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Novel molecularly imprinted polymeric nanospheres (MIPNs) were prepared combining both molecular imprinting and block copolymer self-assembly techniques. A diblock copolymer, poly[(tert-butyl methacrylate)-block-(2-hydroxylethyl methacrylate)] (PtBMA-b-PHEMA), was synthesized by living free radical polymerization. Further postfunctionalization introduced 2-acrylamido-6-carboxylbutylamidopyridine (ACAP) and cross-linkable methacryloyl side groups into the polymer. The resulting final diblock copolymer was able to interact with 1-alkyluracil or 1-alkylthymine derivatives in chloroform to form triple hydrogen bonding complexes. Addition of cyclohexane, a block selective solvent, to this solution produced spherical micelles with uracil or thymine compounds embedded within the core, which was cross-linked in the solution in order to lock-in the MIP structures. The cross-linking has also made the core-shell structure of the micelle particles sufficiently stable for the subsequent extraction and rebinding process, which was confirmed by TEM and FTIR study. After cross-linking and extraction, these uniform nanospheres showed good dispersibility in organic solvents and demonstrated specific rebinding preponderancies to the target molecules of nucleotide bases, uracil, or thymine compounds. Comparing with the traditional bulk MIPs, these MIPNs demonstrated higher rebinding capacities and comparable size and shape selectivity.

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Pb- and La-doped (Bi,Pb)2(Ba,La)2Co2Oy ceramics were prepared by solid-state reaction method and the effect of element doping on the thermoelectric characteristics was investigated. Pb and La doping increased the electrical conductivity and transformed the conduction from a metal-like behavior to a semiconducting one. Different from the undoped samples, the values of Seebeck coefficients decreased with the increase of the temperature in the Pb- and La-doped samples. Pb doping in Bi2Ba2Co2Oy system improved the thermoelectric characteristics at high temperature and Pb/La co-doping improved thermoelectric characteristics at low temperature.

The superconducting nominal "non-doped" La1.85Y0.15CuO4 (LYCO) thin films are successfully prepared by dc magnetron-sputtering and in situ post-annealing in vacuum. The best TC0 more than 13K is achieved in the optimal LYCO films with highly pure c-axis oriented T'-type structure. In the normal state, the quasi-quadratic temperature dependence of resistivity, the negative Hall coefficient and effect of oxygen content in the films are quite similar to the typical Ce-doped n-type cuprates, suggesting that T'-LYCO shows the electron-doping nature like known n-type cuprates, and is not a band superconductor as proposed previously. The charge carriers are considered to be induced by oxygen deficiency.

Resistivity under magnetic field, thermopower and Hall coefficient are systematically studied for the [Bi2Ba1.3K0.6Co0.1O4]RS[CoO2]1.97 single crystal. In-plane resistivity (ρab(T)) shows metallic behavior down to 2 K with a T2 dependence below 30 K, while out-of-plane resistivity (ρc(T)) shows metallic behavior at high temperature and a thermal activation semiconducting behavior below about 12 K. The striking feature is that magnetic field induces a ln(1/T) diverging behavior in both ρab and ρc(T) at low temperature. The positive magnetoresistance (MR) could be well fitted by the formula based on multiband electronic structure. The ln(1/T) diverging behavior in ρab and ρc(T) could arise from the magnetic-field-induced 2D weak localization or spin density wave.

Bi2Sr2Co2-xCuxOy (x=0.0, 0.2, 0.4) samples were prepared by solid-state reaction method and the effect of Cu substitution on the high-temperature thermoelectric properties was investigated. The presence of Cu element improved the grain size and the thermoelectric properties increased owing to the simultaneous increase of conductivity and Seebeck coefficients. The optimal thermoelectric performance was obtained in x=0.2 sample and the power factor was two times as large as that in Cu-free sample at 923K.

The isothermal magnetoresistance (MR) with magnetic field (H) parallel to and perpendicular to ab plane is systematically studied on the single crystal Na0.52CoO2 with charge ordering at ∼ 50 K and an in-plane ferromagnetism below 25 K. The isothermal MR behavior with H ab plane and H ⊥ ab plane is quite different. When H ab plane, the MR is always negative and the inplane ferromagnetic behavior is enhanced. While the MR with H ⊥ ab plane changes from negative to positive with decreasing temperature or increasing H, and the in-plane ferromagnetic behavior is suppressed. A striking feature is that the MR with H ⊥ ab plane shows a hysteresis behavior below 25 K, which is absent for the case of H ab plane. These results provide strong evidence for a spin-flop transition of small moments of Co 3.5−δ sites induced by H ⊥ ab plane, leading to a metamagnetic transition for small moments of Co 3.5−δ sites. These complex magnetism suggests an unconventional superconductivity in NaxCoO2 system because the NaxCoO2 around x=0.5 is considered to be the parent compound of superconductivity.