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Pyrex glasses with different ZnS: Mn2+ contents were prepared by melting method. It has been found that Mn ion may occupy two sites: (Mn2+)sub, and (Mn2+)int from photoluminescene (PL) and photoluminescence excitation (PLE) spectra. The results were confirmed by the further electron panmagnetic resonance (EPR) experiments and the three types of states (Mn2+)sub, (Mn2+)int,and Mn clusters were identified. It was observed that theg-factor and the hyperfine structure (HFS) constant increase with the decreasing size of nanocrystallite. This may result from hybridization of sp3 electron states of ZnS and 3d5 electron states of Mn by the effects of quantum confinement and the surface states.

ZnS:Mn2+ nanocrystals embedded in Pyrex glass matrices have been studied systematically. It has been found by photoluminescence (PL) and excitation (PLE) spectra that doped Mn impurities can be classified as two types, occupying substitutional sites (Mn2+)sub and interstitial sites (Mn2+)int. EPR experiments support this conclusion. In addition, Mn clusters were also identified from the EPR spectra. We observed the increases in the g1 factors and hyperfine structure (HFS) constants with decreasing diameters of the nanocrystals. These increases are due to the hybridization between s-p states of ZnS and d states of the Mn ions by quantum confinement effects and the surface states.

Electron spin resonance (ESR) is a sensitive tool to detect the electron-transfer processes in some specified systems from the change of the ESR signals. In this paper, the interaction between poly(N,N-dimethylaniline) (PDMA) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) was investigated by ESR spectra based on the stability of their radicals in ethanol. It is shown that an electron-transfer process occurs from nitrogen atoms of PDMA molecules to those of DPPH molecules which makes PDMA form more stable radical cations and eliminates the radicals on DPPH.

Reported here is the study on various types of ESR spectra of the propagating radical in polystyrene. Spectrum simulation, analysis of the hyperfine coupling constant, and calculations of the conformation energy show that the propagating radical of styrene has two stable inner-rotation conformations R1 and R2. R1 corresponds to a 6-line spectrum which, in some special conditions, can appear as a 4-line or 3-line spectrum. R2 corresponds to an 8-line spectrum which, in some special conditions, appear as a 6-line spectrum. All the ESR spectra observed in the polymerization process can be regarded as the superposition of some of these spectra. The concentration ratio of R1 to R2 is affected by rotational interchange between R1 and R2, as well as the propagating reaction

The ammonium sulfate-iron oxide system treated at different temperatures has been characterized by ESR, IR and Mossbauer spectroscopy. Results show that during the heat treatment some interaction between ammonium sulfate and iron oxide takes place. As a result of this interaction a surface sulfato complex of iron is formed. The complex is involved in the sites responsible for activity for acid catalytic esterification. Above 573 K, the sulfato complex will gradually decompose with a further increase in temperature. A new structure scheme of the sulfato complex is proposed.

A set of L-band electron spin resonance imaging (ESRI) equipment suitable for biological species was developed and an ESRI experiment model for viable skin samples was established. The mechanic process of nitroxide free radical TEMPO (2,2, 6, 6-tetramethyl-1-piperidinyloxy) penetrating through skin sample and the spin density distribution of TEMPO after it interacted with skin sample were detected by the developed ESRI method. Skin samples were extracted from mice back. The experimental samples were prepared by cutting the skin pieces into square shape of 2 x 2 cm2 and then the samples were divided into three groups by treating them with three different methods: Method A, simple treatment by simply cutting the hair; method B, 8% Na2S depilation treatment for 10 min; method C, 8% Na2S depilation and then 5% pancreatic digestion treatment for 2 hours. The liposoluble solvent DMSO (dimethyl sulfoxide) and distilled water were used as two kinds of solvent for the TEMPO liquor. The results indicated that the skin-penetration properties of TEMPO were significantly different among samples treated with different methods and the surface cornifin of skin offered remarkable resistance to TEMPO. The TEMPO liquor of water could hardly penetrate through skins, whereas about 20%-30% of the original TEMPO compounds that solved in liposoluble solvent DMSO could penetrate through the skin sample treated with method C after 16 hours of interaction. Furthermore, the penetration rate of TEMPO through the skin tissue was a strong time dependent process. The preliminary application results suggested that ESRI technique could provide an effective and applicable method for dynamically researching skin-penetration properties of some special kinds of materials such as paramagnetic compounds.