The morphological structures of polystyrene-block-poly(ethylene oxide), PS-b-PEO, have been investigated under humidity controlled environments during film formation. Well-defined cylindrical microdomains oriented normal to the surface were induced by the high humidity during spin coating. Effects of the relative humidity (RH) on such ordered structures have also been studied. The results show that, the orientation and the ordering of the copolymer structures are very sensitive to the humidity of the environment during the film formation. Such ordered structure is stable at a variety of the RHs, and the phase contrast between the cylindrical PEO domains and the PS matrix domains can be significantly enhanced by the elevated RH. After the incorporation of the nanoparticles, however, the morphological structures of the PS-b-PEO are modified.

There is tremendous interest in using low loadings of multiwalled carbon nanotubes (MWNTs) to enhance the multifunctional properties of polymers, with functionalization often pursued to increase the dispersion and effective reinforcement of MWNTs within the polymer. In our interest to understand the effect of MWNT functionalization on Poly (butylene terephthalate) (PBT) crystallization kinetics, morphology and mechanical properties, nanocomposites were fabricated with both as-received and carboxyl group (-COOH) functionalized MWNTs. Initial results indicate as-received and functionalized nanotubes alter the crystallization temperature and crystal size for quiescent samples. In addition, isothermal crystallization studies using an Advanced Rheometric Expansion System (ARES) show that the addition of MWNTs increases the rate of PBT crystallization. However, functionalization was found to decrease the rate of nanocomposite crystallization as compared to nanocomposites samples prepared using pristine MWNTs, suggesting that nanotube functionalization weakens the nucleation effect observed in the nanocomposite samples. These results suggest that semicrystalline polymer nanocomposite crystallization kinetics and morphology can be significantly influenced by nanoparticle functionalization and chemistry. Further study of how these changes impact the rheological and multifunctional properties of semicrystalline nanocomposite systems are ongoing.

Three sulfur-containing styrene monomers with different leaving groups, 4-vinylphenyl ethanethioate, 1,2-bis(4-vinylphenyl)disulfane, and butyl(4-vinylphenyl)sulfane, were synthesized through nucleophilic substitution/addition reactions and purified through column chromatography. In aqueous solution, these monomers could bind to the surface of gold nanoparticles and form self-assembled monolayers (SAMs). SAMs were analyzed by Raman spectroscopy and showed SERS activity with enhancement factors of more than 105. In addition, SAMs were also formed on the surface of gold/silver nano-island films. The bulk Raman and SERS spectra of monomers on different gold nanostructured materials were very similar. The enhancement factors and the formation of SAMs depended on monomer structure and fabrication method. Also depending on the deposition conditions, laser induced polymerization of the mercaptostyrene monomers SAMs was observed.

New copper rich alloys with elemental additions of transition metals and group IIIA and IVA elements have been prepared by casting and rapid solidification. The prepared alloys show very interesting microstructures; a thick surface layer with nanocrystalline eutectic like structure, while in the bulk the microstructure is coarser lamellar or dendritic. Their microhardness was found to be exceptionally high for Cu rich alloys, reaching values of 450-550HV. Furthermore, the microhardness of the surface layer is higher than that in the bulk, indicating that these alloys can be considered for a variety of applications including tribological and structural.

Magnetic nanophases nucleated within horse spleen apoferritin nanotemplates under in vivo physiological conditions and in vitro reconstitution were characterized by Mössbauer spectroscopy in lyophilized form. Mössbauer spectra recorded at 80 K indicate that for the in vivo produced ferritin the presence of phosphates within the ferritin biomineral core results in larger quadrupole splittings, both at interior and surface sites, 0.62 mm/s and 1.06 mm/s, respectively, as compared to 0.56 mm/s and 0.75 mm/s for the reconstituted ferritin. Data collected at lower temperatures give blocking temperatures of 55 and 40 K for in vitro and in vivo samples. At 4.2 K, both samples give similar saturation hyperfine field values for the interior (495 kOe) and surface (450 kOe) iron sites. The temperature dependence of the reduced hyperfine magnetic fields at the interior iron sites is consistent with the collective magnetic excitations model, due to the particle's magnetization precession about the anisotropy axis. In contrast, a marked decrease in the reduced hyperfine field at surface sites with increasing temperature indicates a more complex spin excitation energy landscape at the surface.

Nanophosphors correspond to nanostructured inorganic insulator materials that emit light under particle or electromagnetic radiation excitation. In this work we investigate the structure and luminescent properties of Ce-doped Lu2SiO5 (LSO) nanophosphors prepared by solution combustion synthesis with the Ce content 0.1 to 12 at. %. Samples were characterized by transmission electron microscopy (TEM), line scan electron energy-loss spectroscopy (EELS), x-ray diffraction (XRD), and electron paramagnetic resonance (EPR) spectroscopy. Photoluminescence excitation and emission spectra are composed of two major bands centered at 360 and 430 nm, respectively. These results reveal a red-shift and enhanced Stokes shift for the nanophosphors when compared to bulk. Ce content was also found to affect photoluminescence emission intensity and fluorescent lifetime. The nanophosphor concentration quenching curve presents a broad maximum centered at 1 at.%. Lifetime measurements show a continuous decrease from 34 to 21 ns as Ce content is increased.

Thermoporometry was employed to monitor the mesopore evolution in wet, drying and heat-treatment stages of monolithic macro/mesoporous silica with SBA-15 like structure. Direct comparison of mesopores in wet state was only possible with the samples extracted with sulfuric acid. In good agreement with the preceding study, the sulfuric acid not only removed the surfactant but also modified the silica gel network into that with reduced amount of micropores and increased stability against the drying stress. Thermoporometry revealed that the structural evolution takes place completely in the wet condition, which accompanies a decrease in the thickness of non-freezable water.