Morphological and Mechanical Properties of Electrospun Polycaprolactone Scaffolds: Effect of Applied Voltage

The aim of this work is to investigate the effect of the applied voltage on the morphological and mechanical properties of electrospun polycaprolactone (PCL) scaffolds for potential use in tissue engineering. The morphology of the scaffolds was characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), and the BET techniques for measuring the surface area and pore volume. Stress-strain curves from tensile tests were obtained for estimating the mechanical properties. Additional studies for detecting changes in the chemical structure of the electrospun PCL scaffolds by Fourier transform infrared were performed, while contact angle and X-ray diffraction analysis were realized for determining the wettability and crystallinity, respectively. The SEM, AFM and BET results demonstrate that the electrospun PCL fibers exhibit morphological changes with the applied voltage. By increasing the applied voltage (10 to 25 kV) a significate influence was observed on the fiber diameter, surface roughness, and pore volume. In addition, tensile strength, elongation, and elastic modulus increase with the applied voltage, the crystalline structure of the fibers remains constant, and the surface area and wetting of the scaffolds diminish. The morphological and mechanical properties show a clear correlation with the applied voltage and can be of great relevance for tissue engineering.

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Poly(furfuryl alcohol)-Polycaprolactone Blends

Polymers ◽

10.3390/polym11061069 ◽

2019 ◽

Vol 11 (6) ◽

pp. 1069 ◽

Cited By ~ 3

Author(s):

Gabriele Nanni ◽

José A. Heredia-Guerrero ◽

Uttam C. Paul ◽

Silvia Dante ◽

Gianvito Caputo ◽

...

Keyword(s):

Mechanical Properties ◽

Furfuryl Alcohol ◽

Barrier Properties ◽

Tensile Tests ◽

Attenuated Total Reflection ◽

Toxicity Tests ◽

Scanning Calorimetry ◽

Blend Films ◽

Force Microscopy ◽

Atomic Force

Poly(furfuryl alcohol) (PFA) is a bioresin synthesized from furfuryl alcohol (FA) that is derived from renewable saccharide-rich biomass. In this study, we compounded this bioresin with polycaprolactone (PCL) for the first time, introducing new functional polymer blends. Although PCL is biodegradable, its production relies on petroleum precursors such as cyclohexanone oils. With the method proposed herein, this dependence on petroleum-derived precursors/monomers is reduced by using PFA without significantly modifying some important properties of the PCL. Polymer blend films were produced by simple solvent casting. The blends were characterized in terms of surface topography by atomic force microscopy (AFM), chemical interactions between PCL and PFA by attenuated total reflection-Fourier transform infrared (ATR-FTIR), crystallinity by XRD, thermal properties by differential scanning calorimetry (DSC), and mechanical properties by tensile tests and biocompatibility by direct and indirect toxicity tests. PFA was found to improve the gas barrier properties of PCL without compromising its mechanical properties, and it demonstrated sustained antioxidant effect with excellent biocompatibility. Our results indicate that these new blends can be potentially used in diverse applications ranging from food packing to biomedical devices.

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Microscopic Methods for Characterization of Selected Surface Properties of Biodegradable, Nanofibrous Tissue Engineering Scaffolds

Materials Science Forum ◽

10.4028/www.scientific.net/msf.890.213 ◽

2017 ◽

Vol 890 ◽

pp. 213-216 ◽

Cited By ~ 12

Author(s):

Adrian Chlanda ◽

Ewa Kijeńska ◽

Wojciech Święszkowski

Keyword(s):

Mechanical Properties ◽

Tissue Engineering ◽

Young’S Modulus ◽

Young's Modulus ◽

Force Spectroscopy ◽

Operating Mode ◽

Tissue Engineering Scaffolds ◽

Force Microscopy ◽

Atomic Force

Biodegradable polymeric fibers with nanoand submicron diameters, produced by electrospinning can be used as scaffolds in tissue engineering. It is necessary to characterize their mechanical properties especially at the nanoscale. The Force Spectroscopy is suitable atomic force microscopy mode, which allows to probe mechanical properties of the material, such as: reduced Young's modulus, deformation, adhesion, and dissipation. If combined with standard operating mode: contact or semicontact, it will also provide advanced topographical analysis. In this paper we are presenting results of Force Spectroscopy characterization of two kinds of electrospun fibers: polycaprolactone and polycaprolactone with hydroxyapatite addition. The average calculated from Johnson-Kendall-Roberts theory Young's modulus was 4 ± 1 MPa for pure polymer mesh and 20 ± 3 MPa for composite mesh.

