PROPERTIES OF SURFACE-MODIFIED COLLOIDAL PARTICLES

Show simple item record

dc.contributor.author Breiner J.M.
dc.contributor.author Anderson M.A.
dc.contributor.author Tom H.W.K.
dc.contributor.author Graham R.C.
dc.date.accessioned 2024-02-10T04:47:51Z
dc.date.available 2024-02-10T04:47:51Z
dc.date.issued 2006
dc.identifier https://elibrary.ru/item.asp?id=53350633
dc.identifier.citation Clays and Clay Minerals, 2006, 54, 1, 12-24
dc.identifier.issn 0009-8604
dc.identifier.uri https://repository.geologyscience.ru/handle/123456789/42520
dc.description.abstract The reactivity of colloidal particles is regulated by their surface properties. These properties affect the wettability, flocculation-dispersion characteristics, ion exchange, sorption capacities and transport of inorganic colloids. Most studies have focused on hydrophilic, charged-particle surfaces, often ignoring the alterations in surface properties produced by the adsorption of natural organic matter, surfactants and other compounds. Adsorption of these substances can potentially render a surface substantially more hydrophobic. Nevertheless, comparatively little is known about changes in surface properties and reactivity of minerals upon sorption of hydrophobic organic compounds. In this study, the properties of four minerals (kaolinite, pyrophyllite, montmorillonite and Min-U-Sil®) and two inorganic materials (X-ray amorphous Al hydroxide and X-ray amorphous Si oxide) were compared before and after treatment with the common silylating agent, trimethylchlorosilane (TMCS). The samples were characterized by measurements of total carbon, cation exchange capacity (CEC), particle size, specific surface area (SSA), electrophoretic mobility, contact angle, particle aggregation, and by X-ray diffraction and diffuse reflectance infrared spectroscopy. For the layer silicates, surface coverage was limited to ~2% trimethyl silane (TMSi). TMSi covered 7.5% of the Min-U-Sil® surface and 33% of the X-ray amorphous Si oxide. Treatment did not affect the structure of the minerals but reduced the CEC, SSA and electrophoretic mobilities. Water contact angles increased to between 18 and 114° with treatment. While the apolar characteristic of the surfaces decreased minimally with treatment, the Lewis acid/base properties were substantially reduced and interfacial free energy shifted from positive to negative values indicating a more hydrophobic surface character. For all the samples except kaolinite, these changes affected the stability of the colloids in suspension depending upon solution pH. Although the grafting of TMSi altered colloidal mineral surface properties and increased their hydrophobicity, these changes were not sufficient to predict colloid aggregation behavior.
dc.subject CONTACT ANGLE
dc.subject HYDROPHOBIC SURFACE
dc.subject KAOLINITE
dc.subject MONTMORILLONITE
dc.subject PYROPHYLLITE
dc.subject QUARTZ
dc.subject TRIMETHYLCHLOROSILANE
dc.title PROPERTIES OF SURFACE-MODIFIED COLLOIDAL PARTICLES
dc.type Статья
dc.identifier.doi 10.1346/ccmn.2006.0540102


Files in this item

This item appears in the following Collection(s)

  • ELibrary
    Метаданные публикаций с сайта https://www.elibrary.ru

Show simple item record