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We prepared various pyrazoline derivatives which possess dimethylamino-, ethoxy-, isopropyl-phenyl ring at the 5-position of pyrazoline. The nanoparticles of pyrazoline derivative ranging from tens to hundreds of nanometers by the reprecipitation method have been successfully prepared and their optical size-dependent properties have been investigated with UV-vis, fluorescence spectroscopy, DLS (Dynamic Light Scattering) and SEM. The size-dependent optical properties of pyrazoline organic nanoparticles have been observed in the order of dimethylamino- > ethoxy- > isopropyl- in electro-donating characters.

SiO2 nanoparticles were synthesized from different three precursors, namely, TEOS (tetraethyl orthosilicate), sodium metasilicate and sodium silicate. First, SiO2 nanoparticles were prepared by a controlled hydrolysis of TEOS. In another method, SiO2nanoparticles were prepared by precipitation in an emulsion medium from sodium metasilicate and hydrochloric acid solution. Finally, SiO2 nanoparticles were also synthesized from sodium silicate by an emulsion method. In this study, we concentrated on dispersion and compatibility between nanosized SiO2 particles and EVA (ethylene vinyl acetate). Therefore, surface modification of synthesized SiO2 nanoparticles was accomplished with MPS (3-mercaptopropyl trimethoxysilane) to enhance homogeneous dispersion and compatibility between the obtained SiO2 nanoparticles and EVA. Finally, nanocomposites of surface treated SiO2 nanoparticles and EVA were prepared. By inserting the MPS-coated SiO2 nanoparticles into EVA, abrasion resistance and hardness were increased rem...

Indium tin oxide (ITO) nanoparticles with In/Sn = 9:1 (at.%) were synthesized by chemical coprecipitation method in an aqueous solution. The coprecipitate prepared at room temperature showed the crystal structure of indium oxide in X-ray diffraction when it was annealed at the temperature above 300°C under air atmosphere. Reduction process was accomplished to improve the electrical property of ITO powder and it changed powder color from yellow to dark green. Green ITO powder with particle sizes in the range of 15–30 nm was well dispersed by an addition of polyvinylpyrrolidone in an aqueous solution. The dispersibility of ITO sol solution was detected with ζ-potential analyzer. Near-IR reflective film was prepared by spin coating method using ITO sol solution. Transmission electron microsopy (TEM) and energy dispersive X-ray spectrometer (EDS) were used to characterize morphology and composition of ITO nanoparticles. Near-IR (NIR) spectrometer was used to determine reflectance on the surface of ITO film in the NIR-radiation region.

1-Phenyl-3-naphthyl-5-((dimethylamino)phenyl)-2-pyrazoline nanoparticles with different sizes from 190 to 40 nm were prepared by the reprecipitation method and polymerized with methyl methacrylate and ethylene glycol dimethacrylate and controlled by changing the concentration of surfactants. We found that pyrazoline nanoparticles possess a special size dependence in their optical properties. As the nanoparticle size decreased, the absorption and emission peak of pyrazoline nanoparticles were observed to shift to the high-energy side due to the aggregate formation and increased intermolecular interaction in the nanoparticles. The electronic ink particles of pyrazoline organic nanoparticles were successfully prepared by dispersion polymerization in aqueous alcohol medium for full color electronic paper, which is expected to substitute for the future display. In order to improve their mobility, the surfactant was added as a charge control additive. The electrophoretic mobility of the resulting electronic inks was −x-7.5 to −3.6 × 10−5 cm2/V·s in the presence of surfactants.

A study on the method for the synthesis of alkyl urethane acrylate oligomers has been performed with 2-isocyanatoethyl acrylate. Alkyl urethane acrylate oligomers for UV curable coating agents were synthesized from 2-mercaptoethanol (2-MEOH), alkyl (methyl, butyl, 2-ethylhexyl) acrylate, 2,2'-azobisisobutyronitrile (AIBIN, initiator) and dibutyltin dilaurate as a catalyst. 2-MEOH was used for functional chain transfer agent. The urethane acrylate oligomers were obtained by the reaction of alkyl acrylate oligomers and 2-isocyanatoethyl methacrylate. The molecular structure of alkyl urethane acrylate oligomers was characterized by FT-NMR, FT-IR, and GPC. And thermal property of the synthesized oligomers was confirmed by rheometer and DSC. The alkyl urethane acrylate oligomers can be applied for UV curable coatings, inks and adhesives.

1-Phenyl-3-naphthyl-5-((dimethylamino)phenyl)-2-pyrazoline with different diameters of 40 - 190 nm were prepared by the reprecipitation method and polymerized with poly(methyl methacrylate-co-ethylene glycol dimethacrylate) using cationic surfactants for full color electronic paper, which is expected to substitute for the future display. The electronic ink particles of pyrazoline organic nanoparticles polymerized by poly(methylmethacrylate-co-ethylene glycol dimethacrylate) were prepared and monodispersed successfully in aqueous alcohol medium. The size of mono-dispersed electronic ink particles is from 160 to 550 nm. The ink particle size was found to decrease with increasing concentration of the surfactant. The effect of surfactant was significant. The appropriate additions of surfactants result in an increase in electrophoretic mobility. The electrophoretic mobility of the resulting electronic inks was −7.5 to −3.6 × 10−5 cm2/ V·s in the presence of surfactants.

1-Phenyl-3-naphthyl-5-((dimethylamino)phenyl)-2-pyrazoline nanoparticles with sizes ranging from tens to hundreds of nanometers were prepared by the reprecipitation method and polymerized with methyl methacrylate and ethylene glycol dimethacrylate using surfactants. The electronic ink particles of pyrazoline organic nanoparticles were successfully prepared by dispersion polymerization in aqueous alcohol medium for full color electronic paper, which is expected to substitute for the future display. In order to improve their mobility, the surfactant was added as a charge control additive. The electrophoretic mobility of the resulting electronic inks was 3.059 × 10−4 cm2/V · s in the presence of 3 wt% surfactants.

Nanoparticles of 1-phenyl-3-naphthyl-5-((ethoxy)phenyl)-2-pyrazoline with sizes ranging from tens to hundreds of nanometers were prepared by the reprecipitation method. Their excitonic transitions responsible for absorption and emission, as compared with those of diluted solution, have been investigated as a function of nanoparticle size. We found that pyrazoline nanoparticles possess an ambiguous size dependence on their optical properties. As the nanoparticle size decreased, the absorption peak of pyrazoline nanoparticles was observed to be shifted to the high-energy side due to size effect.