| Abstrakt: |
Achieving functional styrene–maleic anhydride (SMA) copolymer dispersant is highly attractive but still remains a challenge. Conventional modified SMA dispersants have complex modification steps, poor performance, and limited applications. Thus, a series of styrene–maleimide (SMI) copolymers with different functionality as amphiphilic dispersants for dispersing nano-SiO2 in an aqueous solution were synthesized using a simple preparation process. The changes in the maleic anhydride groups during imidization were tracked using FTIR spectroscopy, 1H-NMR, and GPC. A rotational viscometer and an inverted bottle method were used to measure the viscosity and coagulation time of the nano-SiO2 aqueous dispersion system, respectively, after adding the SMI dispersants. The particle size, size distribution, and dispersant adsorption amount of the dispersion were analyzed using laser particle size analysis; FTIR spectroscopy and SEM; and TGA, respectively. The results showed that the hydrogen bonds formed between the amino groups in the dispersant and the hydroxyl groups on the SiO2 surface during stirring allowed the dispersant to be adsorbed onto the SiO2 surface after being added to the nano-SiO2 aqueous system. The addition of the SMI dispersant enhanced the steric hindrance and electrostatic repulsion between the nanoparticles, thus making it possible for the SiO2 nanoparticles not to easily aggregate in water, improving their dispersity and stability. Additionally, the type and amount of SMI dispersant used significantly affected the SiO2 nanoparticles' ability to disperse in water. This makes SiO2 particles convenient to use and transport, not produce dust pollution, and easy to store. [ABSTRACT FROM AUTHOR] |
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