Study Set Content:
the length of the lines that bisects the particle image into halves.
Martin diameter
uses a series of standard sieves calibrated by the National Bureau of Standards
Sieve Analysis –
Sieve Analysis – uses a series of standard sieves calibrated by the
National Bureau of Standards
Performed using a nest or stack of sieves where each lower sieve has a smaller (blank) than that of the sieve above it
aperture size
used for grading coarser particles; if extreme care is used, however, they can be employed for screening material as fine as 44um
Sieve
44um
(no. 325 sieve).
sieving errors can arise from a number of variables including sieve loading and duration and intensity of agitation.
Disadvantages of sieving
smallest sieve opening through which 50% or more of the material passes 12 Sedimentation Techniques
d50
355 - 1000
Coarse
>1000
Very coarse
125 - 180
Fine
180 - 355
Moderately coarse
90 - 125
Very Fine
application of ultracentrifugation to determine the molecular weight of high polymers - Stokes’s Law
Sedimentation method
Sedimentation rate and free flaw velocity of particles
Sedimentation method
(Apparatus) for sedimentation method
Anderson pipet
For Stokes’s Law to apply, a further requirement is that the flow of dispersion medium around the particle as its sediments is (blank)
laminar or streamline.
Whether the flow is laminar or turbulent is indicated by the dimensionless
Reynold’s number
Whether the flow is laminar or turbulent is indicated by the dimensionless Reynold’s number: Stokes’s law cannot be used if Reynold’s number (Re) is greater than (blank) because turbulence appears at this value.
0.2
The rate of sedimentation of a particle must not be so rapid that turbulence is set up, because this in turn will affect the (blank) of the particles.
sedimentation
