Influence of PAMAM dendrimers on seed precipitation in sodium aluminate solution

Generations-0.5-4.5G (G is generation) of poly (amid amine) (PAMAM) dendrimer were synthesized using ethylenediamine and methyl acrylate as raw materials by divergent method. Their structures were characterized by infrared spectra. After caustic aluminate solution was added to the stainless reactor,the PAMAM was diluted and the seeds were added to the reactor. The results show that PAMAM has good adsorptive force in the surface of aluminium trihydroxide seeds,and PAMAM dendrimer containing—COOCH3 terminal groups is better than that containing —NH2 terminal groups as additives which can enhance the seed precipitation speed and precipitation ratio. The enhancement of PAMAM of half-generation increases with the build-up of PAMAM generation before 2.5G (include 3.5G) and decreases with the build-up of generation after 2.5G. 2.5G PAMAM were added in the sodium aluminate 2solutions,the precipitation ratio improves by 11.1 %,product particle size (45μm) increases by 3.45%,compared with the condition that no additives are added. The enhancement of PAMAM increases with the build-up of its concentration of solution.