The synthesis of Sialon ecomaterials drived from solid waste of containing silican and aluminum provides a new method to utilize the solid waste high-technically, and a new green process for low-cost preparation of Sialon material. Blast furnace slag, coal gangue, fly ashes, sediment, tailings, etc, are briefly introduced. It could be designed to synthesize a-Sialon, β-Sialon, O′-Sialon, etc, composite materials based on the chemical composition of these solid waste. The present development and prospects of Sialon ecomaterials drived from solid waste are reviewed and predicted.

High quality NaYF₄: Yb³⁺, Er³⁺ / SiO₂ core-shell structures with different sizes were prepared by coating silica shell onto 100 nm size hydrophilic and 20 nm size hydrophobic up-conversion nano particles through hydrolysis of TEOS using ethanol and cyclohexane as main solvent respectively. Effects of reaction time and precursor concentration on the synthesis of core-shell structure were studied. The results show that the core shell structure could be easily dispersed in polar solvent with uniform silica coating on hydrophobic and hydrophilic, big and small NaYF₄: Yb³⁺, Er³⁺ nano particles. Up-conversion spectrum characterizations of the nano structure were conducted under room temperature. There were no changes of the emission intensity and emission center for particles before or after silica coating. Green light around 550 nm and red light around 670 nm could be observed with 980 nm laser excitation.

Ethyl orange (EO^-) and 4-aminoazobenzene-4-sulfonic anion(4A^-) were intercalated into the layered double hydroxide (LDH), [Mg _0.66 Al _0.34 (OH) ₂] (CO₃) _0.17·0.67H₂O or exchanged on the external surface of the host by the method of ion-exchange procedures. The obtained compounds were characterized by X-ray diffraction, infrared and thermogravimetry techniques. The photophysical properties of the obtained compounds were studied by UV-Vis absorption and fluorescence spectroscope. The guest molecular sizes and structures were investigated utilizing an ab initio (HF/6-31G) method by G03w. These anions were arranged in the interlayer space as a monolayer of species with the main axis perpendicular to the layer plane. These results indicated that the fluorescence of intercalated sample of Mg-Al-EO-LDH increased greatly due to a more rigid and constrained environment of the host. However, the fluorescence of intercalated sample of Mg-Al-4A-LDH decreased due to the concentration quenching. Compared with those observed in the pure microcrystalline EO and 4A, the fluorescence intensity of the samples containing only surface-exchanged EO or 4A reduced because the charge transfer between EO or 4A molecules was enhanced. It suggests that the photophysical properties of guests can be changed by the guest-host interaction or guest-guest interaction.

WC/TiO₂ precursor was fabricated by ball-milling a mixture of titania and ammonium metatungstate, then WC/TiO₂ nanocomposites were obtained after carbonization under CH₄/H₂ atmosphere at 900℃. The as-prepared samples were characterized by XRD, SEM, HRTEM, STEM and EDX, and their electrocatalytic activities were measured by microelectrode approach with three electrodes in basic solution. The results show that the crystal phase of tungsten species in the samples changes according to the following order: WO₃ →WO₂→W→W₂C or WC in the carbonization process. The tungsten carbide nanoparticles, which are decorated on the surface of titania, generally have a diameter less than 20 nm. The sample carbonized for 6h mainly have two catalytic active phases of very small size, namely WC and W₂C, which are uniformly dispersed on the surface of TiO₂ particles. The electrocatalytic measurement shows the sample is most active.

TiO₂ nanotube arrays were fabricated by anodization of the Ti foils in aqueous phosphoric acid and sodium fluoride solutions at 20V under ultrasonic field. The resulting nanotubes had the similar tube diameter (100nm) and the similar wall thickness (15-20nm). The tube lengths of the nanotubes anodized for 1h, 3h and 7h were 600, 1000, 900nm, respectively. Employing a 500W high-pressure mercury lamp as the light source, the open-circuit potential and the photocurrent, the flat band potential and the charge carrier densities of TiO₂ nanotubes arrays annealed at  500℃ were analyzed by the open-circuit potential curves, the voltammetry curves and Mott-Schottky plots. The results showed that the photocurrent, the flat band potential, the charge carrier densities of the resultant samples reduced with the increase of oxidation time. The decrease of photocurrent density was more than that of the open-circuit potential. It can be ascribed to partial fracture and detachment of the nanotubes and the growth of the barrier layer with the inrease of anodization time, which led to the augment of the charge transfer resistance and the decrease of the charge carrier densities.

