水基SiC悬浮液的流变特性

THE RHEOLOGICAL PROPERTIES OF AQUEOUS SILICON CARBIDE SUSPENSIONS

研究了pH、四甲基氢氧化铵(TMAH)、离子强度及碱处理对水基SiC悬浮液流变性的影响。pH值对水基SiC悬浮液的流变性具有至关重要的作用。在pH=11附近时,SiC悬浮液可以达到最佳的稳定状态,此时TMAH几乎不起作用,而且过量的TMAH会降低SiC悬浮液的分散稳定性;在其它pH值时,虽然TMAH具有一定的分散作用,但SiC悬浮液的稳定性明显低于pH=11时。在pH=11时,SiC悬浮液的流变性对离子强度较敏感,其微量增加会显著地降低SiC悬浮液的流变性。在相同的pH值、TMAH添加量、固含量的条件下,碱处理后SiC悬浮液的流变行为明显得到改善。

Influence of pH, tetramethyl ammonium hydroxide （TMAH）, ionic strength and alkali treatment on the rheological properties of aqueous SiC suspensions was investigated. The value of pH plays a dominant role for aqueous SiC suspension and the optimum rheological properties of SiC suspensions are achieved around pH 11. The results exhibits that the dispersant TMAH has no visible effect on SiC suspension at pH 11, moreover, excessive TMAH reduce the rheology of SiC suspension remarkably, but both suspensions without and with appropriate TMAH at pH 11 obtain better dispersion than at other pH. The stability of SiC suspension at pH 11 is highly sensitive to ionic strength and the rheological behavior of the suspension deteriorate observably with the small increase of the electrolyte concentration. The rheological properties of SiC suspension are improved dramatically bv alkali treatment.