Preparazione e studio delle proprieta' ottiche di dispersioni di nanoparticelle d'oro e di complessi di Ni e Cu in matrice polimerica.

E' stato svolto uno studio sulle proprietà ottiche di dispersioni polimeriche contenenti aggregati di molecole di dimensioni micro- e nanometriche. A tale scopo sono stati preparati e dispersi in polietilene (UHMWPE) sia complessi metallici di Cu e Ni derivati dalla salicilimmina aventi catene alchiliche di lunghezze diverse, che nanoparticelle d'oro stabilizzate da tioli e tioeteri alifatici e aromatici ottenute per riduzione in soluzione. Sono stati inoltre preparate delle particelle d'oro di dimensioni nanometriche) disperse in poli(etilene-co-vinilalcol) per fotoriduzione in situ di Au(III) in presenza di glicole etilenico. Le dispersioni sono state caratterizzate attraverso misure calorimetriche (TGA, DSC), spettroscopiche (UV-Vis, IR, ESI), microscopiche (TEM, SEM) e di diffrazione (ED, XRD). I film ottenuti dai materiali preparati, mostrano proprietà ottiche modulabili sia in assorbimento che in emissione, in particolare dopo stiro meccanico uniassiale le dispersioni risultano caratterizzate da proprietà dicroiche

Low-THz Vibrations of Biological Membranes

A growing body of work has linked key biological activities to the mechanical properties of cellular membranes, and as a means of identification. Here, we present a computational approach to simulate and compare the vibrational spectra in the low-THz region for mammalian and bacterial membranes, investigating the effect of membrane asymmetry and composition, as well as the conserved frequencies of a specific cell. We find that asymmetry does not impact the vibrational spectra, and the impact of sterols depends on the mobility of the components of the membrane. We demonstrate that vibrational spectra can be used to distinguish between membranes and, therefore, could be used in identification of different organisms. The method presented, here, can be immediately extended to other biological structures (e.g., amyloid fibers, polysaccharides, and protein-ligand structures) in order to fingerprint and understand vibrations of numerous biologically-relevant nanoscale structures

Low-THz Vibrations of Biological Membranes

A growing body of work has linked key biological activities to the mechanical properties of cellular membranes, and as a means of identification. Here, we present a computational approach to simulate and compare the vibrational spectra in the low-THz region for mammalian and bacterial membranes, investigating the effect of membrane asymmetry and composition, as well as the conserved frequencies of a specific cell. We find that asymmetry does not impact the vibrational spectra, and the impact of sterols depends on the mobility of the components of the membrane. We demonstrate that vibrational spectra can be used to distinguish between membranes and, therefore, could be used in identification of different organisms. The method presented, here, can be immediately extended to other biological structures (e.g., amyloid fibers, polysaccharides, and protein-ligand structures) in order to fingerprint and understand vibrations of numerous biologically-relevant nanoscale structures