Preparation of Nano-Convex and Nano-Concave-Patterned Polyimide Surfaces and Their Nano-Tribological Behavior

NANO ◽  
2017 ◽  
Vol 12 (04) ◽  
pp. 1750049 ◽  
Author(s):  
Chunxia Wu ◽  
Xiaoliang Zhang ◽  
Hongwei Che ◽  
Jingbo Mu ◽  
Guangshuo Wang ◽  
...  
Keyword(s):  
Self Assembly ◽  
Applied Load ◽  
Tribological Behavior ◽  
Surface Friction ◽  
Adhesive Force ◽  
Sliding Velocity ◽  
Friction Forces ◽  
Colloidal Probe ◽  
Atomic Force ◽  
Adhesive Forces

In this work, nano-convex-patterned polyimide surface (notated as 1-sample) and nano-concave-patterned polyimide surface (notated as 2-sample) were prepared by self-assembly and etching. Atomic force microscope (AFM) with a colloidal probe was used to examine the adhesion and nano-tribological behavior of the 1-sample and 2-sample. Results suggest that the 1-sample and 2-sample can decrease the surface friction and adhesive forces because of the decreased contact area between the contacting pairs. The friction forces of the 1-sample and 2-sample increased with the increase in sliding velocity and applied load. Moreover, the nano-concave pattern is more effective in reducing the adhesive force than the nano-convex pattern because of its higher surface roughness. However, the nano-convex patterning is more effective in reducing the friction force than the nano-concave patterning because of the smaller area of contact between the 2-sample and the colloidal probe.

Effect of Colloidal Probe Random Surface Features on Adhesion

2005 ◽  
Author(s):  
Seung Ho Yang ◽  
Stephen M. Hsu
Keyword(s):  
Adhesive Force ◽  
Wafer Surface ◽  
Random Surface ◽  
Surface Features ◽  
Colloidal Probe ◽  
Glass Spheres ◽  
Atomic Force ◽  
Colloidal Probes ◽  
Topography Data ◽  
Adhesive Forces

We have uncovered the fact that colloidal probes often have random surface features which when not properly accounted for, can significantly affect the magnitudes of the measured adhesive forces using atomic force microscopes (AFM). Colloidal probes have been used to measure the pull-off forces between the probe and surfaces. We prepared a series of colloidal probes by attaching glass spheres (radii of 3.3 μm to 17.4 μm) to the end of AFM cantilevers. Adhesive force between the probes and a silicon wafer surface was measured using an AFM under various loads from 6 nN to 100 nN in dry air. Results showed that the values of the pull-off forces did not correlate with the radii of the probes. Direct imaging of the glass sphere surface using a sharp tip revealed substantial random surface features which altered the size of real contact areas. We extracted the load-bearing areas from the topography data and used them to normalize the adhesion data. The measured adhesive force, after being normalized, was found to be independent of the load and the sphere radii, in agreement with prevailing contact mechanics theory.

Circular AFM Mode: A New AFM Mode for Investigating Surface Properties

2011 ◽  
Vol 1318 ◽  
Author(s):  
Olivier Noel ◽  
Pierre-Emmanuel Mazeran ◽  
Hussein Nasrallah
Keyword(s):  
Surface Properties ◽  
Stationary State ◽  
High Speed ◽  
Operating Mode ◽  
Relative Displacement ◽  
Sliding Velocity ◽  
Friction Forces ◽  
First Time ◽  
Mode A ◽  
Adhesive Forces

ABSTRACTFor the first time, a new AFM mode is presented that simultaneously allows the measuring of adhesion and friction forces at different constant and continuous sliding velocities. Our methodology consists of implementing a circular relative displacement of the contact to reach a constant sliding velocity, with no stop periods. Some of the main advantages of performing a circular displacement is that continuous and high sliding velocities (more than 1 mm/s) can be reached compared to the low sliding velocities (up to 10 μm/s) available when using commercial AFM. Also, a stationary state is reached when doing measurements. Moreover, the circular mode can be coupled with the classical operating mode, for instance, force spectrum. Main applications of this circular mode are related to metrological measurements in physics that require high speed displacements. As an example, we report the evolution of friction and adhesive forces measured in air at different high sliding velocities.

