Cationic polymeric chemical inhibitors and multifunctional blends for the control of silica scale in process waters

Water is used globally for cooling purposes in industry. During its re-use, scaling and deposition can develop due to the high content of dissolved species. Among the toughest to combat is silica scale, or amorphous silicon dioxide. In this paper, we present how certain chemical interventions in the water chemistry can be beneficial for inhibiting silica polycondensation. Specifically, we have used chemical additives known as dendrimers. These are dendrimeric molecules based on polyaminoamide backbones that possess amine moieties as surface groups. These become protonated at circumneutral pH, hence charging the dendrimer molecules cationically. Their blends with anionic polymers such as polyvinylphosphonic acid are also studied for their silica scale inhibition efficiency.