Acid-base interactions in adhesion

Vrbanac, M.D., Acid-Base Interactions in Adhesion and Wetting, Dissertation Thesis, University of Washington, 1989. 

For the sake of completeness, it is worthwhile to briefly discuss role of acid-base interactions in adhesion. In this context, the term acid refers to a Lewis acid (an electron acceptor) and a Lewis base (electron donor), rather than the more conventional acid and base definitions. The role of acid-base interactions in adhesion is discussed in detail by Lee [105]. 

Although Eq. 11 tries to take into account the effect of polar interactions, the role of acid/base interactions in adhesion became clear and theories describing them have been more and more accepted [35]. The boimdary case of such interactions is the formation of covalent bonds between the surfaces. Such interactions cannot be described by Eq. 11. As a consequence Fowkes [36] suggested that the reversible work of adhesion should be defined as ... 

The aim of the present contribution is to review the role of acid-base interactions in adsorption, wetting, and adhesion, and the methodologies and techniques to characterize the acid-base properties of materials. Examples have been selected from the authors research work and from a survey of the literature. This chapter is organized into the following three sections definition, properties, and strength of acid-base interactions theory of acid-base interactions in adhesion and experimental assessment of acid-base properties of polymers and other materials. 

The background to acid base interactions in adhesion science and technology has been reviewed with the emphasis on polymers, metal oxides, fillers, fibers, and pigments. When... 

Finally, AFM appears as an extraordinary technique to study acid-base interactions at the molecular scale. It enables the determination of pXa for surface confined carboxylic and other Bronsted groups. With the systematic studies which have appeared over recent years using thiol-treated tips and surfaces, clearly AFM has become a very well established and powerful tool for fundamental and applied research studies on acid-base interactions in adhesion. 

The importance of acid-base interactions in adhesion continues to attract several researchers, however, still there seems to be a lack of consistency in the approaches as stated by K. L. Mittal in the Preface of [19]. It is hoped that Round Tables will be organized in order to define common strategies for polymers, fillers, fibers, etc. which will permit inter-laboratory comparison. 

The first discussion of acid-base interactions in adhesion science was due to Bolger and Micheals. These authors described Bronsted-Lowrey interactions at oxide/ organic interfaces by means of standard equilibrium... 

Also, Fowkes [26,148] actually developed a technique for the determination of the work of adhesion, WA, by applying a four-parameter equation for acid-base interaction in the system of solid-liquid using Eqs. (29) and (32)... 

Polymer Surfaces and Interfaces Acid-Base Interactions and Adhesion in Polymer-Metal Systems... 

Berg, J. C., The importance of acid-base interactions in wetting, adhesion and related phenomena, Nordic Pulp Paper Res. J 75-85 (19931). 

Polymer Surfaces and Interfaces Acid-Base Interactions and Adhesion in Polymer-Metal Systems Irina A. Starostina, DSc, Oleg V. Stoyanov, DSc, and Rustam Ya. Deberdeev, DSc... 

Fowkes, F.M., Acid-base interactions in polymer adhesion. Physicochemical Aspects of Polymers Surfaces (K.L. Mittal, ed.), Vol. 2, Plenum Press, New York, 1983. 

The interaction between solid and liquid due to polar groups has been considered by Fowkes [48] to be defined by acid-base interactions. In this model, Fowkes assumes that the interaction between two materials can be described by a component due to dispersion interactions in the form of a geometric mean relationship plus a component due to acid-base interaction. The acid-base interaction indicates the ability of a polar group on one surface to donate or accept electrons from polar groups on the other surface. The work of adhesion is then described by Eq. (5). 

Fowkes was one of the first people to emphasize the importance of acid-base interactions in the context of adhesion. The volume of papers collected to honour his 75 birthday provides an important source of detailed information. Fowkes has argued that the acid-base component of the work of adhesion can be related to the molar enthalpy, for the acid-base reaction by... 

There is some consideration of such acid-base interactions in the section helow on contact angles. The application to adhesion has been reviewed by Chehimi [41]. 

The acid-base interactions in adsorption of polymers onto surfaces such as fillers involve the acidic or basic surface sites of the adsorbent, the acidic or basic sites of the polymer, and also the acidic or basic sites of the solvent, if present. The acid-base contribution to the work of adhesion, Wab, can be related to the interface population of acid-base pairs, and the heat of acid base interaction ... 

Besides the Lifshitz-van der Waals interactions, there are short-range (<0.2 nm) forces due to the donor-acceptor interaction(67-69) or the acid-base interaction.( o) xhe role of the acid-base interaction in polymer adhesion has been studied by Fowkes(7i 72) and Bolger and Michaels.( 73) Recently Good et have examined the role of the interfacial hydrogen bond... 

We attempt to extend the Hard-Soft Acid-Base (HSAB) principle for the reactions in solutions to interactions in solids. First we point out the important link between the absolute hardness of acid-and-base and the average energy gap. Then we discuss the electronic band structures of various solids, e.g., metals, semimetals, semiconductors and insulators. On the basis of energy gaps, we elaborate various consequences of the acid-base interactions in solids. The applications of HSAB principle and the frontier orbital concept to the solid adhesion and surface interactions between metals and polymers will be verified by experimental results reported in the literature. The new findings reported in this paper should be beneficial to those who are carrying out research in or processing thin-film microelectronic devices or thick-film multilayer structures. 

The donor-acceptor interaction and the acid-base interaction have been reviewed. In many occasions, the two terms, though different, have been used interchangeably to describe the interactions involving the exchange of electrons between a donor and an acceptor. For polymer adhesion, Fowkes and Bolger et alhave pointed out the important role of the acid-base interaction in the formation of an adhesive bond. 

For the acid-base interaction in solutions, in 1963, Pearson proposed the hard-soft acid-base (HSAB) principle to describe some basic rules about the kinetics and equilibrium of the reaction. In this paper, we attempt to apply the HSAB principle to solid interactions with the aid of the frontier orbital method. We shall first describe the HSAB principle as it has been evolved in recent years " and then the band structures of solids. After we demonstrate the compatibility between the HSAB principle and the band structures in the solid state, we then illustrate with several examples of adhesion and tribointeractions between metals and... 

One method which has been used to characterize interfacial forces is based on specific donor-acceptor (acid-base) interactions between adhesive and substrate molecules. Here, functional groups in each material are assigned an acid or base strength, which then can be used to calculate expected bond strengths. Further discussion of this approach is delayed to a later section. 

Abel M-L, Watts JF (2005b) Inverse gas chromatography and acid-base interactions. In Packham DE (ed) Handbook of adhesion. Wiley, Chichester, pp 255-257 ASTM (2002) F 22-02 Standard test method for hydro-phobic surfece films by the water break test. ASTM, West Conshohocken, PA, USA Baer DR, Lea AS, Cazaux J, Geller JD, Hammond JS, Kover L, Powell CJ, Seah MP, Suziki M, Wolstenholme J, Watts JF (2010) J Elec Spec 176 80-94 Binnig G, Rohrer H, Gerber Ch, Weidel E (1982) Phys Rev Lett 49 57... 

Fowkes FM. Acid—base interactions in polymer adhesion. In Mittal KL, Anderson H, editors. Hiysicochemical aspects of polymers surfaces, the Netherlands Brill 1991. 

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