Insights into structural characteristics and the mechanism of silicate-based calcium phosphates with phosphoric acid modulation

2020 ◽  
Vol 46 (3) ◽  
pp. 3456-3463 ◽  
Author(s):  
Zhengwen Ding ◽  
Qiyi Zhang ◽  
Yanan Wu ◽  
Mizhi Ji ◽  
Hong Chen ◽  
...  
Keyword(s):  
Phosphoric Acid ◽  
Calcium Phosphates ◽  
Structural Characteristics

scholarly journals The solubility of calcium phosphates in citric acid

1917 ◽  
Vol 8 (3) ◽  
pp. 277-298 ◽  
Author(s):  
A. A. Ramsay
Keyword(s):  
Citric Acid ◽  
Hydrochloric Acid ◽  
Phosphoric Acid ◽  
Calcium Chloride ◽  
Tricalcium Phosphate ◽  
Sodium Phosphate ◽  
Calcium Phosphates ◽  
Bone Ash

The results of these investigations show1. The substances sold as “Phosphate of lime” and “Calcium Phosphas B.P.” are not pure tricalcic phosphate but are mixtures of di- and tricalcic phosphates.2. Sodium phosphate (Na2HPO4) added to ammoniacal calcium chloride and the resulting precipitate washed with water yields a mixture of di- and tricalcic phosphate and calcium hydrate.3. Bone ash dissolved in hydrochloric acid and precipitated with ammonia, the precipitate being well washed, yields also a mixture of di- and tricalcium phosphate and calcium hydrate.4. When three equivalents of lime (3CaO) are made to act on one equivalent of phosphoric acid (P2O5) and the resulting precipitate removed with little delay pure tricalcium phosphate is obtained.

scholarly journals Antibacterial Poly(ε-CL)/Hydroxyapatite Electrospun Fibers Reinforced by Poly(ε-CL)-b-Poly(Ethylene Phosphoric Acid)

2021 ◽  
Vol 22 (14) ◽  
pp. 7690
Author(s):  
Ilya Nifant’ev ◽  
Dmitry Gavrilov ◽  
Alexander Tavtorkin ◽  
Maria Chinova ◽  
Victoria Besprozvannykh ◽  
...  
Keyword(s):  
Phosphoric Acid ◽  
Wound Dressing ◽  
Bone Repair ◽  
Mechanical Characteristics ◽  
High Efficiency ◽  
Calcium Phosphates ◽  
Close Attention ◽  
Bone Surgery ◽  
Biodegradable Polyesters ◽  
Poly Ethylene

In bone surgery and orthopedics, bioresorbable materials can be helpful in bone repair and countering post-op infections. Explicit antibacterial activity, osteoinductive and osteoconductive effects are essential to achieving this objective. Nonwoven electrospun (ES) fibers are receiving the close attention of physicians as promising materials for wound dressing and tissue engineering; potentially, in high contrast with dense materials, ES mats hamper regeneration of the bone extracellular matrix to a lesser extent. The use of the compositions of inherently biodegradable polyesters (poly(ε-caprolactone) PCL, poly(lactoglycolide), etc.), calcium phosphates and antibiotics is highly prospective, but the task of forming ES fibers from such compositions is complicated by the incompatibility of the main organic and inorganic ingredients, polyesters and calcium phosphates. In the present research we report the synthesis of hydroxyapatite (HAp) nanoparticles with uniform morphology, and demonstrate high efficiency of the block copolymer of PCL and poly(ethylene phosphoric acid) (PEPA) as an efficient compatibilizer for PCL/HAp mixtures that are able to form ES fibers with improved mechanical characteristics. The materials obtained in the presence of vancomycin exhibited incremental drug release against Staphylococcus aureus (St. aureus).

scholarly journals A novel surfactant-assisted dilute phosphoric acid plus steam explosion pretreatment of poplar wood for fermentable sugar production

2021 ◽  
Author(s):  
Denghui Tong ◽  
Peng Zhan ◽  
Weifeng Zhang ◽  
Yongcai Zhou ◽  
Yilei Huang ◽  
...  
Keyword(s):  
Phosphoric Acid ◽  
Residence Time ◽  
Steam Explosion ◽  
Biomass Conversion ◽  
Structural Characteristics ◽  
Enzymatic Saccharification ◽  
Sugar Production ◽  
Fermentable Sugar ◽  
Steam Explosion Pretreatment ◽  
Before And After

