KSV Sigma 70 - Powder Wettability; Measurement

Powder
Wettability
:
Measurement
As
discussed
in
the
previous
section
,
measurement
of
contact
angles
for
powders requires
at
least
two
steps
.
First
the material
constant
,
C
,
must
be
assayed using
a
completely
wetting
liquid
.
Then the
contact
angles
for
other
liquids
can
be measured
using
this
C
value
.
It
is
important
that
the solid
samples
be
as
identical
as
possible
for
each
step
.
For
porous
solids
you
should
attempt
to
use
identical size
samples
.
For
powders
you
should
use
the
same
container
and
packing
technique
for
each
sample
.
The
software for
this
measurement
also allows
you
to
subtract
out
the
effect of
the container
from
the
powder adsorption
graph
.
Simply
perform
a
Powder
Wettability
experiment
using the
empty
container and the
test
liquid
and then
you
can
use
it
as
a
‘
calibration file
’
when analyzing the data
.
Choose
New
Experiment
to enter
Experimental
Setup
.
Complete
Exp
Setup
(
see
pg
58
)
.
Select Controls
and
proceed
as
explained
below
.
You
may
wish
to
lower
your
probe
close
to
the
surface
prior
to
actually starting
your
experiment
to
avoid
a
long delay
as
the
probe
should
move
slowly
during
the actual
experiment
.
As
the
experiment
proceeds
you
may
find
it
helpful
to
monitor
the
comments
in
the
Status
bar
at
bottom
of
window
.
Termination
of
the
experiment
is automatic
.
After
you
have
filled
out
the
Experimental
Setup
fields and
entered
Start
your
screen
should
appear
as
follows
:
1
-
1
1
x
1
M
Powder
wettability
meatuieisenl
fie
£
<
*
V
*
w
£
artffote
Mass
squared
versus
time
i
1.00
0.75
Q
.
50
*
5
CTI
“
0.25
•
T
5
U
0
)
-
-
ra
3
0.00
-
t
tr
<
f
>
in
2
-
0.25
5
•
0.50
-
0.75
l
i i
i
i
i i
l
i
i
-
1.00
-
1.00
-
0.75
-
0.50
-
0.25 0.00
Time
[
s
]
0.25
0.50
0.75 1.00
Statua
:
lot
Stall
The items
across
the
top
bar
menu are
as
follows
:
File
:
—
>
New
experiment
:
Enter
Experimental
Setup
for
new
experiment
56