4(%3)3 - Ecole nationale supÃ©rieure de chimie de Montpellier

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8.2.7 Translocation ExperimentsThe membranes were first compressed to their maximum by performing water permeationexperiments using the experimental set-up described in the first section. After 2 hours ofpermeation test, the filtration cell was disconnected from the water reservoir. It was filled with 10ml of the feed solution (For example: PEGs solution or PS solution) and connected directly tocompressed air supply. The whole process was executed very quickly so as to avoid thedecompression of the membrane due to release of pressure. Additionally, to keep the feed solutionhomogeneous inside the cell, magnetic stirring was started at 300 rpm. At the outlet of the filtrationcell, a small vial was attached to obtain 1.5 ml permeate at each pressure drop value. Once therequisite amount of permeate was collected, the experiment was stopped and the retentate samplewas obtained from the remaining solution in the filtration cell.In case of PEGs, the collected permeates and retentates were first filtered using PTFE filter(Millipore®; 0.45 µm) before passing for GPC analysis.In case of BSA, the collected permeates and retentates were filtered and analyzed by theUV-Visible spectrometer to obtain the corresponding absorbance values.In case of Polystyrene and Silica nanoparticles, the collected permeates and retentates werealso filtered using PTFE filters (Millipore®; 2µm) before being analyzed using PCCS. The vial wasultrasonicated for 15 minutes before being introduced into the instrument. The duration of analysisfor each sample was kept at 60 minutes per scan at 25 o C. Three such scans were conducted for eachsample. The theoretical model for the correlation was chosen to be NNLS.8.3 BLOCK COPOLYMER MICELLES’ ZIPPER ASSEMBLY8.3.1 Synthesis of Octadecyl MethacrylateIn a dried two neck round bottom flask (RB), 15.0 g (0,0554 moles) 1-octadecanol was takenalong with a magnet. It was stirred at 500 rpm in 120 ml freshly distlilled Tetrahydrofuran (THF)(Carlo Erra Reagents®, >99.7 %). On one neck of the RB, a dropping funnel containing 30 ml ofdistilled THF was connected having provision for outlet for nitrogen, which was introduced at a briskrate from the second neck. After 30 minutes of complete dissolution, about 16ml (0,111 moles)149
Triethylamine (TEA) (Sigma-Aldrich®, >99.99%) was added via a syringe. The mixture was blendedfor further 15 minutes at 25 o C after which 11 ml (0,111 moles) Methacrylolyl chloride (Sigma-Aldrich®, >99.9 %) was added to the dropping funnel via a syringe. The nitrogen flow was stoppedand the chloride/THF mixture was then introduced into the RB in a slow drop by drop manner whilemaintaining the temperature at 25 o C. The content of the RB soon became densely white as moreand more chloride reacted with the alcohol. The system was kept on stirring for 24 hours afterwhich, 5 ml of Methanol (Sigma-Aldrich®, 99.8%) was added via a syringe to the RB and to react withany unreacted Methacrylolyl Chloride. After 10 minutes, the content of the RB was filtered over asintered glass filter (porosity 3) to obtain a yellow color liquid filtrate and white color salt residue.The filtrate was concentrated over a rotavapor and the concentrated solution was precipitated intoa mixture (50/50 by volume) of ultrapure water and ethanol kept in ice bath. The pale whiteprecipitate thus obtained was separated from the rest of the solution via filtration over a sinteredglass filter (porosity 3) followed by room temperature vacuum drying. The solid thus obtained wasthen re-dissolved in minimum amount of Cyclohexane (Carlo Erra Reagent®, 99.5 %) and cooled at –80 o C for 5 hours after which, the solid content was allowed to slowly anneal at room temperature.The crystallized Octadecyl Methacrylate (ODMA) remained in solid form while the Cyclohexanebecame liquid. The majority of the solvent was removed via simple decantation while the rest wasremoved by employing strong tertiary vacuum at room temperature to obtain a pale white coloredwaxy solid. The product was weighted (13.3412 g) and stocked at -5 o C in an air tight bottle, to beused for further reactions.8.3.2 Synthesis of PMMA by Uncontrolled Radical PolymerizationMethyl Methyacrylate (MMA) (Sigma-Aldrich®, 99.9 %) was passed over a short aluminacolumn to remove the inhibitor and 10 g (9.988 x 10 -2 moles) of this purified MMA was sealed in adried Schlenk tube containing 0.1 g (6.09 x 10 -4 moles) of Azobisisobutyonitrile (AIBN) (Sigm-Aldrich®, 98 %) (recyrstallized from methanol). The mixture was given four freeze-pump-thaw cyclesto remove oxygen completely and placed in a constant temperature oil bath at 70 o C for 70 minutes.The system was quenched in liquid nitrogen to stop further polymerization and then annealed atroom temperature. The flask was connected to rotary evaporator to evaporate any remaining MMAfollowed by addition of 30 ml dichloromethane (Sigma-Aldrich®, >99 %) to dissolve the gelovernight. The viscous solution thus obtained was then precipitated 2 times in cold methanol,150
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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
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This apparent morphological switchi
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In a further qualitative analysis,
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noteworthy and though its feasibili
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Furthermore within this range, lowe
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Figure - 2.22: Scanning Electron Mi
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While the resistance measurements g
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In conclusion, a self-healing membr
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23 Giacomelli, F. C., Riegel, I. C.
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micelles enabled the membrane to se
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The second class is represented by
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To avoid the probable clogging of t
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181614SP2 - iNumber of Particles121
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1000900800y = 3E+06xR² = 0,9911y =
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very high value of 1.5 g.l -1 . Thi
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Since the only change in the membra
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100Retention (%)8060400,100,20,40,6
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(Figure - 3.20). A cursory look at
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When compared to poly(styrene) NPs,
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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
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Page 122 and 123: mg/ml),the micelles’ hydrodynamic
Page 124 and 125: Figure - 4.15: The monolayer and mu
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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
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Page 142 and 143: Figure - 5.10: 1HNMR spectra obtain
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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: solution was ultrasonicated for 15
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
Page 170 and 171: ELABORATION DES MEMBRANES POLYMERES
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4(%3)3 - Ecole nationale supÃ©rieure de chimie de Montpellier

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