scholarly journals Electrospun cotton–wool-like silica/gelatin hybrids with covalent coupling

2020 ◽  
Author(s):  
Maria Nelson ◽  
Francesca Tallia ◽  
Samuel J. Page ◽  
John V. Hanna ◽  
Yuki Fujita ◽  
...  
Keyword(s):  
Regenerative Medicine ◽  
Coupling Agent ◽  
Sol Gel ◽  
Covalent Bonding ◽  
Electrospinning Process ◽  
Cotton Wool ◽  
Process Variables ◽  
Synthesis Conditions ◽  
Covalent Coupling ◽  
Sol Gel Synthesis

Abstract Inorganic/organic sol–gel hybrids consist of co-networks of inorganic and organic components that can lead to unique properties, compared to conventional composites, especially when there is covalent bonding between the networks. The aim here was to develop new electrospun silica/gelatin sol–gel hybrids, with covalent coupling and unique 3D cotton–wool-like morphology for application as regenerative medicine scaffolds. Covalent coupling is critical for obtaining sustained dissolution of the fibres and we identified the sol–gel synthesis conditions needed for coupling within the electrospun fibres. Under carefully controlled conditions, such as constant humidity, we investigated the effect of the electrospinning process variables of sol viscosity (and aging time) and amount of coupling agent on the 3D morphology of the fibres, their structure (bonding) and dissolution, identifying a detailed optimised protocol for fibre scaffold production.

Effect of sol–gel synthesis conditions on the physical properties of silica hydrogels

2020 ◽  
Vol 30 (6) ◽  
pp. 812-814
Author(s):  
Ekaterina S. Dolinina ◽  
Anton S. Kraev ◽  
Elena V. Parfenyuk
Keyword(s):  
Physical Properties ◽  
Sol Gel ◽  
Synthesis Conditions ◽  
Silica Hydrogels ◽  
Sol Gel Synthesis

Effect of the Sol-Gel Synthesis Parameters on the Incorporation of an Anti-inflammatory Drug in a Ceramic Material

2007 ◽  
Vol 1007 ◽  
Author(s):  
Aracely Hernandez ◽  
Patricia Esquivel-Ferriño ◽  
Idalia Gomez ◽  
Lucia Cantu
Keyword(s):  
Ceramic Material ◽  
Sol Gel ◽  
Nitrogen Adsorption ◽  
Molar Ratio ◽  
Inflammatory Drug ◽  
Synthesis Conditions ◽  
Synthesis Parameters ◽  
Anti Inflammatory ◽  
Drug Incorporation ◽  
Sol Gel Synthesis

ABSTRACTIn the present work, sol-gel method was used to incorporate in a ceramic material a non steroidal anti-inflammatory drug (piroxicam) as model drug. The incorporation of the drug in the SiO2 network was carried out at different sol-gel synthesis parameters, such as pH (3 and 5) and the alkoxide/water ratio (1:6 and 1:8). The biomaterial obtained was analyzed by thermal analysis TGA-DTA, infrared spectroscopy (FTIR), Scanning Electronic Microscopy (SEM) and X-ray diffraction (XRD); specific surface area and porosity were analyzed from nitrogen adsorption isotherm. Better drug incorporation into the material was achieved at the synthesis conditions of pH 5 and 1:6 alkoxide/water molar ratio.

scholarly journals Synthesis of Silica Nanostructures and Optimization of their Size and Morphology by Use of Changing in Synthesis Conditions

2012 ◽  
Vol 9 (2) ◽  
pp. 659-668 ◽  
Author(s):  
A. Elsagh
Keyword(s):  
Drug Delivery Systems ◽  
Sol Gel ◽  
Molar Ratio ◽  
Synthesis Conditions ◽  
Acid Type ◽  
Silica Nanostructures ◽  
Size And Morphology ◽  
Sol Gel Synthesis ◽  
Optimized Conditions ◽  
Cracking Products

The aim of the present research was optimization of practical conditions of the sol-gel synthesis. In so doing, silica particles were synthesized using sol-gel method and their size and morphology were investigated by use of SEM and TEM images. The effect of changing molar ratio of reactive including acids and silica pre-matter on the particles' morphology and size was studied. Also, acid type and silica pre-matter used in reaction was examined and the result product of the reaction were investigated in the presence of several acids and two types of silica pre-matter. The reaction time was studied as a very important factor in products' digestion phase which plays a significant role in determining particles’ size and rate of cracking products. Finally, in optimized conditions 50-80 nm diameter nanostructures were synthesized. These products can be used as drug delivery systems.

