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proceeds, lesser monomer is available for further reaction. This decreases the overall rate ofcopolymerization and is more pronounced in case of DP = 15 in comparison to DP = 37.1,71,61,51,4DPth=15DPth=37DPth=60DPth= 295PDI1,31,21,110 10 20 30 40 50 60 70 80 90 100% ConversionFigure – 4.10: Variation of polydispersity index with respect to % conversion for different degree of polymerizationvaluesLastly, the polydispersity index (PDI) of the obtained copolymer revealed that higher DP valuesresulted in lowest PDI with DP = 295 showing between 1.21 – 1.15 (Figure – 4.10). In general, a PDI closeto 1.15 was achieved with higher % conversion for all DP values.Figure – 4.11: General reaction for the polymerization of octadecyl methacrylate with PMMA macroinitiatorFinally, the copolymer (PMMA – b – PODMA) was synthesized (Figure – 4.11) with an optimumtheoretical DP =100 at 80 o C for a reaction time of 150 minutes to obtain a molecular weight M n ,PODMA=13500 g/mol ( 1 HNMR); M n ,PODMA – b – PMMA =21200 g/mol ( 1 HNMR) (Figure – 4.12) and a PDI valueof 1.12 as determined by size exclusion chromatography.110
Figure – 4.12: 1 HNMR of Poly(methyl methacrylate)-b-Poly(octadecyl methacrylate)4.2 MICELLES PREPARATION AND THEIR SELF-ASSEMBLYThe classification of block copolymer micelles can be done on the basis of the type ofintermolecular forces segregating the core segment from the aqueous milieu. The first category isrepresented by amphiphilic micelles (hydrophobic interactions), second by polyion complex micelles(electrostatic interactions) and third represented by micelles emanating from metal complexation 30 .Generally, when the hydrophilic segment exceeds the core block in length, resulting micelle is sphericalin shape. By increasing the length of the core segment beyond that of the corona-forming chains, onemay generate various non-spherical structures including rods and lamellae 31 . In the present case, thecopolymer contains 65 % PODMA which is much more hydrophobic than 35 % PMMA block. To obtainspherical micelles from the copolymer, it was first dissolved in THF followed by slow addition ofcyclohexane which is a good solvent for PODMA but a poor one for PMMA. As the concentration ofcyclohexane increases more and more, the PMMA part is forced into forming the core while PODMAblock forms the corona. For a mixture of cyclohexane and THF (9/1; vol%) and concentration of (3.5111
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THESISPRESENTED ATNATIONAL GRADUATE
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As the human civilization progress
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CHAPTER - 1 SELF-HEALING POLYMERIC
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8.1.5 Atomic Force Microscopy …
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Synthetic engineering materials in
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esponse to a specific external stim
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The first work based on this approa
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een prepared from urea-formaldehyde
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monomer systems. The addition of EN
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Figure - 1.10: Self-healing process
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was required to reach healing effic
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In addition to above works, some ot
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that have been identified to be tak
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part of the chapter, these material
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Figure - 1.17: Self-healing of the
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commercialized under tradenames; Nu
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joined together at temperature high
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Inspired by these findings, the fir
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temperature greater than 80 o C in
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Figure - 1.27: Sulfur chemistry bas
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A different kind of sulfur chemistr
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Figure - 1.29: Dynamic covalent che
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cracks. The recovered droplets afte
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23 White, S. R. et al. Autonomic he
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65 Taber, D. F. & Frankowski, K. J.
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107 Kushner, A. M., Vossler, J. D.,
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148 Park, J. S., Kim, H. S. & Hahn,
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The value of subscripts “n”,
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The formation of spherical micelles
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the micelle assembly showed the pre
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gain onto the electrodes by buildin
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The resistance R can be further exp
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empty-tower velocity U only depends
Page 70 and 71: This apparent morphological switchi
Page 72 and 73: In a further qualitative analysis,
Page 74 and 75: noteworthy and though its feasibili
Page 76 and 77: Furthermore within this range, lowe
Page 78 and 79: Figure - 2.22: Scanning Electron Mi
Page 80 and 81: While the resistance measurements g
Page 82 and 83: In conclusion, a self-healing membr
Page 84 and 85: 23 Giacomelli, F. C., Riegel, I. C.
Page 86 and 87: micelles enabled the membrane to se
Page 88 and 89: The second class is represented by
Page 90 and 91: To avoid the probable clogging of t
Page 92 and 93: 181614SP2 - iNumber of Particles121
Page 94 and 95: 1000900800y = 3E+06xR² = 0,9911y =
Page 96 and 97: very high value of 1.5 g.l -1 . Thi
Page 98 and 99: Since the only change in the membra
Page 100 and 101: 100Retention (%)8060400,100,20,40,6
Page 104 and 105: (Figure - 3.20). A cursory look at
Page 106 and 107: When compared to poly(styrene) NPs,
Page 110 and 111: REFERENCES1 Metzler, R. & Klafter,
Page 112 and 113: 46 Bemporad, D., Luttmann, C. & Ess
Page 114 and 115: In this chapter, preparation of 3D
Page 116 and 117: obtain complex macromolecular archi
Page 118 and 119: The polymerization was conducted at
Page 122 and 123: mg/ml),the micelles’ hydrodynamic
Page 124 and 125: Figure - 4.15: The monolayer and mu
Page 126 and 127: monolayer of micelles and topmost l
Page 128 and 129: The presence of the dispersed micel
Page 130 and 131: Heating the multilayer micelle asse
Page 132 and 133: stable zipping of the micelles. Mul
Page 134 and 135: 24 Moad, G., Rizzardo, E. & Thang,
Page 136 and 137: The concept of nano-gel based self-
Page 138 and 139: Figure - 5.4: Size distribution of
Page 140 and 141: In a typical process, the two compo
Page 142 and 143: Figure - 5.10: 1HNMR spectra obtain
Page 144 and 145: The 1 HNMR spectrum obtained for th
Page 146 and 147: REFERENCES1 White, S. R. et al. Aut
Page 148 and 149: healing ability shown by the membra
Page 150 and 151: 7. PERSPECTIVESBeing the first such
Page 153 and 154: 8. MATERIALS & METHODSThis chapter
Page 155 and 156: 8.1.3 PEG Filtration MeasurementsTh
Page 157 and 158: addition of TEOS due to formation o
Page 159 and 160: solution was ultrasonicated for 15
Page 161 and 162: Triethylamine (TEA) (Sigma-Aldrich
Page 163 and 164: To prepare the monolayer assembly o
Page 165 and 166: was added followed by addition of 0
Page 168 and 169: ELABORATION OF SELF-HEALING POLYMER
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ELABORATION DES MEMBRANES POLYMERES
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4(%3)3 - Ecole nationale supÃ©rieure de chimie de Montpellier

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