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Chapter 12 Colloids and macromolecules 12.1 Colloids Dispersed system Dispersed phase Dispersed medium Colloid dispersed system: 1-1000nm(10 -9 ~ 10 -6 m) Coarse dispersed system: >1 m(10 -6 m)
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Colloid or sol (lyophobic colloid) Associated colloid (colloide electrolyte) Macromolecular solution(lyophilic colloid)
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Table 12-1Classfication of Dispersed System
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preparation Colloid system 1nm ~ 1000nm Solution <0.1nm Agglomeration Disperse Coarse dispersed system >1 m Replacing solvent reaction Physical agglomeration rubbingultrasonic arc
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12.2 Properties of Colloid 12.2.1 Tyndall Phenomena
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12.2.2 Movement Properties of Colloid Fick’s first law of diffusion (1) Diffusion
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(2) Sedimentation Sedimentation equilibrium
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12.2.3 The electrical double layer2 Stern potential ; Moving potential Thermodynamic potential e ; + + + + + + + + + - - - - - - - + + + + + + + + - - - - - - + - - - Closed layer (stern layer) Diffusion layer ee Stern model - - Solid surface Stern section Movable section
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– + + + + – IHP OHP 固体表面 水化阳离子 特性吸附阴离子 第一层水分子 第二层水分子 (b) 博克里斯模型 – 滑动面
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12.2.4 Structure of Colloids AgNO 3 +KI AgI 固相紧密层扩散层 [ ( AgI ) m nAg + ( n-x ) NO 3 ] x+ xNO 3 - 溶液 本体 胶核 胶粒滑动面 胶团
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NO 3 - ( AgI ) m Ag +
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12.2.5 Stabilization of Colloid Kinetic stabilization Coagulation stabilization 1. The effect of electrolyte on coagulation Coagulation value Schulze--Hardy rule 2. The effect of macromolecules on coagulation bridging effect dehydration effect electric neutralization effect
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12.2.6 DLVO theory U R ∝ exp{ - x} U max F C {x}{x} 0 Born repulsion {U}{U} U UA∝UA∝ —Debye parameter
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12.3 Macromolecules MacromoleculeM B >1 ~ 10 4 kg.mol -1 Number-average molar mass weight-average molar mass 12.3. 1 Osmotic Pressure of Macromolecules Solution
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12.3. 2 Membrane Equilibrium Donnan equilibrium Na + (b) Na + (b ' ) P x- (b ' ) Cl - (b) Na + (b) Na + (b ' ) P 2- (b ' /2) Cl - (b) P 2 - Cl - Na + Na + (b ' +b x ) P 2 - (b ' /2) Cl - (b x ) Na + (b - b x ) Cl - (b - b x )
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At equilibrium For dilute solution
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12.3. 3 Viscosity of Macromolecular Solution Relative viscosity Intrinsic viscosity
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12.4 Coarse Dispersed System 12.4.1 Emulsion
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Emulsifier Demulsification 12.4.2 Foam 12.4.3 Suspension
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表 10-2 胶体分散系统小结
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