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a Leica RM2165 microtome equipped with a cooling chamber. FIB surface etching was performed using a Hitachi 2000A Ga + focused ion beam operated at 30 keV and 0.8 nA, with a dwelling time of 3 μsec. The etched surface was then analyzed by tapping mode atomic force microscopy (AFM) using a scanning probe microscope Dimension 3100 from Veeco Instruments equipped with a Nanoscope IVa controller. Silicon tips, model PPP-NCH-W from Nanosensors, with a force constant of 10-130 N/m (nominal value of 42 N/m) and resonance frequency of 204- 497 kHz (nominal value of 330 kHz), were used. The cantilever was oscillated at approximately 98% of the resonance frequency and topographic (height) images were taken at approximately 95% of the free oscillating amplitude. The samples were fixed on a metallic support using graphite tape. This procedure is thoroughly described in a previous paper (Virgilio, Favis, Pepin, Desjardins, & L'Esperance, 2005b). A-1.3. Results and Discussion Initially, the continuity development of the PMMA phase in binary HDPE/PMMA blends was examined in order to determine the boundaries required to achieve co-continuity in HDPE/PMMA. After preparation by melt-mixing, the blends were immediately quenched in liquid nitrogen to freeze-in the morphology. To measure the continuity of the PMMA phase in each blend, a selective solvent extraction of the PMMA phase, using acetic acid, was performed. As the PMMA volume fraction increases from 30% to 40%, the continuity increases very rapidly from 17% to 95%. A further increase of the PMMA volume fraction to 45% yields a 98% continuous PMMA phase and results in a binary co-continuous polymer blend. Subsequently, ternary HDPE/PS/PMMA blends were prepared at different compositions (given in Table A-1.3) based on the co-continuity region found for HDPE/PMMA binary blends. The qualitative microstructural features of the blends were analyzed using a Focused Ion Beam (FIB)-Atomic Force Microscopy (AFM) method described in a previous article (Virgilio, et al., 2005b). FIB etching involves the interaction of a gallium ion beam with the blend surface and is a surface preparation step prior to the AFM surface analysis. Since the gallium ion beam has significantly different etching rates for each of the individual components, this etching process induces a topological contrast between the different phases, each surface level corresponding to a specific phase. Observation of these surfaces by AFM in the topological mode allows for the 240
acquisition of images with a very high contrast. Since all the three polymers are immiscible, the three different levels observed on the AFM images each correspond to a given polymer. In HDPE/PS/PMMA ternary blends, PS is the less etched material, and thus corresponds to the high-level domains, while HDPE corresponds to the mid-level domains and PMMA to the lowlevel ones. This method of analysis is particularly useful for multicomponent blends and for fine structure analysis since the etching process is sensitive to the nature of the materials and eliminates some artifacts related to classical microtomy and staining preparation methods. a) b) HDPE PMMA PS layer PS droplet PMMA PS layer PS droplet 0 nm 65 nm 0 nm 65 nm HDPE 5 5 Figure A-1.3. FIB-AFM images of HDPE/PS/PMMA ternary blends: a) 50/10/40(% vol.) and b) 50/12.5/37.5. Images were taken at 95% of the free oscillation amplitude. Scan sizes are 20 μm x 20 μm. The white line in Figure A-1.3b indicates the section analyzed below. 241
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© Sepehr Ravati, 2010. UNIVERSITÉ
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DEDICATED To my parents iii
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RÉSUMÉ Cette thèse présente, po
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devenir une structure hiérarchique
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ABSTRACT This thesis presents, for
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system can be increased from 10 -15
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CONDENSÉ EN FRANÇAIS Dans ce trav
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deuxième coquille de PS. Les phase
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structures à percolation multiple
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autre sous-type de morphologie dans
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TABLE OF CONTENTS DEDICATION.......
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xxiii 2.4.1.1.1 Charged Polymer Ads
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5.3.4 Annealing Test ..............
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xxvii REFERENCES ..................
