a) b - École Polytechnique de Montréal

More documents

Recommendations

Info

Figure 5-3 illustrates a comparison between binary co-continuous structures (single percolated) and a ternary one (double percolated) and shows that continuous phases can be generated at lower concentrations of each phase in the latter case due to the lower percolation threshold of those phases. In Figure 5-3a, it is shown that a double percolated HDPE/PMMA/PVDF blend, after PMMA and PVDF extraction, can result in a porous substrate of 33% HDPE which demonstrates a homogeneous, perfectly interconnected structure while a binary blend of 33% HDPE and 67% PVDF yields an imperfect continuous structure of HDPE (Figure 5-3b). Extraction experiments indicate that 98% of the PMMA and PVDF were extracted in the ternary blend proving their high levels of continuity. In the case of the 33%HDPE/67%PVDF binary blend, extraction of PVDF resulted in a value of 108% of material indicating a significant quantity of HDPE present as dispersed entities within the PVDF. The fully continuous binary 50% HDPE/50% PVDF blend is also shown for comparison (Figure 5-3c). Clearly, a double-percolated morphology is a route towards fully continuous phases at low phase concentrations. The subsequent extraction of PMMA and PVDF leaves behind a fully interconnected porous HDPE substrate of low surface area. In this work, as HDPE substrates were exposed to polyelectrolyte solutions, extra-large pores also facilitated the penetration of the solution inward to the interconnected porous area. The addition of a fourth component to form a quaternary blend with a triple-percolated morphology between adjacent phases is also possible providing that the spreading coefficients of the fourth phase and the engulfed phases satisfy Harkins equations. A more detailed study of the generation of such structures is presented in a separate paper(Ravati & Favis, 2010). A triplepercolated morphology is particularly interesting in the present work since it provides a route towards the generation of porous channels of highly uniform size distribution. Figure 5-4 demonstrates such a structure in which PMMA situates at the interface of PS and PVDF in an HDPE matrix. Thus this triple-percolated morphology follows the order HDPE/PS/PMMA/PVDF (Figures 5-4a and 5-4b). Figures 5-4a and 5-4b represent quaternary blends with the PMMA phase extracted, yielding PS layers engulfed in an HDPE matrix while the PVDF phase remains at the core encapsulated by extracted PMMA. The removal of the PS phase separates HDPE/PS/PMMA/PVDF into two parts: the HDPE matrix and PMMA/PVDF core (Figure 5-4c). These figures unambiguously show that the PS and PMMA phases are situated between HDPE and PVDF, and a hierarchical structure of four different phases is 150
spontaneously self-assembled. After the removal of all other phases, the final HDPE porous substrate exhibits a continuous structure with large pore sizes and macro-channels of highly uniform distribution. The uniformity of the double-percolated morphology represented in Figure 5-3a and that of the triple-percolated one shown in Figure 5-4d are compared morphologically. The reason for the more uniform structure in the triple-percolated system is the phases are distributed between three interfaces as opposed to be distributed between two interfaces in the double-percolated system. Thus, the triple-percolated structure system appears to form phases which, after extraction, result in a substrate with a more uniform pore size distribution. a) b) c) d) HDPE PVDF Figure 5-4. Scanning electron micrographs of quaternary polymer blends for various compositions compounded via melt-blending (a) 50/16/16/16 HDPE/PS/PMMA/PVDF after extraction of PMMA by acetic acid, (b) 50/20/10/20 HDPE/PS/PMMA/PVDF after extraction of PMMA by acetic acid, (b) 50/20/10/20 HDPE/PS/PMMA/PVDF after extraction of PS by cyclohexane, and d) 40/10/40/10 HDPE/PS/PMMA/PVDF after extraction of all phases except HDPE 151
Page 1 and 2:
© Sepehr Ravati, 2010. UNIVERSITÉ
Page 3 and 4:
