Chemical Adjustment

The chemical adjustment of charge density is another potentially rewarding technique. It does, however, require either the synthesis of new polymers or the chemical modification of preformed polymers (e.g., supersulfation of hyaluronic acid [16]). This procedure has not been evaluated in our screening. 

Drag-out solution or static wash may be reduced to about 25Z of the volume. A chemical adjustment can be done to match the plating solution, then, use this solution to "top up" the plating tank. In this manner there is no sludge to dispose of as a hazardous waste. 

For the encapsulation of pigments by miniemulsification, two different approaches can be used. In both cases, the pigment/polymer interface as well as the polymer/water interface have to be carefully chemically adjusted in order to obtain encapsulation as a thermodynamically favored system. The design of the interfaces is mainly dictated by the use of two surfactant systems, which govern the interfacial tensions, as well as by employment of appropriate functional comonomers, initiators, or termination agents. The sum of all the interface energies has to be minimized. 

Deflocculation, including its secondary effects, is a result of ion exchange on the surface of clay particles. The efficacy of this colloid-chemical adjustment is illustrated by the example reported by Norton (1952) addition of NaOH solution to mono-disperse fraction of H -kaolinite prepared by dialysis gives rise to an (approximately) 200-fold decrease in apparent viscosity, affected instantaneously in the region of pH 5-6, where complete exchange of ions for Na " has taken place. 

Coetsier, C.M., Testa, F., Carretier, E., Ennahali, M., Laborie, B., Mouton-amaud, C., Fluchere, O., Moulin, P., 2011. Static dissolution rate of tungsten film versus chemical adjustments of a reused slurry for chemical mechanical polishing. Appl. Surf. Sci. 257 (14), 6163-6170. 

The whole process can take from several months to several years however, from the results one can understand the function and the role of the respective protein in the metabolic cycle and eventually one can decide the way in which this function and the basic structure should be changed - for example, by a metallic insert - to comply with specific needs of structural (chemical) adjustment and metabolic (biological) action. 

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