Investigation on the surface free energy of a single flax fiber through adhesion measurement by atomic force microscopy

2018 ◽  
Vol 52 (23) ◽  
pp. 3233-3239
Author(s):  
Shabbir Ahmed ◽  
Xinnan Wang ◽  
Kai Li ◽  
Chad A Ulven
Keyword(s):  
Free Energy ◽  
Composite Materials ◽  
Surface Energy ◽  
Surface Free Energy ◽  
Adhesion Force ◽  
Fiber Surface ◽  
Flax Fiber ◽  
Interfacial Bond Strength ◽  
Dispersive Component ◽  
Atomic Force

Surface free energy of a fiber is an important parameter for predicting the interfacial bond strength of fiber-matrix adhesion of composite materials. For mechanical characterization of bio-composite materials, the measurement of the surface energy of individual single microfibers is complicated due to their surface roughness, formation of chemical bonds, wicking characteristics, etc. This paper demonstrates a novel method for determining the dispersive component of surface free energy [Formula: see text] of single flax fiber by directly measuring the adhesion force between the probe tip of an atomic force microscope and the fiber surface. Johnson–Kendal–Roberts theory was employed to correlate the adhesion force with the surface energy and tip radius. Finally, the value of [Formula: see text] was determined, and its significance with respect to other methods was analyzed.

The effects of humidity and surface free energy on adhesion force between atomic force microscopy tip and a silane self-assembled monolayer film

2010 ◽  
Vol 25 (3) ◽  
pp. 556-562 ◽  
Author(s):  
Chien-Chao Huang ◽  
Lijiang Chen ◽  
Xiaohong Gu ◽  
Minhua Zhao ◽  
Tinh Nguyen ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Free Energy ◽  
Surface Free Energy ◽  
Adhesion Force ◽  
Capillary Condensation ◽  
Self Assembled Monolayer ◽  
Force Microscopy ◽  
Atomic Force ◽  
Rate Of Increase ◽  
Self Assembled

The relationship between atomic force microscopy probe-sample adhesion force and relative humidity (RH) at five different levels of surface free energy (γs) of an organic self-assembled monolayer (SAM) has been investigated. Different γs levels were achieved by exposing a patterned SiO2/CH3-terminated octyldimethylchlorosilane SAM sample to an ultraviolet (UV)/ozone atmosphere. A model consisting of the Laplace-Kelvin theory for capillary condensation for nanosized probe and probe-sample molecular interaction was derived to describe the adhesion force as a function of RH from 25 to 90% for different SAM γs values. The equations were solved analytically by using an equivalent curvature of the probe tip shape. Experimental results show that the adhesion force increases slightly with RH for nonpolar SAM. However, for polar SAM surfaces, it increases at first, reaches a maximum, and then decreases. Both the rate of increase and the maximum of the adhesion force with humidity are γs-dependent, which is in good agreement with theoretical prediction. The large rise in the adhesion force in this RH range is due to the capillary force.

Examination of the lubricant storing and releasing ability of thermally sprayed surfaces

2011 ◽  
Vol 2 (2) ◽  
pp. 101-105
Author(s):  
L. Fazekas ◽  
Z. S. Tiba ◽  
G. Kalácska
Keyword(s):  
Free Energy ◽  
Surface Energy ◽  
Surface Free Energy ◽  
Essential Role ◽  
Index Number ◽  
Adhesion Ability ◽  
Thermally Sprayed ◽  
Proper Operation

Abstract The lubricant storing and releasing ability of the thermally sprayed surfaces plays an essential role in the proper operation of the components. In the case of porous sprayed surfaces the lubricant storing and releasing ability depends mainly on porosity and the surface energy (adhesion susceptibility). The adhesion ability can also be expressed indirectly with an index number that is by determining the surface free energy.

Insights into graphene wettability transparency by locally probing its surface free energy

Nanoscale ◽  
2019 ◽  
Vol 11 (16) ◽  
pp. 7944-7951 ◽  
Author(s):  
Jin-You Lu ◽  
Tuza Olukan ◽  
Srinivasa Reddy Tamalampudi ◽  
Abdulrahman Al-Hagri ◽  
Chia-Yun Lai ◽  
...  
Keyword(s):  
Free Energy ◽  
Chemical Vapor Deposition ◽  
Surface Energy ◽  
Surface Free Energy ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Multilayer Graphene ◽  
Natural Graphite

In this work, we study the surface energy of monolayer, bilayer and multilayer graphene coatings, produced through exfoliation of natural graphite flakes and chemical vapor deposition.

Surface Free Energy Change of UV Exposed Composites and Coatings via Acid-Base Interactions

2011 ◽  
Author(s):  
R. Asmatulu ◽  
M. Ghaddar
Keyword(s):  
Free Energy ◽  
Service Life ◽  
Surface Energy ◽  
Surface Free Energy ◽  
Uv Light ◽  
Free Energy Change ◽  
Energy Change ◽  
Acid Base ◽  
Coating Materials ◽  
Base Interaction

Surface free energy of composite and coatings are critically important for the performance of the materials since the change in surface free energies can drastically affect the physical, chemical and physicochemical properties, and hence the service life of them. The characterization of the surface free energy is the key issue to understand the mechanisms of the surface degradation. Acid-base interaction is one way of determining the surface free energy change on these surfaces. In the present study, we exposed composite and coating surfaces to UV light, and then measured the contact angle values using various liquids (e.g., DI water, diiodomethane and glycerol). Using the van Oss approach, we calculated the surface energy changes of the surfaces exposed to the UV light. We found that the surface energy, acidity and basicity of the composite and coating materials were drastically changed as a function of UV exposure time. This study can be useful for the moisture uptake of composites, composite degradation, aging and service life of these products.

