This thesis studies properties of hydrogel, which arises on the basis of electrostatic and hydrophobic interactions between hyaluronan chain and micelles of cationic surfactant. A native sodium hyaluronan at molecular weight 750–1 000 kDa and a cationic surfactant CTAB (cetyltrimethylammonium bromide) were used. This hydrogel was assessed as a material for drug delivery systems. The hydrogels were made by mixing 200mM CTAB with 0.5% hyaluronan, both dissolved in 0.15M aqueous solution of NaCl simulating physiological solution. Methods used in this study were steady-state and time-resolved fluorescence spectroscopy, more accurately time-resolved emission spectra (TRES) and deconvolution of steady-state emission spectra of a whole sample by means of parameters gained from fluorescence intensity decays at a set of wavelenghts. Selected systems were investigated by three fluorescent probes, prodan, laurdan and rhodamine 6G. The first two mentioned probes were in hydrogel localized only within micelles in three different microenvironments. Rhodamine 6G pointed out that in hydrogel the aqueous environment is significantly restricted in comparison to purely micellar solution. In addition, rhodamine informed about less available micelle surfaces, caused by hyaluronan chains occupation. There were no interactions between the probes and hyaluronan chains. Freshly made hydrogels showed almost the same results as after a week of maturation under its supernatant.

This thesis establishes methods to locally and effciently detect the fluorescence from photonic crystals (PCs) in dependence on wavelength and direction. These are applied to three dimensional (3D) PCs grown by vertical deposition of polystyrene beads. The experiments allow conclusions about the local 3D structure of a sample, about defects in its volume and about spatial structural variations. They thus provide more information than typical spectroscopy measurements that average over large areas and methods that only image the surface structure like scanning electron microscopy. A focused laser is used to excite emitters in the sample only locally. The fluorescence is then collected by a microscope objective. Every point in this objective’s back focal plane (BFP) corresponds to a certain direction. This property is utilized in two ways. When observing a small spectral range of the emission in the BFP, stop bands appear as intensity minima since they hinder the emission into the corresponding directions. Thus, back focal plane imaging (BFPI) allows to visualize stop bands of many directions at the same time. The detected patterns permit to find the in-plane and out-of-plane orientation of the PC lattice and to conclude on the presence of stacking faults. Spatial variations of the structure are observed on a length scale of a few micrometers. The depth of the stop band is reduced at sample positions, where structural changes occur. In back focal plane spectroscopy (BFPS), a slit selects light from certain points in the BFP, which is spectrally dispersed subsequently. This allows to record spectra from many directions simultaneously. From them, a lattice compression along the sample normal of about 4% is found. Small deformations are also observed for other directions. Scattering at defects redistributes the emission. This increases the detected intensity compared to homogeneous media at some stop band edges in a broad spectral range for samples thicker than the scattering mean free path. Thinner samples show a narrow enhancement due to an increase in the fractional density of optical states and thus in emission. BFPI and BFPS are also used to observe the growth of PCs from drying droplets. The experiments show that the beads initially form a non-close packed lattice. This causes stress as the lattice constant decreases, which is released by cracking of the PCs.

