Influence of the Processes Parameters on the Properties of The ...
Influence of the Processes Parameters on the Properties of The ...
Influence of the Processes Parameters on the Properties of The ...
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Chapter 4.<br />
Experimental Procedures and Protocols for Analyses<br />
<strong>The</strong> foams obtained after process are mostly in circular shape, <str<strong>on</strong>g>the</str<strong>on</strong>g> diameter variati<strong>on</strong>s in not very<br />
high, however thick varies to some extent. Porosity obtained by geometric method compared with mercury<br />
intrusi<strong>on</strong> porosimetry produced results 5 to 7% higher.<br />
4.2 2D Image Analysis<br />
<strong>The</strong> scanning electr<strong>on</strong> microscope (SEM) used in our study was a, LEO 435 VP model. <strong>The</strong><br />
secti<strong>on</strong>s <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>the</str<strong>on</strong>g> foams were mounted <strong>on</strong> an aluminum stub with a carb<strong>on</strong> adhesive and <str<strong>on</strong>g>the</str<strong>on</strong>g>n coated with<br />
silver/gold (120 sec, Arg<strong>on</strong> atmosphere). <strong>The</strong> SEM micrographs were digitized <strong>on</strong> a matrix <str<strong>on</strong>g>of</str<strong>on</strong>g> 10241024<br />
pixels with 256 gray levels. In order to study <str<strong>on</strong>g>the</str<strong>on</strong>g> foams porosity, image analysis was performed using <str<strong>on</strong>g>the</str<strong>on</strong>g><br />
SCION ® image s<str<strong>on</strong>g>of</str<strong>on</strong>g>tware. <strong>The</strong> first stage is to obtain c<strong>on</strong>ductive materials by using a device called a "sputter<br />
coater."<br />
4.2.1 Sputter Coater<br />
If powder particles were to be analyzed, <str<strong>on</strong>g>the</str<strong>on</strong>g>y were dispersed <strong>on</strong> double-sided carb<strong>on</strong> c<strong>on</strong>ductive<br />
adhesive tape attached to <str<strong>on</strong>g>the</str<strong>on</strong>g> studs. Double sided adhesive tape permits quick mounting <str<strong>on</strong>g>of</str<strong>on</strong>g> samples without<br />
using liquid or colloidal adhesives. <strong>The</strong>se studs are fixed <strong>on</strong> <str<strong>on</strong>g>the</str<strong>on</strong>g> sample holder.<br />
For foams after being frozen in liquid nitrogen for 2 min, <str<strong>on</strong>g>the</str<strong>on</strong>g> specimens were fractured using a<br />
razor blade and tweezers in <str<strong>on</strong>g>the</str<strong>on</strong>g> directi<strong>on</strong>s parallel and perpendicular to <str<strong>on</strong>g>the</str<strong>on</strong>g> surface, <str<strong>on</strong>g>the</str<strong>on</strong>g>n placed <strong>on</strong> <str<strong>on</strong>g>the</str<strong>on</strong>g> holder<br />
with <str<strong>on</strong>g>the</str<strong>on</strong>g> help <str<strong>on</strong>g>of</str<strong>on</strong>g> isopropanol base graphite paint. <strong>The</strong> resulting transverse and l<strong>on</strong>gitudinal secti<strong>on</strong>s were<br />
sputter-coated with platinum/gold. <strong>The</strong> holder mounted with samples is placed in <str<strong>on</strong>g>the</str<strong>on</strong>g> chamber. Sputter<br />
coater uses an electric field and arg<strong>on</strong> gas. <strong>The</strong> metalizing chamber is closed and placed under vacuum. A<br />
stream <str<strong>on</strong>g>of</str<strong>on</strong>g> arg<strong>on</strong> eliminates <str<strong>on</strong>g>the</str<strong>on</strong>g> oxygen in <str<strong>on</strong>g>the</str<strong>on</strong>g> chamber. Gold or gold-palladium is preferred if <str<strong>on</strong>g>the</str<strong>on</strong>g> sample has<br />
a very irregular surface.<br />
Carb<strong>on</strong> c<strong>on</strong>ductive<br />
adhesive tapes<br />
Particle image<br />
Particulate<br />
Sample<br />
Particle sample<br />
<strong>on</strong> holder<br />
Coated<br />
particle sample<br />
Polymer foams<br />
Sputter<br />
Coater<br />
SEM LEO 435 VP<br />
Foam<br />
Coated<br />
foam sample<br />
Dipping foam in<br />
liquid nitrogen<br />
Tweezers to<br />
break foam<br />
Sample<br />
Holders<br />
Isopropanol Base<br />
c<strong>on</strong>ductive adhesive<br />
(Graphite paint)<br />
Foam pore<br />
Image<br />
Figure 4.22: Sputter coating and SEM processing flow diagram.<br />
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