Kompozitní systémy π-konjugovaných polymerů a plasmonických kovových nanočástic: příprava, morfologie a optické vlastnosti

Department of Physical and Macromolecular ChemistryKatedra fyzikální a makromol. chemieFaculty of SciencePřírodovědecká fakult

Studie mechanismu laserové fragmentace nanočástic stříbra ve vodném prostředí

The paper reports on the investigation of interaction of a high energy pulsed laser irradiation with a highly polydisperse hydrosol containing Ag nanoparticles. The study is focused on the process of nanoparticles fragmentation with respect to their shapes and sizes, and to the wavelength and energy of the NdYAG laser pulses used for the fragmentation

Změny velikostí zlatých nanočástic vysokoenergetickými laserovými pulsy

We focused on the interaction of gold nanoparticles of various mean size embedded in aqueous environment with nanosecond pulsed laser irradiation of various energy per pulse at wavelength 355 and 532 nm, respectively. We performed a sequence of in-situ surface plasmon extinction (SPE) measurements of the fragmented hydrosol as well as ex-situ TEM studies to evaluate the size distribution of resulting Au nanoparticles. It was found that laser pulses of 355 nm wavelength provide smaller nanoparticles compared with 532 nm pulses at the same absorbed energy

Fotoindukovaná cis/trans izomerizace alkanthiolového derivátu azobenzenu zakotveného na Au nanočásticích

Photoinduced trans/cis isomerization of -[4-(4-octyloxy-phenylazo)-phenoxy]-pentane-1-thiol (ABT) attached to geld nanoparticles was investigated in Au organosol/ABT system as well as on glass slides functionalized by gold nanoparticles

Ivabradine Hydrochloride (S)-Mandelic Acid Co-Crystal: In Situ Preparation during Formulation

The pharmaceutical salt ivabradine hydrochloride is indicated for the symptomatic treatment of chronic stable angina pectoris and chronic heart failure. It exhibits extensive polymorphism and co-crystallization, which could be a way to provide an alternative solid form. We conducted a co-crystal screen, from which two hits were identified: with (S)-mandelic and (R)-mandelic acid. Both structures were determined from single-crystal X-ray diffraction data as co-crystals. The co-crystals were further characterized by common solid-state techniques, such as X-ray powder diffraction (XRPD), differential scanning calorimetry (DSC), solid-state NMR, IR and Raman spectroscopy, and dynamic vapor sorption (DVS). The co-crystal with (S)-mandelic acid was selected for further development; its physical and chemical stability was compared with two different polymorphs of the hydrochloride salt. The co-crystal exhibited a similar stability with the polymorph used in the original drug product and was, therefore, selected for formulation into the drug product. During the pre-formulation experiments, the in situ formation of the co-crystal was achieved during the wet granulation process. The following formulation experiments showed no influence of in situ prepared co-crystal on the overall stability of the bulk, when compared with pre-prepared co-crystal formulation