En utilisant les spectroscopies d'absorption UV-vis et d'émission stationnaire et résolue dans le temps (femto- et sub–nanoseconde, caméra à balayage de fente), nous avons étudié, au cours de cette thèse, les processus photophysiques au sein de différentes molécules et supramolécules. Les propriétés photophysiques de nouveaux complexes de Ru(II) polypyridine et de Ir(III) cyclométallé présentant un transfert d'énergie électronique réversible entre le noyau métallique et les chromophores organiques auxiliaires énergétiquement appariés (anthracène et pyrène) ont été analysées en détail. Les caractéristiques de la séparation de charge entre un donneur d'électron (OPV) et un accepteur (PB) à travers un pont d'oligoquinoline au sein de foldamères de longueurs croissantes ont été précisées dans une échelle de temps inférieure à la nanoseconde. De nouvelles sondes luminescentes à base de lanthanides ont été réalisées pour la détection en temps réel de l’ion Cu(I), leurs propriétés optiques étant modulées par effet «d’antenne» par le biais d'interactions cations-nuagePi. L'étude de sondes fluorescentes off-on en proche IR formées de colorantsBF2-AzaBODIPY fixés de manière covalente sur des nanoparticules (100 nm) polymériques a été réalisée, et étendue à de nouvelles sondes sensibles au pH émettant dans le proche IR. Des études de photoisomérisation ont été effectuées sur deux systèmes azobenzéniques capables de libérer/capturer des ions Ca(II) (azobenzène-éther«lasso», azobenzène-BAPTA) – l'impact de l'eau sur la photoisomérisation cis-trans d’hydroxychalcones a été mis en évidence dans CH3CN et H2O/CH3OH (v/v=1/1). / In the present work photophysical processes of different molecular and supramolecular systems were studied using steady-state and time-resolved femto- and sub-nanosecond (streak-camera detection) UV-vis absorption and emission spectroscopies. Detailed photophysical studies of novel Ru(II) polypyridine and cyclometalatedIr(III) complexes showing reversible electronic energy transfer between metallic core and auxiliary organic energetically-matched chromophores anthracene and pyrene, respectively were performed. Time-resolved characterization of charge separation between electron donor (OPV) and acceptor (PB) in the sub-nanosecond timescale through an oligoquinoline bridge in foldamers of increasing oligomeric length was carried out. Novel lanthanide-based luminescent probes were investigated for time-gated detection of Cu(I) ion, being modulated by an antenna effect through cation-pi interactions.The study on NIR fluorescent off-on probes, based on BF2-aza-BODIPY dyes, covalently attached to the surface of polystyrene 100 nm nanoparticles, along with related novel NIR pH-responsive fluorescence probes were conducted. Photoisomerization studies focused on azobenzene-based (azobenzene-lariat ether, azobenzene-BAPTA)Ca(II)-ion release/capture systems, while the impact of water on the cis−trans photoisomerizationof hydroxychalcones was studied in CH3CN and H2O/CH3OH (v/v=1/1).

This thesis establishes methods to locally and effciently detect the fluorescence from photonic crystals (PCs) in dependence on wavelength and direction. These are applied to three dimensional (3D) PCs grown by vertical deposition of polystyrene beads. The experiments allow conclusions about the local 3D structure of a sample, about defects in its volume and about spatial structural variations. They thus provide more information than typical spectroscopy measurements that average over large areas and methods that only image the surface structure like scanning electron microscopy. A focused laser is used to excite emitters in the sample only locally. The fluorescence is then collected by a microscope objective. Every point in this objective’s back focal plane (BFP) corresponds to a certain direction. This property is utilized in two ways. When observing a small spectral range of the emission in the BFP, stop bands appear as intensity minima since they hinder the emission into the corresponding directions. Thus, back focal plane imaging (BFPI) allows to visualize stop bands of many directions at the same time. The detected patterns permit to find the in-plane and out-of-plane orientation of the PC lattice and to conclude on the presence of stacking faults. Spatial variations of the structure are observed on a length scale of a few micrometers. The depth of the stop band is reduced at sample positions, where structural changes occur. In back focal plane spectroscopy (BFPS), a slit selects light from certain points in the BFP, which is spectrally dispersed subsequently. This allows to record spectra from many directions simultaneously. From them, a lattice compression along the sample normal of about 4% is found. Small deformations are also observed for other directions. Scattering at defects redistributes the emission. This increases the detected intensity compared to homogeneous media at some stop band edges in a broad spectral range for samples thicker than the scattering mean free path. Thinner samples show a narrow enhancement due to an increase in the fractional density of optical states and thus in emission. BFPI and BFPS are also used to observe the growth of PCs from drying droplets. The experiments show that the beads initially form a non-close packed lattice. This causes stress as the lattice constant decreases, which is released by cracking of the PCs.