Newly designed diblock dispersant for powder stabilization in water-based suspensions

• Published in: Journal of colloid and interface science Vol. 506; pp. 180 - 187
• Main Authors: Li, Chia-Chen, Chang, Shinn-Jen, Wu, Chi-Wei, Chang, Cha-Wen, Yu, Ruo-Han
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 15.11.2017
• Subjects: Adsorption; Dispersant; Dispersion; DLVO theory; Polyacrylate; Titania; Dispersant; Polyacrylate; Adsorption; Titania; DLVO theory; Dispersion
• ISSN: 0021-9797; 1095-7103
• DOI: 10.1016/j.jcis.2017.07.045

[Display omitted] A newly designed dispersant for water-based suspensions, ammonium poly(methacrylate)-block-poly(2-phenoxyethyl acrylate) (PMA-b-PBEA), is proposed in this study. According to the results of rheological analysis, the dispersion efficiency of this new dispersant is superior to that of the commercially available ammonium polyacrylate (PAA-NH4). The diblock structure of PMA-b-PBEA, which simultaneously contains a low-polar anchoring head group and a water-dissociable stabilizing moiety, is the main cause for its extremely high efficiency for powder dispersion. The unique structure not only results in effective adsorption approximately double that of PAA-NH4, but also produces a low number of counter-ions that compress the electrical double layer and ruin powder stabilization. Based on Derjaquin-Landau-Verwey-Overbeek calculations, the large adsorbance of PMA-b-PBEA gives the powder, titania (TiO2) in this study, a high steric stabilization energy. In addition, PMA-b-PBEA provides TiO2 with a remarkably high electrostatic energy because it generates fewer counter-ions. This energy provides excellent dispersity of powder in the suspensions with a high solid content of 60wt% without showing any rheological hysteresis.