scholarly journals Effect of Carbon Sources and Synthesis Conditions on the LiFePo4/C Cathode Properties

2018 ◽  
Vol 57 (2) ◽  
pp. 183-192 ◽  
Author(s):  
R.R. Kapaev ◽  
S.A. Novikova ◽  
A.A. Chekannikov ◽  
D.Yu. Gryzlov ◽  
T.L. Kulova ◽  
...  
Keyword(s):  
Discharge Capacity ◽  
Polyvinylidene Fluoride ◽  
Annealing Temperature ◽  
Sol Gel ◽  
Carbon Sources ◽  
Water Mixture ◽  
Synthesis Conditions ◽  
Size Growth ◽  
Graphite Structure ◽  
Sol Gel Synthesis

Abstract The sol-gel synthesis and precipitation from dimethyl sulfoxide (DMSO)-water mixture were used to obtain LiFePO4. Sucrose (sucr), citric acid (CA), phthalic acid (phth), polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), polyvinylidene fluoride (PVDF), polyethylene glycol (PEG), polyacrylic acid (PAA) were investigated as carbon precursors. Increasing of the annealing temperature from 600 °» to 800 °» leads to a certain perfection of graphite structure with simultaneous particle size growth. Higher capacities were observed for the materials synthesized at 600 °». The best results for the sol-gel synthesis were obtained when PVDF was used as a source of carbon coating due to the partial fluorination of LiFePO4 (discharge capacity of LiFePO4/ C-PVDF was ~160 and 70 mAh g-1 at 20 mA g-1 and 800 mA g-1 currents, respectively). For nanocrystalline LiFePO4 obtained by precipitation from DMSO-water mixture the best results were obtained when PEG was used as carbon source (discharge capacity LiFePO4/C-PEG was 158 and 77 mAh g-1 at 20 mA g-1 and 800 mA g-1, respectively).

scholarly journals Facile Sol-gel Synthesis of Porous Silicas Using Poly(propylene)imine Dendrimers as Templates

2000 ◽  
Vol 15 (8) ◽  
pp. 1842-1848 ◽  
Author(s):  
Gustavo Larsen ◽  
Edgar Lotero ◽  
Manuel Marquez
Keyword(s):  
Single Molecule ◽  
Sol Gel ◽  
Three Dimensional ◽  
X Ray Diffraction ◽  
Template Removal ◽  
Synthesis Conditions ◽  
Transmission Electron ◽  
Argon Adsorption ◽  
Poly Propylene ◽  
Sol Gel Synthesis

Commercially available poly(propylene)imine (DAB-Am-32 and DAB-Am-64) dendrimers were used as single-molecule templates to tailor the porosity of silicas via a nonacidic sol-gel method. X-ray diffraction on both the as-prepared (oven-dried at 373 K) and the calcined (833 K) materials revealed that modest contraction took place on template removal and that the cavities created did not achieve three-dimensional ordering under the current synthesis conditions. Transmission electron microscopy of “Pt-stained” samples supported this picture. A modified Horvath–Kawazoe analysis of the argon adsorption isotherms indicated that DAB-Am-64 is a much more effective template than DAB-Am-32. Pyrolysis and oxidation protocols for template removal are also presented.

scholarly journals Peculiarities of sol-gel synthesis of co-modified by nitrogen and metal ions (Zn2+, Zr4+, Pt2+) semiconductive TiO2 films

2020 ◽  
pp. 67-74
Author(s):  
О.P. Linnik ◽  
◽  
N.P. Smirnova ◽  
A.М. Eremenko ◽  
◽  
...  
Keyword(s):  
Metal Ions ◽  
Sol Gel ◽  
Complex Compounds ◽  
Chemical Compositions ◽  
Reaction Products ◽  
Synthesis Conditions ◽  
No Formation ◽  
Titania Films ◽  
Sol Gel Synthesis ◽  
Urea Decomposition

According to the XPS investigation of titania films co-modified by nitro gen and metal ions obtained via sol-gel method, the formation of common bonds between elements occurs due to the presence of metal ions. The mechanism of urea thermolysis is changed as a result of the ability of metal ions to form the complex compounds with urea molecules under the reported synthesis conditions that, in turn, depends on the nature of metal ions, leading to the different chemical compositions of materials’ surface. The XPS data show that nitrogen atoms are surrounded by nonmetal ones on the surface of the films modi fied by Zn2+ or Zr4+ ions. It is suggested that no formation of the complexes between Ті, Zn, or Zr atoms with urea occurs due to its protonation through an oxygen atom leading to the formation of O,N-containing reaction products. In the case of Pt2+ doping, the substitutional nitrogen incorporation in the titania lattice, as well as the formation of N-containing fragments, have been detected. The chemical nature of Pt ions allows them to interact with urea molecules through an N atom of the amino group. As a result, the transformation of urea molecules in the complexes occurs at higher temperatures concurrently with the titania crystallization that is recognized as a catalyst for the intermediates of the urea decomposition leading to the formation of common bonds between N and Ti atoms.

