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Surface tension - Wikipedia, the free encyclopedia A related quantity is the energy of cohesion, which is the energy released when two bodies of the same liquid become joined by a boundary of unit area. A similar concept, the energy of adhesion, applies to two bodies of different liquids. Energy of adhesion is linked to the surface tension of an interface between two liquids. en.wikipedia.org /wiki/Surface_tension   (918 words)

Adhesion - Wikipedia, the free encyclopedia Adhesion is the molecular attraction exerted between bodies in contact. It is of particular interest to engineers who wish to stick objects together and to biologists to understand the workings of cells. The strength of the adhesion between two materials depends on which of the above mechanisms occur between the two materials, and the surface area over which the two materials contact. en.wikipedia.org /wiki/Adhesion   (403 words)

Polymer surface modification paper Because the adhesion force measured by AFM is determined from a nanometer-scale contact area between the tip and surface (the tip radius is on an order of 20 nm), it is clear that the increase in surface energy or the improvement of the wettability on the UV/ozone treated polymer film is occurring on a nanometer-scale. Assuming that the adhesion force of the "surrounding area" on the unwashed sample is similar to that of the washed sample, the adhesion force remains greater than the sample treated for 3 minutes. We were able to detect adhesion force differences between these two structures at the surface and show that the mounds/droplets had a higher adhesion force than the surrounding material and that the surrounding material had a higher adhesion force than surfaces treated for 3 minutes. publish.uwo.ca /~hnie/pdf/adhesion2.html   (6051 words)

Adhesion Between Polymers and Other Substances — A Review of Bonding Mechanisms, Systems and Testing   (Site not responding. Last check: 2007-10-26) Adhesion of the polyimide deposited on a metal is therefore a different problem than adhesion of a metal deposited on the cured polyimide. The adhesion energy, measured in either tack or peel tests, is known to be strongly influenced by the viscoelastic nature of the adhesive. Increasing the ease of interfacial slip by increasing the molecular mobility of the substrate causes a strong decrease on the peel energy. www.azom.com /details.asp?ArticleID=2089   (4553 words)

Clean Seal, Inc. Adhesion is the molecular force of attraction between unlike materials. The strength of attraction is determined by the surface energy of the material. The higher the surface energy, the greater the molecular attraction. www.cleanseal.com /information-05.htm   (403 words)

UV/EB Corner Without going into a deep explanation of surface energy, suffice it to say that the general rule for wetting states that the wetting fluid (ink or coating) should be roughly 10 points lower than the surface energy of the substrate to be wetted. It is often difficult to lower the surface energy of the wetting fluid to improve wetting. Due to the difficulty of lowering the surface energy of the wetting fluid, the common practice is to treat the substrate (corona, ozone or primer) to raise its surface energy and provide the desired ~10 point difference. www.inkworldmagazine.com /UVEB/Oct02UVEBCorner.htm   (1109 words)

jmps1 - K.D. Murphy The resulting mechanical response is used with theoretical models to estimate the interface adhesion energy, as well as quantify the energy dissipated during cyclic loading. The experiments reveal interesting behaviors related to adhesion: (i) path-dependence during mechanical loading of adhered beams, (ii) history dependence of interfacial adhesion energy during repeated loading, and (iii) energy dissipation during cyclic loading scales, which roughly with estimated cyclic changes in the size of the adhered regions. The experimental results are interpreted in the context of elementary fracture-based adhesion and contact models, and briefly discussed in terms of their implications regarding the nature of adhesion and future modeling to establish adhesion mechanisms. www.engr.uconn.edu /~kdm/jmps1.html   (196 words)

PRA: Physical: Surface Energy and Contact Angle Energy is defined as the capacity to do work and if we take the example of the average wooden desk top it is difficult to find evidence that it is engaged in any form of work. Surface energy is quantified in terms of the forces acting on a unit length at the solid-air or the solid-liquid interface. The numerical difference between the surface tension of a coating and the surface energy of a substrate has a profound effect on the way in which the liquid coating flows out over the substrate and on the strength of the adhesive bond between the substrate and the dry film. www.pra.org.uk /technical/testingphysicalsurfacetension.htm   (1878 words)

