Study on the design and synthesis of P(AM-DMDAAC)and its flocculation properties on microfine kaolinite particles
WANG Lujun
MIN Fanfei
NGUYEN A V
SONG Chang
SUN Kangkang
HU Shangyu
Abstract：In order to achieve efficient flocculation of fine clay mineral particles in tailings water such as coal slurry water,the differences in adsorption properties of different cationic monomer flocculants on kaolinite(001)surface were calculated by molecular dynamics simulation using microfine kaolinite particles as the object of study.Dimethyldiallyl ammonium chloride was preferred as the optimal cationic polymerization monomer,and the polymer P(AM-DMDAAC)was prepared by ultrasound-assisted free radical copolymerization,referred to as PDA.The synthesis conditions were optimized using orthogonal experiments,and the synthesized poly-mer products were characterized using Fourier transform infrared spectroscopy(FTIR),hy-drogen nuclear magnetic resonance spectroscopy(1H NMR),thermogravimetric analysis(TGA)and scanning electron microscopy(SEM).The flocculation performance of PDA under different salinity conditions was studied through flocculation and sedimentation experiments.The results show that PDA is able to reduce the water molecule density on the kaolinite(001)surface and weaken the interaction between the two to enhance the flocculation effect on the microfine kaolinite suspension.The time of ultrasound and the amount of initiator have a high-ly significant effect on the performance of PDA,with ultrasound time＞interaction＞initiator amount.The FTIR and 1H NMR results indicate that the polymer PDA has been successfully prepared,and the optimal synthesis conditions are ultrasound time of 25 min and initiator dos-age of 700 μL;TGA indicates that PDA is stable and not easily decomposed at room tempera-ture;SEM observation shows that PDA has a porous and spatial three-dimensional mesh struc-ture.In the range of ion concentration below 0.1 mol/L,the metal cations promoted the for-mation of microaggregates of kaolinite particles through electrical neutralization.The forma-tion time of flocs was shortened and the compactness of flocs was enhanced,which synergisti-cally enhanced the flocculation performance of PDA in the order of AlCl3＞MgCl2＞NaCl.The research results can enrich flocculation theory and guide the design and synthesis of new floccu-lants.
Keywords：molecular dynamics simulationdimethyldiallyl ammonium chlorideflocculantorthogonal experimentultrasound
Publication Date：2025-03-30
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：13( 458-470 )