Collate solution

a system formed by one or more substances dispersed in another medium is called a dispersion system. Dispersed substances are called dispersed phases, while continuous media are called dispersed media. For example, salt water solution, salt is a dispersion system and divided into omnispheric dispersion system and multiphate dispersion system. The low-molecular solution and the polymer solution are both dispersed. The sol and coarse dispersion systems are multi-phase dispersion systems.

dispersion system often changes with the size of the dispersed phase particles, so the dispersion system can be divided into three categories by the size of the dispersed phase mass (Table 9-1): low molecules (or Ion) dispersion system (the line size of its particles is less than 1nm), colloidal dispersion system (the line size of its particles is between 1-100nm), and coarse dispersion system (the line size of its particles is more than 100nm). There is no clear line between the three.

1, coarse dispersion system

< "tt1" > in the coarse dispersion system, dispersed phase particles are greater than 100nm, because its particles are larger with the naked eye or ordinary"can be observed scattered phase particles. Because its particles are large enough to prevent light from passing through, the appearance is cloudy and opaque. In addition, due to the large dispersion phase particles, < a href"" > filteror semi-permeable membrane. At the same time, it is susceptible to gravity and automatically subsides, so it is unstable.

the coarse dispersion system is divided into suspended turbidity (solid dispersion in liquids - e.g. mud) and emulsions (liquid dispersion in liquids - e.g. milk) according to the dispersion phase.

2, low molecular dispersion system

scattered phase particles less than 1nm, because the dispersed phase particles are small, can not prevent light from passing through, so the solution is transparent. This solution is highly stable and, no matter how long it is placed, the dispersed phase particles do not sink due to gravity and are not separated from the solution. Dispersed phase particles can spread quickly through >" filter paper or semi-permeable membranes, such as salt water and sugar water.

three, colloidal dispersion system

colloidal dispersion system, i.e. colloidal solution, dispersion phase particle size between 1-100nm, belongs to this class of dispersion system of sol and polymersolution. Because the collocial particles of this dispersion system are bigger than the dispersed phase particles of the low-molecular dispersion system and smaller than the dispersed phase particles of the coarse dispersion system, the collocial particles of the collocational dispersion system can penetrate the filter paper, but not through the semi-permeable membrane. The appearance of the collectant solution is not cloudy, with the naked eye or ordinary microscope can not be distinguished.

collome is a dispersed state of matter, regardless of any substance, as long as the particles between 1-100nm scattered in another substance, become a colleome. For example, sodium chloride is a low-molecular dispersion system when dispersed into ions in water. In benzene, the aggregate is dispersed into ions, and the size of the aggregate particles is between 1-100nm, which belongs to the collosus solution. Many < a href" > protein , starch, glycogen solution and blood, lymphatic fluid, etc. belong to the collosal solution.

Table 9-1 classification of the decentralized system

<"center" >< > particle size

type

td width

<"118" >< "center" > nature

instance

<1nm low-molecule dispersion system atoms, ion >s or small molecules< Filter paper, semi-permeable membrane, the formation of a true solution sucrose, sodium chloride, acetic acid aqueous solution, etc.

1 to 100nm

collosal dispersion system

polymer

118<" >td width" 118" > phase, stable system, slow diffusion, can not pass through the semi-permeable membrane, can filter paper, ultra-microscope can not be seen, the formation of a true solution protein, >, < a href> "" nucleic acid aqueous solution, etc

sol

< td width "118" > gum particles (aggregations of atoms or molecules) multi-phase, unstable system, slow diffusion, can not pass through the semi-permeable membrane, can penetrate the filter paper, Invisible under a microscope to form a true solution 118" >Fe (OH) 3, As2S3, gold sol, etc

>100nm

thick Dispersion system

arse particles< td width s"118" > multi-phase, unstable system, diffusion is slow or non-proliferation, rapid subterranean sinking, Can not be filtered paper and semi-permeable membrane, the formation of suspended turbid liquid, emulsion "118" turbid mud water, milk, soy milk and other