Preparation And Characterization Of Nanoparticles From Optical Functional Small Organic Molecules

With the development of the research on organic optoelectronic behaviors, many small organic molecule compounds with unique optoelectronic behaviors have been exploited, the catagories of which are various. Their nanostructures have some unique properties, which have great dependences on the morphologies and sizes of the corresponding nanostructures. In this paper the nanoparticles of some typical small organic molecule compounds were prepared by reprecipitation method and physical vapor deposition method, respectively. The morphologies and structures of the as-prepared nanoparticles were characterized and the chiral properties were studied.Using reprecipitation method, the nanoparticles of a kind of azobenzene small organic molecule compound------2-(4-hydroxyphenyl-azo) benzoic acid (HABA) were prepared in the presence of sodium dodecyl sulfate (SDS) as a stabilizer and template agent. The as-prepared HABA nanoparticles have ribbon-like shape, the morphology regularity, size uniformity and monodispersity of which improved with the increasing of SDS concentration in the preparation system. The circular dichroism spectra show that the as-prepared HABA nanoparticles have optical properties, i.e. chirality. And the mechanism of the formation of the chirality was studied.In the presence of L-Arginine as a stabilizer, template and chiral inducer, HABA nanoparticles were prepared by reprecipitation method. The as-prepared HABA nanoparticles have ribbon-like shape. HABA nanoparticles prepared by injecting 30μLof 20 mM HABA/EtOH solution into 3 mL of 0.08 mM L-Arginine aqueous solution adjusted to pH3 have the best morphology regularity, size uniformity and monodispersity. The circular dichroism spectra show that the as-prepared HABA nanoparticles have negative exciton coupling signal, the chromophore groups of the azobenzenes assemble in H-aggregation mode.The nanoparticles of a kind of small organic molecule compound with fluorescence------1-pyrene butyric acid (PBA) were prepared by reprecipitation method in the presence of sodium deoxycholate (NaDC) as a stabilizer, template and chiral inducer, The as-prepared PBA nanoparticles are amorphous flake-shaped with the thickness of several tens nanometers to 100 nm. The concentration of chiral inducer NaDC plays an important role of controlling the chiral signal of the as-prepared PBA nanoparticles. We prepared PBA nanoparticles in the presence of L-Arginine as a stabilizer, template and chiral inducer by reprecipitation method. The as-prepared PBA nanoparticles are narrow flake-shaped nanoparticles with the thickness of about 100 nm, which have good monodispersity. The circular dichroism spectra show that the as-prepared PBA nanoparticles have exciton coupling signal in the region attributed to the PBA aggregates absorption in the corresponding UV-Vis spectra.In the presence of cetyltrimethyl ammonium bromide (CTAB) as a stabilizer and template, we prepared nanoparticles of a kind of small organic molecule compound with fluorescence ------9,10-diphenylanthracene by reprecipitation method. The as-prepared DPA nanoparticles have ribbon-like shape. CTAB plays an important role as stabilizer and template in the preparation of nanoparticles.Using physical vapor deposition method, we prepared HABA nanoparticles, and in the preparation process we introduced the adsorbent------actived carbon. The HABA nanoparticles prepared under higher deposition temperature have larger sizes. The introducing of actived carbon adsorbent improved the morphology regularity, monodispersity and size uniformity of the as-prepared HABA nanoparticles.