DEDICATED To my parents iii
Page 5 and 6:
RÉSUMÉ Cette thèse présente, po
Page 7 and 8:
devenir une structure hiérarchique
Page 9 and 10:
ABSTRACT This thesis presents, for
Page 11 and 12:
system can be increased from 10 -15
Page 13 and 14:
CONDENSÉ EN FRANÇAIS Dans ce trav
Page 15 and 16:
deuxième coquille de PS. Les phase
Page 17 and 18:
structures à percolation multiple
Page 19 and 20:
autre sous-type de morphologie dans
Page 21 and 22:
TABLE OF CONTENTS DEDICATION.......
Page 23 and 24:
xxiii 2.4.1.1.1 Charged Polymer Ads
Page 25 and 26:
5.3.4 Annealing Test ..............
Page 27 and 28:
xxvii REFERENCES ..................
Page 29 and 30:
LIST OF FIGURES xxix Figure 1-1. a)
Page 31 and 32:
Figure 2-12. SEM photomicrograph of
Page 33 and 34:
Figure 2-34. Schematic view of diff
Page 35 and 36:
Figure 4-8. SEM micrographs of vari
Page 37 and 38:
Figure 5-6. a),b) Scanning electron
Page 39 and 40:
and c) triangular concentration dia
Page 41 and 42:
n number of moles p concentration o
Page 43 and 44:
AFM atomic force microscopy LIST OF
Page 45 and 46:
PS-co-PMMA copolymer of PS and PMMA
Page 47 and 48:
1.1 Introduction CHAPTER 1 - INTROD
Page 49 and 50:
Figure 1-2. Human heart, longitudin
Page 51 and 52:
One of the applications for porous
Page 53 and 54:
On the other hand, a novel tri-cont
Page 55 and 56:
2.1 Polymer Blends CHAPTER 2 - LITE
Page 57 and 58:
Based on Sterling’s approximation
Page 59 and 60:
Antonoff’s rule (Equation 2-13) i
Page 61 and 62:
2.1.2.1 Binary Polymer Blends 2.1.2
Page 63 and 64:
Some other studies(Everaert, Aerts,
Page 65 and 66:
where the parameter z is dependent
Page 67 and 68:
“compatibilization” was suggest
Page 69 and 70:
a) λ BC A and B are matrices, b) C
Page 71 and 72:
Reignier & Favis, 2000, 2003a; Reig
Page 73 and 74:
measure the interfacial tension of
Page 75 and 76:
a) b) Figure 2-6. Dependence of the
Page 77 and 78:
Omonov et al. found double percolat
Page 79 and 80:
2.1.2.2.3 Effect of Composition on
Page 81 and 82:
a) b) C B A c) Figure 2-12. SEM pho
Page 83 and 84:
In the case where PS is the matrix,
Page 85 and 86:
Posthuma de Boer, 1999) (Kumin & Ch
Page 87 and 88:
lattice, such as square lattice, wi
Page 89 and 90:
magnetization, which is a function
Page 91 and 92:
Polymers have long been thought of
Page 93 and 94:
epoxy as a function of nanotube wei
Page 95 and 96:
Figure 2-19. Approaching the percol
Page 97 and 98:
Figure 2-21. Transmission electron
Page 99 and 100:
Figure 2-22: Dependence of PE conti
Page 101 and 102:
Figure 2-24. Plot of the total numb
Page 103 and 104:
chain provides the conductive path
Page 105 and 106:
2.3.1.2.1 Polyaniline One of the mo
Page 107 and 108:
CoPA/LLDPE/PANI blend and a poor-qu
Page 109 and 110:
Narkis and co-workers extended and
Page 111 and 112:
Figure 2-31: Conductivity of PVDF/P
Page 113 and 114:
organic thin films, a novel and str
Page 115 and 116:
on the topic have been reported in
Page 117 and 118:
succeeded in creating thin films wi
Page 119 and 120:
Addition of salt to the solution of
Page 121 and 122:
different from that of linear homop
Page 123 and 124:
Figure 2-39. Macromolecule with a)
Page 125 and 126:
polyanion such as hyaluronan (HA)(P
Page 127 and 128:
2.4.1.1.7 Effect of Salt on Multila
Page 129 and 130:
2.4.1.1.8 Overcompensation of the M
Page 131 and 132:
important factors determining the g
Page 133 and 134:
As shown in Figure 2-44, swelling a
Page 135 and 136:
increasing the pH value due to a de
Page 137 and 138:
CHAPTER 3 - ORGANIZATION OF THE ART
Page 139 and 140:
discussed above, HDPE, PS, PMMA, an
Page 141 and 142:
CHAPTER 4 - LOW PERCOLATION THRESHO
Page 143 and 144:
or model which predicts where the p
Page 145 and 146: concentration threshold for the ons
Page 147 and 148: chemical and weathering resistance,
Page 149 and 150: Table 4-1. Material Characteristics
Page 151 and 152: filled with blend pellets. To facil
Page 153 and 154: 4.3.6 Conductivity Measurements DC
Page 155 and 156: experimentally in this research gro
Page 157 and 158: a) b) c) d) Figure 4-4. Schematic i