Microstructural and electromagnetic properties of FeCoB-SiO₂ films prepared on PET substrates by radio- frequency sputtering were investigated. The as-deposited FeCoB-SiO₂ films are found to be amorphous with an electrical resistivity of 1755.73 μΩ·cm and a saturation magnetization of 0.7 T. Because of the existence of nonmagnetic matrix resistance to magnetic wall displacement, those FeCoB-SiO₂ films have a substantially higher coercivity of 13130.205 A/m over that of traditional amorphous magnetic films. Complex permeability μ was measured by a microwave network analyzer using the coaxial transmission technique, and double resonance peaks in microwave magnetic permeability were observed in the frequency range of 3.8-5 GHz. This is beneficial for the films to be used as a micro absorber at large bandwidths, resulting in μ'>2.5 in the frequency range of 500 MHz-12 GHz and μ''>6 for 3.6-8 GHz. The experimental results demonstrate that the FeCoB-SiO2 films deposited on flexible substrates have good potential for high frequency applications.

Magnetoelectric nano-composites xCoAl_0.2Fe_1.8O₄+(1-x)BaTiO₃ were prepared by Sol-Gel method. The presence of perovskite BaTiO₃ and spinel CoAl_0.2Fe_1.8O₄ in the sintered composites was proved by XRD patterns. SEM images showed that particle size of composite was uniform. The magnetic property of composites was tested by magnetic hysteresis loops and dispersion of dielectric constant was explained with Koops two layer inhomogeneous dielectric structure model. The maximum value of magnetoelectric voltage coefficient viz. 1.075×10^-2V/A was obtained for 0.20CoAl_0.2Fe_1.8O₄+0.80BaTiO₃ composite at the DC magnetic bias field of 1.35×10⁵A/m.

Hydrothermal-solvothermal method was used to synthesize (K, Na)NbO₃ powders with the addition of isopropanol. The influence of mineralizer concentration, reactive materials concentration on the phase, particle size, morphology and chemical composition of the products were investigated. The obtained powders were characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) and scanning electron microscope (SEM). Then, the obtained (K, Na)NbO₃ powders were used to fabricate lead-free piezoelectric ceramics using the traditional sintering process, and its piezoelectric property was also studied. The results indicate that the pure (K, Na)NbO₃ powders with perovskite structure were successfully synthesized by hydrothermal-solvothermal method with the mineralizer solution concentration of 2mol/L and the addition of isopropanol. With increase of K+ content in the starting solutions, K+ content in the products also increased. The K/(K+Na) molar ratio in the products is lower than that in the staring solutions. Moreover, the specimen with the composition of K_0.22Na_0.78NbO₃ exhibites high piezoelectric constant up to d₃₃ = 120 pC/N, which is equivalent with the specimen of (K_0.5,Na_0.5)NbO₃ synthesized by traditional solid-state reaction method. Therefore, it can be forecasted that the (K_0.5,Na_0.5)NbO₃ ceramic sintered from the powders synthesized by hydrothermal-solvothermal method will acquire higher piezoelectric property.

Lead-free (K_0.5Na_0.5)_0.94-2xLi_0.06Sr_xNb_0.98Sb_0.02O₃ (KNLSN-Sr_x; x=0-0.03) piezoelectric ceramics were prepared by conventional solid-state sintering process. The sintering characteristic, the microstructure, dielectric, piezoelectric and ferroelectric properties of KNLSN-Sr_x ceramics were investigated. XRD results show that all samples exhibite a pure perovskite phase with tetragonal symmetry, indicating that the Sr²⁺ has diffused into the KNLSN lattices to form a solid solution. The grain size of KNLSN-Sr_x ceramics was increased with the increasing of Sr-doping level. The proper sintering temperature of KNLSN-Sr_x ceramics shifted to higher temperature with increasing the content of Sb. Higher d₃₃ and kp, lower tanδ and Qm were obtained as Li, Sr and Sb were added into KNN ceramics. The comprehensive good properties of doped (K_0.5Na_0.5)NbO₃ ceramics were obtained when Sr content was 2mol% (d₃₃=130pC/N, k_p=34.5%, tanδ=4.2%).