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LIST OF FIGURES xxix Figure 1-1. a)
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Figure 2-12. SEM photomicrograph of
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Figure 2-34. Schematic view of diff
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Figure 4-8. SEM micrographs of vari
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Figure 5-6. a),b) Scanning electron
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and c) triangular concentration dia
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n number of moles p concentration o
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AFM atomic force microscopy LIST OF
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PS-co-PMMA copolymer of PS and PMMA
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1.1 Introduction CHAPTER 1 - INTROD
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Figure 1-2. Human heart, longitudin
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One of the applications for porous
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On the other hand, a novel tri-cont
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2.1 Polymer Blends CHAPTER 2 - LITE
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Based on Sterling’s approximation
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Antonoff’s rule (Equation 2-13) i
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2.1.2.1 Binary Polymer Blends 2.1.2
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Some other studies(Everaert, Aerts,
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where the parameter z is dependent
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“compatibilization” was suggest
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a) λ BC A and B are matrices, b) C
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Reignier & Favis, 2000, 2003a; Reig
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measure the interfacial tension of
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a) b) Figure 2-6. Dependence of the
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Omonov et al. found double percolat
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2.1.2.2.3 Effect of Composition on
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a) b) C B A c) Figure 2-12. SEM pho
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In the case where PS is the matrix,
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Posthuma de Boer, 1999) (Kumin & Ch
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lattice, such as square lattice, wi
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magnetization, which is a function
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Polymers have long been thought of
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epoxy as a function of nanotube wei
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Figure 2-19. Approaching the percol
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Figure 2-21. Transmission electron
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Figure 2-22: Dependence of PE conti
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Figure 2-24. Plot of the total numb
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chain provides the conductive path
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2.3.1.2.1 Polyaniline One of the mo
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CoPA/LLDPE/PANI blend and a poor-qu
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Narkis and co-workers extended and
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Figure 2-31: Conductivity of PVDF/P
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organic thin films, a novel and str
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on the topic have been reported in
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succeeded in creating thin films wi
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Addition of salt to the solution of
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different from that of linear homop
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Figure 2-39. Macromolecule with a)
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polyanion such as hyaluronan (HA)(P
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2.4.1.1.7 Effect of Salt on Multila
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2.4.1.1.8 Overcompensation of the M
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important factors determining the g
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As shown in Figure 2-44, swelling a
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increasing the pH value due to a de
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CHAPTER 3 - ORGANIZATION OF THE ART
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discussed above, HDPE, PS, PMMA, an
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CHAPTER 4 - LOW PERCOLATION THRESHO
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or model which predicts where the p
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concentration threshold for the ons
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chemical and weathering resistance,
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Table 4-1. Material Characteristics
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filled with blend pellets. To facil
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4.3.6 Conductivity Measurements DC
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experimentally in this research gro
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a) b) c) d) Figure 4-4. Schematic i
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microstructure of the quaternary bl
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a) b) c) d) Figure 4-6. SEM microgr
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a) b) PVDF PS PMMA c) d) e) HDPE PS
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Uniform layers of PS and PMMA situa
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the concentration of HDPE is increa
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a) b) c) e) Figure 4-11. SEM microg
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melt-processable and contains 25 wt
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One question that should be address
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Conductivity(S/cm) Ternary Blend 1,
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phase(PMMA), the concentration of P
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(6) Virgilio, N.; Desjardins, P.; L
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ONION MORPHOLOGY HDPE PVDF PS Contr
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work described above has focused on
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thermodynamic explanation to predic
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four-point probe increases continuo
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in the rheology tests were compress
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5.3.6 Layer-by-Layer Deposition The
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prepare a polymer blend structure w
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a) b) c) Figure 5-3. Scanning elect
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spontaneously self-assembled. After
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a) b) c) d) e) f) g) h) Figure 5-5.
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Since the ultra-low surface area va
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c) a) b) Figure 5-6. a),b) Scanning
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salt to a PSS polyelectrolyte solut
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A relationship between macropore si
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close together. It is interesting t
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Figure 5-9. Mass increase (%) indic
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In this work the conductance of the
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deposited PANI layers increases unt
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(52) Guo, H. F.; Packirisamy, S.; G
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6.2 Introduction It is well-known t
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modified version of Harkins theory(
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6.3 Experimental 6.3.1 Materials Co
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Complex voscosity (Pa.s) 1,0E+04 1,
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6.3.5.2 Focused Ion Beam (FIB) and
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a) c) b) d) e) f) PMMA PMMA HDPE HD
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y Harkins theory, PS will always si
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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: Table A-1.2. Interfacial tensions a
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
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