scholarly journals Geopolymers Based on Phosphoric Acid and Illito-Kaolinitic Clay

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
S. Louati ◽  
S. Baklouti ◽  
B. Samet
Keyword(s):  
Compressive Strength ◽  
Phosphoric Acid ◽  
Three Dimensional ◽  
Aluminum Phosphate ◽  
Molar Ratio ◽  
Calcined Clay ◽  
Modest Contribution ◽  
Maximum Value ◽  
Kaolinitic Clay ◽  
Xrd Patterns

New three-dimensional geopolymer materials based on illito-kaolinitic clay and phosphoric acid were synthesized. The effect of Si/P molar ratio on the geopolymers properties was studied. Raw, calcined clay, and geopolymers structures were investigated using XRD, IR spectroscopy, and SEM. The phosphoric acid-based geopolymers mechanical properties were evaluated by measuring the compressive strength. The Si/P molar ratio was found to increase with the increase of the compressive strength of the obtained geopolymers, which attained a maximum value at Si/P equal to 2.75. Beyond this ratio, the mechanical strength decreases. The XRD patterns of these geopolymers samples have proven that when the Si/P molar ratio decreases, the amorphous phase content increases. Besides, the structural analyses have revealed the presence of aluminum phosphate and Si-O-Al-O-P polymeric structure, whatever the Si/P molar ratio is (between 2.25 and 3.5). The obtained results have confirmed that the presence of the associated minerals such as hematite and quartz in the clay does not prevent the geopolymerization reaction, but the presence of illite mineral seems to have a modest contribution in the geopolymerization.

scholarly journals Preparation of acid aluminum phosphate solutions for metakaolin phosphate geopolymer binder

RSC Advances ◽  
2021 ◽  
Vol 11 (51) ◽  
pp. 32258-32268
Author(s):  
Jean Noël Yankwa Djobo ◽  
Rachel Yanou Nkwaju
Keyword(s):  
Compressive Strength ◽  
Phosphoric Acid ◽  
Aluminum Phosphate ◽  
Molar Ratio ◽  
Phosphate Solutions ◽  
Geopolymer Binder

The acid aluminum phosphate solutions having the molar ratio Al/P of 1/3 are the most reactive and give rise to phosphate geopolymer with improved compressive strength. as compared to phosphate geopolymer obtained with pure phosphoric acid.

Calcium pyrophosphate powder synthesized from phosphoric acid and calcium carbonate

2020 ◽  
pp. 42-48
Author(s):  
Tatiana Safronova ◽  
◽  
Tatiana Shatalova ◽  
Snezhana Tikhonova ◽  
Yaroslav Filippov ◽  
...  
Keyword(s):  
Calcium Carbonate ◽  
Phosphoric Acid ◽  
Functional Materials ◽  
Bone Defects ◽  
Thermal Conversion ◽  
Calcium Pyrophosphate ◽  
Molar Ratio

Powders of calcium pyrophosphate Ca2P2O7 in the form of γ- и β-modifications have been produced as a result of thermal conversion of brushite CaHPO4∙2H2O synthesized from phosphoric acid H3PO4 and calcium carbonate CaCO3 at the molar ratio P / Ca = 1.1. The resulting powders can be used for production of various functional materials including biocompatible and bioresorbable ones for the treatment of bone defects.

scholarly journals Hydrothermally Assisted Fabrication of TiO2-Fe3O4 Composite Materials and Their Antibacterial Activity

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4715
Author(s):  
Adam Kubiak ◽  
Marta Kubacka ◽  
Elżbieta Gabała ◽  
Anna Dobrowolska ◽  
Karol Synoradzki ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Composite Materials ◽  
Bet Surface Area ◽  
Molar Ratio ◽  
Oxide Content ◽  
Gram Positive ◽  
Gram Negative ◽  
Transmission Electron ◽  
Xrd Patterns ◽  
Oxide Composites

The TiO2-Fe3O4 composite materials were fabricated via the hydrothermal-assisted technique. It was determined how the molar ratio of TiO2 to Fe3O4 influences the crystalline structure and morphology of the synthesized composite materials. The effect of the molar ratio of components on the antibacterial activity was also analyzed. On the basis of XRD patterns for the obtained titanium(IV) oxide-iron(II, III) oxide composites, the two separate crystalline forms—anatase and magnetite —were observed. Transmission electron microscopy revealed particles of cubic and tetragonal shape for TiO2 and spherical for Fe3O4. The results of low-temperature nitrogen sorption analysis indicated that an increase in the iron(II, III) oxide content leads to a decrease in the BET surface area. Moreover, the superparamagnetic properties of titanium(IV) oxide-iron(II, III) oxide composites should be noted. An important aim of the work was to determine the antibacterial activity of selected TiO2-Fe3O4 materials. For this purpose, two representative strains of bacteria, the Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus, were used. The titanium(IV) oxide-iron(II, III) oxide composites demonstrated a large zone of growth inhibition for both Gram-positive and Gram-negative bacteria. Moreover, it was found that the analyzed materials can be reused as antibacterial agents in three consecutive cycles with good results.