Ciba® Prime IT™ To improve wettability and therefore adhesion, several physical treatments such as flame, corona or plasma, are usually applied on the surface, with a final effect of introducing polar groups and enhancing surface energy. Moreover the improved adhesion of the functional layers is due to a purely physical interaction or to the formation of weak bonds. However, adhesion of UV inks on plastics is sometimes poor, making it necessary to use physical or chemical treatments (as primers). www.cibasc.com /primeit   (215 words)

Adhesion energy of receptor-mediated interaction measured by elastic deformation Biophysical Journal - Find Articles The surface energies for different combinations of modified surfaces in solution were obtained from reflection interference contrast microscopy (RICM)) measurements of the contact area formed by the bead and the coverslip. Cell adhesion appears to be a dynamic process (Diamond and Springer, 1994), mediated by the specific interactions of adhesion molecules on apposing cell membranes. Here, cell adhesion is regulated by the transient interaction between lymphocyte function-associated antigen-1 (LFA-1), an integrin expressed on the T cell surface, and intercellular adhesion molecule 1 (ICAM-1) on the APC (Dustin and Springer, 1989). www.findarticles.com /p/articles/mi_qa3938/is_199903/ai_n8844042   (434 words)

Equistar Chemical Company - Plexar® - Factors Affecting Adhesion in Coextrusion Higher melt and die temperatures generally improve adhesion since the rate of reaction and diffusion (i.e., chain entanglement) is accelerated. While higher temperatures generally improve adhesion, it is important not to exceed the recommended processing temperatures due to potential processing problems, gel formation or even resin degradation. This difference in adhesion performance between these LLDPE tie-layer resins can be attributed to the overall physical properties of the resin and the level of functionality. www.equistarchem.com /html/polymer/performance_polymers/Plexar_factors.htm   (434 words)

Iran and Nuclear Energy: Adhesion to the Quick Inspections Protocol is not enough   (Site not responding. Last check: 2007-10-26) The nuclear energy is one of the cheapest forms of energy available to all countries. The so-called reformists of Iran who have wasted the time and energy of Iranians in the past several years, have proved to be less than a puppet in the hands of real powerful figures in Iran and we can forget them for good. Adhesion to the protocol of quick and unscheduled inspections is only the start, not the end of Iranian nuclear dilemma. www.payvand.com /news/03/sep/1055.html   (1851 words)

Estimating Physical Properties   (Site not responding. Last check: 2007-10-26) The development of Girifalco and Good suggests that the free energy of adhesion per unit area can be approximated by twice the geometric mean of the two cohesive surface free energies. Another restriction on the application of the geometric mean approximation to surface free energy, is that it is most accurate when the intermolecular distance at the interface (i.e., normal to the interface) is close in magnitude to the intermolecular distances of the two individual phases (Girifalco and Good, 1957). We expect that spiral growth occurs, and that the spiral is bounded by the one stable edge and a roughened growth front that is approximately perpendicular to it. engin.umich.edu /dept/che/aichej/Doherty/Combo/Paper/clickback3.html   (1680 words)

Membrane Tethers Formed from Blood Cells with Available Area and Determination of Their Adhesion Energy -- Hochmuth and ... Fundamental to all mammalian cells is the adherence of the lipid bilayer membrane to the underlying membrane associated cytoskeleton. We see that the value for the adhesion energy for neutrophils is 130 pN/µm, whereas that for red cells is 60 to 90 pN/µm. Energy of dissociation of lipid bilayer from the membrane skeleton of red blood cells. www.biophysj.org /cgi/content/full/82/6/2964   (3321 words)

