A novel core-shell structured composite, titania (TiO2) coated Mn-Zn ferrite nanoparticle, was prepared byhydrolysis of titanium (Ⅳ) chloride (TiCl4) in the presence of Mn-Zn ferrite nanoparticles synthesized with stearic acid gel method. The obtained samples were characterized by energy dispersive X-ray spectroscopy (SEM-EDS), X-ray diffraction (XRD) and transmission electron microscopy (TEM). Results show that spinel structural Mn-Zn ferrite nanoparticles (6 nm average diameter) or their aggregates are coated by TiO2 nanoshell with anatase structure for annealed sample. The magnetic measurements were carried out on a vibrating sample magnetometer (VSM), and the measurement results indicate the reduction of the magnetization of the TiO2 coated Mn-Zn ferrite nanoparticles compared with the uncoated ferrite nanoparticles. High coercivity also shows that the prepared uncoated and coated ferrite nanoparticles are not superparamagnetic.

An alternative activation method was developed via binding electroless catalysts onto silicon substrates with 3-aminopropyltriethoxysilane (APTS) self-assembled monolayers (SAMs). Atomic force microscopy, Auger electron spectroscopy and X-ray photoelectron spectroscopy were used to characterize the laden of tin-free Pd(Ⅱ)-based nanoparticles on silicon surfaces. The results indicate that the formation of coordination bonds between Pd ions and nitrogen atoms of APTS SAMs serves the important binding mechanism. Electroless copper deposition was successfully initiated by the catalyzed substrates and high quality Cu deposition was obtained. Owing to the chemically bound catalyst, this approach has advantages over the conventional Sn-Pd combined activation process, including reduced steps and improved longevity of initiator and enhanced adhesion of the deposition to the substrates.

The specific absorption rate (SAR) values of aqueous suspensions of magnetite particles with different diameters varying from 7.5 to 416nm were investigated by measuring the time-dependent temperature curves in an external alternating magnetic field (80kHz, 32.5kA/m). Results indicate that the SAR values of magnetite particles are strongly size dependent. For magnetite particles larger than 46nm, the SAR values increase as the particle size decreases where hysteresis loss is the main contribution mechanism. For magnetite particles of 7.5 and 13nm which are superparamagnetic, hysteresis loss decreases to zero and, instead, relaxation losses (Neel loss and Brownian rotation loss) dominate, but Brown and Neel relaxation losses of the two samples are all relatively small in the applied frequency of 80kHz.

The one-dimensional coagulation of gold colloidal particles dispersed in organic solvent was investigated with transmission electron microscopy. The results indicate that the length of the nanoparticle chains can be modulated by changing the concentration of the solutions. It was also demonstrated that thewetting of the substrate surface hardly influenced themorphology of the nanoparticle chains, which revealed that the particle chains had been formed in the solution before deposition on the substrates. A general theoretical interpretation is provided to explain the linear coagulation of gold colloidal particles, on the basis of the asymmetrical distribution of the charges absorbed on the surface of the gold colloidal particles, as well as the action of the solvent molecules.

Magnetite nanoparticles were prepared by coprecipitation of Fe2+ and Fe3+ with NH4OH, and then, amino silane was coated onto the surface of the magnetite nanoparticles. Transmission electronic microscopy shows the average size of 7.5nm in diameter. Powder X-ray diffraction and electronic diffraction measurements show the spinel structure for the magnetite nanoparticles. FT-IR spectra indicate that amino silane molecules have been bound onto the surface of the magnetite nanoparticles by Fe-O-Si chemical bonds. Energy dispersive X-ray spectroscopy (SEM-/EDS) indicates atomic ratio of 96.75:3.25 for Fe:Si, implying a nearly monolayer coating of amino silane on the magnetite particle surface according to a rough calculation. By an enzyme-linked assay, it was proved that the amino silane-coated magnetite nanoparticles could significantly improve the protein immobilization.