Raman study of the variation in anatase structure of TiO2 nanopowders due to the changes of sol–gel synthesis conditions

2008 ◽  
Vol 49 (3) ◽  
pp. 311-319 ◽  
Author(s):  
A. Golubović ◽  
M. Šćepanović ◽  
A. Kremenović ◽  
S. Aškrabić ◽  
V. Berec ◽  
...  
Keyword(s):  
Sol Gel ◽  
Anatase Structure ◽  
Synthesis Conditions ◽  
Raman Study ◽  
Tio2 Nanopowders ◽  
Sol Gel Synthesis

scholarly journals Effect of Precursor Nature and Sol-Gel Synthesis Conditions on TiO2 Aerogel’s Structure

Molecules ◽  
2021 ◽  
Vol 26 (16) ◽  
pp. 5090
Author(s):  
Jolanta Doneliene ◽  
Egle Fataraite-Urboniene ◽  
Matas Rudzikas ◽  
Saulius Pakalka ◽  
Nina Danchova ◽  
...  
Keyword(s):  
Optical Properties ◽  
Structural Parameters ◽  
Anatase Phase ◽  
Sol Gel ◽  
Amorphous Structure ◽  
Drying Methods ◽  
High Porosity ◽  
Structural And Optical Properties ◽  
Synthesis Conditions ◽  
Sol Gel Synthesis

The aim of this investigation was to synthesize high porosity TiO2 aerogel by applying sol-gel and subcritical drying methods and to identify the influence of reagent’s nature and synthesis conditions on their structural and optical properties. Methods of XRD, FT-IR, BET, STA, SEM, and UV-vis were applied to investigate and compare the properties of synthesized TiO2 aerogels and to determine the most effective synthesis route. The structural parameters of the synthesized materials can be varied by changing the precursor type (titanium (IV), isopropoxide (TIP), or tetrabutylorthotitanate (TBOT)) and the nature of the solvent used for additional exchange (n-hexane (nH), cyclohexane (CH), or diethyl ether (DE)). All of the subcritical dried samples show the amorphous structure, which tends to crystallize into the anatase phase after calcination. The number of micro and mesopores and the specific surface area depends on the synthesis conditions. The pores with the highest diameter have been found for additionally nH exchanged and aged aerogel synthesized from precursor TIP. Despite the imperfections in the structure, the produced aerogels show structural and optical properties typical of the TiO2 structures mentioned in the literature.

Influence of the Sol-Gel Synthesis Conditions on the Properties of Thin PbTiO3 Films

1994 ◽  
Vol 361 ◽  
Author(s):  
P.J. Retuert ◽  
T.P. Velilla ◽  
V. Del C. Martin ◽  
R.E. Avila
Keyword(s):  
Thin Films ◽  
Sol Gel ◽  
Sem Analysis ◽  
Relative Dielectric Permittivity ◽  
Titanium Tetraisopropoxide ◽  
Synthesis Conditions ◽  
Current Voltage ◽  
Current Voltage Characteristics ◽  
Sol Gel Synthesis ◽  
Perovskite Type

ABSTRACTTetragonal, perovskite type, powders and thin films of PbTiO3 have been synthesized by the sol-gel method, using trihydrate lead acetate and titanium tetraisopropoxide as starting alkoxides. The thermal treatment has been established from differential thermal and thermogravimetric analysis. An interpretation is presented for the various processes occurring during the gel to dense oxide conversion. The optimal process towards thin films includes annealing stages at 180, 400 and 650°C. Thin films were prepared by spinning on Si and Pt-covered Si. By SEM analysis the films appear cracked, porous, or homogeneous, with 0.5 to 1 um per solution coating. Current-voltage characteristics of Al/PT/Pt/Si capacitors exhibit a resistivity of 0.5 to 20·108Ωm, nondestructive breakdown in the range of 4 to over 20V, and relative dielectric permittivity of 100.

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