Sodium lignosulfonate, conductivities

Conductivities of sulfur lignin (SL), sodium lignosulfonate (NaLS), and some common materials are represented in Table III. 

Polyaromatic sodium lignosulfonate and sulfur lignin resin can be made conducting by doping. The conductivity increases by several decades through doping with electron acceptors and donors as shown in Table IV. 

We have doped sulfur lignin and sodium lignosulfonate in vapor-phase (iodine, bromine, and ammonia) and in liquid phase (sodium and ferrichlo-ride). The conductivity mainly depends on the nature of the dopant ion and the doping degree. Doping can be monitored by IR-spectroscopy. The intensities of the peaks decrease, and the fine structure vanishes, when the... 

Table IV. Conductivities of sodium lignosulfonate (NaLS) and sulfur lignin (SL) with some dopants ...

When sodium lignosulfonate or sulfur lignin are compounded, for instance, with iodine or bromine, complexes supposedly form (16-17). These systems are conductors with mixed ionic and electronic nature. Presumably they are charge transfer complexes, since the electronic conductivity predominates (18-19). These compounded materials form charge transfer structures (20). Water is supposed to introduce ionic conductivity to the system. Impurities affect conductivity, too (21). In any case, the main models of conductivity are probably based on the band model and/or the hopping model. 

Ramachandran and LoweryP l applied conduction calorimetry to the study of the relative effects of various retarders on the hydration of cement. The retarders used were calcium gluconate, glucose, glycolic acid, molasses, sodium borate, sodium citrate, sodium heptonate, sodium hexametaphosphate, sodium pyrophosphate, sugar-free lignosulfonate, and sucrose. The dosage of the chemicals varied between 0.025 and 1.2%. 

In gypsum-less cement, a conduction calorimetric study showed that a strong retardation of hydration occurred in the presence of a lignosulfonate-based superplasticizer containing sodium carbonate. l... 

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