Synthesis of metal (Fe or Pd)/alloy (Fe–Pd)‐nanoparticles‐embedded multiwall carbon nanotube/sulfonated polyaniline composites by γ irradiation

Composites of multiwall carbon nanotubes (MWCNTs) and sulfonated polyaniline (SPAN) were prepared through the oxidative polymerization of a mixture of aniline, 2,5‐diaminobenzene sulfonic acid, and MWCNTs. Fe, Pd, or Fe–Pd alloy nanoparticles were embedded into the MWCNT–SPAN matrix by the reduction of Fe, Pd, or a mixture of Fe and Pd ions with γ radiation. Sulfonic acid groups and the emeraldine form of backbone units in SPAN served as the source for the reduction of the metal ions in the presence of γ radiation. The existence of metallic/alloy particles in the MWCNT–SPAN matrix was further ascertained through characterization by high‐resolution transmission electron microscopy (HRTEM), Fourier transform infrared spectroscopy, ultraviolet–visible spectroscopy, thermogravimetric analysis, and conductivity measurements. HRTEM pictures clearly revealed the existence of Fe, Pd, and Fe–Pd nanoparticles of various sizes in the MWCNT–SPAN matrices. There were changes in the electronic properties of the MWCNT–SPAN–M composites due to the interaction between the metal nanoparticles and MWCNT–SPAN. Metal‐nanoparticle‐loaded MWCNT–SPAN composites (MWCNT–SPAN–M; M = Fe, Pd, or Fe–Pd alloy) showed better thermal stability than the pristine polymers. The conductivity of the MWCNT–SPAN–M composites was approximately 1.5 S cm^?1, which was much higher than that of SPAN (2.46 × 10^?4 S cm^?1). Metal/alloy‐nanoparticle‐embedded, MWCNT‐based composite materials are expected to find applications in molecular electronics and other fields. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 3355–3364, 2006     

Multidimensional Inverse Heat Conduction Calculations

Inverse Heat Conduction Problems (IHCPs) have been extensively studied over the last 50 years. They have numerous applications in many branches of science and technology. The problem consists in determining the temperature and heat flux at inaccessible parts of the boundary of a 2- or 3-dimensional body from corresponding data – called ‘Cauchy data’ – from accessible parts of the boundary. It is well-known that IHCPs are illposed which means that small perturbations in the data may cause large errors in the solution. In this contribution we give a short overview over our contributions to multidimensional IHCP's and indicate what computational results for which sort of problems we have obtained. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)     

Experimental and quantum-chemical investigation of thermolysis of adamantyl-substituted organosilicon peroxides

The kinetics and mechanism of thermal decomposition of adamantyl-containing organosilicon peroxides in a solution inn-nonane were studied. The relationship between the structure of the peroxide and the rate and mechanism of thermolysis was established. The effect of the peroxide structure on the electronic characteristics of the peroxide bond was studied by the MNDO method. The heterolytic rearrangement occurring during the decomposition of peroxides was analyzed. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya No. 7, pp. 1317–1320, July, 1998.     

Determination of Metals in Fruits of Cucurbitaceae Species from South Korea,to Characterize Potential Effects on Human Health

Recent research studies have confirmed that the dietary intake of vegetables and fruits has a positive and profound impact on human health, performance, and disease. This research was designed to determine the concentrations of essential trace elements; cobalt (Co), chromium (Cr), copper (Cu), manganese (Mn), selenium (Se), vanadium (V), and zinc (Zn), toxic metals; cadmium (Cd), mercury (Hg), and lead (Pb); and a metalloid; arsenic (As) in fruits of seven species of Cucurbitaceae family including gourd, zucchini, pumpkin, sweet pumpkin, melon, watermelon, and oriental melon commonly consumed in South Korea. The concentrations of As, Cd, Co, Cr, Cu, Pb, Se, and Zn were determined using inductively coupled plasma mass spectrometry, and Hg by a mercury analyzer. To analyze the samples after microwave digestion for the validation of analytical techniques, satisfactory values of all quality parameters of linearity, detection limits, precision, accuracy, and recovery experiments were obtained in all cases. On the whole, all analyzed elements were found in accordance to the published literature around the world and well within the critical recommended standards by CODEX and Ministry of Food and Drug Safety, Korea. The estimated daily intake values, and hazard quotients and indices of the analyzed samples were all below the World Health Organization, Joint Food and Agriculture Organization/World Health Organization Expert Committee on Food Additives, and European Food Safety Authority limits.     

Micropatterning of proteins on ion beam‐induced poly(acrylic acid)‐grafted polyethylene film

Micropatterns of proteins were created by using patterned ion beam irradiation onto a polyethylene film and graft polymerization of acrylic acid. Acrylic acid was selectively graft polymerized on the irradiated regions. The results of the grafting study revealed that the optimum fluence to achieve the maximum grafting degree was 1 × 10¹⁵ ions/cm². Biotin was covalently immobilized on the grafted regions of the polyethylene film. Protein patterning was achieved through specific binding of biotin and streptavidin. The resolved protein patterns with the maximum fluorescence intensity were achieved on the poly(acrylic acid) (PAA)‐grafted polyethylene films prepared at the fluence of 1 × 10¹⁵ ions/cm². This method can be used for patterning of various biomolecules and for further biological applications. Copyright © 2010 John Wiley & Sons, Ltd.