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 />
<str<strong>on</strong>g>of</str<strong>on</strong>g> pores in <str<strong>on</strong>g>the</str<strong>on</strong>g> foams are present in functi<strong>on</strong> <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>the</str<strong>on</strong>g> nature <str<strong>on</strong>g>of</str<strong>on</strong>g> polymers (P L,D LA) under <str<strong>on</strong>g>the</str<strong>on</strong>g> same scCO 2<br />
c<strong>on</strong>diti<strong>on</strong>s T sat = 55°C, P sat = 80 bar, t sat = 30 min, dP/dt=4.5 bar/s (cf. Figure 4.26).<br />
Compairing all <str<strong>on</strong>g>the</str<strong>on</strong>g> graphs provide a clearer picture about <str<strong>on</strong>g>the</str<strong>on</strong>g> foam morphology SEM image is in<br />
2D and it is already supposed that <str<strong>on</strong>g>the</str<strong>on</strong>g> pore diameter obtained from SCION ® image analysis is <str<strong>on</strong>g>of</str<strong>on</strong>g> a circular<br />
pore, so if we c<strong>on</strong>sider pore volume <str<strong>on</strong>g>the</str<strong>on</strong>g> calculati<strong>on</strong> <str<strong>on</strong>g>of</str<strong>on</strong>g> equivalent pore diameter, <str<strong>on</strong>g>the</str<strong>on</strong>g>re will be ano<str<strong>on</strong>g>the</str<strong>on</strong>g>r<br />
hypo<str<strong>on</strong>g>the</str<strong>on</strong>g>sis that <str<strong>on</strong>g>the</str<strong>on</strong>g> pores are sphere which is not possible. Hence to make <str<strong>on</strong>g>the</str<strong>on</strong>g> result more close to <str<strong>on</strong>g>the</str<strong>on</strong>g> real<br />
foam pore surface area is c<strong>on</strong>sidered for calculati<strong>on</strong>s. SCION ® image analysis also provide informati<strong>on</strong><br />
about <str<strong>on</strong>g>the</str<strong>on</strong>g> nature <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>the</str<strong>on</strong>g> pores ei<str<strong>on</strong>g>the</str<strong>on</strong>g>r <str<strong>on</strong>g>the</str<strong>on</strong>g>y are el<strong>on</strong>gated, regular or irregular. Figure 4.26 (A) presents <str<strong>on</strong>g>the</str<strong>on</strong>g><br />
percentage <str<strong>on</strong>g>of</str<strong>on</strong>g> micro, meso and macro pores in a scaffold while Figure 4.26 (B) presents <str<strong>on</strong>g>the</str<strong>on</strong>g> percentage <str<strong>on</strong>g>of</str<strong>on</strong>g><br />
pore surface area. <strong>The</strong> number <str<strong>on</strong>g>of</str<strong>on</strong>g> macro pores are though in less percentage but <str<strong>on</strong>g>the</str<strong>on</strong>g> area <str<strong>on</strong>g>of</str<strong>on</strong>g> macro pores has<br />
highest value. Figure 4.26 (C) presents <str<strong>on</strong>g>the</str<strong>on</strong>g> volume <str<strong>on</strong>g>of</str<strong>on</strong>g> each poreand we can see that macro pores almost<br />
c<strong>on</strong>sist <str<strong>on</strong>g>of</str<strong>on</strong>g> 95% <str<strong>on</strong>g>of</str<strong>on</strong>g> total scaffold volume. <strong>The</strong> shape <str<strong>on</strong>g>of</str<strong>on</strong>g> pores is calculated by equati<strong>on</strong> 4.2 and for P L,D LA<br />
regular, irregular and el<strong>on</strong>gated pores are 68%, 23% and 9% as presented in Figure 4.26 (D).<br />
Micro<br />
Meso<br />
Macro<br />
Pie Graph 1<br />
Micro<br />
Meso<br />
Macro<br />
Pie Graph 1<br />
(A)-Percentage <str<strong>on</strong>g>of</str<strong>on</strong>g> pore quantitity.<br />
(B)-Percentage <str<strong>on</strong>g>of</str<strong>on</strong>g> pore surface area.<br />
Micro<br />
Meso<br />
Macro<br />
Pie Graph 1<br />
El<strong>on</strong>gated<br />
Irregular<br />
Regular<br />
Pie Graph 1<br />
(C)-Percentage <str<strong>on</strong>g>of</str<strong>on</strong>g> pore volume.<br />
(D)-Percentage <str<strong>on</strong>g>of</str<strong>on</strong>g> pore types.<br />
Figure 4.26: Pore distributi<strong>on</strong> comparis<strong>on</strong> in a foam with different aspects.<br />
4.3 3D Hg Intrusi<strong>on</strong> Porosity<br />
Porosity and pore diameter <str<strong>on</strong>g>of</str<strong>on</strong>g> randomly selected foams were determined by AutoPore IV 9500<br />
(cf. Figure 4.27) mercury porosimeter located at <str<strong>on</strong>g>the</str<strong>on</strong>g> CIRIMAT/UPS and analysis were performed by Sophie<br />
Cazalbou. Mercury intrusi<strong>on</strong> porosimeter (Pascal 140, <strong>The</strong>rmo- Quest) was used to study <str<strong>on</strong>g>the</str<strong>on</strong>g> pore structure<br />
<str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>the</str<strong>on</strong>g> PLGA scaffolds. For each different pore diameter scaffolds, three measurements were performed.<br />
Dimensi<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> porous scaffolds with mass approximately 0.1 g were first measured and placed in <str<strong>on</strong>g>the</str<strong>on</strong>g><br />
ultramacropore dilatometer for out-gassing. <strong>The</strong> dilatometer was <str<strong>on</strong>g>the</str<strong>on</strong>g>n filled with mercury up to 1800 mm 3<br />
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