Physical bonds

If produced gas contains water vapour it may have to be dried (dehydrated). Water condensation in the process facilities can lead to hydrate formation and may cause corrosion (pipelines are particularly vulnerable) in the presence of carbon dioxide and hydrogen sulphide. Hydrates are formed by physical bonding between water and the lighter components in natural gas. They can plug pipes and process equipment. Charts such as the one below are available to predict when hydrate formation may become a problem. 

The adhesion between two solid particles has been treated. In addition to van der Waals forces, there can be an important electrostatic contribution due to charging of the particles on separation [76]. The adhesion of hematite particles to stainless steel in aqueous media increased with increasing ionic strength, contrary to intuition for like-charged surfaces, but explainable in terms of electrical double-layer theory [77,78]. Hematite particles appear to form physical bonds with glass surfaces and chemical bonds when adhering to gelatin [79]. 

Hydrogen Bond Formation. This faciUtates adsorption if the mineral and the adsorbate have any of the highly electronegative elements S,0,N,F, and hydrogen. A weak (physical) bond is estabflshed between the sohd wall and the reagent through the alignment of the cited elements. 

An intensity factor—the specific activity of the filler-polymer interface causing chemical and/or physical bonding. 

An investigation of the mechanism of adhesive failure of polydimethylsiloxane elastomers was conducted [75]. The study showed that the total adhesive failure energy could be decomposed into energies for breaking chemical bonds, breaking physical bonds and deforming the bulk viscoelastic elastomer. 

For a surface treatment process to be practical, not only does it have to produce a clean, stable surface suitable for chemical or physical bonding to the... 

Arabinogalactans (AGs) are widely spread throughout the plant kingdom. Many edible and inedible plants are rich sources of these polysaccharides. AGs occur in two structurally different forms described as type I and type II, associated with the pectin cell-wall component by physical bonds and some of them are covalently linked to the complex pectin molecule as neutral side chains. Commercial pectins always contain AG 10-15%). AG of type I has a linear (1 4)-y0-o-Galp backbone, bearing 20-40% of of-L-Ara/ residues (1 5)-linked in short chains, in general at position 3. It is commonly found in pectins from citrus, apple and potato [6]. Recently, this AG type has been isolated from the skin of Opuntia ficus indica pear fruits [372]. 

Naturally occurring fibers such as cotton, cellulose, etc., have short whiskers protruding from the surface, which help to give a physical bond when mixed with rubber. Glass, nylon, polyester, and rayon have smooth surfaces and adhesion of these fibers to the rubber matrix is comparatively poor. In addition, these synthetic fibers have chemically unreactive surfaces, which must be treated to enable a bond to form with the mbber. In general, the fibers are dipped in adhesives in the latex form and this technology is the most common one used for continuous fibers. The adhesion between elastomers and fibers was discussed by Kubo [128]. Hisaki et al. [129] and Kubo [130] proposed a... 

Strongly influences adsorption, because hydrogen ions play an active role in both chemical and physical bonding processes. Mobility of heavy metals is strongly influenced by pH. Adsorption of some organics is also pH-dependent. 

Physical adsorption, in which physical bonds form between the adsorbent and the adsorbate. 

Buttkus H. On the nature of the chemical and physical bonds which contribute to some structural properties of protein foods a hypothesis. J. Food Sci. 1974 39 484 189. 

It is generally unwise to think of ionic compounds as holding together with physical bonds it is better to think of an array of point charges, held together by the balance of their mutual electrostatic interactions. (By mutual here, we imply equal numbers of positive and negative ions, which therefore impart an overall charge of zero to the solid.)... 

Physical aging, defined, 10 424 Physical analysis, of wine, 26 324 Physical bonding processes, 17 496 Physical-chemical waste treatment,... 

The adsorption process can be described as molecules leaving a solution and being held on the solid surface by chemical and physical bonding. If the bonds that form between the adsorbate and adsorbent are very strong, the process is almost always irreversible [97-99], and chemical adsorption (i.e., chemisorption) is said to have occurred. On the other hand, if the bonds that are formed... 

Adhesion between metallic/organic interfaces is facilitated by a combination of mechanical interlocking, chemical and physical bonding. Physical bonding alone cannot provide for durable, temperature resistant bonds, as van-der-Waals forces present between the metal surface and adhesive molecules are relatively weak. 

Apparently, the chemical bonding present at the paint/adhesive interface is much stronger than that occurring at either the phosphate/adhesive or the phosphate/topcoat interfaces. In the case of ZM, phosphating to improve durability is not necessary, and in fact, was proven to be detrimental. The paint provides a moisture resistant barrier layer which reduces the activity of water at the interface providing for a surface receptive to the chemical and physical bonds necessary to promote good adhesion and enhance durability. 

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