Assignment 01: Discuss the different ways of particle diameter expression. Also to calculate the equation of particle number for 1 gram of powder sample. A little assignmen on the topic based on micromeritics.

1. ASSIGNMENT - 1
Assignment 01: Discuss the different ways of particle diameter
expression. Also to calculate the equation of particle number for 1
gram of powder sample.
Name: Shivam Dubey
Physical Pharmaceutical – II
Instructor Name: Dr. Shivam Tayal
Date: 18/04/2020

2. ASSIGNMENT - 2
Different Methods For Determinig Particle
Diameter
Numerous techniques accessible for deciding molecule size, for example,
optical microscopy, sieving, sedimentation and molecule volume estimation.
1. Optical microscopy (0.2-100 µm).
2. Sieving (40-9500 µm).
3. Sedimentation (0.08-300 µm).
4. Molecule volume estimation (0.5-300 µm).
Optical Microscopy
➢ Molecule size in the scope of 0.2 – 100 µm can be estimated.
➢ This technique gives number conveyance which can be changed over
to weight appropriation
➢ Optical magnifying lens focal point has restricted settling power
➢ Propelled magnifying lens have better settling control and can gauge
size in nano go: Ultramicroscope, Electron magnifying lens Scanning
Electron magnifying instrument (SEM), Transmission Electron
magnifying instrument (TEM).
ADVANTAGES
✓ One can see particles
✓ Any totals distinguished
✓ Contamination of particles distinguished
✓ Use of spread slip for capturing movement of particles Easy and
straightforward
DISADVANTAGES
 Length and broadness can be distinguished however profundity or
thickness of particles can't be estimated
 Slow-tedious , monotonous, off base
 Number of particles to be estimated is more
 Large example required

3. ASSIGNMENT - 3
Sieving Method
❖What Is Sieve?
⬧ Mesh number number of openings per inch ™
⬧ Sieve opening actual size of openings between wires
➢ It is broadly utilized as a strategy for the molecule size investigation
➢ Sieve examination is normally done utilizing dry powders. In spite of
the fact that, for powders in fluid suspension or which agglomerate
during dry sieving, a procedure of wet sieving can be utilized.
➢ Sieving technique straightforwardly gives weight conveyance.
➢ It discover application in measurements structure improvement of
tablets and cases.
➢ Normally, 15% of fine powder ought to be available in granulated
material to get legitimate progression of material and accomplish great
compaction.
➢ Thus percent of coarse, moderate, fine powder is evaluated by this
strategy.
➢ This method uses a series of standard sieves ™
➢ Range : 44 - 1000 μ m
ADVANTAGES

4. ASSIGNMENT - 4
✓ Cheap, Simple, Rapid, Reproducible outcomes (if parameters are
normalized)
DISADVANTAGES
 Lower limit is 50 microns
 Powder if sodden, can cause stopping up of openings
 Attrition between particles during the procedure may cause size
decrease giving incorrect outcomes.
Sedimentation Method
➢ In this strategy molecule size can be dictated by looking at the powder
as it dregs out.
➢ Sample readiness: Powder is scattered in an appropriate dissolvable
➢ If the powder is hydrophobic, it might be important to add scattering
specialist to help wetting of the powder.
➢ In the event that where the powder is dissolvable in water it will be
important to utilize non-watery fluids or complete the investigation in
a gas.
Andreasen Pipette Technique:
➢ One of the most mainstream of the pipette strategies was that created
by Andreasen and Lundberg and usually called the Andreasen pipette.
➢ In this strategy , known volumes of suspension are drawn off and the
fixation contrasts are estimated concerning time.
➢ It includes estimating the % of solids that settle with time in a
graduated vessel.
The diameter is obtained by gravity sedimentation:
The particle size is determined in terms of stokes’ diameter (the diameter of
a particle measured during sedimentation at constant rate) using modified
Stokes' equation.
V =
ℎ
𝑡
=
𝑑𝑠𝑡2( 𝑝s – 𝑝o) 𝑔
18ηo

5. ASSIGNMENT - 5
dst = √
18ηo
(𝑝s−𝑝o)𝑔𝑡
Where,
ν : rate of settling ƒ
h : distance of fall in time t ƒ
𝑝s : density of particle ƒ
𝑝o: density of dispersion medium ƒ
g : acceleration due to gravity ƒ
ηo : viscosity of medium
Reynolds Number Re
Re =
𝑣𝑑𝑝o
ηo
R e > 0.2 {Stoke’s law cannot be used (due to turbulence)}
Equation Of Particle Number For 1 Gram Of
Powder Sample.
Considering the particle shape is spherical, the following relationship may
be expressed:
Volume of particle =
1𝑥𝜋𝑑𝑣𝑛3
6
…………. (1)
dvn = Volume Number Diameter
So now,
Mass of particle = Voluma x Diameter
Weight of particle =
1𝑥𝜋𝑑𝑣𝑛3
6
𝑥𝜌 …………..(2)

6. ASSIGNMENT - 6
Now, Again let suppose relationship between weight of particle and weight
of powder.
So, Weight of powder =
𝑊𝑒𝑖𝑔ℎ𝑡 𝑜𝑓 𝑃𝑜𝑤𝑑𝑒𝑟
𝑁𝑜 .𝑂𝑓 𝑃𝑎𝑟𝑡𝑖𝑐𝑙𝑒𝑠
Given, the weight of powder is 1 grams.
So, Putting the above values in equation (2), we get
1𝜋𝑑𝑣𝑛3𝑥𝜌
6
=
1
𝑁
Rearranging the equation, we get
Particle Number(N) =
6
𝜋𝑑3𝑣𝑛𝑥𝑝
in a 1 gram of powder sample.
References
o http://lms.itmuniversity.ac.in/pluginfile.php/27919/mod_resource/content/
1/MICROMERITCS.pdf
o https://www.slideshare.net/AparajitaVarshneya1/micromeritics-100415301
o https://en.wikipedia.org/wiki/Stokes%27_law
o https://www.particletechlabs.com/analytical-testing/particle-size-
distribution-analyses
o https://link.springer.com/chapter/10.1007/978-94-011-6746-8_3