Skip to main content

Zeolites

Zeolites

  • Zeolites are crystalline solid structures made of silicon, aluminium and oxygen that form a framework with cavities and channel inside where cations, water or small molecules may reside.
    Example of zeolites
    Examples of zeolites.
  • They are often also reffered to as molecular sieves.
    Sieve and molecular sieve.
  • Many of them occur naturally as minerals and are extensively mined in many parts of the world finding application in industry and medicine. However, most of zeolites have been made synthetically.
  • Zeolites are of two types
   1) Natural zeolite.
   2) Synthetic zeolite.
  • Natural zeolite: There are about 40 naturally occurring zeolites. Natural zeolite are non porous. For example; Natrolite.
  • Synthetic zeolite: Synthetic (artificial) zeolites (around 150) have been designed for specific purposes. Synthetic zeolite are porous. Mordenite is a synthetic zeolite.
  • Natural zeolites are used as animal feed, odour control, water purification and water treatment.
  • Natural zeolites are also used as oil absorbent and catalyst.
  • Synthetic zeolites are used as catalyst, detergents etc. Next

Comments

Post a Comment

Popular posts from this blog

Determination of molecular weight of polymers by viscosity method.

Determination of molecular weight of polymers by viscosity method. It is a simple method for determining the molecular weight of polymers. Addition of polymers in the solvent increases the viscosity of the solvent, due to introduction of inhomogeneities by the polymers. If η₀ is the viscosity of the solvent and η is the viscosity of the solution at the same temperature, then the relative viscosity is given by Relative viscosity. Specific viscosity:  It is defined as the relative increase in viscosity and is given as Specific viscosity. Reduced viscosity: It is defined as the relative increase in viscosity per unit concentration (C) of polymer and is given as Reduced viscosity. Intrinsic viscosity: The reduced viscosity is dependent on concentration (C). If a graph is plotted between  reduced viscosity vs concentration then the extraplotation value when C=0 is called intrinsic viscosity. Intrinsic viscosity. Graph of reduced viscosity vs concentr
2 comments
Read more

Determination of molecular weight by Light scattering method.

Determination of molecular weight by Light scattering method. Due to big size macromolecules in solution, turbidity is produced. The light rays get scattered, when pass through macromolecule solution due to turbidity. The turbidity T is given by Where I₀ is the intensity of incident light. Iₜ is the intensity of transmitted light after passing through a solution of length l.        In case of proteins or higher polymers the turbidity is small and is determine from the intensity of light scattered at 90° to the beam. This can be done by using a simple photometer as shown in figure below. Turbidity increase with increase in concentration as well as molecular weight. The Turbidity is related to molecular weight by the equation given by Debye. Hc/T=1/M+2Bc Where B is second virial coefficient and H is a constant. If we plot a graph between Hc/T vs c we get a straight line with intercept 1/M. Thus This curve was plotted by Zimm, so is called Zimm's Curve. Thus the c
Post a Comment
Read more

Polypropylene (PP)

Polypropylene (PP). Polypropylene (PP) is also known as polypropene. Polypropylene is made from the polymerisation of propylene gas in the presence of Zeiglar Natta catalyst or metallocene catalyst. Polypropylene. Thus propene (or propylene) is the monomer of polypropylene. Polypropylene is a highly flammable material. It is sensitive to microbial attacks, such as bacteria and mold. It exhibits excellent resistance to diluted and concentrated acids, alcohols and bases. Polypropylene is used to make lunch boxes, margarine containers, yogurt pots, syrup bottles etc. Disposable syringes is the most common medical application of polypropylene. Polypropylene rope and twine are very strong and moisture resistant very suitable for marine applications. Polypropylene, highly colorfast, is widely used in manufacturing carpets, rugs and mats. Uses of Polypropylene. Questions on polypropylene; Q1) What is polypropylene? Ans) Polypropylene is a polymer of propylen
Post a Comment
Read more