Relationship between cement grinding aids and surfactants

Strictly speaking, it is only active and cannot be called a surfactant. (hereinafter referred to as surfactant) surfactant in aqueous solution, a small amount can make the surface tension drop sharply, when it reaches a certain amount, it will not drop (or slowly decline), and the concentration of the inflection point is called the surfactant. The minimum micelle concentration. For example, sodium fatty acid (component of soap), sodium dodecylbenzenesulfonate (ingredient of washing powder), and the like. When the general alcohol is added to water, the surface tension is only slowly decreased, and there is no inflection point. In the absence of a test instrument, the simple way to distinguish is to agitate the solution separately, the foam is the surfactant, and the foam is not the surfactant. 2, the surfactant is divided into anion, cation, amphoteric, nonionic, and also the bipartite active agent researched and developed in recent years. Most surfactants can be formulated with cement grinding aids, but the hydrophilic and lipophilic values are not suitable for grinding aids because of their poor water solubility. Some surfactants with high foaming properties are also not suitable as grinding aids. 3. The hydroxyl group of the alcohol and the hydrophilic group of the surfactant can adsorb on the surface of the clinker and the cement particles, reduce the surface strength and penetrate into the crack, and improve the grindability. When grinding to a certain degree of fineness, the alcohol or surfactant adsorbed on the surface of the fine particles acts to isolate each other and eliminate static electricity, preventing secondary agglomeration of the fine particles. Why do grinding aids use Amines, polyols, alcoholamines, etc., because when the cement has the same fineness, it covers the surface of the particles to form a so-called monomolecular film, the weight of the Grinding Aid required, and the materials used related. The small molecular weight is small, and the molecular weight is large. The molecular weight of the general surfactant is much larger than that of ethylene glycol, propylene glycol, glycerol, and triethanolamine. Another is that triethanolamine is a recognized organic early strength agent. As for lignosulfonate, it is a mixture of molecular weights from tens of thousands to tens of thousands to millions, and it is mainly cheaper than it is a grinding aid.