Nb-modified Bi₄Ti₃O₁₂ (BIT+xmol%Nb₂O₅) layer-structured piezoelectric ceramics were prepared by the solid state reaction method (at the pressure of about 12MPa). The quantity of grain growth along a-b plane is much more than that along c-axis with the increasing amount of Nb₂O₅. After Nb₂O₅ doping, the size of grain becomes small and unanimity. The electrical conductivity and dielectric loss are significantly reduced, while relative density, piezoelectric activity and electromechanical properties of Bi₄Ti₃O₁₂-based ceramics are improved by the modification of Nb₂O₅. The electrical conductivity of BIT+4.00mol% Nb₂O₅ (10^-13S/cm) decreases by 2 orders of magnitude compared with the undoped one. Besides, the BIT+4.00mol% Nb2O5 ceramic exhibits optimum electrical properties: relative density r=98.7%, tanδ=0.23%, d₃₃=18pC/N, Q_m=2804, k_p=8.1%, k_t=18.6%, N_p=2227Hz·m and N_t=2025Hz·m, and the d₃₃ remains 17pC/N after annealing at 600℃, which indicates that the ceramic is a potential material for high temperature applications.

Novel urchin-like boehmite (AlOOH) superstructures consisting of nanorods were successfully synthesized by a template-free hydrothermal synthetic route in an ethanol-water solution. The crystal structures and the morphologies of boehmites were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM) and selected area electron diffraction (SAED). The effects of the precursors, the volume ratio of EtOH/H₂O and reaction temperatures on the morphologies were also discussed. It is shown that the 3D urchin-like boehmite of uniform morphology and good dispersibility is prepared using AlCl₃·6H₂O as the precursor at 200℃ with the volume ratio (EtOH/H₂O) of 1:2. The diameter of the urchin-like boehmite is 6-10μm, which is consisted of nanorods with the diameter of 60-80nm. The SAED pattern reveals the polycrystalline nature of the urchin-like boehmite. The oriented attachment mechanism plays a key role on the formation of urchin-like boehmite superstructures.

In order to reduce the resistivity of Fe@Ag composite particles, the influence of heat-treatment temperature (T) on the structure, resistivity and magnetic properties of the Fe@Ag composite particles, and the shielding effectiveness (SE) of the electromagnetic shielding rubber containing the Fe@Ag composite particles were studied. The results show that with heat-treatment temperature increasing from 120℃ to 170℃, the Fe@Ag composite particles heat-treacted at 140℃ have the most compact silver-shells and the lowest volume resistivity, while the saturation magnetization almost keeps unchanged. The electromagnetic shielding rubber containing the Fe@Ag composite particles heat-treated at 140℃ has SE of -28 dB to -53 dB, which is -10 dB to -15 dB higher than that of the particles without heat-treatment. The morphology evolution and related property changes with T are reasonably explained by the interface wetting theory and crystal growth theory. Low-temperature heat-treatment provides a simple and convenient approach to obtain electromagnetic shielding fillers with high performance.

The effect of potassium aminocarboxylates on crystallization of calcium oxalate (CaOxa) was investigated in silica gel system by means of scanning electron microscopy and X-ray diffraction. These aminocarboxylates included potassium aminoacetate (KGLY), dipotassium glycoletherdiaminotetraacetate (K₂EGTA), dipotassium aminotriacetate (K₂NTA), dipotassium diethylenetriaminepenteacetate (K₂DTPA), dipotassium ethylene diamine tetraacetate (K₂EDTA) and dipotassium cyclohexanediamine tetraacetate (K₂CDTA). All these aminocarboxylates could induce the formation of calcium oxalate dihydrate (COD), inhibit the aggregation of calcium oxalate monohydrate (COM) and decrease the specific surface area of COM aggregates. The ability to induce COD formation follows the order: K₂DTPA (55wt%) > K₂EDTA ≈K₂CDTA (50wt%) > K₂NTA (43wt%) >> K₂EGTA (4wt%) > KGLY (2wt%), and the ability to inhibit COM aggregation follows the sequence: K₂DTPA>K₂NTA > K₂CDTA≈K₂EDTA > K₂EGTA > KGLY. These results are discussed in terms of their molecular structure, relative content of carboxylic groups, spatial location of carboxyl groups in aminocarboxylates, and their coordination capacity and modes with Ca²⁺ ions. It is proved that K₂NTA and K₂DTPA can be the potential drugs for preventing the formation of CaOxa stones.

