Adhesives, microscopy studies

Hooton JC, German CS, Allen S, et al. An atomic force microscopy study of the effect of nanoscale contact geometry and surface chemistry on the adhesion of pharmaceutical particles. Pharm Res 2004 21(6) 953-961. 

SCANNING FORCE MICROSCOPY STUDY OF ACTIVATED HUMAN PLATEUETS SHAPE CHANGE AFTER ADHESION EVENT AND AFTER ADDITION OF PHYSIOLOGICAL AGONISTS... 

Zhang, H., Grim, P. C. M., Vosch, T., Wiesler, U.-M., Berresheim, A. J., MuUen, K., and De Schryver, F. C. 2000. Discrimination of dendrimer aggregates on mica based on adhesion force A pulsed mode atomic force microscopy study, Langmuir 16, 9294-9298. 

Clear SC, Nealey PF (1999) Chemical force microscopy study of adhesion and friction between surfaces functionalized with self-assembled monolayers and immersed in solvents. J Colloid Interface Sci 213 238-250... 

Often, structurally bonded metals exhibit apparent interfacial failure when viewed either optically or at higher magnifications using electron microscopy. However, when viewed on the atomic scale, for example, using XPS, it is frequently found that mechanical loading will induce failure of the boundary polymer immediately adjacent to the metal surface. With structural Epoxide adhesives, recent studies have shown that this boundary polymer may have chemical and mechanical properties radically different from the bulk adhesive material and which are not incorporated within current models. 

Two more examples of the application of microscopy techniques to adhesive structural studies are fiber finishes and adhesive labels. Glass fibers are usually pretreated with a polymer coating which protects the fibers during... 

The structure and properties PE3-C. T blends with a poly(amino ether) (PAE) resin obtained by direct injection molding have been examined. Although the blends were almost immiscible, electron microscopy studies showed extensive intermixing between the two components. Improved mechanical and barrier properties were achieved for these blends due to the small dispersed particle sizes and their good interfacial adhesion (148). 

Moon, S., Swearingen, S. Foster, M. D. (2004). Scanning Probe Microscopy Study of Dynamic Adhesion Behavior of Polymer Adhesive Blends. Polymer, Vol. 45, pp. 5951-5959, ISSN 0032-3861... 

W. R. Bowen and T. A. Doneva, J. Colloid Interface Sci., 229, 544 (2000). Atomic Force Microscopy Studies of Membranes Effect of Surface Roughness on Double-Layer Interactions and Particle Adhesion. 

W.R. Bowen, T.A. Doneva, Atomic force microscopy studies of membranes Effect of surface roughness on double-layer interactions and particle adhesion, J Colloid Interf Sci, 229 (2000) 544-549. 

Perhaps the most significant complication in the interpretation of nanoscale adhesion and mechanical properties measurements is the fact that the contact sizes are below the optical limit ( 1 t,im). Macroscopic adhesion studies and mechanical property measurements often rely on optical observations of the contact, and many of the contact mechanics models are formulated around direct measurement of the contact area or radius as a function of experimentally controlled parameters, such as load or displacement. In studies of colloids, scanning electron microscopy (SEM) has been used to view particle/surface contact sizes from the side to measure contact radius [3]. However, such a configuration is not easily employed in AFM and nanoindentation studies, and undesirable surface interactions from charging or contamination may arise. For adhesion studies (e.g. Johnson-Kendall-Roberts (JKR) [4] and probe-tack tests [5,6]), the probe/sample contact area is monitored as a function of load or displacement. This allows evaluation of load/area or even stress/strain response [7] as well as comparison to and development of contact mechanics theories. Area measurements are also important in traditional indentation experiments, where hardness is determined by measuring the residual contact area of the deformation optically [8J. For micro- and nanoscale studies, the dimensions of both the contact and residual deformation (if any) are below the optical limit. 

Carpick, R.W., The study of contact, adhesion, and friction at the atomic scale by atomic force microscopy. University of Califomia-Berkeley, Berkeley, CA, 1997. 

Hayes, R.A. and Ralston, J., Application of atomic force microscopy in fundamental adhesion studies. In Mittal, K.L. and Pizzi, A. (Eds.), Adhesion Promotion Techniques — Technological Applications. Dekker, New York, 1999, pp. 121-138. 

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