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- Huldén, M, et al.
(author)
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Adsorption in latex paints in relation to some of the properties of the mill base and the final coating
- 1994
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In: JCT. - 0361-8773. ; 66:836, s. 99-105
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Journal article (peer-reviewed)abstract
- The rheological properties, gloss, hiding power and water absorption of some model latex paints were analysed in terms of the adsorption of surfactants, dispersing agent and thickener onto the latex and pigment particles. Special attention was paid to the order of addition of poly(acrylic acid) and ethyl(hydroxyethyl)cellulose, because this has an effect on the adsorption of the polymers onto the TiO2 pigment. The order of addition also affects the rheological properties of the mill base dispersion and the gloss of the paint. The gloss was also affected by the surfactant used to stabilise the latex. Higher gloss was obtained using a nonionic surfactant than with an anionic surfactant.
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2. |
- Huldén, M, et al.
(author)
-
Adsorption of some common surfactants and polymers on TiO2 pigments
- 1990
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In: Progress in Colloid and Polymer Science. - 0340-255X .- 1437-8027. ; 82, s. 28-37
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Journal article (peer-reviewed)abstract
- The adsorption of nonylphenol deca (oxyethyleneglycol) monoether (NPE10), sodium dodecyl sulphate (SDS), polyacrylic acid sodium salt (PAA) and ethyl hydroxyethyl cellulose (EHEC) on TiO2-pigment coated with different mineral oxides is reported. The adsorption isotherms are compared with data obtained by electrophoretic mobility measurements. Despite the limitationsinherent in the mobility measurements, we show that this technique can be used to gain adequate information on the adsorption.-Coating of the TiO2-pigment with different mineral oxides has a strong influence on the adsorption. This can be understood from the different acid/base characteristics of the coatings, e.g., TiO2 coated with Al2 O3 or (Al2 O 3 + SiO2) results in a basic and an acidic surface, respectively. SDS, PAA, and EHEC adsorb on the basic pigment, but not on the acidic one. NPE10 does not adsorb on either pigment, nor does it adsorb on pigment stabilized with pre-adsorbed PAA. The competitive adsorption of PAA and EHEC was studied by the consecutive addition of the polymers to the pigment dispersion. The total amount of adsorbed polymer was always larger with two polymers present compared to one single polymer. EHEC does not significantly influence the adsorption of PAA, irrespectively of whether it is adsorbed before or after the PAA. Conversely, 45% of the preadsorbed EHEC desorbs upon the addition of PAA. When EHEC is added to a pigment with pre-adsorbed PAA, the final amount of EHEC on the surface is significantly lower than the amount adsorbed on the bare pigment.
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