The dependence of growth rate of (100) face of KDP crystal on supersaturation was measured using the laser polarization interference technique. Morphologies of both elementary steps and macrosteps were investigated by using AFM technique at a serial of supersaturation. Furthermore, the bunching process as well as the influence of supersaturation on bunching process was analyzed according to the AFM results. The results show that at the supersaturation of 1.8%, elementary steps are in priority on (100) face, whose height is 0.366 nm, equivalent to half of the unit cell. When the supersaturation is increased, elementary steps begin bunching together. At the initial bunching stage, the step height and step width are increased. With a rise of supersaturation, more elementary steps participate in the bunching process, and the velocity of the macrosteps increasease as well. At the same time, the slops of the macrosteps reach stable ultimately.

CdGeAs₂ polycrystal was synthesized by the raw materials of 99.9999% Cd, Ge and As in stoichiometric weights with proper excess of Cd and As through mechanical and temperature oscillation of melt(MTOM). An integral, crack free CdGeAs₂ single crystal with size of 15 mm×40 mm was obtained by modified vertical descending cubic technique. The CdGeAs₂ polycrystal and as-grown crystals were characterized by X-ray diffraction and infrared spectroscopy. XRD riteveld analysis indicates that the synthetic product is high-purity CdGeAs₂ polycrystal in chalcopyrite structure, the lattice constants of a and c are 0.5946nm and 1.1217nm, respectively. The as-grown crystal is integrated in structure and crystallized well. It is also found that the cleavage plane of the crystal is (101). CdGeAs₂ wafer with 1.0 mm thickness is transparent in range of 589-4250cm^-1, and the band width is calculated to be 0.67eV.

Oxidation behavior of 2D C/SiC composites modified by boron carbide self-sealing matrix was investigated at low temperature of 700℃ in wet oxygen. Oxidation tests were conducted under a creep stress of 100MPa up to 60h. Microstructural evolution of the modified composites was explored by SEM and TEM. Results show that the modified composites hold better inoxidizability than the conventional C/SiC composites, which is caused by the self-heal of matrix cracks (and the stress enlarged ones) with oxidation induced B₂O₃ and the inhibition of C oxidation. The unoxidized B-C is identified as a coagent of B₂O₃ to fulfill the healing. Healing ability of the modified matrix is preserved in 60h and is valid for longer periods of time.

Extensive research efforts have been devoted to develop a new substance which could achieve effective lubrication in a broad temperature range. Pb(ReO₄)₂, composed of the double oxides of PbO and Re₂O₇, exists in low shear strength. The anti-friction behavior of Pb(ReO₄)₂ was tested by Universal Micro-Tribotester (UMT-2M) with ball (Si₃N₄) on disc (superalloy) at elevated and declined temperature in the range of 22℃ to 600℃. Composition of debris and morphologies of worn tracks were determined by X-ray diffraction (XRD) and scanning electron microscope (SEM), and contact resistance between the worn surface and steel ball was measured by UMT. The results show that Pb(ReO₄)₂ is a superior lubricant at elevated and declined temperatures, and the friction coefficient is much lower than that without lubricant. The superior lubricating properties should be attributed to the formation of an anti-frictional surface film. And higher temperature could result in the formation of a more complete and durable film. For Pb(ReO₄)₂ melts at 566℃, the fused product is much easier to flow and generate a film which could separate the tribo-pairs perfectly. Subsequently, the lowest friction coefficient is gained at 600℃, and good lubrication can be maintained till to 22℃.

