scholarly journals Enhanced model protein adsorption of nanoparticulate hydroxyapatite thin films on silk sericin and fibroin surfaces

Author(s):  
Selçuk Özcan ◽  
Muhsin Çiftçioğlu

AbstractHydroxyapatite coated metallic implants favorably combine the required biocompatibility with the mechanical properties. As an alternative to the industrial coating method of plasma spraying with inherently potential deleterious effects, sol-gel methods have attracted much attention. In this study, the effects of intermediate silk fibroin and silk sericin layers on the protein adsorption capacity of hydroxyapatite films formed by a particulate sol-gel method were determined experimentally. The preparation of the layered silk protein/hydroxyapatite structures on glass substrates, and the effects of the underlying silk proteins on the topography of the hydroxyapatite coatings were described. The topography of the hydroxyapatite layer fabricated on the silk sericin was such that the hydroxyapatite particles were oriented forming an oriented crystalline surface. The model protein (bovine serum albumin) adsorption increased to 2.62 µg/cm2 on the latter surface as compared to 1.37 µg/cm2 of hydroxyapatite on glass without an intermediate silk sericin layer.

2017 ◽  
Vol 19 (1) ◽  
pp. 55-62 ◽  
Author(s):  
Sutapa Roy Ramanan ◽  
Ramanan Venkatesh

Hydroxyapåtite (HAP) coatings were prepared on glass substrates by sol-gel dip coating method, using a isopropanol solution of calcium nitrate and 2-butanol solution of phosphorous pentoxide as starting precursors and mixing them to get a coating solution with Ca/P ratio of 1.67. The prepared coatings were dried at 150°C and subsequently  fired at 500°C to obtain dense coatings. Multilayer coatings were prepared to increase the final thickness. For some samples, SiO2, TiO2, Al2O, and Zr02 coatings modified the interface between the glass and HAP. X-ray diffraction, scanning electron microscopy, FTIR and DTA/TG were used for characterization. All the coatings obtained at 500°C in air had only crystalline hydroxyapatite phase, characteristics FTIR signature peaks of HAP and dense and smooth morphology with the apparent presence of micropores. The cross-sectional microstructure of the coatings showed presence of smooth interface.


2020 ◽  
pp. 2050044
Author(s):  
SAHAR MORADI ◽  
HASSAN SEDGHI

Nanostructured Fe:SnO2 thin films were deposited on glass substrates through sol–gel spin coating method. Films were synthesized with different iron quantities including 0%, 4%, 8% and 12% (wt.%). The effects of Fe concentration on optical properties of films were investigated by spectroscopic ellipsometry (SE) technique. SE measured ([Formula: see text]) parameters for films in the wavelength range between 300[Formula: see text]nm to 800[Formula: see text]nm. Optical properties including the refractive index, extinction coefficient, transmittance, dielectric constants and optical conductivity were determined by fitting the SE measured ([Formula: see text]) parameters and data obtained from the optical model-based analysis. Results showed that the transmittance values increase by increment of Fe concentration from 0% to 12%. The bandgap energy ([Formula: see text] of prepared thin films was also calculated. [Formula: see text] values were between 3.44 and 3.58[Formula: see text]eV. Dispersion parameters including the high frequency dielectric constant ([Formula: see text] and the ratio of free carrier concentration to effective mass (N/m[Formula: see text] were then obtained for the prepared films.


2014 ◽  
Vol 903 ◽  
pp. 73-77
Author(s):  
Peh Ly Tat ◽  
Karim bin Deraman ◽  
Rosli Hussin ◽  
Wan Nurulhuda Wan Shamsuri ◽  
Zuhairi Ibrahim

ZnO thin films were deposited on the glass substrates via the sol-gel dip coating method. The films were annealed at various temperatures ranging from 350 °C to 550 °C. X-ray diffraction (XRD), and atomic force microscopy (AFM) were used to investigate the effect of annealing temperature on the structural and morphology properties of the films. The as grown films exhibited amorphous pattern while annealed films were polycrystalline structure with (002) preferential growth along c-axis orientation. The AFM micrographs revealed that the RMS roughness of the films increased as the annealing temperature increased. The grain size was ranging from 32.1 nm to 176.0 nm as the annealing temperature increased from 350 °C to 450 °C and decreased to 56.1 nm for 550 °C.


2015 ◽  
Vol 1109 ◽  
pp. 593-597
Author(s):  
M.F. Nasir ◽  
Mohd Hannas ◽  
Mohamad Hafiz Mamat ◽  
Mohamad Rusop

This project has been focused on the electrical and optical properties on the effect of Indium doped zinc oxide (ZnO) thin films at different dopant concentrations. These thin films were doped with different In dopant concentrations at 1 at%, 1.5 at%, 2 at%, 3 at%, 4 at% and 5 at% was selected as the parameter to optimize the thin films quality while the annealing temperature is fixed 500 oC. In doped ZnO solutions were deposited onto the glass substrates using sol-gel spin coating method. This project was involved with three phases, which are thin films preparation, deposition and characterization. The thin films were characterized using Current Voltage (I-V) measurement and UV-Vis-NIR spectrophotometer for electrical properties and optical properties. The electrical properties show that the resistivity is the lowest at 4 at% In doping concentration which is 8.27× 103Ωcm-1The absorption coefficient spectrum obtained from UV-Vis-NIR spectrophotometer measurement shows all films exhibit very low absorption in the visible (400-800nm) and near infrared (NIR) (>800nm) range but exhibit high absorption in the UV range.