Investigation of Template Releasing Energy in Nanoimprint Lithography

2013 ◽  
Vol 1499 ◽  
Author(s):  
Tomoki Nishino ◽  
Norihiro Fujikawa ◽  
Hiroaki Kawata ◽  
Yoshihiko Hirai
Keyword(s):  
Free Energy ◽  
Surface Energy ◽  
Surface Free Energy ◽  
Nanoimprint Lithography ◽  
Perpendicular Direction ◽  
Single Side ◽  
Lift Off ◽  
Releasing Process

ABSTRACTTo investigate template releasing process in nanoimprint lithography, template releasing energy (i.e. surface energy between the template and the resist polymer) in various releasing conditions is evaluated using multi-axial controlled releasing system. The releasing energy is in proportion to the surface free energy of the template, but does not depend on the velocity of releasing. Also, a peeling mode where the template is released from a single side and a lift-off mode where the template is removed in the perpendicular direction to the resist are examined. The result shows that the releasing energy by peeling mode is lower than that by lift-off modes.

The specific energy of crystal boundaries in tin

1950 ◽  
Vol 201 (1065) ◽  
pp. 210-215 ◽  
Keyword(s):  
Free Energy ◽  
Surface Energy ◽  
Specific Surface ◽  
Surface Free Energy ◽  
Specific Energy ◽  
Lattice Theory ◽  
Strong Support ◽  
Crystal Boundary ◽  
The Difference ◽  
Crystal Boundaries

Specimens of tin, consisting of three crystals of predetermined orientations, were prepared with various differences of orientation between two of the crystals. The equilibrium angles between the three boundaries were measured. Relative values of specific surface free energy were deduced from the angles, and it was found that the surface energy decreases progressively as the difference of orientation decreases below about 6°. The curve relating surface energy with differences of orientation extrapolates to zero surface energy at zero angle. The result is considered to provide strong support for the ‘transitional lattice’ theory of the crystal boundary.

Biopolymer Blends as Potential Biomaterials and Cosmetic Materials

2013 ◽  
Vol 583 ◽  
pp. 95-100 ◽  
Author(s):  
Alina Sionkowska ◽  
Katarzyna Lewandowska ◽  
A. Planecka ◽  
P. Szarszewska ◽  
K. Krasinska ◽  
...  
Keyword(s):  
Contact Angle ◽  
Free Energy ◽  
Surface Free Energy ◽  
Silk Fibroin ◽  
High Surface ◽  
Force Microscopy ◽  
Angle Measurements ◽  
Atomic Force ◽  
Polymeric Blends ◽  
Contact Angle Measurements

Blends of two polymer, namely chitosan with silk fibroin or partially hydrolysed polyacrylamide (HPAM) were prepared. The surface properties of chitosan/silk fibroin and chitosan/HPAM blended films were investigated using the technique of Atomic Force Microscopy (AFM) and by means of contact angle measurements allowing the calculation of surface free energy. Measurements of the contact angle for diiodomethane (D), and glycerol (G) on the surface of chitosan films and chitosan/silk fibroin films were made and surface free energy was calculated. It was found that chitosan/silk fibroin blend surface is enriched in high surface energy component i.e. silk fibroin. The surface roughness of chitosan, silk fibroin, HPAM, chitosan/silk fibroin and chitosan/HPAM blended films differs with the composition of the blend. Film-forming polymeric blends can be potentially used as biomaterials and cosmetic materials.

Effect of temperature on the surface free energy and acid–base properties of Gabapentin and Pregabalin drugs − a comparative study

RSC Advances ◽  
2015 ◽  
Vol 5 (60) ◽  
pp. 48712-48719 ◽  
Author(s):  
S. Ramanaiah ◽  
Vikram Karde ◽  
P. Venkateswarlu ◽  
Chinmay Ghoroi
Keyword(s):  
Free Energy ◽  
Surface Energy ◽  
Comparative Study ◽  
Surface Free Energy ◽  
Effect Of Temperature ◽  
Temperature Dependent ◽  
Acid Base ◽  
Base Properties

Temperature dependent surface energy variations observed in Gabapentin and Pregabalin drugs.

scholarly journals Термодинамическая модель зародышеобразования кристаллов n-терфенила с анизотропией поверхностной энергии на межфазной границе жидкость-воздух

2019 ◽  
Vol 61 (12) ◽  
pp. 2432
Author(s):  
В.А. Постников ◽  
А.А. Кулишов ◽  
А.А. Островская ◽  
А.С. Степко ◽  
П.В. Лебедев-Степанов
Keyword(s):  
Free Energy ◽  
Crystal Growth ◽  
Surface Energy ◽  
Force Field ◽  
Structural Data ◽  
Field Method ◽  
Experimental Information ◽  
Growth From Solutions ◽  
Atomic Force ◽  
Air Interface

An analysis of the change in the Gibbs free energy ∆G upon the formation of a flat nucleus of a p-terphenyl crystal at the liquid – air interface is presented, taking into account the anisotropy of the surface energy of the faces. The surface energy values of the p-terphenyl crystal faces were calculated by the atomic force field method OPLS, based on structural data. Experimental information on crystal growth from solutions and their surface properties was used to analyze the model.

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