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Role of Polysaccharides on Mechanical and Adhesion Properties of Flax Fibres in Flax/PLA Biocomposite

International Journal of Polymer Science ◽

10.1155/2011/503940 ◽

2011 ◽

Vol 2011 ◽

pp. 1-11 ◽

Cited By ~ 23

Author(s):

Gijo Raj ◽

Eric Balnois ◽

Christophe Baley ◽

Yves Grohens

Keyword(s):

Mechanical Properties ◽

Morphological Changes ◽

Cellulose Microfibrils ◽

Adhesion Properties ◽

Force Microscopy ◽

Flax Fibres ◽

Atomic Force ◽

Multilength Scale ◽

Fibre Morphology

The effect of alkali and enzymatic treatments on flax fibre morphology, mechanical, and adhesion properties was investigated. The multilength scale analysis allows for the correlation of the fibre's morphological changes induced by the treatments with mechanical properties to better explain the adherence properties between flax and PLA. The atomic force microscopy (AFM) images revealed the removal of primary layers, upon treatments, down to cellulose microfibrils present in the secondary layers. The variation in mechanical properties was found to be dependent, apart from the crystalline content, on interaction between cellulose microfibrils and encrusting polysaccharides, pectins and hemicelluloses, in the secondary layers. Finally, microbond tests between the modified fibres and PLA emphasize the important role of the outer fibre's surface on the overall composite properties. It was observed here that gentle treatments of the fibres, down to the oriented microfibrils, are favourable to a better adherence with a PLA drop. This paper highlights the important role of amorphous polymers, hemicellulose and pectin, in the optimisation of the adhesion and mechanical properties of flax fibres in the biocomposite.

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Microstructure and Mechanical Properties of Electroplated Cu Thin Films

MRS Proceedings ◽

10.1557/proc-649-q5.3 ◽

2000 ◽

Vol 649 ◽

Cited By ~ 19

Author(s):

A.A. Volinsky ◽

J. Vella ◽

I.S. Adhihetty ◽

V. Sarihan ◽

L. Mercado ◽

...

Keyword(s):

Mechanical Properties ◽

Elastic Modulus ◽

Focused Ion Beam ◽

Ion Beam ◽

Single Crystal Silicon ◽

Tensile Tests ◽

Crystal Silicon ◽

Cu Films ◽

Force Microscopy ◽

Atomic Force

ABSTRACTCopper films of different thicknesses of 0.2, 0.5, 1 and 2 microns were electroplated on top of the adhesion-promoting barrier layers on <100> single crystal silicon wafers. Controlled Cu grain growth was achieved by annealing films in vacuum.The Cu film microstructure was characterized using Atomic Force Microscopy and Focused Ion Beam Microscopy. Elastic modulus of 110 to 130 GPa and hardness of 1 to 1.6 GPa were measured using the continuous stiffness option (CSM) of the Nanoindenter XP. Thicker films appeared to be softer in terms of the lower modulus and hardness, exhibiting a classical Hall-Petch relationship between the yield stress and grain size. Lower elastic modulus of thicker films is due to the higher porosity and partially due to the surface roughness. Comparison between the mechanical properties of films on the substrates obtained by nanoindentation and tensile tests of the freestanding Cu films is made.

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Investigation on the Microscopic/Macroscopic Mechanical Properties of a Thermally Annealed Nafion® Membrane

Polymers ◽

10.3390/polym13224018 ◽

2021 ◽

Vol 13 (22) ◽

pp. 4018

Author(s):

Tuyet Anh Pham ◽

Seunghoe Koo ◽

Hyunseok Park ◽

Quang Thien Luong ◽

Oh Joong Kwon ◽

...

