Surface solid reinforcement

In this type of system, the polymer chains are constrained by a surface. They can lie between two hard surfaces such as in the galleries within two parallel clay platelets (as is illustrated in Figure 7), have one layer absorbed on to a hard surface as a coating, with the other free (as in Figure 8), they can be absorbed by the surfaces of exfoliated clay platelets (Figure 9), or by the surface of a solid reinforcing particle completely surrounded by an elastomeric phase (Figure 10). 

Carbon materials, such as carbon cloth and carbon paper, are also good substrates for the deposition of photocatalysts, due to their low resistivity and cost. They are also widely used in the proton exchange membrane fuel cell (PEMFC), and are also commercially available at www.fuelcellstore.com. Carbon cloth/paper is supplied with an untreated surface or reinforced with PTFE. Since the photocatal5ftic reactions at the anode side involve three phases liquid electrol)4e, solid anode photocatalyst, and the produced gaseous CO2, carbon materials with hydrophilic surfaces are preferred in the fabrication of photoanodes. Compared to the previous two substrates, carbon material can be used directly without any pretreatment. 

It appears from the evolution of the adhesion index that a distinction has to be made between the interactions carbon blacks are able to have with unsaturated or with saturated (or near-to-saturated) elastomers. Thus, the adhesion index of butyl rubber is enhanced upon oxidation of the black, while the reverse is observed with polybutadiene 38). The improvement of the reinforcing ability of carbon black upon oxidation, in the former case, has been interpreted by Gessler 401 as due to chemical interactions of butyl rubber with active functional groups on the solid surface. Gessler, relating the reinforcing characteristics of the oxidized carbon black for butyl rubber to the presence of carboxyl groups on the surface of the filler, postulated a cationic... 

It appears, beyond all doubt, that filler-elastomer interactions result in the formation of chemical bonds between the polymer and the solid surface, which are due to a reaction of the macromolecule either with the surface chemical groups or with the surface hydrogen atoms. Is, however, the formation of covalent filler elastomer bonds a prerequisite for reinforcement to occur ... 

Applications were not limited to reinforced composites. After working with solid silicate surfaces for many years, I started playing with silane modification of... 

The flotation process is applied on a large scale in the concentration of a wide variety of the ores of copper, lead, zinc, cobalt, nickel, tin, molybdenum, antimony, etc., which can be in the form of oxides, silicates, sulfides, or carbonates. It is also used to concentrate the so-called non-metallic minerals that are required in the chemical industry, such as CaF2, BaS04, sulfur, Ca3(P03)2, coal, etc. Flotation relies upon the selective conversion of water-wetted (hydrophilic) solids to non-wetted (hydrophobic) ones. This enables the latter to be separated if they are allowed to contact air bubbles in a flotation froth. If the surface of the solids to be floated does not possess the requisite hydrophobic characteristic, it must be made to acquire the required hydrophobicity by the interaction with, and adsorption of, specific chemical compounds known as collectors. In separations from complex mineral mixtures, additions of various modifying agents may be required, such as depressants, which help to keep selected minerals hydrophilic, or activators, which are used to reinforce the action of the collector. Each of these functions will be discussed in relation to the coordination chemistry involved in the interactions between the mineral surface and the chemical compound. 

The nature of the interaction of polymers with solid surfaces is of much practical importance, e.g., in coatings and in reinforced polymers, as well as of theoretical interest 3) ... 

Here, the harder partner penetrates the surface of the softer partner resulting in a microcutting process. This problem is particularly pronounced when processing plastics because the fillers and reinforcements that cause wear are added in their pure form, i. e., not coated in melt. The problem applies both for the plastification zone (not in the case of rework materials) as well as for solid fillers. The amount of abrasive wear is primarily determined by ... 

---