Green preparation and characterization of silver nanocolloids used as antibacterial material in soap

This study aimed to assess the characteristics, including morphology, physicochemical properties, and antibacterial properties, of silver nanocolloids obtained by D-glucose reduction. Silver nanoparticles were synthesized in accordance with the principles of green chemistry using D-glucose as a reductor. The obtained nanostructures were characterized by UV–vis spectroscopy, transmission electron microscopy, and dynamic light scattering. Stability tests performed after 1 month of storage revealed that the colloids prepared with and without polyvinylpyrrolidone as a stabilizer had the same properties. Distribution of the nanoparticles was tested using inductively coupled plasma mass spectrometry by doping the silver colloids into a natural soap mass. The antibacterial activity of the soap containing silver nanoparticles was tested on dirty hands. The antibacterial activity test demonstrated that the novel green soap materials improved with D-glucose-reduced silver nanoparticles possessed better antibacterial properties than a pure soap, and thus, they could be recommended for quotidian use by dermatological patients.

Indirekter Nachweis von Assoziaten solubilisierter, polycyclischer, aromatischer Kohlenwasserstoffe in wäßrigen Seifenlösungen durch Lichtabsorption und Fluoreszen / Indirect Evidence for Molecular Association of Polycyclic Aromatic Hydrocarbons in Aqueous Soap Solutions from Light Absorption and Fluorescence

Aqueous solutions of alkyl sulphates containing small amounts of the free alkanol differ in their dissolving properties for polycyclic aromatic hydrocarbons from aqueous solutions of the pure soap in concentrations near the CMC. The differences are observed only near the CMC of the pure soap, where the soap solutions containing free alkanol have a minimum of the surface tension. The observed alterations are deviations from the Lambert-Beer law, energy transfer, and changes of the fluorescence quantum efficiencies, when the soap concentration is varied. The different results are consistent with the assumption that microcristalline molecular van der Waals associations are brought into solution by the soap solutions which were studied.

Studies of aggregation in soap solutions containing salt and simple organic molecules

Using the synthetic soap cetyl pyridinium chloride the effects of added chlorobenzene and sodium chloride upon various physical properties, such as saturation solubilities, viscosity, osmotic pressure, sedimentation velocity, and interfacial tension, have been quantitatively measured. The results suggest that the soap micelle has a very labile structure, the approximately spherical aggregates present in pure soap solutions changing to more asymmetric shapes in the presence of suitable concentrations of sodium chloride and chlorobenzene.