Determination of Dead-Oil Wetting and Adhesive Forces on Carbonate Rocks Using Colloidal-Probe Atomic Force Microscopy

2018 ◽  
Vol 32 (9) ◽  
pp. 9182-9190 ◽  
Author(s):  
Jehad Abed ◽  
Cyril Aubry ◽  
Mouna Zaidani ◽  
Nabil El Hadri ◽  
Rajakumar Devarapalli ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Carbonate Rocks ◽  
Colloidal Probe ◽  
Force Microscopy ◽  
Atomic Force ◽  
Adhesive Forces

scholarly journals The use of atomic force microscopy to assess the quality of cleaning and tribometric properties of a silicon wafer surface

2019 ◽  
Vol 43 (3) ◽  
pp. 507-511
Author(s):  
I.D. Mikheev ◽  
F.Kh. Vakhitov
Keyword(s):  
Silicon Wafer ◽  
Relative Magnitude ◽  
Wafer Surface ◽  
Friction Forces ◽  
Small Areas ◽  
Force Microscopy ◽  
Atomic Force ◽  
Wafer Surfaces ◽  
Adhesive Forces

Differences in the values of adhesive forces of interaction between the probe tip of an atomic force microscope and the cleaned surfaces of silicon wafers during their treatment with isopropyl alcohol and distilled water were investigated experimentally. It was shown that the presence of water molecules on the surface of the substrates leads to a significant (approximately 5 times) change in the value of these forces. It was found that the use of AFM allows the relative magnitude of friction forces in small areas of silicon wafer surfaces to be estimated.

Clathrin-Inspired Coating and Stabilization of Liposomes by DNA Self-Assembly

2019 ◽  
Author(s):  
Kevin N. Baumann ◽  
Luca Piantanida ◽  
Javier García-Nafría ◽  
Diana Sobota ◽  
Kislon Voïtchovsky ◽  
...  
Keyword(s):  
Self Assembly ◽  
Mechanical Stability ◽  
Lipid Vesicles ◽  
The Self ◽  
Force Microscopy ◽  
Atomic Force ◽  
Cryo Electron Microscopy ◽  
Further Development ◽  
Liposome Surface ◽  
Dna Coating

The self-assembly of the protein clathrin on biological membranes facilitates essential processes of endocytosis in biological systems and has provided a source of inspiration for materials design by the highly ordered structural appearance. By mimicking the architecture of clathrin self-assemblies to coat liposomes with biomaterials, new classes of hybrid carriers can be derived. Here we present a method for fabricating DNA-coated liposomes by hydrophobically anchoring and subsequently growing a DNA network on the liposome surface which structurally mimics clathrin assemblies. Dynamic light scattering (DLS), ζ-potential and cryo-electron microscopy (cryo-EM) measurements independently demonstrate successful DNA coating. Nanomechanical measurements conducted with atomic force microscopy (AFM) show that the DNA coating enhances the mechanical stability of the liposomes relative to uncoated ones. Furthermore, we provide the possibility to reverse the coating process by triggering the disassembly of the DNA coating through a toehold-mediated displacement reaction. Our results describe a straightforward, versatile, and reversible approach for coating and stabilizing lipid vesicles by an interlaced DNA network. This method has potential for further development towards the ordered arrangement of tailored functionalities on the surfaces of liposomes and for applications as hybrid nanocarrier.

A study on the microstructure, hardness, and tribological behavior of aluminum-based metal–matrix composite fabricated through recursive friction stir processing

2020 ◽  
pp. 146442072097668
Author(s):  
G Girish ◽  
V Anandakrishnan
Keyword(s):  
Metal Matrix Composite ◽  
Matrix Composite ◽  
Friction Stir Processing ◽  
Metal Matrix ◽  
Applied Load ◽  
Tribological Behavior ◽  
Testing Conditions ◽  
Friction Stir ◽  
The Matrix ◽  
Microstructure Examination

In this work, an Al–Zn–Mg–Cu/TiC metal–matrix composite was fabricated through recursive friction stir processing, and its microstructure, hardness, and tribological properties were investigated. Microstructure examination revealed a homogeneous dispersion of TiC particles in the matrix after six recursive passes. The grains were significantly refined and microhardness of the composite improved due to the presence of TiC particles. Friction coefficient and wear rate of the composite went up with an increase in the applied load and dropped significantly at higher sliding velocities. The morphology of the wear specimens experimented under different testing conditions was analyzed and the corresponding wear mechanisms discussed.

