Surface properties, paper testing

Table VI also shows the relationship between the amount of hydrocarbon in the form of percent Ct and the relative fuse grade. The number of samples in Table VI is reduced from previous tables since many of the papers, because of their properties, were unable to withstand the abrasive fuse grade testing. For example, the sample with high levels of filler separated rather easily and pulled fibers from the surface, invalidating the test procedure. Even without these samples, however, a clear relationship between the amount of hydrocarbon on the surface, either in the form of rosin and rosin salts or lignin, is clearly related to the adhesion of the toner polymers to the paper surface. A least square fit of these data has a (relatively low) correlation coefficient of 0.85, and a slope of -0.8. Although the relationship may not be a linear one, it is clearly reasonable to presume that higher quantities of hydrocarbon on the surface of paper do prevent adequate adhesion of toner. This result corresponds with the previous work done by Borch(16) and also with results presented elsewhere in this symposium volume.

The behavior of liquids towards paper is characterized by the processes of wetting and penetration. In both cases, the characteristic physical property is the surface tension. This value can be measured directly and tensiometricaUy in the case of liquids and indirectly, via the contact angle of test liquid droplets, in the case of solids such as paper. A liquid wets the surface of paper only if its surface tension is lower than that of the paper. The same holds for the wetting of the capillary walls upon penetration of liquids into the capillaries of the paper. 

The sessile drop method has several drawbacks. Several days elapse between each displacement, and total test times exceeding one month are not uncommon. It can be difficult to determine that the interface has actually advanced across the face of the crystal. Displacement frequency and distance are variable and dependent upon the operator. Tests are conducted on pure mineral surfaces, usually quartz, which does not adequately model the heterogeneous rock surfaces in reservoirs. There is a need for a simple technique that gives reproducible data and can be used to characterize various mineral surfaces. The dynamic Wilhelmy plate technique has such a potential. This paper discusses the dynamic Wilhelmy plate apparatus used to study wetting properties of liquid/liquid/solid systems important to the oil industry. 

No specific information on the possible effect of the synthetic sizes on permanence is available, and they are not mentioned in the standard 04), but it seems unlikely that they would be deleterious. Presumably they have been used in comnercial grades of neutral/alkaline paper subjected to accelerated ageing tests. In terms of general effects on paper, the synthetic sizes have a tendency to reduce the surface frictional properties of paper to a greater extent than rosin. For example, this makes it more difficult to stack piles of cut sheets without slippage. However, the effect is less noticeable when high proportions of chalk filler are used, because the blocky particles increase friction. 

Transparent materials interact with light only by absorption. This interaction is formulated quantitatively in the Bouguer-Lambert and Beer s Laws (c.f. i). In paper, however, surface reflection is the dominating type of interaction. This results in very desirable properties like high brightness and opacity, but complicates the interpretation of optical tests with regard to absorption data. The Kubelka-Munk theory attempts to separate the two types of... 

To examine the physical and surface active properties of SAE, three secondary alcohol samples each having three successive carbon numbers, as mentioned earier, were prepared. For practical reasons, blends of alcohols are chosen instead of alcohols having individual carbon numbers. The alcohol samples were ethoxylated to various degrees of polymerization for testing. Two previous papers by other workers are recommended with reference to this subject. One by MacFarland(5) of Union Carbide Corp. deals with a blend of secondary alcohols and the other by Matson(6)... 

In this paper we present results related to the atomic structure and catalytic properties of Pd overlayers on various substrates. A reaction has been chosen to test the catalytic properties of these systems, it is the 1,3-butadiene hydrogenation, a reaction for which Pd is known to be the best catalyst. In the following, after a short description of the experimental approach, the 1,3-butadiene hydrogenation reaction and the specific properties of Pd for this reaction will be presented. Then the reactivity of several Pd overlayers obtained either by surface segregation in Pd-based alloys or by atomic beam deposition on a metal will be investigated and discussed in terms of structure, composition related to surface segregation and surface stress. The influence of the surface orientation of the substrate will be discussed. 

In the papers [41,42] the thermodynamic properties of polyethylene glycol PEG 4000 and silicone oil DC 550 of different quantities deposited on the heterogeneous surface of carbosils were investigated. The surfaces of tested adsorbents were similar to those described by the patch-wise model including local energetic heterogenities. 

The paper presents only some studies of preparation and properties of surface carbon-silica adsorbents. The application of these materials as model adsorbents in investigations of various adsorption processes is discussed. They can be also used for testing the theories describing adsorption and catalytic processes on the heterogeneous surfaces. The influence of such surfaces on the properties of adsorbed gases and liquids as well as their application have been studied. 

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