Volume 42 Issue 12, December 2010

Novel thermal iniferter, synthesized from 1,1,2,2-tetraphenyl-1,2-ethanediol and α-bromoisobutyryl bromide, was used to polymerize styrene and methyl methacrylate through controlled radical polymerization (CRP) mechanism.

In the free-radical cross-linking multiallyl polymerization, the structure of network polymer precursor (NPP) consisting of oligomeric primary polymer chains would become core-shell type dendritic or nanogel-like with the progress of polymerization and then, the NPPs can collide with each other to form cross-links among NPPs, eventually leading to gelation. Thus, the dilution of NPP by newly adding monomer could prevent the cross-link formation between NPPs and consequently, lead to the successive growth of NPP from nanogel to microgel.

Oligothiophene-stacked polymers were synthesized by the Suzuki–Miyaura coupling reaction. Oligothiophene units were layered in proximity, ∼3.0 Å from each other. The polymers were characterized by various spectroscopic and electrochemical methods. The polymers have potential application to optoelectronic devices such as hole-transporting materials.

Recently, polymer matrix-based nanocomposites have become a prominent area of current research and development in optics, optoelectronic, biomedical, electrical and electronic applications. Organic polymer-based electronic devices offer the potential for lower cost and more flexible manufacture but need significant improvements in both efficiency and long-term stability. Therefore, we have made an attempt to synthesize polyaniline (PANI)–zinc oxide (ZnO) using chemical and emulsion polymerization techniques. The properties of ZnO–PANI films were then systematically characterized with several physical techniques. The electrochemical investigations revealed that the individual redox properties of ZnO and PANI can be maintained in a nanocomposite ZnO–PANI system. Further, results indicated that ZnO–PANI films could exhibit a wide potential window. Moreover, we have observed the formation of a single-layer nano-Schottky junction in the ZnO–PANI film, and interesting positive temperature coefficient properties in ZnO–PANI.

The polymer graded index (GRIN) lens with high impact resistance can be made by easy technique, but the thermal stability is not so excellent. In this study, we propose a new method of fabricating organic–inorganic microcomposite cylindrical GRIN lens. This method is based on spontaneous frontal polymerization technique and diffusion of two organic materials with different refractive indices to an inorganic wet-gel. The obtained microcomposite cylindrical GRIN lenses are not only thermally stable, but also have a controlled refractive index profile due to its inorganic matrix.

The scanning electron microscope images show how the pore diameter is changing as the time of thermal treatment is increasing. In the graphic, one can appreciate the oscillatory behavior of the pore size and the fitting curve obtained when the mathematical model is applied to the experimental data.

Polyethylene glycol-containing hematin (PEGylated hematin) was prepared using the Mitsunobu reaction as a water-soluble biomimetic catalyst for polymerization of arbutin in a phosphate buffer solution of pH 7.0. The structure of polyarbutin obtained was characterized by ¹H nuclear magnetic resonance and infrared spectroscopy. PEGylated hematin showed high catalytic activity for arbutin polymerization, indicating that it is a better catalyst compared with horseradish peroxidase.