UV Irradiated Graphene-Based Nanocomposites: Change in the Mechanical Properties by Local HarmoniX Atomic Force Microscopy Detection

Epoxy based coatings are susceptible to ultra violet (UV) damage and their durability can be significantly reduced in outdoor environments. This paper highlights a relevant property of graphene-based nanoparticles: Graphene Nanoplatelets (GNPs) incorporated in an epoxy-based free-standing film determine a strong decrease of the mechanical damages caused by UV irradiation. The effects of UV light on the morphology and mechanical properties of the solidified nanocharged epoxy films are investigated by Atomic Force Microscopy (AFM), in the acquisition mode “HarmoniX.” Nanometric-resolved maps of the mechanical properties of the multi-phase material evidence that the incorporation of low percentages, between 0.1% and 1.0% by weight, of graphene nanoplatelets (GNPs) in the polymeric film causes a relevant enhancement in the mechanical stability of the irradiated films. The beneficial effect progressively increases with increasing GNP percentage. The paper also highlights the potentiality of AFM microscopy, in the acquisition mode “HarmoniX” for studying multiphase polymeric systems.

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Atomic force microscopy measurements probing the mechanical properties of single collagen fibrils under the influence of UV light in situ

Journal of the Mechanical Behavior of Biomedical Materials ◽

10.1016/j.jmbbm.2018.08.039 ◽

2018 ◽

Vol 88 ◽

pp. 415-421 ◽

Cited By ~ 3

Author(s):

Marcus Schulze ◽

Melanie Rogge ◽

Robert W. Stark

Keyword(s):

Mechanical Properties ◽

Atomic Force Microscopy ◽

Uv Light ◽

Collagen Fibrils ◽

Force Microscopy ◽

Atomic Force

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Cytoskeletal Dynamics of Neurons Measured by Combined Fluorescence and Atomic Force Microscopy

MRS Advances ◽

10.1557/adv.2018.101 ◽

2018 ◽

Vol 3 (26) ◽

pp. 1463-1468 ◽

Cited By ~ 1

Author(s):

Peter Moore ◽

Cristian Staii

Keyword(s):

Mechanical Properties ◽

Atomic Force Microscopy ◽

Ambient Temperature ◽

Cortical Neurons ◽

Mechanical Stability ◽

Neuronal Cells ◽

Force Microscopy ◽

Atomic Force ◽

Key Factor ◽

External Forces

ABSTRACTMechanical properties of neurons represent a key factor that determines the functionality of neuronal cells and the formation of neural networks. The main source of mechanical stability for the cell is a biopolymer network of microtubules and actin filaments that form the main components of the cellular cytoskeleton. This biopolymer network is responsible for the growth of neuronal cells as they extend neurites to connect with other neurons, forming the nervous system. Here we present experimental results that combine atomic force microscopy (AFM) and fluorescence microscopy to produce systematic, high-resolution elasticity and fluorescence maps of cortical neurons. This approach allows us to apply external forces to neurons, and to monitor the dynamics of the cell cytoskeleton. We measure how the elastic modulus of neurons changes upon changing the ambient temperature, and identify the cytoskeletal components responsible for these changes. These results demonstrate the importance of taking into account the effect of ambient temperature when measuring the mechanical properties of cells.

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The adsorption of progesterone onto mineral surfaces imaged with high-resolution atomic force microscopy

Mineralogical Magazine ◽

10.1180/minmag.2008.072.1.419 ◽

2008 ◽

Vol 72 (1) ◽

pp. 419-424

Author(s):

B. Goritschnig ◽

K. R. Hallam ◽

T. McMaster ◽

V. Ragnarsdottir

Keyword(s):

Aqueous Solution ◽

Atomic Force Microscopy ◽

High Resolution ◽

Uv Light ◽

Pyrolytic Graphite ◽

Ultra Violet ◽

Mineral Surfaces ◽

Force Microscopy ◽

Atomic Force

AbstractAtomic force microscopy (AFM) has been used to monitor the appearance and behaviour of the hormone progesterone on mineral surfaces, including mica and highly oriented pyrolytic graphite (HOPG). Different solvents have been used resulting in various features on the two substrates. After the application of 254 nm ultra-violet (UV) light, changes in structure of the adsorbed hormone have been observed. To understand the reactions at the progesterone-mica interface in aqueous solution, adsorption has been studied in situ with AFM.

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Surface morphology and mechanical properties of MDCK monolayers by atomic force microscopy

Journal of Cell Science ◽

10.1242/jcs.107.5.1105 ◽

1994 ◽

Vol 107 (5) ◽

pp. 1105-1114 ◽

Cited By ~ 7

Author(s):

J.H. Hoh ◽

C.A. Schoenenberger

Keyword(s):

Mechanical Properties ◽

Atomic Force Microscopy ◽

Plasma Membrane ◽

Mechanical Stability ◽

Physiological Solution ◽

Apical Plasma Membrane ◽

Apical Surface ◽

Force Microscopy ◽

Atomic Force ◽

Contrast Mechanism

We describe the morphology and mechanical stability of the apical surface of MDCK monolayers by atomic force microscopy (AFM). Living cells could be imaged in physiological solution for several hours without noticeable deterioration. Cell boundaries appear as ridges that clearly demarcate neighboring cells. In some cases the nucleus of individual cells could be seen, though apparently only in very thin areas of the monolayer. Two types of protrusions on the surface could be visualized. Smooth bulges that varied in width from a few hundred nanometers to several micrometers, which appear to represent relatively rigid subapical structures. Another type of protrusion extended well above the membrane and was swept back and forth during the imaging. However, the microvilli that are typically present on the apical surface could not be resolved. For comparison, a transformed MDCK cell line expressing the K-ras oncogene was also examined. When cultured on solid substrata at low density, the R5 cells spread out and are less than 100 nm thick over large areas with both extensive processes and rounded edges. Many intracellular structures such as the nucleus, cytoskeletal elements and vesicles could be visualized. None of the intracellular structures seen in the AFM images could be seen by scanning electron microscopy. Both R5 cells and MDCK monolayers required imaging forces of > 2 nN for good image contrast. Force measurements on the MDCK monolayers show that they are very soft, with an effective spring constant of approximately 0.002 N/m for the apical plasma membrane, over the first micrometer of deformation, resulting in a height deformation of approximately 500 nm per nanoNewton of applied force. The mechanical properties of the cells could be manipulated by addition of glutaraldehyde. These changes were monitored in real time by collecting force curves during the fixation reaction. The curves show a stiffening of the apical plasma membrane that was completed in approximately 1 minute. On the basis of these measurements and the imaging forces required, we conclude that deformation of the plasma membrane is an important component of the contrast mechanism, in effect ‘staining’ structures based on their relative rigidity.

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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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