Highly concentrated 0.5 M II-VI semiconductor quantum dot solutions for coating applications can be synthesized employing chalcogenolysis and condensation of functionalized cluster-like cadmium and zinc ethoxyacetates. Furthermore, in nucleation studies on CdSe solutions, new magic clusters between 0.42 and 1.7 nm in size were found exhibiting sharp HOMO-LUMO resonances (lowest absorption features) in the optical absorption spectra. High resolution small angle X-ray scattering (SAXS) measurements performed on 1.7 and 3.4 nm CdSe clusters corroborate the size. Information on the intra-cluster structure was hard to derive with respect to the small cluster size. These species could be Koch pyramids with a fractal dimension Df=2 as well as non-fractal zincblende pyramids (additionally checked by XRD and HFtTEM). In any case rather chain-like (Dt= 1) aggregates are formed. It further will be shown that in alcoholic CdSe sols the initially nucleated "seeds" are highly reactive. Their sharp HOMO-LUMO transitions are found to be strongly modified by externally induced chemical reactions. For example, aminosilane capped 1.7 nm clusters decompose rapidly upon exposure to phosphines. After a period of few hours, they begin to re-grow to their original size or they reorganize to give smaller 0.85 nm subunits depending on the P/N ratio. In contrast, 0.85 nm phosphinecapped clusters double their size if exposed to amines. The last process liberates cadmium ions into the solution as found in complementary polarographic measurements. ~ allel to this work and the sol-gel chemistry of metal oxides, addressing metal ethoxy-acetate derived synthesis of II-VI chalcogenide quantum dots, to provide insights into the cluster-cluster aggregate evolution mechanism within the strong exciton confinement regime. We shall demonstrate that chemical surface reactions can change both the cluster optical absorption and fluorescence spectra related to structural changes within cluster-cluster aggregates. This spectroscopic work is supported by SAXS-, XRDand HRTEM investigations addressing a fractal character of highly concentrated semiconductor cluster materials. Experimental GeneralAU manipulations involving silylchalcogenides and phosphines were carried out under argon using the Schlenk technique. Cadmium and zinc acetate dihydrate were purchased from Fluka. Bis(trimethylsily1)selenium (TMS)2Se prepared according to the procedure described elsewhere [15] was stored at 240 K under argon. Bis(trimethylsily1)sulfide (TMS)$3 and bis(trimethylsily1)tellurium (TMS)2Te were purchased from Aldrich and Acros respectively. Anhydrous heptane, pyridjne, tetrahydrofuran (THF) and 2-butoxyethanol in addition to aUcyl amines and tributylphosphine (TBP) were purchased from Aldrich. 3-Aminopropyltriethoxy-silane (AMEO) was purchased from ABCR. All chemicals were used without additional purification.

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Chemical modification of Schiff base epoxy resins involves introduction of waste PET degradation products into a synthesis reaction between N,N'-bis(2hydroxybenzylidene)-4,4'-oxydianiline and epichlorohydrin or introduction of a flexibility spacer between the mesogenic units in a reaction with epichlorohydrin. This provides the resins with much lower glass transition temperatures. All used Schiff bases are the derivatives of 2-hydroxybenzaldehyde. Synthesized epoxy resins were used as a component of binder of new organic coatings. Xylene-based solution of polyamide based on dimerized fatty acid and polyamines and poly(oxypropylene diamine) were used as a hardener for the synthesized and commercial epoxy resins at room temperatures. Physical and mechanical properties of coatings based on new epoxy resins were determined. Results were compared with those for one selected commercial epoxy resin. The results of investigations prove that coatings based on new epoxy resins have good elasticity, impact resistance, and their adhesion to the substrate is comparable or even better than that of coatings based on the widely used commercial epoxy resin.

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2Kierownik: prof. dr hab. a. dzikiColorectal cancer (CRC) is a serious medical and economical problem of our times. It is the most common gastrointestinal cancer in the world. In Poland, the treatment and detection of CRC are poorly developed and the pathogenesis is still unclear. One hypothesis suggests a role of reactive oxygen species (ROS) in the pathogenesis of CRC. Experimental studies in recent years confirm the participation of ROS in the initiation and promotion of CRC. the aim of the study was to examine the effect of the following coordination compounds coordination compounds: dinitrate (V) tetra(3,4,5-trimethyl-n 1 -pyrazole-ĸn 2