Studying surface charge and suspension stability of hydroxyapatite powder in isopropyl alcohol to prepare stable suspension for electrophoretic deposition

2009 ◽  
Vol 108 (4) ◽  
pp. 241-248 ◽  
Author(s):  
M. Javidi ◽  
M. E. Bahrololoom ◽  
S. Javadpour ◽  
J. Ma
Keyword(s):  
Surface Charge ◽  
Electrophoretic Deposition ◽  
Isopropyl Alcohol ◽  
Suspension Stability ◽  
Stable Suspension ◽  
Hydroxyapatite Powder

Sodium alginate nanoparticles as a new transdermal vehicle of glucosamine sulfate for treatment of osteoarthritis

2017 ◽  
Vol 9 (3-4) ◽  
Author(s):  
Asmaa S. El-Houssiny ◽  
Azza A. Ward ◽  
Dina M. Mostafa ◽  
Salwa L. Abd-El-Messieh ◽  
Kamal N. Abdel-Nour ◽  
...  
Keyword(s):  
Side Effects ◽  
Surface Charge ◽  
Ex Vivo ◽  
In Vitro Release ◽  
Glucosamine Sulfate ◽  
Suspension Stability ◽  
Rat Skin ◽  
Release Studies ◽  
Vitro Release

AbstractGlucosamine sulfate (GS) has been used orally for the treatment of osteoarthritis (OA). However, it may be susceptible to the liver first pass phenomenon, which greatly affects its bioavailability, in addition to its side effects on the gastrointestinal tract. Alginate nanoparticles (Alg NPs) were investigated as a new drug carrier for transdermal delivery of GS to improve its effectiveness and reduce side effects. GS-Alg NPs were characterized by encapsulation efficiency, NP yield, particle size and surface charge properties. The in vitro release studies of GS and the ex vivo permeability through rat skin were determined using a UV-Vis spectrophotometer. GS-Alg NPs are within the nanometer range of size. High negative surface charge values are obtained and indicate the high suspension stability of the prepared formulation. The in vitro release studies showed that GS is released from Alg NPs in a sustained and prolonged manner. The ex vivo permeability of GS through rat skin is enhanced significantly after encapsulation in the negatively charged Alg NPs. We successfully reported a highly stable nanoparticlulate system using Alg NPs that permits the encapsulation of GS for topical administration, overcoming the disadvantages of oral administration.

Preparation of Hydroxyapatite/Chitosan Biological Coatings on Carbon/Carbon Composites

2010 ◽  
Vol 434-435 ◽  
pp. 502-505
Author(s):  
Ying Hua Li ◽  
Li Yun Cao ◽  
Jian Feng Huang ◽  
Xie Rong Zeng
Keyword(s):  
Heat Treatment ◽  
Electrophoretic Deposition ◽  
Isopropyl Alcohol ◽  
Raw Materials ◽  
Composite Coatings ◽  
Thermal Conditions ◽  
Hydrothermal Condition ◽  
Subsequent Heat Treatment ◽  
Carbon Composites ◽  
Deposition Voltage

Hydroxyapatite/Chitosan (HAp/CS) bio-coatings were prepared on the surface of carbon/ carbon (C/C) composites by hydrothermal electrophoretic deposition, using sonochemical process resulted HAp nanoparticles, isopropyl alcohol and chitosan as raw materials. The influences of hydro- thermal conditions and deposition voltage on the microstructures and morphologies of the as-prepared coatings were investigated. It was shown that homogenous and dense HAp/CS coatings on C/C composites are obtained by hydrothermal electrophoretic deposition. With the increase of deposition voltage, density and homogeneity of the as-prepared HAp/CS composite coatings are well improved. Due to the growth of HAp nanoparticles in the hydrothermal condition, the subsequent heat treatment of the HAp/CS coatings is not needed.

scholarly journals Assembly of binary, ternary and quaternary compound semiconductor nanorods: From local to device scale ordering influenced by surface charge