Abstract Pretreatment is an indispensable process in lignocellulosic bioethanol production. In this work, a surfactant agent JFC was introduced into the dilute phosphoric acid plus steam explosion pretreatment scheme for fermentable sugar production using poplar as substrate. Four crucial factors (phosphoric acid concentration, surfactant concentration, pressure, and residence time) affecting the pretreatment efficiency were optimized using the single factor tests. The optimal parameters obtained were as follows: 1:2.5 solid/liquid rate, 2 h pre-soaking time, 1.5 %(v/v) JFC-M + 2.0 wt% phosphoric acid, 2.0 MPa pressure, and 120 s residence time, resulting in a maximum cellulose recovery rate of 86.33 % and enzymatic saccharification rate of 84.62 %, which was 38.97 % higher than that of control. The morphological and structural characteristics of samples before and after pretreatment, were characterized by the scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared (FTIR) method. The addition of JFC-M was of a notable influence in overcoming biomass recalcitrance and boosting cellulose digestion, showing great application potentials in biomass conversion process.

Dielectric and structural characteristics of Ta2O5 anodic films formed in phosphoric acid electrolytes

1987 ◽  
Vol 22 (5) ◽  
pp. 1785-1789 ◽  
Author(s):  
I. Montero ◽  
J. M. Albella ◽  
J. M. Mart�nez-Duart ◽  
L. Soriano
Keyword(s):  
Phosphoric Acid ◽  
Structural Characteristics ◽  
Anodic Films

Microstructure and Mechanical Performances of Plasma-Sprayed Functionally Gradient HA-ZrO2-Bioglass Coatings

2007 ◽  
Vol 280-283 ◽  
pp. 1893-1898 ◽  
Author(s):  
Cheng Yun Ning ◽  
Ying Jun Wang ◽  
W.W. Lu ◽  
Xiao Feng Chen ◽  
Gang Wu ◽  
...  
Keyword(s):  
Calcium Phosphates ◽  
Structural Characteristics ◽  
Functionally Graded ◽  
Net Energy ◽  
Practical Applications ◽  
Functionally Gradient ◽  
Hydroxyapatite Coatings ◽  
Heat Treated ◽  
Mechanical Performances ◽  
Plasma Sprayed

For practical applications such as artifical joints and dental implants, there is a strong demand for hydroxyapatite coatings with excellent performances to ensure long-term fixation. In the present study, functionally gradient HA-ZrO2-Bioglass coatings were prepared using net-energy controlled plasma spraying technology. The structural characteristics andmechanical performances of the coatings were examined by scanning electron microscopy (SEM), X-ray diffraction (XRD) and nanoindentation. The results showed that: (1) Pore sizes and compositions of the coatings changed gradually along the vertical substrate, crystal HA with few calcium phosphates was presented in the heat-treated coatings. (2) Surface of the coating was very rough with nano-sized crystalline grains and micropores; (3) Young’s modulus and hardness changed gradually at the range of coating-Ti6Alo4V interface. Compared with HA coatings, the tensile adhesive strength of the functionally graded HA-ZrO2-Bioglass coatings reached 38.6 MPa, much higher than that of single HA coatings.

Solubility of Phosphates, Rates of Solution of Calcium Phosphates in Phosphoric Acid Solutions

1957 ◽  
Vol 5 (4) ◽  
pp. 266-275 ◽  
Author(s):  
E. O. Huffman ◽  
W. E. Cate ◽  
M. E. Deming ◽  
K. L. Elmore
Keyword(s):  
Phosphoric Acid ◽  
Calcium Phosphates ◽  
Acid Solutions

Zur Frage der nicht-enzymatischen Bildung von kondensierten Phosphaten unter präbiotischen Bedingungen/ Non-Enzymatic Formation of Condensed Phosphates under Prebiotic Conditions

1986 ◽  
Vol 41 (7) ◽  
pp. 815-824 ◽  
Author(s):  
F. Seel ◽  
K.-P. Klos ◽  
D. Recktenwald ◽  
J. Schuh
Keyword(s):  
Phosphoric Acid ◽  
Chemical Evolution ◽  
Calcium Phosphates ◽  
Aqueous System ◽  
Hydrothermal Conditions ◽  
Primitive Earth ◽  
Spontaneous Condensation ◽  
Enzymatic Formation ◽  
Condensed Phosphates

AbstractOne of the problems of chemical evolution on the primitive Earth is the question of the possibility of a non-enzymatic spontaneous condensation o f phosphoric acid and hydrogen phosphates to yield polyphosphoric acids and polyphosphates in aqueous system s, by means of which phosphorus might have entered into early metabolisms. The extra- or intra-cellular formation of magnesium diphosphate under geologically plausible hydrothermal conditions from either magnesium hydrogen phosphates or calcium phosphates in media has been demonstrated.

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