chapter9detergencyofsurfactants-展示頁
2024-07-30 18:07本頁面
【正文】 ls, and etc ? Soft surface – fabric , fiber (2) The soil (the material that is to be removed from the substrate in the cleaning process) ? Liquid soils – oil or fat ? Solid soils – black carbon, dust, and etc (3) The bath or cleaning solution. 2. Force between substrates and soils (1) Mechanical force – soft amp。 porous substrates, particle diameter r of the particles ?, then force?, r 100nm, then difficult to wash off (2) Electrostatic force – surface potentail ?wool/water= 48mV ?cotton/water= 38mV ?silk/water= 1mV cation bridge (陽離子橋 ) polyvalency ions Electrostatic force Mechanical force Soil ++++ (3) Chemical force – polar soils proteins , fats , oxides etc Hydrogen bond and electrovalent bond (4) Van Der Waals force – interactions between polar amp。 nonpolar or nonpolar amp。 ,Cos? 0 ? R= ?? + ?BO Cos ? = 0 , force balance ?If surfactants is added and only adsorbed on interface S/B and O/B, then ?SB ?, ?OB ?, then ?? 0, ? 90176。 , ?? 0, ?BOCos? 0, R = 0, anew force balance (c) Three kinds of rollup ? Complete removal ? Spontaneously rollup (自動卷離 ) ? = 180176。 ? 180176。 Complete removal of oil droplets from substrate Rupture and inplete removal of large oil droplets from substrate (2) Removal of solid soil (A) Mechanism (a) Liquefiable (可液化 ) soil – rollup (b) Particulate soil ? Wetting of the substrate and the soil particles by the bath ? Spreadin
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