Papers by Keyword: Film

Abstract: Lu₂O₃-doped bismuth titanate (Bi_4-xLu_xTi₃O₁₂: BLT) and pure Bi₄Ti₃O₁₂ (BIT) thin films with random orientation were fabricated on Pt/Ti/SiO₂/Si substrates by rf magnetron sputtering technique. These samples had polycrystalline Bi-layered perovskite structure without preferred orientation, and consisted of well developed rod-like grains with random orientation. Lu-doping into BIT caused a large shift of the Curie temperature ( T_C ) from 675 °C to lower temperature and a improvement in dielectric property. The experimental results indicated that Lu doping into BIT also result in a remarkable improvement in ferroelectric property. The P_r and the E_c values of the BLT film with x=0.75 were 28 μC/cm² and 65 kV/cm, respectively.

Abstract: Ho-doped bismuth titanate (Bi_4-xHo_xTi₃O₁₂: BHT) and pure Bi₄Ti₃O₁₂ (BIT) thin films with random orientation were fabricated on Pt/Ti/SiO2/Si substrates by rf magnetron sputtering technique. These samples had polycrystalline Bi-layered perovskite structure without preferred orientation, and consisted of well developed rod-like grains with random orientation. For the samples with x=0.25, 1.0, and 1.25, the current-voltage characteristics exhibited negative differential resistance behaviors and their P-V hysteresis loops were characterized by large leakage current, whereas for the samples with x=0.5 and 0.75, the current-voltage characteristics showed simple ohmic behaviors and their P-E hysteresis loops were the saturated and undistorted hysteresis loops. The remanent polarization ( Pr ) and coercive field (Ec) of the BHT Fims with x=0.75 were above 30μC/cm2 and 60KV/cm , respectively.

Abstract: The cellulose film was prepared from regenerated cellulose fiber residue by dissolving the cellulose in sodium hydroxide solution at low temperature (-15 °C). The properties of the prepared film were investigated by tensile testing, Scanning Electron Microscope (SEM), X-ray Diffractometer (XRD) and also swelling ratio. Curcumin was added into the film with three different concentrations. The color strength of the curcumin-added film was evaluated and the color change of this film in different pH was also reported.

Abstract: ZrN films were prepared by magnetron sputtering on die steel substrates. The objective of this study was to investigate the effect of nitrogen flow rate on the microstructure ,morphology, nanohardness properties determined by X-ray diffraction, field-emission scanning electron microscope, nanoindentation, and pin-on-disk, respectively. The XRD shows that ZrN has (111) and (200) preferred orientation under lower nitrogen flow rates. The surface of coatings revealed smaller grains and uniform dense under lower nitrogen flow rates. With increasing the nitrogen flow rates, this result showed ZrN films lead to poor mechanical properties and hardness values. However, films consisted of up high ernitrogen flow rate had much lower friction coefficient.

Abstract: ndium tin oxide (ITO) and indium tin tantalum oxide (ITTO) films were deposited on glass substrates at room temperature by magnetron sputtering. Properties of the ITO and ITTO films showed a dependence on annealing treatment. ITTO film deposited at room temperature showed the enhancement in (400) orientation and the increasing in grain size. With an increase in annealing temperature, the intensity of XRD peak increased and the grain size showed an evident increasing. The reflection edge in near-IR range and the absorption edge in near-UV range shifted due to the variation in carrier concentration. Ta-doping improved the carrier concentration of the films and widened the corresponding optical band gap. The variations in optical band gap were due to Burstein-Moss effect. The higher value of figure of merit of ITTO films was observed. The tantalum-doped ITO films could find extensive application in some devices.

Abstract: Waterborne UV curable polyurethane emulision containing C=C bond was prepared with self-emulsification. 3% water soluble photoinitiator was added to the polyurethane emulision, and polyurethane films was prepared by ultraviolet irradiation. The structure of the polyurethane emulision and films were confirmed by means of Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM) and thermogravimetric analysis. FTIR test result shows that cross linking and solidification reaction of C=C double bond happened after UV irradiation. When C=C content increases, the particle size of polyurethane emulision increases, crosslinking degree of films increases, water resistance and heat resistance have both been improved. When C=C content is 8.51%, gel content is more than 90% and the lowest water absorption can be 12.5%.

Abstract: Cellulose, the most abundant materials in the plant resources, has been paid more attention. The updated technology of cellulose dissolution and the application of cellulose functional material were reviewed, especially the compounds of cellulose/inorganic (or organic) substance. The review is of benefit to the research in familiarizing with cellulose dissolution and its application.

Abstract: A new microwave imidization method was used to prepare polyimide (PI) film in this paper. FT-IR spectrum and ultraviolet absorption spectrum are measured to study the chemical structure and optical properties of this film. The FT-IR spectrum shows that the characteristic imide groups are observed at the peaks of 727.18 cm^-1, 1379.67 cm^-1 and 1776.51 cm^-1, which confirmed imide formation. The ultraviolet absorption spectrum reveals that optical band gap of the PI is about 2.64 eV.

Abstract: In this paper, a series of polyimide (PI) films with different monomer mole ratios between PMDA and ODA (0.980: 1, 0.990: 1, 1.000: 1, 1.010: 1 and 1.015: 1) were prepared in order to investigate the effect of molecular weight on optical properties. Inherent viscosity values were taken as a measure of the molecular weight. The fluorescence properties of the PI films have been measured. The fluorescence spectra show that three obvious emission peaks can be observed at 583 nm (1.00 dL/g), 594 nm (1.42 dL/g) and 603 nm (1.57 dL/g) respectively. In addition, emission peaks show red-shift with the increase of molecular weight, which can attribute to the decease of orbital energy caused by conjugated effect.

Abstract: In the present study, glycerol was used as plasticizer to prepare silk fibroin (SF)/pearl powder (PP) blend films. The effects of amount of glycerol on structure and properties of the films were investigated. The surface morphology was observed with scanning electron microscopy. The structure of films was investigated by X-ray diffraction and thermal analysis. The mechanical properties of the films were measured on a universal testing machine, and the dissolution rate of SF was examined by ultraviolet spectroscopy. The results showed that surface of pure SF films was smooth, but the surface of films containingPP was uneven, particles of PP dispersed in the films. The structure of the film without glycerol was mainly amorphous structure. The structure of the SF in the film was mainly silk I and silk II when the proportion of glycerol added was in the range of 10%- 20%, while the main structure of the SF in the films was silk I when the proportion of glycerol was more than 20%. The dissolution rate of SF in films without glycerol is rather great, while the dissolution rate had a significant decrease by adding glycerol. There was no significant difference in dissolution rates of SF which were all below 1.3% when the proportion of glycerol is 10-40%. The films without glycerol had very small elongation at break. The elongation at break of SF films increased with the increased amount of glycerol. Compared to films without glycerol, there was a significant difference when the proportion of glycerol was greater than 10%. The tensile strength of the films dropped significantly with the increase of glycerol, but there was no significant difference when the proportion of glycerol was greater than 30%. Therefore, the advisable addition percentage of glycerol is 20%.