CrystEngComm ◽  
2014 ◽  
Vol 16 (40) ◽  
pp. 9446-9454 ◽  
Author(s):  
Kevin M. Ryan ◽  
Shalini Singh ◽  
Pai Liu ◽  
Ajay Singh
Keyword(s):  
Surface Charge ◽  
Electrophoretic Deposition ◽  
Compound Semiconductor ◽  
Quaternary Compound

In this article we outline the assembly of binary, ternary and quaternary nanorods using three separate protocols: (a) droplet based assembly, (b) assembly in a vial, (c) electrophoretic deposition. The rods are the important photoabsorbers CdS, CdSexS1−x, CuInxGa1−xS, and Cu2ZnSnS4.

scholarly journals Kinetic evaluation of YSZ/Al2O3 nanocomposite coatings fabricated by electrophoretic deposition on a nickel-based superalloy

2021 ◽  
Vol 15 (1) ◽  
pp. 1-10
Author(s):  
Leyla Mostafapour ◽  
Saeid Baghshahi ◽  
Masoud Rajabi ◽  
Mahdi Siahpoosh ◽  
Fateme Esfehani
Keyword(s):  
Electrophoretic Deposition ◽  
Weight Percent ◽  
Nanocomposite Coatings ◽  
Time Interval ◽  
Surface Charges ◽  
Kinetic Evaluation ◽  
Aluminium Powder ◽  
Stable Suspension ◽  
Nickel Based Superalloy ◽  
Wide Range

In the current study, the evolution of deposition yields with time for yttria stabilized zirconia (YSZ)/Al2O3 nanocomposite coatings deposited by electrophoretic technique was described by a kinetic model. Aluminium powder was used as a sintering aid and also the source for the formation of Al2O3 during sintering. A mixture of ethanol and acetylacetone was utilized as the solvent. In order to prepare a stable suspension, surface charges and electrostatic interaction between particles in suspensions were evaluated through analyses of pH, zeta potential, and particles size. Electrophoretic deposition (EPD) on Inconel 718 electrodes was successfully carried out by employing three well-dispersed suspensions including nanostructured YSZ with 0, 30 and 50 wt.% of Al particles. The influences of three different applied voltages (25, 45 and 65 V), deposition time and the weight percent of Al particles on the EPD kinetic at a time interval of 0-300 s were studied and quantified based on the Baldisserri equation. It was shown that the results achieved from the Baldisserri model were almost well matched with the experimental data within a wide range of time. It was found that the deposition rate declines with the increase in YSZ nanoparticles content and time. The coated substrates in the final step were dried and sintered at 1150 ?C. The coating quality and surface morphology were characterized by field emission scanning electron microscopy (FE-SEM).

Influence of circumferential annular grooving design of impeller on suspended fluid force of axial flow blood pump

2022 ◽  
pp. 039139882110649
Author(s):  
Liang Wang ◽  
Zhong Yun ◽  
Xiaoyan Tang ◽  
Chuang Xiang
Keyword(s):  
Axial Flow ◽  
Groove Depth ◽  
Blood Pump ◽  
Suspension Stability ◽  
Impeller Blade ◽  
Stable Suspension ◽  
Axial Flow Blood Pump ◽  
The Stability ◽  
The Mathematical Model ◽  
The Relationship

Aiming at insufficient suspension force on the impeller when the hydraulic suspension axial flow blood pump is start at low speed, the impeller suspension stability is poor, and can’t quickly enter the suspended working state. By establishing the mathematical model of the suspension force on the impeller, then the influence of the circumferential groove depth of the impeller on the suspension force is analyzed, and the annular groove depth on the impeller blade in the direction of fluid inlet and outlet was determined as (0.26, 0.02 mm). When the blood pump starts, there is an eccentricity between the impeller and the pump tube, the relationship between the suspension force and the speed of the impeller under different eccentricities is analyzed. Combined with the prototype experiment, the circumferential annular grooving design of the impeller can make the blood pump rotate at about 3500 rpm into the suspension state, when the impeller is at 8000 rpm, the impeller can basically achieve stable suspension at the eccentricity of 0.1 mm in the gravity direction, indicating that the reasonable circumferential annular grooving design of the impeller can effectively improve the suspension hydraulic force of the impeller and improve the stability of the hydraulic suspension axial flow blood pump.