scholarly journals Mechanical Behavior of Hydroxyapatite-Chitosan Composite: Effect of Processing Parameters

Minerals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 213
Author(s):  
Hamid Ait Said ◽  
Hassan Noukrati ◽  
Hicham Ben Youcef ◽  
Ayoub Bayoussef ◽  
Hassane Oudadesse ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Compressive Strength ◽  
Mechanical Strength ◽  
Bone Repair ◽  
Mechanical Stability ◽  
Three Dimensional ◽  
Processing Parameters ◽  
Composite Effect ◽  
Solid Liquid ◽  
The Impact

Three-dimensional hydroxyapatite-chitosan (HA-CS) composites were formulated via solid-liquid technic and freeze-drying. The prepared composites had an apatitic nature, which was demonstrated by X-ray diffraction and Infrared spectroscopy analyses. The impact of the solid/liquid (S/L) ratio and the content and the molecular weight of the polymer on the composite mechanical strength was investigated. An increase in the S/L ratio from 0.5 to 1 resulted in an increase in the compressive strength for HA-CSL (CS low molecular weight: CSL) from 0.08 ± 0.02 to 1.95 ± 0.39 MPa and from 0.3 ± 0.06 to 2.40 ± 0.51 MPa for the HA-CSM (CS medium molecular weight: CSM). Moreover, the increase in the amount (1 to 5 wt%) and the molecular weight of the polymer increased the mechanical strength of the composite. The highest compressive strength value (up to 2.40 ± 0.51 MPa) was obtained for HA-CSM (5 wt% of CS) formulated at an S/L of 1. The dissolution tests of the HA-CS composites confirmed their cohesion and mechanical stability in an aqueous solution. Both polymer and apatite are assumed to work together, giving the synergism needed to make effective cylindrical composites, and could serve as a promising candidate for bone repair in the orthopedic field.

A novel separation method of the valuable components for activated clay production wastewater

2021 ◽  
Vol 19 (1) ◽  
pp. 530-540
Author(s):  
Lvshan Zhou ◽  
Tongjiang Peng ◽  
Hongjuan Sun ◽  
Dong Fu ◽  
Chuan Lai
Keyword(s):  
Aluminum Phosphate ◽  
Iron Phosphate ◽  
Acid Sites ◽  
Precipitation Method ◽  
Molar Ratio ◽  
Precipitation Process ◽  
Iron Aluminum ◽  
Phosphorus Iron ◽  
Optimized Conditions ◽  
Acidic Wastewater

Abstract The acidic wastewater produced by the wet production of activated clay contains valuable components such as iron and aluminum. The precipitation method was successfully introduced to separate iron and aluminum from the activated clay production wastewater step by step, which can not only recover the valuable components, but also avoid environmental pollution. In the separation process, gypsum, iron aluminum phosphate, alumina, and sodium sulfate were prepared, and the phase compositions of separation products were analyzed by XRD and IR. The main influencing factors in the separation of iron and aluminum components were studied by single factor experiment. The results show that at the optimized conditions, phosphorus/iron molar ratio 6.0, the system pH 3.0, the reaction temperature 343 K, and the reaction time 90 min, the iron(iii) ion in the system can form a sodium-containing aluminum iron phosphate double salt, and the filtrate after separating Fe3+ and part of Al3+ can meet the requirements for forming high-purity Al2O3. During the phosphate precipitation process, the hypothesis should be correct that Al3+ reacts with PO 4 3 − {\text{PO}}_{4}^{3-} to form an AlPO4 skeleton, Fe3+ isomorphically replaces Al3+ in the [AlO4] tetrahedron, and adsorption occurs simultaneously, with Na+ occupying the terminal acid sites, P(Al)–OH.

scholarly journals Chitosan/Gelatin/PVA Scaffolds for Beta Pancreatic Cell Culture

Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2372
Author(s):  
Yesenia Sánchez-Cardona ◽  
Claudia E. Echeverri-Cuartas ◽  
Marta E. Londoño López ◽  
Natalia Moreno-Castellanos
Keyword(s):  
Compressive Strength ◽  
Cell Viability ◽  
Pore Size ◽  
Three Dimensional ◽  
Ternary Blend ◽  
Ternary Blends ◽  
Binary Blend ◽  
Pancreatic Cell ◽  
Degradation Rates ◽  
Swelling Rate

