scholarly journals Application of Atomic Force Microscope to Investigate the Surface Micro-Adhesion Properties of Asphalt

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1736 ◽  
Author(s):  
Xiaoping Ji ◽  
Jia Li ◽  
Xugang Zhai ◽  
Haiwei Zou ◽  
Bo Chen
Keyword(s):  
Surface Energy ◽  
Adhesion Properties ◽  
Force Microscopy ◽  
Modified Asphalt ◽  
Surface Energies ◽  
Atomic Force ◽  
Force Curves ◽  
Adhesion Performance ◽  
Oil Source ◽  
Microscope Probe

The surface energy and bonding coefficient of asphalt are important factors that affect the adhesion performance of asphalt/aggregate. In this study, the micro-bee-like-structure of asphalt and force curves between the microscope-probe and asphalt were measured via atomic force microscopy (AFM). To investigate the influence of asphalt properties on micro-adhesion of asphalt, five types of asphalt were used in four states: original, aged at 163 °C, immersed in water and added anti-stripping agent. The results demonstrate that the surface energy of grade 90 asphalt is greater than that of grade 70 asphalt when oil source is the same and that of modified asphalt is greater than matrix asphalt. The surface energies and bonding coefficients of asphalts decreased after aging and immersion. The surface energies of asphalts were greatly improved by adding anti-stripping agent and the bonding coefficients of the asphalts increased by 5.04–37.14% after adding an anti-stripping agent.

Self-Assembled N-Succinyl-Chitosan Nanofibers for Reduced Protein Adhesion

2010 ◽  
Vol 76 ◽  
pp. 36-41
Author(s):  
Eyas Dayyoub ◽  
Udo Bakowsky
Keyword(s):  
Human Serum Albumin ◽  
Serum Albumin ◽  
Human Serum ◽  
Self Assembly ◽  
Adhesion Properties ◽  
Force Microscopy ◽  
Atomic Force ◽  
Biomaterial Surfaces ◽  
Force Curves ◽  
Protein Adhesion

Protein adhesion on biomaterial surfaces plays a major role in determining their biocompatibility and cell responses. The goal of this study was to produce chitosan-based coatings of implant material polyurethane (PUR) for reduced human serum albumin (HSA) adhesion. Succinic anhydride was employed for modifying chitosan and synthesis of N-succinyl-chitosan (NSCS) which was used as a matrix coating of PUR. NSCS showed self-assembly behaviour as nanofiber structures onto PUR surface. Atomic force microscopy (AFM) has emerged as useful tool for the molecular force measurements and therefore it has been chosen to investigate the adhesion properties of Human serum albumin (HSA) on the new matrix coatings and other three implant materials PUR, Silicon and Titanium. HSA molecules were covalently bound to the AFM tip by the use of cyanuric chloride as bivalent linker. Analyzing the force curves demonstrated the antiadhesive properties of the NSCS films in comparison with the uncoated PUR, Silicon and Titanium.

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.

scholarly journals Probing surface interactions of underwater oleophobic polyelectrolyte multilayers

2020 ◽  
Author(s):  
Kai Li ◽  
Wei Wang ◽  
Zhi-Peng Yu ◽  
Hang Jin ◽  
Yun-Tong Ge ◽  
...  
Keyword(s):  
Theoretical Calculations ◽  
Interaction Mechanism ◽  
Polyelectrolyte Multilayers ◽  
Layer By Layer ◽  
Surface Wetting ◽  
Force Microscopy ◽  
Atomic Force ◽  
Layer Deposition ◽  
Nacl Concentration ◽  
Force Curves

Abstract In the present work, the interaction mechanism of specific polyelectrolyte multilayers (PEMs), fabricated by layer-by-layer deposition of polydiallyldimethylammonium chloride (PDDA) and poly(sodium 4-styrenesulfonate) (PSS), is studied using atomic force microscopy. The underwater oil-repellency of PSS-capped PEMs was further explored by measuring the interaction forces between tetradecane droplets and PEMs-coated silica substrates under various salinities. The force curves were analyzed following the Stokes–Reynolds–Young–Laplace theoretical model. Desirable consistency was achieved between the experimental and theoretical calculations at low NaCl concentrations (0.1 mM and 1 mM); however, underestimation of the attractive force was found as the NaCl concentration increases to moderate (10 mM) and high (100 mM) levels. Discrepancy analyses and incorporated features toward a reduced surface charge density were considered based on the previous findings of the orientation of anionic benzenesulfonate moieties (Liu et al. in Angew Chem Int Ed 54(16):4851–4856, 2015. https://doi.org/10.1002/anie.201411992). Short-range steric hindrance interactions were further introduced to simulate “brush” effect stemming from nanoscale surface roughness. It is demonstrated in our work that the PSS-capped PEMs remains a stable underwater lipophobicity against high salinity, which renders it potential application in surface wetting modification and anti-fouling.

