Particle Size And Particle Size Distribution

Question 1

What is particle size

Answer 1

Particle size is a fundamental property. Expressed in particle diameter

Question 2

Classification of the particle size

Answer 2

Symmetrical
Asymmetrical
Monodisperse
Polydisperse

Question 3

Symmetrical particle size

Answer 3

Particle size is easily represented by particle diameter due to their spherical structure

Question 4

Asymmetrical particle

Answer 4

Expressed in surface diameter
Volume diameter
Projected diameter
Stokes diameter
Sieve diameter

Question 5

Monodisperse particle

Answer 5

Here all the particles have same particle size so to determine o size we have to measure p size of anybone of the particle

Question 6

Polydisperse powder

Answer 6

It’s a collection of particle having more than one size so it is difficult to express p size of powder or sample by determining the p size of any one of the particle

Question 7

Polydisperse powder we express the p size in terms of average p size

Answer 7

Avg particle size can be expressed as

ARITHMETIC MEAN DIAMETER

GEOMETERIC MEAN DIAMETER

Question 8

Arithmetic mean diameter

Answer 8

Length number means diameter = £nd/£n

Volume number means diameter = 3✓£nd³/£n

Surface number means diameter=✓£nd²/£n

Volume surface number mean diameter @=£nd³)£nd²

Question 9

Psd ?

Answer 9

PSD is away of expressing the range of sizes of particles in a polydisperse powder.in polydisperse sample PSD gives a better representation of the mean particle size

Question 10

Determination of particles size distribution

Answer 10

Number distribution data curve - determination of number of particle present within each size ranges

Weight distribution curve - determination of the weight of the particles present within each size ranges

Question 11

Representation of PSD

Answer 11

Drawing a graph between no:of particles and avg p size

Or
A graph blw weight of the particle and avg particle size

Question 12

P size graphical

Answer 12

1.Normal frequency distribution curve
2.percentage frequency/s pnsize curve
3.lig normal distribution curve
4.cumulative percentage frequency)s p size curve
5.log probability curve

Question 13

Methods to determine p size

Answer 13

1.optical microscopy (particle counting)
2.sieving method ( particle separation)
3. Sedimentation method(particle separation)
4.conductivity method( particle volume)