One-pot waterborne superhydrophobic pigment coatings at high solids with improved scratch and water resistance
2016 (English)In: Colloids and Surfaces A: Physicochemical and Engineering Aspects, ISSN 0927-7757, E-ISSN 1873-4359, Vol. 495, 79-86 p.Article in journal (Refereed) PublishedText
A pigment coating was developed to achieve superhydrophobicity in one step from a waterborne formulation containing aragonite calcium carbonate, hydrophobized using sodium oleate, latex binder and cross -linker. Coatings formulated <= 50 mass% and applied to polyethylene coated paperboard substrates displayed typical superhydrophobic features: water contact angles >= 150 degrees, low roll-off angle and low stain sizes, but poor scratch and water resistance as well as foaming issues during preparation. Reformulation at higher solids content significantly improved scratch and water resistance properties. Water rinsing of the dried coatings further increased the water barrier capacity due to reduced surfactant-assisted wetting; findings were corroborated by detailed surface chemistry analyses showing the removal of surface-active components after water rinsing of the dried coatings. A plausible cause for the improved durability is the fact that capillary forces increase exponentially with increasing pigment volume fraction (power law exponent of 2.2) leading to efficient binder coverage during the early stage of pigment coating consolidation.
Place, publisher, year, edition, pages
Elsevier, 2016. Vol. 495, 79-86 p.
Superhydrophobicity, Water resistance, Wetting, Contact angle, Coating, Calcium carbonate, Scratch resistance, Durability, Surfactant
IdentifiersURN: urn:nbn:se:kth:diva-184519DOI: 10.1016/j.colsurfa.2016.01.058ISI: 000371395500010ScopusID: 2-s2.0-84957831628OAI: oai:DiVA.org:kth-184519DiVA: diva2:917562
QC 201604072016-04-072016-04-012016-04-07Bibliographically approved