Keyword(s):

Mechanical Properties ◽

Fuel Cell ◽

Annealing Temperature ◽

Essential Element ◽

Tensile Tests ◽

Force Microscopy ◽

Electrolyte Membrane ◽

Atomic Force ◽

Electrolyte Membranes ◽

Temperature Ranges

The Nafion® electrolyte membrane, which provides a proton pathway, is an essential element in fuel cell systems. Thermal treatment without additional additives is widely used to modify the mechanical properties of the membrane, to construct reliable and durable electrolyte membranes in the fuel cell. We measured the microscopic mechanical properties of thermally annealed membranes using atomic force microscopy with the two-point method. Furthermore, the macroscopic property was investigated through tensile tests. The microscopic modulus exceeded the macroscopic modulus over all annealing temperature ranges. Additionally, the measured microscopic modulus increased rapidly near 150 °C and was saturated over that temperature, whereas the macroscopic modulus continuously increased until 250 °C. This mismatched micro/macroscopic reinforcement trend indicates that the internal reinforcement of the clusters is induced first until 150 °C. In contrast, the reinforcement among the clusters, which requires more thermal energy, probably progresses even at a temperature of 250 °C. The results showed that the annealing process is effective for the surface smoothing and leveling of the Nafion® membrane until 200 °C.

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Mechanical Properties of Membrane Surface of Cultured Astrocyte Revealed by Atomic Force Microscopy

Japanese Journal of Applied Physics ◽

10.1143/jjap.39.3711 ◽

2000 ◽

Vol 39 (Part 1, No. 6B) ◽

pp. 3711-3716 ◽

Cited By ~ 15

Author(s):

Hatsuki Shiga ◽

Yukako Yamane ◽

Etsuro Ito ◽

Kazuhiro Abe ◽

Kazushige Kawabata ◽

...

Keyword(s):

Mechanical Properties ◽

Atomic Force Microscopy ◽

Membrane Surface ◽

Force Microscopy ◽

Atomic Force

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Corrosion Behavior and Mechanical Properties of a Nanocomposite Superhydrophobic Coating

Coatings ◽

10.3390/coatings11060652 ◽

2021 ◽

Vol 11 (6) ◽

pp. 652

Author(s):

Divine Sebastian ◽

Chun-Wei Yao ◽

Lutfun Nipa ◽

Ian Lian ◽

Gary Twu

Keyword(s):

Electron Microscopy ◽

Mechanical Properties ◽

Scanning Electron Microscopy ◽

Atomic Force Microscopy ◽

Nanocomposite Coating ◽

Superhydrophobic Coating ◽

Force Microscopy ◽

Atomic Force ◽

Microscopy Images ◽

Scanning Electron

In this work, a mechanically durable anticorrosion superhydrophobic coating is developed using a nanocomposite coating solution composed of silica nanoparticles and epoxy resin. The nanocomposite coating developed was tested for its superhydrophobic behavior using goniometry; surface morphology using scanning electron microscopy and atomic force microscopy; elemental composition using energy dispersive X-ray spectroscopy; corrosion resistance using atomic force microscopy; and potentiodynamic polarization measurements. The nanocomposite coating possesses hierarchical micro/nanostructures, according to the scanning electron microscopy images, and the presence of such structures was further confirmed by the atomic force microscopy images. The developed nanocomposite coating was found to be highly superhydrophobic as well as corrosion resistant, according to the results from static contact angle measurement and potentiodynamic polarization measurement, respectively. The abrasion resistance and mechanical durability of the nanocomposite coating were studied by abrasion tests, and the mechanical properties such as reduced modulus and Berkovich hardness were evaluated with the aid of nanoindentation tests.

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The Infuence of Salicin on Rheological and Film-Forming Properties of Collagen

Molecules ◽

10.3390/molecules26061661 ◽

2021 ◽

Vol 26 (6) ◽

pp. 1661

Author(s):

Katarzyna Adamiak ◽

Katarzyna Lewandowska ◽

Alina Sionkowska

Keyword(s):

Mechanical Properties ◽

Atomic Force Microscopy ◽

Infrared Spectroscopy ◽

Rheological Properties ◽

Silver Carp ◽

Shear Tests ◽

Force Microscopy ◽

Atomic Force ◽

Film Forming ◽

Potential Applications

Collagen films are widely used as adhesives in medicine and cosmetology. However, its properties require modification. In this work, the influence of salicin on the properties of collagen solution and films was studied. Collagen was extracted from silver carp skin. The rheological properties of collagen solutions with and without salicin were characterized by steady shear tests. Thin collagen films were prepared by solvent evaporation. The structure of films was researched using infrared spectroscopy. The surface properties of films were investigated using Atomic Force Microscopy (AFM). Mechanical properties were measured as well. It was found that the addition of salicin modified the roughness of collagen films and their mechanical and rheological properties. The above-mentioned parameters are very important in potential applications of collagen films containing salicin.

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