knowledge about the interaction of copper and its cations with cellular macromolecules in mind, experiments were moved to the next level, and the antimicrobial properties of copper-containing alloys in an "everyday" hospital setting were investigated. The alloys tested decreased the number of colony-forming units on metallic copper-containing surfaces by one third compared to control aluminum or plastic surfaces. Moreover, after disinfection, repopulation of the surfaces was delayed on copper alloys. This study bridges a gap between basic research concerning cellular copper homeostasis and application of this knowledge. It demonstrates that the use of copper-containing alloys may limit the spread of multiple drug-resistant bacteria in hospitals.

Atomistic simulations are used to characterize the molecular dynamics (MD) of alkyl chains with different functionalizations in different water/acetonitrile mixtures (80/20 and 50/50). Starting from fully equilibrated solvent systems (flat density profile for both components), microheterogeneous structuring of the solvent in the chromatographic system is found for both mixtures. Depending on the functionalization of the alkyl chain (nitrile, amide, nitro, phenyl), differences in the density profiles of the two solvents (water/acetonitrile), the effective width of the stationary phase and the solvent gradients in the overlap region are observed. The solvent mixture (mobile phase) in RPLC is a liquid which is directly involved in the physical process and must be included explicitly. Far from the surface, the solvent displays bulk properties; closer to it the mixed solvent partitions due to the presence of the stationary phase. This creates a gradient in solvent strength perpendicular to the surface which influences the motions of the analyte. The surface is found to define the amount of water that can bind to it and defines its hydrophilic character. Proposals from the literature, such as the existence of persistent water filaments extending from the functionalized silica layer towards the bulk solvent, are discussed. Simulations of acridine orange near a -NH(2)- and -phenol-functionalized surface highlight the different dynamical behaviour (insertion vs. adsorption) of an analyte depending on the functionalization of the surface.

The binary phase diagram of amphiphilic poly(ethylene oxide)‐block‐poly(γ‐methyl‐ε‐caprolactone) block copolymers in water is examined for four polymers having the same hydrophilic block length but different hydrophobic block lengths across the whole concentration range. The bulk polymers show no ordered morphology. With increasing water concentration the polymers undergo transitions from lamellar phases to packed vesicles and subsequently all polymers self‐assemble into vesicles in dilute aqueous solutions. Additionally, the largest polymer forms an inverse hexagonal phase, and the smallest polymer self‐aggregates into rod‐like micelles and showed a hexagonal phase. magnified image

Novel π-conjugated copolymers based on a soluble electroactive benzo[1,2-b:4,5-b 0 ]difuran (BDF) chromophore have been synthesized by the introduction of thiophene/benzo[c][1,2,5]thiadiazole/ 9-phenylcarbazole comonomer units. These copolymers cover broad absorption ranges from 250 to 700 nm with narrow optical band gaps of 1.71-2.01 eV. Moreover, their band gaps as well as their molecular electronic energy levels are readily tuned by copolymerizing the BDF core with different π-conjugated electron-donating or withdrawing units in different ratios. Bulk heterojunction solar cell devices are fabricated using the copolymers as the electron donor and PCBM ([6,6]-phenyl-C 61 -butyric acid methyl ester) as the electron acceptor. Preliminary research has revealed power conversion efficiencies of 0.17-0.59% under AM 1.5 illumination (100 mW/cm 2 ).

Two well‐defined alternating π‐conjugated polymers containing a soluble electroactive benzo[1,2‐b:4,5‐b′]difuran (BDF) chromophore, poly(BDF‐(9‐phenylcarbazole)) (PBDFC), and poly(BDF‐benzothiadiazole) (PBDFBTD) were synthesized via Sonogashira copolymerizations. Their optical, electrochemical, and field‐effect charge transport properties were characterized and compared with those of the corresponding homopolymer PBDF and random copolymers of the same overall composition. All these polymers cover broad optical absorption ranges from 250 to 750 nm with narrow optical band gaps of 1.78–2.35 eV. Both PBDF and PBDFBTD show ambipolar redox properties with HOMO levels of −5.38 and −5.09 eV, respectively. The field‐effect mobility of holes varies from 2.9 × 10−8 cm2 V−1 s−1 in PBDF to 1.0 × 10−5 cm2 V−1 s−1 in PBDFBTD. Bulk heterojunction solar cell devices were fabricated using the polymers as the electron donor and [6,6]‐phenyl‐C61‐butyric acid methyl ester as the electron acceptor, leading to power conversion efficiencies of 0.24–0.57% under air mass 1.5 illumination (100 mW cm−2). These results indicate that their band gaps, molecular electronic energy levels, charge mobilities, and molecular weights are readily tuned by copolymerizing the BDF core with different π‐conjugated units. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012