2010 ◽  
Vol 09 (04) ◽  
pp. 355-358 ◽  
Author(s):  
T. S. SENTHIL ◽  
M. THAMBIDURAI ◽  
N. MUTHUKUMARASAMY ◽  
R. BALASUNDARAPRABHU

TiO2 thin films have been deposited onto well cleaned glass substrates by sol–gel spin coating method. The prepared TiO2 films have been annealed at different temperatures (350°C, 450°C and 550°C). The structural properties of the films have been studied using X-ray diffraction method and High Resolution Transmission Electron Microscope (HRTEM). The as-deposited films have been found to be amorphous in nature. The crystalline quality has been observed to improve with annealing temperature. The annealed TiO2 films have been found to exhibit anatase phase. The optical properties have been studied using transmittance spectrum.


2016 ◽  
Vol 1133 ◽  
pp. 414-418 ◽  
Author(s):  
Nurul Fadzilah Ab Rasid ◽  
Siti Nooraya Mohd Tawil ◽  
Norhidayah Che Ani ◽  
Mohd Zainizan Sahdan

Rare earth Gd-doped ZnO thin films were prepared by a simple sol-gel spin coating method in order to search for a new functional diluted magnetic semiconductor for potential application in spintronics. The thin films were deposited onto glass substrates with zinc acetate dehydrate, monoethanolamine and 2-methoxyethanol as a starting material, stabilizer and solvent, respectively. The dopant percentage was increased up to 8%. Optical investigation showed that the crystallinity of the thin films was changing due to the increase of the Gd concentrations and optical band gap energy (Eg) value was estimated to be around 3.12 ~ 3.28 eV using Tauc's model. The crystallite size determined from XRD spectra and the results was found that the value is in the range of 14.42 ~ 21.98 nm.


2013 ◽  
Vol 16 (1) ◽  
pp. 92-100
Author(s):  
Chien Mau Dang ◽  
Dam Duy Le ◽  
Tam Thi Thanh Nguyen ◽  
Dung Thi My Dang

In this study, we have successfully synthesized Fe3+ doped SiO2/TiO2 thin films on glass substrates using the sol-gel dip-coating method. After synthesizing, the samples were annealed at 5000C in the air for 1 hour. The characteristics and optical properties of Fe3+ doped SiO2/TiO2 films were then investigated by X-ray diffraction (XRD), ultraviolet-visible spectroscopy (UV-vis) and Fourier transform infrared spectroscopy (FT-IR). An antifogging ability of the glass substrates coated with the fabricated film is investigated and explained by a water contact angle under visible-light. The analyzed results also show that the crystalline phase of TiO2 thin films comprised only the anatase TiO2, but the crystalline size decreased from 8.8 to 5.9 nm. We also observed that the absorption edge of Fe3+- doped SiO2/TiO2 thin films shifted towards longer wavelengths (i.e. red shifted) from 371.7nm to 409.2 nm when the Fe3+-doped concentration increased from 0 to 1 % mol.


2016 ◽  
Vol 852 ◽  
pp. 1118-1122
Author(s):  
Rui Ying He ◽  
Chang Ping Wei ◽  
Guo Dong Wang ◽  
Jing San

By using sol-gel method, Nb/SnO2 gel was prepared,and spin coating method was used to coat on glass substrates, which dried and calcined to obtain a homogeneous Nb / SnO2 composite films.Under the same experimental conditions, the different doping amount of nickel, calcination temperature on the structure and morphology of Nb/SnO2 film were discussed. By using XRD, IR, SEM and other testing methods, the structure and morphology of Nb / SnO2 composite film were characterized.At 500 °C, the film particle had high crystallization and small size,and the surface of the film was well-distributed.Its optical and electrical properties were tested by the ultraviolet-visible spectrophotometer and four-probe resistivity meter.UV-Vis spectra showed that Nb / SnO2 film absorbance in the near ultraviolet region had increased significantly, but the absorbance showed a downward trend with the increasing amount of Nb5+ doped;Conductivity analysis showed: Nb5+ doping amount of 8% (the amount of material), the conductivity of Nb/SnO2 composite films was best.


MRS Advances ◽  
2017 ◽  
Vol 2 (49) ◽  
pp. 2701-2706
Author(s):  
Guillermo Carbajal-Franco ◽  
Pedro A. Ortiz-Vázquez ◽  
Alejandro Ávila-García

ABSTRACTGas monitoring is a relevant activity for industrial and domestic applications due to usage of dangerous gases as methane, which has been increasingly used as domestic and industrial fuel. In this field of research, metallic oxides such as SnO2, ZnO and Fe2O3 have been widely studied, but we are far from reaching the total understanding of all the parameters that can be varied; in order to improve the gas sensing properties of the metallic oxides. In this work, we present the change of properties derived from using different solvents during the preparation of SnO2 nanoparticles via the sol-gel process. The nanoparticles suspended in two different solvents were deposited on glass substrates by the dip-coating method. The addition of Sb as a dopant was studied at two different Sb:Sn ratios of 1:99 and 1:2. SEM showed differences in the nanostructured topology of the samples and EDS analysis was performed to determine the elemental composition of the samples and the ratios of doping. XRD spectroscopy was used to determine the phase of the materials and the crystallite size. Measurements of the electric response of the coatings to methane, under controlled conditions at different temperatures, were carried out and curves of sensitivity versus temperature were obtained.


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