Study of mechanical properties of light-emitting polymer films by nano-indentation technique

2005 ◽  
Vol 477 (1-2) ◽  
pp. 111-118 ◽  
Author(s):  
Kaiyang Zeng ◽  
Zhi-Kuan Chen ◽  
Lu Shen ◽  
Bin Liu
Keyword(s):  
Mechanical Properties ◽  
Polymer Films ◽  
Light Emitting ◽  
Nano Indentation ◽  
Indentation Technique

Evaluation of Mechanical Properties of Graphite Layers on a Nuclear Fuel Particle by Kinetic Nano-Indentation Technique

2007 ◽  
Vol 345-346 ◽  
pp. 1177-1180 ◽  
Author(s):  
K.S. Choi ◽  
Y. Choi ◽  
Bong Goo Kim ◽  
Y.W. Lee
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Fuel Particle ◽  
Small Specimen ◽  
Indentation Method ◽  
Nano Indentation ◽  
Indentation Technique ◽  
Simple Geometry ◽  
Kinetic Indentation ◽  
High Temperature Gas

Small specimen with simple geometry has advantage for irradiation tests because the tests have limits for experiments and nuclear wastes after irradiation tests. In this study, a kinetic indentation technique is applied to evaluate mechanical properties of coated layers of a particle fuel of a high temperature gas cooled reactor. Hardness of buffer, IPyC and OPyC are 0.55, 0.874 and 2.726 GPa, respectively. The density, strength and friction coefficient estimated by kinetic indentation method are 1.08, 1.15 and 1.81 g/cm3, and 174, 291 and 606 MPa, and 0.51, 0.45 and 0.4, respectively.

scholarly journals Nano-mechanical properties of novel intermetallic coatings on 316L bioimplant material

2019 ◽  
Vol 6 (1) ◽  
pp. 119-127
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Room Temperature ◽  
Intermetallic Layer ◽  
Nano Indentation ◽  
Indentation Technique ◽  
316L Austenitic Stainless Steel ◽  
Intermetallic Coatings

In the present work, Nano-mechanical properties of intermetallic layer formed on 316L austenitic stainless steel have been investigated. Hot dip aluminizing technique applied on stainless steel samples for coating and composition of Al-Si alloys maintained as 8%, 10%, 12% and 14%. Nano-mechanical properties of the Intermetallic formed have been evaluated using Nano-indentation technique at room temperature and results were compared. On the basis of our observations and obtained results it is concluded that with increasing silicon percentage the thickness of the intermetallic layer increases. However, the Nano-mechanical results showed that this layer is brittle in nature. Therefore, it can be inferred that for bio-implant application the thickness of the layer needs to be at lower level as possible.

Polylactide-based stent coatings: biodegradable polymeric coatings capable of maintaining sustained release of the thrombolytic enzyme streptokinase

2020 ◽  
Vol 92 (8) ◽  
pp. 1329-1340
Author(s):  
A. G. Kolmakov ◽  
A. S. Baikin ◽  
S. V. Gudkov ◽  
K. N. Belosludtsev ◽  
E. O. Nasakina ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Polymer Films ◽  
De Novo ◽  
Membrane Surface ◽  
Aqueous Media ◽  
Polymeric Coatings ◽  
Short Term ◽  
Thrombolytic Activity ◽  
Viable Cells ◽  
Nitinol Stents

AbstractThe paper describes synthesis and testing of novel biodegradable polylactide-based polymer membranes with desired mechanical properties, which are capable of sustained and directed release of biomacromolecules with high molecular weight (in particular, streptokinase; m.w. 47 kDa). Streptokinase is a pharmaceutical agent, possessing a pronounced thrombolytic activity. The membranes synthesized had a percentage elongation of 2–11% and tensile strength of 25–85 MPa. They were biodegradable – yet being stored in aqueous media in the absence of biological objects, would be dissolved by no more than 10% in 6 months. The synthesized membranes were capable of controlled release of streptokinase into the intercellular space, with the enzyme retaining more than 90% of its initial activity. The rate of streptokinase release from the membranes varied from 0.01 to 0.04 mg/day per cm2 of membrane surface. The membrane samples tested in the work did not have any short-term toxic effects on the cells growing de novo on the membrane surface. The mitotic index of those cells was approximately 1.5%, and the number of non-viable cells on the surface of the polymer films did not exceed 3–4% of their total amount. The implantation of the synthesized polymers – as both individual films and coatings of nitinol stents – was not accompanied by any postoperative complications. The subsequent histological examination revealed no abnormalities. Two months after the implantation of polymer films, only traces of polylactide were found in the implant-surrounding tissues. The implantation of stents coated with streptokinase-containing polymers resulted in the formation of a mature and thick connective-tissue capsules. Thus, the polylactide membranes synthesized and tested in this work are biodegradable, possess the necessary mechanical properties and are capable of sustained and directed release of streptokinase macromolecules.

Investigation on mechanical properties of P92 steel using ball indentation technique

2015 ◽  
Vol 624 ◽  
pp. 92-101 ◽  
Author(s):  
Dipika R. Barbadikar ◽  
A.R. Ballal ◽  
D.R. Peshwe ◽  
J. Ganeshkumar ◽  
K. Laha ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
P92 Steel ◽  
Indentation Technique ◽  
Ball Indentation

Measurement of Young's Modulus and Poisson's Ratio of Thin Film by Combination of Bulge Test and Nano-Indentation

2008 ◽  
Vol 33-37 ◽  
pp. 969-974 ◽  
Author(s):  
Bong Bu Jung ◽  
Seong Hyun Ko ◽  
Hun Kee Lee ◽  
Hyun Chul Park
Keyword(s):  
Thin Film ◽  
Mechanical Properties ◽  
Young’S Modulus ◽  
Poisson’S Ratio ◽  
Young's Modulus ◽  
Applied Pressure ◽  
Indentation Test ◽  
Poisson's Ratio ◽  
Bulge Test ◽  
Nano Indentation

This paper will discuss two different techniques to measure mechanical properties of thin film, bulge test and nano-indentation test. In the bulge test, uniform pressure applies to one side of thin film. Measurement of the membrane deflection as a function of the applied pressure allows one to determine the mechanical properties such as the elastic modulus and the residual stress. Nano-indentation measurements are accomplished by pushing the indenter tip into a sample and then withdrawing it, recording the force required as a function of position. . In this study, modified King’s model can be used to estimate the mechanical properties of the thin film in order to avoid the effect of substrates. Both techniques can be used to determine Young’s modulus or Poisson’s ratio, but in both cases knowledge of the other variables is needed. However, the mathematical relationship between the modulus and Poisson's ratio is different for the two experimental techniques. Hence, achieving agreement between the techniques means that the modulus and Poisson’s ratio and Young’s modulus of thin films can be determined with no a priori knowledge of either.

Sign in / Sign up

Export Citation Format

Share Document