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Microstructural information collected by SEM (Figure 5-6c) and AFM (Figure 5-6d) depicts a relatively thick polyelectrolyte multilayer as wide as 5.5μm for 38 layers of PSS and PANI on the surface of the filled sample (B). Picart et al.(Picart, Lavalle, et al., 2001) also reported a very thick multilayer film of 1μm for 16 layers. They proposed that this thickness increase can be attributed to a diffusion of polyelectrolyte inwards and outwards in the multilayer during the LbL process. They also reported an exponential growth of layer thickness similar to the mechanism of mass growth in this work. 5.4.5 Mass Deposition Dynamics of PSS/PANI Although the structural information for the construction of ultra-thin multi-layers is extremely difficult to obtain, gravimetric measurements can interpret the molecular topology of the films that play the most important role in the formation of multi-layers. Figure 5-7 shows the quantification of mass deposition of each layer as measured by gravimetric techniques for various substrates in both the absence and presence of salt. It shows an unusual oscillating behavior of thickness growth. After dipping the substrate in the PSS solution, the deposition mass increases, followed by a decrease in deposition mass in a PANI solution due to the partial removal of a previously adsorbed layer. Some previous works(Dubas & Schlenoff, 2001c; Schoeler, et al., 2002; Tjipto, Quinn, & Caruso, 2007) have also reported on the oscillating behavior of PSS polyelectrolytes due to the partial removal of previously adsorbed layers in subsequent operations. Schoeler et al.(Schoeler, et al., 2002) related the extent of removed material to the critical charge density of the polyelectrolyte. Charge density for a polyelectrolyte is defined as the fraction of monomers in the polymer which are charged. If this fraction is much smaller than 1, the polyelectrolyte is weakly charged. Normally, weak polyelectrolytes tend to demonstrate an oscillating deposition. Dubas et al.(Dubas & Schlenoff, 2001c) concluded that the drawing out of water molecules unassociated with specific ion pairs due to increasing external osmotic pressure is the main reason for the decrease in thickness at low salt concentrations. Tjipto et al.(Tjipto, et al., 2007) related the oscillating behavior of a multilayer formed of poly(4-styrenesulfonic acid-co-maleic acid) and PDADMAC to the heterogeneity and roughness of the samples. Later in this paper it will be shown that all of these explanations are likely responsible for the oscillating deposition observed in this work. The addition of 1 molar 158
salt to a PSS polyelectrolyte solution magnifies the extent of the oscillation behavior (Figures 5- 7a-d) and this will also be discussed in more detail in the next section. a) b) Mass Increase(%) Mass Increase(%) 1,8 1,6 1,4 1,2 1 0,8 0,6 0,4 0,2 0 2,2 2 1,8 1,6 1,4 1,2 1 0,8 0,6 0,4 0,2 0 PANI PSS Sample (A) with salt 0 5 10 15 20 25 30 35 Number of layers PANI PSS Sample (B) with salt Sample (A) without salt Sample (B) without salt 0 5 10 15 20 25 30 35 Number of layers 159
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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
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 and 196: a) b) c) Figure 5-3. Scanning elect
Page 197 and 198: spontaneously self-assembled. After
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: c) a) b) Figure 5-6. a),b) Scanning
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
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CONCLUSION AND RECOMMENDATIONS In t
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REFERENCES A. K. Gupta, K. R. S. (1
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Caruso, F. (2003). Hollow Inorganic
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Domenech, S. C., Bortoluzzi, J. H.,
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Geuskens, G., Gielens, J. L., Geshe
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Hou, S., Harrell, C. C., Trofin, L.
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Krass, H., Papastavrou, G., & Kurth
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Macdiarmid, A. G., Jin-Chih, C., Ha
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Niziol, J., & Laska, J. (1999). Con
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Reghu, M., Yoon, C. O., Yang, C. Y.
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Shirakawa, H., Louis, E. L., MacDia
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Utracki, L. A. (1991). On the visco
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Yasuda, K., Armstrong, R., & Cohen,
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literature has examined factors inf
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(Reignier & Favis, 2000, 2003a; Rei
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Table A-1.2. Interfacial tensions a
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acquisition of images with a very h
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Table A-1.3. Continuity of the PMMA
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(17) Reignier, J.; Favis, B. D., Ma
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PANI. Theoretically, the extent of
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Equation A-2.7 0( ) 0 1. 5 σ = σ
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Cumulative Mass × 10 5 (g) dipping
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of PANI, and an increase in the con
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Resistance(ohm) 1.0E+12 1.0E+11 1.0
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esistance value. Samples containing
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The results of resistance for PS/PE
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Caruso, F., & Schuler, C. (2000). E
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