Cross-Sectional Nanoindentation of Alumina Thin Films Deposited by Pulsed Laser Deposition Process

2006 ◽  
Author(s):  
Sudheer Neralla ◽  
Sergey Yarmolenko ◽  
Dhananjay Kumar ◽  
Devdas Pai ◽  
Jag Sankar
Keyword(s):  
Thin Films ◽  
Pulsed Laser Deposition ◽  
Pulsed Laser ◽  
High Hardness ◽  
Deposition Process ◽  
Laser Deposition ◽  
Cross Sectional ◽  
Adhesion Properties ◽  
Force Microscopy ◽  
Atomic Force

Alumina is a widely used ceramic material due to its high hardness, wear resistance and dielectric properties. The study of phase transformation and its correlation to the mechanical properties of alumina is essential. In this study, interfacial adhesion properties of alumina thin films are studied using cross-sectional nanoindentation (CSN) technique. Alumina thin films are deposited at 200 and 700 °C, on Si (100) substrates with a weak Silica interface, using pulsed laser deposition (PLD) process. Effect of annealing on the surface morphology of the thin films is studied using atomic force microscopy. Xray diffraction studies revealed that alumina thin films are amorphous in nature at 200 °C and polycrystalline with predominant gamma alumina phase at 700 °C.

scholarly journals Surface Structure and Nanomechanical Properties of Shewanella putrefaciens Bacteria at Two pH values (4 and 10) Determined by Atomic Force Microscopy

2005 ◽  
Vol 187 (11) ◽  
pp. 3864-3868 ◽  
Author(s):  
Fabien Gaboriaud ◽  
Sidney Bailet ◽  
Etienne Dague ◽  
Frédéric Jorand
Keyword(s):  
Atomic Force Microscopy ◽  
A Priori ◽  
Linear Part ◽  
Shewanella Putrefaciens ◽  
Nonlinear Part ◽  
Force Microscopy ◽  
Nanomechanical Properties ◽  
Ph Values ◽  
Atomic Force ◽  
Force Curves

ABSTRACT The nanomechanical properties of gram-negative bacteria (Shewanella putrefaciens) were investigated in situ in aqueous solutions at two pH values, specifically, 4 and 10, by atomic force microscopy (AFM). For both pH values, the approach force curves exhibited subsequent nonlinear and linear regimens that were related to the progressive indentation of the AFM tip in the bacterial cell wall, including a priori polymeric fringe (nonlinear part), while the linear part was ascribed to compression of the plasma membrane. These results indicate the dynamic of surface ultrastructure in response to changes in pH, leading to variations in nanomechanical properties, such as the Young's modulus and the bacterial spring constant.

scholarly journals Dissipation signals due to lateral tip oscillations in FM-AFM

2014 ◽  
Vol 5 ◽  
pp. 2048-2057 ◽  
Author(s):  
Michael Klocke ◽  
Dietrich E Wolf
Keyword(s):  
Atomic Force Microscopy ◽  
Surface Energy ◽  
Unit Cell ◽  
Ionic Crystals ◽  
Force Microscopy ◽  
Normal Oscillation ◽  
Line Scan ◽  
Atomic Force ◽  
Dissipation Mechanism ◽  
Lateral Excitation

We study the coupling of lateral and normal tip oscillations and its effect on the imaging process of frequency-modulated dynamic atomic force microscopy. The coupling is induced by the interaction between tip and surface. Energy is transferred from the normal to the lateral excitation, which can be detected as damping of the cantilever oscillation. However, energy can be transferred back into the normal oscillation, if not dissipated by the usually uncontrolled mechanical damping of the lateral excitation. For certain cantilevers, this dissipation mechanism can lead to dissipation rates larger than 0.01 eV per period. The mechanism produces an atomic contrast for ionic crystals with two maxima per unit cell in a line scan.

Sign in / Sign up

Export Citation Format

Share Document