Darbe tirta Co6Om (m=0-9) nanodalelių ir PPI dendrimerų optinės savybės, siekiant nustatyti ar PPI dendrimerai galėtų būti naudojami dirbtinių neuroninių tinklų, skirtų aptikti Co nanodaleles, kūrimui. Tyrimo rezultatai yra: 1) Co6Om (m=0-9) nanodalelių absorbcijos spektrų tyrimai parodė, kad absorbcijos intensyvumas 500-700 nm intervale mažėja, kai deguonies atomų skaičius didinamas iki 5. Absorbcijos intensyvumas vėl pradeda didėti, kai deguonies atomų skaičius tampa 6. 2) Teoriškai ir eksperimentiškai ištirta glikodendrimero su triptofano molekulėmis spektro prigimtis 200 - 400 nm intervale. Nustatyta, kad minėtame bangų ilgių diapazone stebimas triptofano molekulės π→π* sužadinimas. 3) Tirti PPI dendrimerai galėtų būti naudojami kaip neuroniniai tinklai, skirti aptikti Co nanodaleles. / In this research our aim was to investigate possibilities to use PPI dendrimers as a neural network for detecting Co nanoparticles. Our investigation results are: 1) Intensity of absorption of the Co6Om (m=0-9) particles should decrease in the 500-700 nm region with increasing of oxygen number till 5, and should increase again when number of oxygen atom is 6; 2) Nature of spectrum of PPI dendrimers with Tryptophan molecule in 200-400 nm range was investigated both theoretically and experimentally. It is obtained, that in above mentioned wavelength region absorption is due to π→π* excitation of tryptophan units; 3) Investigated PPI dendrimers could be used as an artificial neural network for detecting Co nanoparticles.

Darbe tirtos funkcionalizuotų dendrimerų optinės savybės sintetinant sidabro nanodaleles panaudojus glikodendrimerą kaip terpę. Keičiant išorinius faktorius, tokius kaip temperatūra (20 oC ir 45 oC), medžiagų koncentracija (1:5, 1:10 ir 1:20) ar skirtingo bangos ilgio šviesa (532nm ir 632,8nm), užauginome sidabro nanodaleles. Gauti rezultatai rodo, jog sidabro nanodalelių dydžiui didžiausią įtaką daro tik [dendrimeras/AgNO3] santykis. Kuo jis didesnis – tuo sidabro dalelės yra didesnės. Tuo tarpu tiek temperatūra, tiek šviesa didesnės reikšmės dalelių susiformavimui neturi. Remiantis gautais rezultatais galime tvirtinti, kad tirti PPI-G4 glikodendrimerai gali būti naudojami kaip matrica sidabro nanodalelių formavimui. / We prepared silver nanoparticles using a fourth-generation PPI glycodendrimer were about from 5nm to 10nm in size, and that the higher the [dendrimer/AgNO3] ratio, the larger were the metal particles. The results suggest that the temperature and different wavelength of light does not affect the nanoparticle size by using PPI-G4 glycodendrimer as a template. The characteristic absorption peak at around 400nm corresponds to a plasmon band. The splasmon spectrum of nanoparticles is affected by the nature of the metal and the status of aggregation of the particles. The single peak indicates that the silver particles are of spherical shape.

When a molecule, which possess a permanent dipole moment is exposed to an intense electric field, its absorption spectrum may be altered. These alterations are manifest as shifts in energy and as changes in band shape and intensity. The electric dichroism of absorption bands can be used to probe the excited state that is formed when a molecule undergoes a transition. The properties that may be investigated include transition polarization, excited state dipole moment and mean polarizability, and field-induced mixing of symmetrically equivalent excited states. The theoretical model and experimental devices that have been developed to determine these properties are presented and discussed. The data, taken in total, and its combination with other existing evidence, adds credence to the assignment of the second excited singlet of aldehydes and ketones to be extravalent, accompanied by relatively large delocalization of electronic charge, and polarized in-planiie and perpendicularly to the C-0 axis.