The interaction of the antibacterial polymer–branched poly(ethylene imine) substituted with quaternary ammonium groups, PEO and alkyl chains, PEI25QI5J5A815–with a solid supported lipid bilayer was investigated using surface sensitive optical waveguide spectroscopy. The analysis of the optogeometrical parameters was extended developing a new composite layer model in which the structural and optical anisotropy of the molecular layers was taken into consideration. Following in situ the change of optical birefringence we were able to determine the composition of the lipid/polymer surface layer as well as the displacement of lipid bilayer by the antibacterial polymer without using additional labeling. Comparative assessment of the data of layer thickness and optical anisotropy helps to reveal the molecular mechanism of antibacterial effect of the polymer investigated.

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Abstract A relationship between the local structure and the visible-light activated photocatalytic effect was investigated in the glass and glass ceramics prepared by recycling waste slag, which was discharged from a Tokyo Household Garbage Combustion Plant. For the preparation of a homogeneous sample of waste slag recycled glass, (WSRG), 10 wt% of Na2CO3 and 10–50 wt% of Fe2O3 were added. 57Fe-Mössbauer spectra of WSRG recorded at liquid nitrogen temperature showed three types of magnetic hfs; one due to FeII(Oh) with δ of 1.21 mm s−1 and Hint of 46.7 T, one due to FeIII(Oh) with δ of 0.46 mm s−1 and Hint of 44.1 T, and the other due to FeIII(Td) with δ of 0.38 mm s−1 and Hint of 47.8 T. They were superimposed on a relaxation spectrum due to superparamagnetic hematite. Methylene blue (MB) degradation test with 40 mg of the heat treated WSRG (50 wt% Fe2O3), under the visible-light irradiation for 6 h showed a marked decrease in the concentration of MB from 20 to 7.7 μmol L−1 with a rate constant (k) of 2.7×10−3 min−1 which was close to the k, 9.26×10−3 min− 1, recently obtained in 15Na2O⋅15CaO⋅40Fe2O3⋅ 11Al2O3⋅19SiO2 glass.

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