The oxidation-resistant Si-Al-Y co-deposition coatings on a Nb-Ti-Si based ultrahigh temperature alloy were prepared by halide activated pack cementation processes. SEM, EDS and XRD analyses were used to study the influences of the holding temperature and the content of Al in pack mixtures on the microstructural formation of the coatings. The results show that the coatings prepared with the pack mixture of 10Si-10Al-3Y-5NaF-72Al₂O₃ (wt%) at different temperatures (1050℃, 1080℃ and 1150℃, respectively) have a similar structure, consisting of a (Nb,X)Si₂(X represents Ti, Cr and Hf elements) outer layer, a (Nb, X)5Si3 mid layer, a sub-inner layer composed of (Cr,Al)₂(Nb,X) and (Nb,X)Al₃ phases, and a very thin inner layer consisting of (Nb,X)2Al phase. The microstructure of the coatings prepared at 1050℃ for 10h changes evidently with the content of Al in the pack mixtures (10Si-xAl-3Y-5NaF-(82-x)Al₂O₃ (wt%) (x=10, 15, 20, respectively)). Increasing the content of Al in the pack mixture to 15wt%, the constituent phases of the mid layer of the coating change into (Nb,X)Al₃ and (Nb,X)₅Si₃, but the constituent phases remain unchanged in the outer layer, sub-inner layer and inner layer in the coating. The main constituent phases of the outer layer of the coating prepared with the pack mixture containing 20wt% Al are (Nb,X)Si₂ and (Nb,X)₃Si₅Al₂, while the constituents phases of the other layers in this coating are the same as those in the coating prepared with the pack mixture containing 15wt% Al. The scale developed on Si-Al-Y co-deposition coating which was prepared with 10Si-15Al-3Y-5NaF-67Al₂O₃ (wt%) pack mixture at 1050℃ for 10h, upon oxidation at 1250℃ for 0.5h, is about 10μm thick, and composed of Al₂O₃, TiO₂ and SiO₂.

Combining digital image processing with finite element mesh generation, finite element models based on actual microstructures of plasma sprayed zirconia coatings were built. By employing finite element method in conjunction with Fourier’s equation, the apparent thermal conductivity of zirconia coatings affected by defects, including pores and cracks were calculated. For comparison, the coating’s thermal conductivity was measured by the laser pulse method. The difference between values of the finite element method and experimental results are told to analyze effects of defects and splat interfaces on the thermal conductivity. The results show that splat interfaces are as equally important as defects in defining the thermal conductivity of plasma sprayed coatings in the spray direction.

Cadmium sulfide(CdS) nanoparticles with efficient photocatalytic activity were synthesized using water/CTMAB/n-butyl alcohol/n-heptanes reverse micelle system. The particles exhibited various photocatalytic activities with the different ω values (ω = [Water]/[CTMAB] = 25, 35, 50), and the optimal ω value was 25. Based on the X-ray diffraction (XRD) and transmission electron microscope (TEM) analysis, CdS nanoparticles were ascribed to the cubic sphalerite and the average size of CdS particle (ω=25) was about merely 9nm. Moreover, the ω values could directly affect the particle size and electrical property of CdS nanoparticles by means of cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Under visible light (λ≥420nm) irradiation, Malachite Green (MG) was used as a probe to investigate the effect of preparation conditions on photocatalytic activity of CdS nanoparticles. It can be concluded that MG could fade out within 70min and attain the 50% mineralization after 30h under visible light irradiation, and the degradation process mainly referred to the hydroxyl radical (OH) and H₂O₂.

Micro-patterned BiFeO₃ thin films were prepared successfully on glass substrates by photolithography-self-assembly method. The characterizations of samples were carried out through XRD, SEM, AFM, XPS and EDS. The results of AFM and contact angle test show that the modification of octadecyltrichlorosilane (OTS) monomolecular layer is achieved by UV-irradiation through a photomask, generating hydrophilic silanol areas and hydrophobic self-assembled monolayer (SAM) regions. XRD and XPS indicate that the films absorbed to the glass substrates are pure rhombohedrally distorted structure BiFeO₃. In addition, SEM and EDS are employed to confirm that no continuous BiFeO₃ particles deposited on SAM regions could be easily peeled off by ultrasonication, while a uniform and clear patterned film with good adherence is site-selectively formed in the hydrophilic silanol regions.