Sol–gel–xerogel transformations in the thin layer at the salt solution–gaseous reagent interface and the synthesis of new materials with microtubular morphology

2019 ◽  
Vol 92 (2) ◽  
pp. 342-348
Author(s):  
Vladislav Gurenko ◽  
Larisa Gulina ◽  
Valeri Tolstoy
Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2059
Author(s):  
Piotr Prochor ◽  
Żaneta Anna Mierzejewska

In recent years, scientists have defined two main paths for orthopedic implant fabrication: searching for new materials with properties closest to natural bone in order to reduce the stress-shielding effect or creating individually adapted geometry of the implant with the use and Rapid Prototyping methods. Therefore, materials such as PEEK GRF30 and Ti6Al4V selective laser melting (SLM) are of interest. They are defined as materials suitable for implants, however, the knowledge of their bioactivity, a feature which is one of the most desirable properties of biomaterials, is still insufficient. Using Simulated Body Fluid and Hank’s Balanced Salt Solution, the bioactivity of PEEK GRF30 and Ti6Al4V SLM was assessed, as well as commercial Ti6Al4V as a reference material. Ten cylindrical samples of each material were prepared and immersed in solutions per period from 2 to 28 days at 37 °C. Optical analysis of the changes on the examined surfaces suggested that right after 2-day crystals with different morphologies were formed on each material. Further analysis of the chemical composition of the altered surfaces confirmed the formation of a calcium phosphate layer on them, however, the Ca/P ratio was slightly different from 1.67. On the basis of the obtained results, it can be concluded that both PEEK GRF30 and Ti6Al4V SLM are characterized by appropriate—comparable to Ti6Al4V—bioactivity.


2021 ◽  
Vol 1038 ◽  
pp. 468-479
Author(s):  
Olga Skorodumova ◽  
Olena Tarakhno ◽  
Olena Chebotaryova ◽  
Oleg Bezuglov ◽  
Fatih Mehmet Emen

Based on the generalization of research results on the processes of obtaining SiO2 sols using tetraethoxysilane and ethyl silicates, the main factors influencing the elasticity of silica coatings on cotton fabrics and their fire-retardant properties are considered. The possibility of forming covalent bonds between the functional groups of cellulose, gel coating and flame retardant layer is considered, which explains the strong fixation of a thin layer of coating on the fibers of the fabric and improve its fire protection. The use of the developed compositions for fire-retardant elastic coatings based on ethyl silicate allows to increase the time of complete burning of cotton from 30s (untreated fabric) to 600s (treated with binary coating).


1984 ◽  
Vol 67 (3) ◽  
pp. 580-582 ◽  
Author(s):  
Steven P Swanson ◽  
Richard A Corley ◽  
Donald G White ◽  
William B Buck

Abstract A rapid and inexpensive method has been developed for the analysis of zearalenone and zearalenol in grains and animal feeds. The method involves extraction with 75% methanol, precipitation of pigments with lead acetate, and defatting with petroleum ether. The mycotoxins are subsequently partitioned into toluene–ethyl acetate, chromatographed on high performance thin layer chromatographic plates, and detected after treatment with Fast Violet B salt solution. Sensitivity of the method is better than 80 ng/g for zearalenone and 200 ng/g for zearalenol. Ten samples can be completed in less than 2 h. The method is applicable for zearalenone in corn, wheat, barley, millet, and swine feeds.


1995 ◽  
Vol 10 (9) ◽  
pp. 2271-2276 ◽  
Author(s):  
V. Pierre ◽  
D. Pierre ◽  
A.C. Pierre

New materials were made by infiltration of sol-gel boehmite thin films with copper acetate. The structure and phase transformation of these materials during heat treatment were studied. It was found that infiltration in the boehmite state did not end up in the same material as direct infiltration in the θ-alumina derived from boehmite, even after both types of materials were heat-treated at 900 °C. Infiltration in boehmite makes it possible to synthesize sandwich structures comprised of alternate layers of CuO and of γ-alumina.


1998 ◽  
Vol 550 ◽  
Author(s):  
Stephen E. Rankin ◽  
Alon V. McCormick

AbstractHydrolytic polycondensation of silicon alkoxides and organically modified alkoxides shows promise as a route to new materials for medicine. Mathematical models of this polymerization accelerate the development of these materials and processes for their production. With a reliable model, one can rapidly explore a wide variety of options for controlling material properties. Here we describe a model for kinetics of sol-gel copolymerization of a simple pair of ethoxysilanes: (CH3)3Si(OC2H5) and (CH3)2Si(OC2H5)2. We then describe how reactor configuration alone can be used to control of polymer structure by choosing how to mix the reactants. An example is shown of maximizing homogeneity at any reactor residence time of interest in the model copolymer system by using the time of addition of the faster-reacting monomer.


2014 ◽  
Vol 13 (1) ◽  
pp. 1
Author(s):  
Tanti Haryati ◽  
Novita Andarini ◽  
Mellisa Ika Febrianti

The incorporation of TiO and ZnO material as a composite, to increase the activity of the catalyst. Synthesis of ZnO-TiO2 thin layer made using a sol-gel method with a variation of PEG as a solvent. The purpose of this research was to investigate the structure and morphology of ZnO-TiO2 thin layer on the variation of PEG as a solvent by sol-gel method . Preparation of ZnO sol of the precursor , while the TiO2 sol synthesized by dissolving the anatase TiO2 structure into polyethilen glycol . Sol of ZnO and TiO2 sol do sol mixing to form ZnO–TiO2 after it coated on a glass substrate and then calcined . Products were then characterized by X-ray diffraction to determine the crystal structure and SEM to determine its morphology . The test results show the crystal structure by XRD based difaktogram intensity , the greater the molecular weight of the PEG peak intensity of ZnO-TiO2 showed the lower. While based on morphological examination , it can be seen that the larger molecular weight PEG , ZnO - TiO2 granular greater.


2020 ◽  
Vol 5 (1) ◽  
pp. 11-20
Author(s):  
Rahmi Dewi ◽  
Krisman Krisman ◽  
Zulkarnaen Zulkarnaen ◽  
Rahmi Afrida Syahraini ◽  
TS Luqman Husein

A thin layer of Barium Strontium Titanate Ba0.15Sr0.85TiO3 (BST) was developed on a glass substrate using a sol-gel method with annealing temperatures and spin coating process at 3500 rpm for 30 seconds. The annealing temperature varied from 600oC, 650oC, and 700oC.  Characterization of optical properties was developed using UV-Vis spectroscopy to determine the energy bandgap. The values of the BST thin layer energy band at the annealing temperature were 3.55 eV, 3.32 eV, and 3.10 eV, respectively. The results indicate that the BST thin film was a semiconductor material.


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