Adsorption of non-ionic ABC triblock copolymers: Surface modification of TiO2 suspensions in aqueous and non-aqueous medium

• Published in: Applied surface science Vol. 419; pp. 713 - 719
• Main Authors: Lerch, Jean-Philippe, Atanase, Leonard Ionut, Riess, Gérard
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15-10-2017
• Subjects: Adsorption; Dispersing agents; Poly(2-vinylpyrridine); TiO2; Triblock copolymers; Poly(2-vinylpyrridine); Adsorption; Dispersing agents; Triblock copolymers; TiO2
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2017.05.062

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•PB-P2VP-PEO triblock copolymers were used as dispersants of TiO2 in water and heptane.•The adsorption and the chain densities are higher in heptane than in water.•The molecular and the adsorption characteristics of the ABC copolymers are correlated.
A series of non-ionic ABC triblock copolymers, such as poly(butadiene)-b-poly(2-vinylpyrridine)-b-poly(ethylene oxide) (PB-P2VP-PEO) were synthesized by sequential anionic polymerizations. For these copolymers comprising an organo-soluble PB and a water-soluble PEO block, their P2VP middle block has been selected for its anchoring capacity on solid surfaces. The adsorption isotherms on TiO2 were obtained in heptane and in aqueous medium, as selective solvents. In both of these cases, the P2VP middle block provides the surface anchoring, whereas PB and PEO sequences are acting as stabilizing moieties in heptane and water respectively. By extension to ABC triblock copolymers of the scaling theory developed for diblock copolymers, the density of adsorbed chains could be correlated with the molecular characteristics of the PB-P2VP-PEO triblock copolymers. From a practical point a view, it could be demonstrated that these copolymers are efficient dispersing agents for the TiO2 pigments in both aqueous and non-aqueous medium.