Page 159 and 160: microstructure of the quaternary bl
Page 161 and 162: a) b) c) d) Figure 4-6. SEM microgr
Page 163 and 164: a) b) PVDF PS PMMA c) d) e) HDPE PS
Page 165 and 166: Uniform layers of PS and PMMA situa
Page 167 and 168: the concentration of HDPE is increa
Page 169 and 170: a) b) c) e) Figure 4-11. SEM microg
Page 171 and 172: melt-processable and contains 25 wt
Page 173 and 174: One question that should be address
Page 175 and 176: Conductivity(S/cm) Ternary Blend 1,
Page 177 and 178: phase(PMMA), the concentration of P
Page 179 and 180: (6) Virgilio, N.; Desjardins, P.; L
Page 181 and 182: ONION MORPHOLOGY HDPE PVDF PS Contr
Page 183 and 184: work described above has focused on
Page 185 and 186: thermodynamic explanation to predic
Page 187 and 188: four-point probe increases continuo
Page 189 and 190: in the rheology tests were compress
Page 191 and 192: 5.3.6 Layer-by-Layer Deposition The
Page 193 and 194: prepare a polymer blend structure w
Page 195: a) b) c) Figure 5-3. Scanning elect
Page 199 and 200: a) b) c) d) e) f) g) h) Figure 5-5.
Page 201 and 202: Since the ultra-low surface area va
Page 203 and 204: c) a) b) Figure 5-6. a),b) Scanning
Page 205 and 206: salt to a PSS polyelectrolyte solut
Page 207 and 208: A relationship between macropore si
Page 209 and 210: close together. It is interesting t
Page 211 and 212: Figure 5-9. Mass increase (%) indic
Page 213 and 214: In this work the conductance of the
Page 215 and 216: deposited PANI layers increases unt
Page 217 and 218: (52) Guo, H. F.; Packirisamy, S.; G
Page 219 and 220: 6.2 Introduction It is well-known t
Page 221 and 222: modified version of Harkins theory(
Page 223 and 224: 6.3 Experimental 6.3.1 Materials Co
Page 225 and 226: Complex voscosity (Pa.s) 1,0E+04 1,
Page 227 and 228: 6.3.5.2 Focused Ion Beam (FIB) and
Page 229 and 230: a) c) b) d) e) f) PMMA PMMA HDPE HD
Page 231 and 232: y Harkins theory, PS will always si
Page 233 and 234: a) b) c) d) e) f) PS Figure 6-6. a)
Page 235 and 236: a) b) HDPE : black PS : grey PMMA :
Page 237 and 238: 6.4.6 Continuity, Co-continuity, an
Page 239 and 240: c) V III II I VII I IV VI Figure 6-
Page 241 and 242: Continuity Scheme (a) Figure 6-10.
Page 243 and 244: Addition of a low concentration of
Page 245 and 246: Addition of small amounts of HDPE t
Page 247 and 248:
icontinuous network with the HDPE.
Page 249 and 250:
Three examples are shown in Figure
Page 251 and 252:
(9) Mekhilef, N.; Verhoogt, H. Poly
Page 253 and 254:
structures are formed due to the co
Page 255 and 256:
CONCLUSION AND RECOMMENDATIONS In t
Page 257 and 258:
REFERENCES A. K. Gupta, K. R. S. (1
Page 259 and 260:
Caruso, F. (2003). Hollow Inorganic
Page 261 and 262:
Domenech, S. C., Bortoluzzi, J. H.,
Page 263 and 264:
Geuskens, G., Gielens, J. L., Geshe
Page 265 and 266:
Hou, S., Harrell, C. C., Trofin, L.
Page 267 and 268:
Krass, H., Papastavrou, G., & Kurth
Page 269 and 270:
Macdiarmid, A. G., Jin-Chih, C., Ha
Page 271 and 272:
Niziol, J., & Laska, J. (1999). Con
Page 273 and 274:
Reghu, M., Yoon, C. O., Yang, C. Y.
Page 275 and 276:
Shirakawa, H., Louis, E. L., MacDia
Page 277 and 278:
Utracki, L. A. (1991). On the visco
Page 279 and 280:
Yasuda, K., Armstrong, R., & Cohen,
Page 281 and 282:
literature has examined factors inf
Page 283 and 284:
(Reignier & Favis, 2000, 2003a; Rei
Page 285 and 286:
Table A-1.2. Interfacial tensions a
Page 287 and 288:
acquisition of images with a very h
Page 289 and 290:
Table A-1.3. Continuity of the PMMA
Page 291 and 292:
(17) Reignier, J.; Favis, B. D., Ma
Page 293 and 294:
PANI. Theoretically, the extent of
Page 295 and 296:
Equation A-2.7 0( ) 0 1. 5 σ = σ
Page 297 and 298:
Cumulative Mass × 10 5 (g) dipping
Page 299 and 300:
of PANI, and an increase in the con
Page 301 and 302:
Resistance(ohm) 1.0E+12 1.0E+11 1.0
Page 303 and 304:
esistance value. Samples containing
Page 305 and 306:
The results of resistance for PS/PE
Page 307 and 308:
Caruso, F., & Schuler, C. (2000). E
show all

a) b - École Polytechnique de Montréal

Create successful ePaper yourself

Delete template?

Save as template?