Yu Lv

Twin structures of epitaxial SnO2 films grown on a-cut sapphire by metalorganic chemical vapor deposition

SnO2 films have been grown on a-cut (112¯0) sapphire substrates by metalorganic chemical vapor deposition. X-ray diffraction and transmission electron microscopy were employed to characterize the epitaxial relationship and film structure. The films were (101) oriented with pure rutile structure. The in-plane relationship was determined to be SnO2 [010]//Al2O3 [0001] and SnO2 [101¯]//Al2O3 [11¯00]. There are three kinds of {101} twins in the SnO2 film. These twins caused high density of planar defects in the film and slight misorientation of the growth plane. The film/substrate interface was flat, while the film surface was rough with steps and inclinations.

Structural and Optical Properties of α-Ga2O3 Films Deposited on Sapphire (10‾10) and (01‾12) Substrate by MOCVD

Ga2O3 thin films were grown on sapphire m-cut () and r-cut () orientations substrates at different temperatures by metal-organic chemical vapor deposition. Structural and optical properties of the Ga2O3 films were investigated including the influence by annealing for the obtained films. The Ga2O3 films on sapphire () and () substrate are α-Ga2O3. The crystallization of the films decreases after annealed at 900 °C. The average transmittance of the samples in the visible wavelength range was over 86% and the optical band gap Eg was about 4.755.15 eV. The Eg of the samples increases after annealing at 900 °C.

The Process Performance Test Study of Pure Chitin Fiber Spunlace Nonwoven

In this paper, the pure chitin fiber spunlace nonwoven was made from raw material chitin 100 fiber, and its processing technique was improved from traditional one. The performance comparison tests under different processes and traditional process were conducted, test results showed that pure chitin fiber spunlace nonwoven made under improved process studied in this paper had better mechanical properties and fabric quality.

Surface and Porous Characteristics of Spray Dried Hydroxyapatite Microspheres

Surface and porous characteristics of spray dried hydroxyapatite microspheres were studied by surface area and pore size analyzer, field-emission scanning electron microscope, Fourier transform infrared spectroscope, etc. The results indicated dehydration did not happened for those samples calcined at 1000°C, and the intensity of OH- absorption bands increased. Hydroxyapatite microspheres were composed of near-spherical crystals with the diameter of 20-50nm. Besides, it was interesting to find that hydroxyapatite crystals formed small aggregate firstly during drying, and then the small aggregate united together and formed particles with spherical structure.

Effect of Crystals Size, Surface Area and Pore Size of Hydroxyapatite Microspheres on the Loading Ability of Bovine Serum Albumin

Effect of crystals size, surface area, pore size and porosity of hydroxyapatite microspheres on the loading ability of bovine serum albumin was studied in this paper. The surface morphology, specific surface area and porosity of hydroxyapatite microspheres were characterized by scanning electron microscope, specific surface area and pore size analyzer, respectively. The concentration of BSA in aqueous solutions both before and after adsorption was determined by ultraviolet-visible spectrophotometer. The results indicated that the adsorption behavior of bovine serum albumin appeared to obey the Langmuir-type isotherm model. Fast adsorption appeared at the beginning, and then decreased gradually. Hydroxyapatite microspheres calcined at 600°C had the maximum capacity, and those calcined at 800°C showed lower adsorption ability. The loading ability of hydroxyapatite microspheres depended on its crystal size, specific surface area, pore size and porosity, etc.