Chitosan scaffolds based on blending polymers are a common strategy used in tissue engineering. The objective of this study was evaluation the properties of scaffolds based on a ternary blend of chitosan (Chi), gelatin (Ge), and polyvinyl alcohol (PVA) (Chi/Ge/PVA), which were prepared by cycles of freeze-thawing and freeze-drying. It then was used for three-dimensional BRIN-BD11 beta-cells culturing. Weight ratios of Chi/Ge/PVA (1:1:1, 2:2:1, 2:3:1, and 3:2:1) were proposed and porosity, pore size, degradation, swelling rate, compressive strength, and cell viability analyzed. All ternary blend scaffolds structures are highly porous (with a porosity higher than 80%) and interconnected. The pore size distribution varied from 0.6 to 265 μm. Ternary blends scaffolds had controllable degradation rates compared to binary blend scaffolds, and an improved swelling capacity of the samples with increasing chitosan concentration was found. An increase in Young’s modulus and compressive strength was observed with increasing gelatin concentration. The highest compressive strength reached 101.6 Pa. The MTT assay showed that the ternary blends scaffolds P3 and P4 supported cell viability better than the binary blend scaffold. Therefore, these results illustrated that ternary blends scaffolds P3 and P4 could provide a better environment for BRIN-BD11 cell proliferation.

Simulation of Three-Dimensional Stress Distribution in Compression Dies

2008 ◽  
Vol 575-578 ◽  
pp. 449-454
Author(s):  
Chu Yun Huang ◽  
Sai Yu Wang ◽  
Tao Yang ◽  
Xu Dong Yan
Keyword(s):  
Stress Distribution ◽  
Computer Aided Design ◽  
Three Dimensional ◽  
Distribution Model ◽  
Extrusion Dies ◽  
Maximum Value ◽  
Multiple Unit ◽  
Stress Freezing Method ◽  
Experimental Values ◽  
Aided Design

The stress fields of rectangular and T shape compression dies were simulated by three dimensional photo-elasticity of stress freezing method. The rules of stress distribution of σx, σy, σz on the surface of rectangular and T-shaped dies were discovered, and the rules were also found inside the dies. The results indicate that the stress distribution of rectangular die is similar to that of T shape die. Obvious stress concentration in corner of die hole was observed. σz rises from die hole to periphery until it achieves maximum value then it diminishes gradually, and σz between die hole and fix diameter zone is higher than it is in other position. At the same time, the equations of stress field of extrusion dies were obtained by curved surface fitting experimental values in every observed point with multiple-unit regression analysis method and orthogonal transforms. These works can provide stress distribution model for die computer aided design and make.

Two- and three-dimensional coordination polymers based on zinc(II) and furan-2,5-dicarboxylic acid: structure variation due to metal-to-linker ratio

2018 ◽  
Vol 74 (12) ◽  
pp. 1719-1724 ◽  
Author(s):  
Yimin Mao ◽  
Peter Y. Zavalij
Keyword(s):  
Dicarboxylic Acid ◽  
Coordination Polymers ◽  
Three Dimensional ◽  
Molar Ratio ◽  
Monoclinic Space Group ◽  
Structure Variation ◽  
Space Group ◽  
Hydrogen Bonding Pattern ◽  
Solvent Molecules ◽  
A Chain

Two ZnII-based coordination polymers (CPs) were synthesized by the hydrothermal method, using Zn(NO3)2·6H2O and furan-2,5-dicarboxylic acid (FDCA) in dimethylformamide (DMF) solvent, at 95 °C. Poly[tetrakis(dimethylazanium) [tetrakis(μ2-furan-2,5-dicarboxylato-κ2 O 2:O 5)dizinc(II)]], {(C2H8N)4[Zn2(C6H2O5)4]} n or {[DMA]4[ZnII 2(FDC)4]} n (DMA = dimethylazanium and FDC = furan-2,5-dicarboxylate), (1), was obtained with a 1:1 molar ratio of ZnII and FDCA. It crystallized in the monoclinic space group C2/c. Coordinated by ZnII ions, FDC2− ligands form 21 double-stranded helices propagating along the b axis. The helices are interconnected and extend laterally in the a direction, forming a two-dimensional (2D) sheet-like network. The 2D sheets are stacked along the c direction without interconnections. DMA cations are cocrystallized in (1) and are hydrogen bonded with carboxylate O atoms of the FDC2− ligands. The hydrogen-bonding pattern consists of R 2 2(4) and R 2 2(10) motifs alternating in a chain. Poly[bis(dimethylazanium) [bis(μ4-furan-2,5-dicarboxylato-κO 2:κO 2′:κO 5:κO 5)bis(μ3-furan-2,5-dicarboxylato-κO 2:κO 2′:κO 5)dizinc(II)] dimethylformamide 3.08-solvate], {(C2H8N)2[Zn2(C6H2O5)4]·3.08C3H7NO} n or {[DMA]2[ZnII 3(FDC)4]·3.08DMF} n , (2), was obtained with a 1:2 molar ratio of ZnII and FDCA. It crystallized in the monoclinic space group P21/c, forming a three-dimensional network. The pores are filled with DMA cations and DMF solvent molecules.

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