Aging Behavior of Yttria Stabilized Zirconia (YSZ) in Non Aqueous Suspensions for Electrophoretic Deposition Application

2009 ◽  
Vol 412 ◽  
pp. 279-285 ◽  
Author(s):  
Iman Azarian Borojeni ◽  
Babak Raissi ◽  
Amir Maghsoudipour ◽  
Mahmood Kazemzad ◽  
Ehsan Marzbanrad
Keyword(s):  
Aging Time ◽  
Electrophoretic Mobility ◽  
Electrophoretic Deposition ◽  
Yttria Stabilized Zirconia ◽  
Suspension Stability ◽  
Stabilized Zirconia ◽  
Aging Behavior ◽  
Electrical Field ◽  
Aqueous Suspensions ◽  
Conductivity Variation

In this research aging behaviors of yttria stabilized zirconia (YSZ) in non aqueous suspensions, namely ethanol, isopropanol, n-propanol, acetylacetone and the mixture of ethanol-acetylacetone were investigated. For this purpose, electrical conductivity, electrophoretic mobility and suspension stability during aging time (6 to 7 days) were evaluated. Except for the ethanol-acetyl acetone mixture, each suspension contained 0 to 0.8 g/L iodine. It was revealed that, the alcoholic suspensions indicated lower conductivity in comparison with acetylacetone suspensions. However, acetylacetone suspension showed lower conductivity variation with time. Although iodine could improve the electrophoretic mobility of ethanol and acetylacetone suspensions, it had little effect on electrophoretic mobility of isopropanol and n-propanol suspensions. Also, it was indicated that iodine as a dispersant was not helpful for alcoholic suspensions stability. It was concluded that the mixture of acetylacetone-ethanol suspension was the best candidate in this study for electrophoretic deposition of YSZ, owing to its little behavior variation with the aging time, low conductivity and high electrophoretic mobility. High quality crack-free layers were electrophoretically deposited from this suspension on the substrate by applying 50 V/cm electrical field.

scholarly journals Electrophoretic Deposition of 45S5 Bioglass® Coatings on the Ti6Al4V Prosthetic Alloy with Improved Mechanical Properties

Coatings ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1192
Author(s):  
Imen Azzouz ◽  
Joël Faure ◽  
Kaouther Khlifi ◽  
Ahmed Cheikh Larbi ◽  
Hicham Benhayoune
Keyword(s):  
Mechanical Properties ◽  
Electrophoretic Deposition ◽  
Scratch Test ◽  
X Ray Diffraction ◽  
X Ray ◽  
Stable Suspension ◽  
Test Study ◽  
Before And After ◽  
Titanium Alloy Ti6al4v ◽  
45S5 Bioglass

In this paper, 45S5 Bioglass® coatings were elaborated by electrophoretic deposition (EPD) on the titanium alloy Ti6Al4V. An adequate grinding protocol was developed to obtain a stable suspension of submicrometric particles in isopropanol. The voltage and the deposition time of EPD were optimized. An optimal voltage of 30 V and two deposition times (30 and 90 s) were chosen to obtain two different coatings with thicknesses of 21 and 85 µm, respectively. The as-deposited coatings were thermally treated following a two-step protocol: one hour at 120 °C followed by one hour at 450 °C. The surface morphology and the chemical analysis of the 45S5 Bioglass® coatings were assessed, before and after heat treatment, by scanning electron microscopy associated to X-ray microanalysis (SEM-EDXS). Their structural analysis was performed by X-ray diffraction (XRD). A scratch test study was developed for mechanical properties analysis. The obtained results revealed that the obtained coatings were homogeneous, weakly crystallized with an important compactness. An increase in the critical load LC associated with the cohesive limit of the film (from Lc = 3.39 N to Lc = 5.18 N) was observed when the coating thickness was decreased from 85 to 21 µm. After the thermal treatment, the chemical composition of the coatings was not altered, and their mechanical properties were improved.

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