Micropipette aspiration studies of lipid membrane fusion mechanisms and polymersome adhesion energies Micropipette aspiration was used to study the interactions of a fusion peptide with lipid vesicles, fusion between lipid vesicles, and the adhesion energy between polymer vesicles. Finally, the water permeability and energy of adhesion were measured for polymersome GUVs. The osmotic depletion-driven adhesion of OB-2, OB-9 and 90:10::OB2:OB9 polymersomes was seen to be a strong function of the concentration of 10kDa or 37.5kDa dextran in solution, similar to the effect seen with SOPC vesicles. repository.upenn.edu /dissertations/AAI3109174   (402 words)

hemocompatible interfaces - Micropipet Aspiration Cell Adhesion Assays   (Site not responding. Last check: 2007-10-26) Analysis of the equilibrium shape of cells at different suction forces permits to derive the energy density of adhesion or fracture provided that the mechanical properties of cells are known [2, 3, 4]. The adhesion of erythrocytes was stimulated by physisorption of monoclonal antibodies of transmembrane proteins (glycophorin A, glycophorin C) onto the polymers. Significant differences between the separation energies of erythrocytes from different polymer substrates were observed after preadsorption of antibodies in similar solutions and interpreted in terms of surface properties of the polymers and adsorption pattern of the antibodies [5]. www.ipfdd.de /research/res16/a6/a6.html   (375 words)

Energy of Adhesion of Human T Cells to Adsorption Layers of Monoclonal Antibodies Measured by a Film Trapping Technique ... Energy of Adhesion of Human T Cells to Adsorption Layers of Monoclonal Antibodies Measured by a Film Trapping Technique -- Ivanov et al. Energy of Adhesion of Human T Cells to Adsorption Layers of Monoclonal Antibodies Measured by a Film Trapping Technique energy of cell adhesion to the antibody adsorption layers. www.biophysj.org /cgi/content/full/75/1/545   (6148 words)

Adhesion of Pseudomonas fluorescens (ATCC 17552) to Nonpolarized and Polarized Thin Films of Gold -- Busalmen and de ... Adhesion of bacteria to solid surfaces is a general phenomenon associated with numerous medical, industrial, and ecological Interaction energy curves were calculated for the DLVO interactions between gold and bacteria in water. Adhesion of Staphylococcus epidermidis to biomedical polymers: contributions of surface thermodynamics and hemodynamic shear conditions. aem.asm.org /cgi/content/full/67/7/3188   (4002 words)

IngentaConnect Adhesion characteristics of plasma-surface-treated carbon fiber-e...   (Site not responding. Last check: 2007-10-26) The load capabilities of carbon fiber-epoxy composite adhesive joints are affected by surface characteristics of the composite adherends such as surface free energy and chemical composition, which can be altered by plasma surface treatment and the type of release film for demolding carbon fiber-epoxy composites from metal molds. The effects of plasma surface treatment on the surface free energy and adhesion strength of carbon fiber-epoxy composites were experimentally investigated with respect to surface treatment time. Also, the surface and adhesion characteristics of carbon fiber-epoxy composites were investigated with respect to release films such as fluorinated ethylene propylene (FEP), high density polyethylene (PE) and Nylon 6.6. api.ingentaconnect.com /content/vsp/ast/2004/00000018/00000004/art00007   (358 words)

Physiology Biophysics- Graduate Program & Training for PhD Students & Postdocs, & Medical Research @U. Miami To shed light on this subject, we developed an assay to measure the changes in adhesion energy of two surfaces in contact as a function of the equilibrium constant. Energy landscape of streptavidin-biotin complexes measured by atomic force microscopy. Adhesion energy of receptor-mediated interaction measured by elastic deformation. chroma.med.miami.edu /physiol/faculty-moy_v.htm   (697 words)

Department of Physics and Astronomy - University of Aarhus - Research activities The shape of a supported nanocrystal is uniquely determined once the orientation of the cluster, as well as the surface free energies of all the involved facets, are known. Now that we know the orientation of the cluster and the symmetry of the side facets, we can derive the adhesion energy, as the adhesion energy is intimately connected to the detailed cluster shape. It is not really possible to derive the absolute adhesion energy, but we can find it relative to the surface free energy of a (111) surface, and then use a calculated surface free energy to convert to an absolute value. www.phys.au.dk /camp/hot0009.shtm   (465 words)