Nanoscale Evaluation of Multi-Walled Carbon Nanotube’s Performance on Resisting Oxidization of Asphalt

2020 ◽  
Vol 982 ◽  
pp. 195-200
Author(s):  
Abdullah Al Mamun ◽  
Okan Sirin
Keyword(s):  
Adhesive Force ◽  
Force Microscopy ◽  
Modified Asphalt ◽  
Atomic Force ◽  
Resistance To Oxidation ◽  
Pavement Engineering ◽  
Multi Walled Carbon Nanotubes ◽  
Polymer Modified Asphalt ◽  
Styrene Butadiene ◽  
Walled Carbon Nanotubes

Nanotechnology has contributed significantly to different subfields of the construction industry, including asphalt pavement engineering. The improved properties and new functionalities of the nanomaterials have provided different desired properties of asphalt. In this study, the effectiveness of multi-walled carbon nanotubes (MWCNT) in resisting the oxidation of polymer-modified asphalt was measured. A total of three different percentages (0.5%, 1%, and 1.5%) of MWCNT were used to modify the Styrene-Butadiene (SB) and styrene–butadiene–styrene (SBS) modified asphalt (4% and 5%). The laboratory oxidized asphalt samples were evaluated by an atomic force microscopy machine. The oxidation of the polymer-MWCNT modified asphalt is measured by simulating the existing functional group of the asphalt and as a function of the adhesive force. It is observed that the use of MWCNT in SB and SBS can increase the resistance to oxidation.

Graphite Particle Adhesion to Hastelloy X: Measurements of the Adhesive Force with an Atomic Force Microscope

2014 ◽  
Vol 186 (1) ◽  
pp. 45-59 ◽  
Author(s):  
Naphtali M. Mokgalapa ◽  
Tushar K. Ghosh ◽  
Sudarshan K. Loyalka
Keyword(s):  
Atomic Force Microscope ◽  
Graphite Particle ◽  
Adhesive Force ◽  
Particle Adhesion ◽  
Hastelloy X ◽  
Atomic Force

Tribological Behavior of Mesophase Carbon Added with Titanium and Copper

2011 ◽  
Vol 80-81 ◽  
pp. 60-63
Author(s):  
Xue Qing Yue ◽  
Hua Wang ◽  
Shu Ying Wang
Keyword(s):  
Wear Resistance ◽  
High Temperature ◽  
Friction Coefficient ◽  
Ball Mill ◽  
Friction And Wear ◽  
Applied Load ◽  
Tribological Behavior ◽  
Metallic Elements ◽  
X Ray Diffraction ◽  
X Ray

Incorporation of metallic elements, titanium and copper, into carbonaceous mesophase (CM) was performed through mechanical alloying in a ball mill apparatus. The structures of the raw CM as well as the Ti/Cu-added CM were characterized by X-ray diffraction. The tribological behavior of the Ti/Cu-added CM used as lubricating additives was investigated by using a high temperature friction and wear tester. The results show that, compared with the raw CM, the Ti/Cu-added CM exhibits a drop in the crystallinity and a transition to the amorphous. The Ti/Cu-added CM used as lubricating additive displays an obvious high temperature anti-friction and wear resistance effect, and the lager the applied load, the lower the friction coefficient and the wear severity.

Hydrogen-Bonding Layer Protecting Polyelectrolyte Capsules and Its Mechanical Property Study with Atomic Force Microscope

2008 ◽  
Vol 8 (6) ◽  
pp. 2996-3002 ◽  
Author(s):  
Liqin Ge ◽  
Xing Wang ◽  
Long Ba ◽  
Zhongze Gu
Keyword(s):  
Hydrogen Bonding ◽  
Atomic Force Microscope ◽  
Elastic Deformation ◽  
Self Assembly ◽  
Laser Scanning ◽  
Confocal Laser ◽  
Bonding Layer ◽  
Layer By Layer ◽  
Assembly Method ◽  
Atomic Force

The hydrogen-bonding multilayered polyelectrolyte capsules with sizes around 6 μm were fabricated by layer-by-layer self-assembly method. The morphology of the obtained capsules was observed with Scanning Electron Microscope (SEM), Confocal Laser Scanning Microscope (CLSM) and Atomic Force Microscope (AFM), respectively. The elastic properties of the capsules were studied with AFM. The capsule was pressed by cantilever with different lengths, a glass bead glued at the end of the cantilever. The force curves were measured on the capsule in air. The Young's modulus of the capsule was obtained (E = 170 MPa for the loading). Results show that this model can predict the elastic deformation of the microcapsule. The accuracy of the elastic deformation of polymer capsule can be ensured using a cantilever of mediate stiffness. Our results show that the existence of the hydrogen-bonding layer makes the multilayered polyelectrolyte harder in comparison with the pure multilayered polyelectrolyte capsules.

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