Microfabricated Structures for the Measurement of Adhesion and MechanicaL Properties of Polymer Films

1988 ◽  
pp. 501-508 ◽  
Author(s):  
Mark G. Allen ◽  
Stephen D. Senturia
Keyword(s):  
Mechanical Properties ◽  
Polymer Films

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.

scholarly journals Friction and Mechanical Properties of AFM-Scan-Induced Ripples in Polymer Films

2021 ◽  
Vol 7 ◽  
Author(s):  
Sebastian Friedrich ◽  
Brunero Cappella
Keyword(s):  
Mechanical Properties ◽  
Polymer Films ◽  
Mechanical Response ◽  
Butyl Methacrylate ◽  
Clear Correlation ◽  
Contact Mode ◽  
Cantilever Deflection ◽  
Atomic Force ◽  
Volume Measurements ◽  
Force Volume

When compliant samples such as polymer films are scanned with an atomic force microscope (AFM) in contact mode, a periodic ripple pattern can be induced on the sample. In the present paper, friction and mechanical properties of such ripple structures on films of polystyrene (PS) and poly-n-(butyl methacrylate) (PnBMA) are investigated. Force volume measurements allow a quantitative analysis of the elastic moduli with nanometer resolution, showing a contrast in mechanical response between bundles and troughs. Additionally, analysis of the lateral cantilever deflection when scanning on pre-machined ripples shows a clear correlation between friction and the sample topography. Those results support the theory of crack propagation and the formation of voids as a mechanism responsible for the formation of ripples. This paper also shows the limits of the presented measuring methods for soft, compliant, and small structures. Special care must be taken to ensure that the analysis is not affected by artefacts.

INFLUENCE OF THICKNESS OF HOMOPHASE AND HETEROPHASE POLYMER FILMS ON THEIR MECHANICAL PROPERTIES

2004 ◽  
Vol 53 (8) ◽  
pp. 685-696 ◽  
Author(s):  
S. V. Vlasov ◽  
E. A. Shcherbakova ◽  
A. V. Markov ◽  
V. N. Kuleznev
Keyword(s):  
Mechanical Properties ◽  
Polymer Films

Adaptable Eu-containing polymeric films with dynamic control of mechanical properties in response to moisture

Soft Matter ◽  
2020 ◽  
Vol 16 (9) ◽  
pp. 2276-2284 ◽  
Author(s):  
Zichao Wei ◽  
Srinivas Thanneeru ◽  
Elena Margaret Rodriguez ◽  
Gengsheng Weng ◽  
Jie He
Keyword(s):  
Mechanical Properties ◽  
Optical Properties ◽  
Polymer Films ◽  
Dynamic Control ◽  
Polymeric Films ◽  
Self Healing ◽  
Healing Efficiency

Moisture that competes with dipicolylamine to bind Eu dynamically controls the mechanical and optical properties of polymer films, as well as their self-healing efficiency.

Mechanical properties of plasma polymer films

1992 ◽  
Vol 73 (5) ◽  
pp. 1067-1069 ◽  
Author(s):  
M. HLAVÁČ ◽  
M. OHLÍDAL ◽  
D. SLAVÍNSKÁ ◽  
H. BIEDERMAN
Keyword(s):  
Mechanical Properties ◽  
Polymer Films ◽  
Plasma Polymer

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

Effects of coating pressure on the thermal and mechanical properties of glow discharge polymer films

2011 ◽  
Vol 20 (7) ◽  
pp. 1042-1045 ◽  
Author(s):  
J.C. Yan ◽  
Z.B. He ◽  
J.J. Wei ◽  
Y. Zhang ◽  
L. Zhang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Glow Discharge ◽  
Polymer Films ◽  
Thermal And Mechanical Properties

Theory and Simulation of Polymers at Interfaces

MRS Bulletin ◽  
1997 ◽  
Vol 22 (1) ◽  
pp. 13-15 ◽  
Author(s):  
Anna C. Balazs
Keyword(s):  
Mechanical Properties ◽  
Polymer Films ◽  
Colloidal Particles ◽  
Structural Integrity ◽  
Solid Surfaces ◽  
Polymer Layer ◽  
Polymer Interfaces ◽  
New Materials ◽  
Immiscible Polymers ◽  
The Individual

The articles in this issue illustrate how various theoretical and computer models have been used to probe behavior of polymers at penetrable and impenetrable interfaces. Interest in polymer interfaces stems from the control interfaces commonly have over macroscopic properties—such as the strength or biocompatibility of the material. Consider the “alloying” or blending of existing polymers. This technique provides an inexpensive means of fabricating new materials that can display the desirable properties of the individual components. Most polymer pairs however are immiscible, and the mixture segregates into macroscopic domains separated by relatively weak interfaces. To enhance the structural integrity of the blend, copolymer “compatibilizers” are added to the mixture. These chains localize at the interface between the immiscible polymers, enhance the adhesion between the phase-separated regions, and thereby improve the mechanical properties of the blend.On an impenetrable interface, polymer films or coatings are commonly used to modify the properties of the underlying substrate. For example the polymer layer can be utilized to tailor biocompatibility, wettability, or roughness of the surface. Polymers anchored to solid surfaces can also be used to control the interaction between these surfaces. Thus the tethered layer can promote the adhesion between dissimilar solids or prevent the aggregation of colloidal particles.

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