Adhesion Energy of Receptor-Mediated Interaction Measured by Elastic Deformation -- Moy et al. 76 (3): 1632 -- ... The contact radius a is a function of the bead radius, surface energy W, and elastic modulus of the bead K. An important application of the surface energy measurement is the analysis of cell adhesion dynamics. The reaction-limited kinetics of membrane-to-surface adhesion and detachment. www.biophysj.org /cgi/content/full/76/3/1632   (3644 words)

Caltech Authors - Stiction, adhesion energy, and the Casimir effect in micromechanical systems We measure the adhesion energy of gold using a micromachined cantilever beam. Stress and stiffness of the beam are characterized by measuring the spectrum of mechanical vibrations and the deflection due to external force. We induce stiction between the beam and a nearby surface, employing capillary forces to determine the adhesion energy γ. resolver.caltech.edu /CaltechAUTHORS:BUKprb01   (224 words)

TRANSFER ADHESIVES Excellent adhesion to a wide variety of surfaces such as ferrous and non-ferrous metals, natural and synthetic rubbers, polyesters, etc. Excellent balance of quick stick and superior shear properties as well as good cold flow characteristics. Excellent adhesion to a wide variety of surfaces such as (ferrous and non-ferrous) metals, natural and synthetic rubbers, polyesters, etc. Excellent balance of quick stick; superior shear properties; good cold flow characteristics. Superior adhesion to most impervious materials; aluminum, polycarbonate, stainless steel, ABS plastic, painted metals, etc. Nameplates, decals, mounting requiring high cohesive strength and performance at elevated temperatures. www.venturetape.com /section4.html   (1254 words)

Selecting Laminating Adhesives (by Steven Label) The difference is similar to the behavior of water on the finish of a car. Surface energy is measured by dynes per centimeter. On high surface energy plastics choose a “harder” adhesive designed for that purpose. www.stevenlabel.com /Adh.htm   (280 words)

The adhesion and surface energy of elastic solids An equilibrium theory of adhesion between elastic solids is developed. Adhesion is shown to depend on the interfacial surface energy and on the geometry and elastic constants of the adherent bodies. The theory is used to interpret the well-known adhesion tests - the pull-off, peel and scratch tests - and the spontaneous peeling of thin films is discussed. stacks.iop.org /0022-3727/4/1186   (217 words)

MSU ChE Faculty Listing Surface and interfacial phenomena, polymer adsorption, adhesion, polymer surface modification, interfaces between fiber and matric in composite materials, surface atomic and molecular characterization, polymer composite processing. Most often this means that the measurement of adhesion is a necessary component of these research efforts. Adhesion of Carbon Reinforcing Fibers to Thermoset Epoxy Matrices 2. www.chems.msu.edu /php/faculty.php?user=drzal   (1685 words)

43 There is a need in industry to be able to deposit hard coatings, such as titanium nitride, on non-conducting materials, such as plastics and glass for improved wear resistance, lower friction, and, in the case of glass, better optical properties -- all of which can lead to lower energy usage. Adhesion of the coatings to such materials is greatly enhanced if the surface is implanted with metal ions prior to the deposition. This project is to develop a production capable surface modification system employing metal ions rather than gas ions resulting in less blistering, greater adhesion, and improved performance. www.er.doe.gov /SBIR/Awards_Abstracts/sbir/cycle15/phase1/43.htm   (321 words)

Publications of Markus Deserno   (Site not responding. Last check: 2007-10-26) The contact energy of adhesion is balanced by the tension and curvature energies of the vesicle membrane under the constraint of fixed volume, with the geometry of the complex determined by a variational calculation. Physical observables, like the degree of penetration or the membrane tension, are investigated as functions of colloidal size and adhesion-, tension- and bending-energies. Particular emphasis is put on the transition from the partly to the fully wrapped state, and on unbinding of the complex at weak adhesion energy or small colloidal size. www.chem.ucla.edu /~markus/pubs/p_13.html   (158 words)

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