The surface free energies of talc and pyrophyllite

摘要: The components of the interfacial surface tension talc and pyrophyllite were determined by measuring rate capillary rise a number liquids through thin, sedimented deposits powdered minerals. liquid in powder is related to contact angle between solid Washburn equation. angles thus derived used determine apolar (Lifshitzvan der Waals) component, γ LW , polar, electronacceptor electron-donor parameters, γ ⊕ γ ⊖ respectively, Lewis acid/base component total energy using Young values for (31.5 34.4 mJ/m2) are slightly smaller than smectite clay minerals (e.g., value hectorite 39.9 mJ/m2), electron donor parameter roughly comparable (γ ⊕ = 2.4 1.7 as acceptor (γ ⊖ 2.7 3.2 mJ/m2). well-known hydrophobicity these two due remarkably small (for silicate minerals) γ ⊖(γ⊕ normally or zero silicates many other oxides). both mean that interactions highly polar water molecules very weak. In contrast, low-charge smectites, most similar chemically structurally pyrophyllite, have much greater (≥ 30 hydrophyllic.