山东大学：《物理化学》课程教学资源（讲义资料）8.10 Preparation and purification of colloids-for students

8.10 Preparation and purification of colloids

8.10 Preparation and purification of colloids

8.10 Preparation and purification of colloids 8.10.1 Preparation of colloids: (1) Principles for colloid preparation Small particles(molecules Large block or ions) The intrinsical diameter of colloids is 10-910-6 m Dispersion method: by disintegrating Condensation method: by building down the bulk material to the colloidal up the particles from single molecules article

(1) Principles for colloid preparation Large block Small particles (molecules or ions) The intrinsical diameter of colloids is 10-9 ~ 10-6 m. Condensation method: by building up the particles from single molecules. 8.10.1 Preparation of colloids: Dispersion method: by disintegrating down the bulk material to the colloidal particles. 8.10 Preparation and purification of colloids

8.10 Preparation and purification of colloids 8.10. 2 methods for colloid preparation Dispersion methods Colloid mill: mechanical dispersion 2)arc method: evaporation-condensation 3)ultrasonic method: dispersion 4) peptization method repulsion Redig’sarc Medium t alkali method Coarse dispersion Ultrasonic generator colloid mill

Dispersion methods: colloid mill Coarse dispersion 1) colloid mill: mechanical dispersion 2) arc method: evaporation-condensation 3) ultrasonic method: dispersion; 4) peptization method: repulsion. Bredig’s arc method Ultrasonic generator 8.10 Preparation and purification of colloids 8.10.2 methods for colloid preparation

8.10 Preparation and purification of colloids 8.10. 2 methods for colloid preparation condensation method /aggregation method Chemical condensation ysical condensation 1)reduction: AgNO3 tannin+ K2CO3 for 1)Change of solvent: sulfur/alcohol -> Ag sol sulfur /water 2)Redox: H2S+ So2 for S sol 3)Hydrolysis: FeCl3 boiling water for 2)Condensation of vapor: hydrosol of h Fe(OH)a sol Na sol in benzene 4)Precipitation: AgNO3 + Kl; NaSiO3+ HCl

condensation method / aggregation method Chemical condensation: 1) reduction: AgNO3 + tannin + K2CO3 for Ag sol 2) Redox: H2S + SO2 for S sol 3) Hydrolysis: FeCl3 + boiling water for Fe(OH)3 sol 4) Precipitation: AgNO3 + KI; NaSiO3 + HCl Physical condensation: 1) Change of solvent: sulfur/alcohol → sulfur / water 2) Condensation of vapor: hydrosol of Hg, Na sol in benzene 8.10.2 methods for colloid preparation 8.10 Preparation and purification of colloids

8.10 Preparation and purification of colloids 8.10.2 methods for colloid preparation Micelle Non-spherical Vesicle Micelle 费费身 Reverse ●命 Micelle Bilayer

8.10 Preparation and purification of colloids 8.10.2 methods for colloid preparation

8.10 Preparation and purification of colloids 8.10.3 Basic requirements for preparation of colloids: FeCl3+ 3H,O(boiling)-> Fe(OH)3(sol)+ 3HCI 1)Low solubility 2)Low concentration 3) Addition of stabilizing reagent?

1) Low solubility 2) Low concentration 3) Addition of stabilizing reagent？ FeCl3 + 3H2O (boiling) ⎯→ Fe(OH)3 （sol）+ 3HCl 8.10.3 Basic requirements for preparation of colloids: 8.10 Preparation and purification of colloids

8.10 Preparation and purification of colloids 8.10.3 Basic requirements for preparation of colloids: Nucleation and growth precipitation e concentration 10-4c10-5 mol dm-3. sol 102210-'mol dm-3, precipitation, crystalline solid 2-3 mol dm-3, gel

10-4 ~ 10-5 mol dm-3 , sol; 10-2 ~ 10-1 mol dm-3 , precipitation, crystalline solid 2~3 mol dm-3 , gel sol gel precipitation concentration diameter Nucleation and growth 8.10.3 Basic requirements for preparation of colloids: 8.10 Preparation and purification of colloids

8.10 Preparation and purification of colloids 8. 10.4 Purification of colloids: (1) Dialysis and electrodialysis 2)ultrafiltration Dialysing membrane Parchment membrane

(1) Dialysis and electrodialysis Parchment membrane Dialysing membrane 2) ultrafiltration 8.10.4 Purification of colloids: 8.10 Preparation and purification of colloids

8.10 Preparation and purification of colloids 8. 10.4 Purification of colloids: Hemodialysis of medical application back next

Hemodialysis of medical application 8.10.4 Purification of colloids: 8.10 Preparation and purification of colloids