Visualization, manipulation and force spectroscopy of cylindrical polymer brushes [Elektronische Ressource] / Nikhil Arun Gunari

Ac Nielsen

Informations

• Publié par: johannes_gutenberg-universitat_mainz
• Publié le: 01 janvier 2005
• Nombre de lectures: 7
• Langue: English
• Poids de l'ouvrage: 3 Mo

Extrait

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VISUALIZATION, MANIPULATION AND FORCE
SPECTROSCOPY OF CYLINDRICAL POLYMER
BRUSHES

Dissertation
For attaining the degree of
Doctor of Natural Sciences


At the Faculty of Chemistry
Of Johannes Gutenberg University


Nikhil Arun Gunari

Born in Pune, India

Mainz, 2005
2
CONTENTS

CHAPTER 1

INTRODUCTION..................................................................................................1
1.1 Cylindrical Polymer Brushes...............................................................1
1.2 Properties of Cylindrical Polymer Brushes ...............................…....2
1.1.1. Solution Properties..................................................................2
1.1.2. Bulk Properties........................................................................3
1.1.3. Mechanical Properties of Cylindrical Brushes........................4
1.1.4. Responsive Molecules.............................................................4
1.3 Conformation of 2D Confined Cylindrical Polymer Brushes...........5
1.4 Applications of cylindrical polymer brushes......................................5
1.5 Objectives...............................................................................................7
1.6 Research Impact and Significance.......................................................8
1.7 References..............................................................................................8

CHAPTER 2

SCANNING PROBE MICROSCOPY......................…………………………..11

2.1 Introduction..........................................................................................11
2.2 Scanning Force Microscopy................................................................11
2.3 Resolution of AFM...............................................................................15
2.4 Imaging Modes.............................................................…....................16
2.4.1 Contact Mode...................................................….........…......16
2.4.2 Non-contact Mode...................................…...................….....16
2.4.3 Intermittent Contact Mode or Tapping Mode AFM.........…...17
2.5 Lateral Force Microscopy (LFM)......................................................18
2.6 References............................................................................................19

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CHAPTER 3

SINGLE MOLECULE FORCE SPECTROSCOPY AND POLYMER
MODELS ………............................................................................................…….…..20
3.1 Introduction to Single Molecule Force Spectroscopy (SMFS)......……...20
3.2 SMFS: The Technique....................................................................………..22
3.3 Force-Distance Curves...................................................................….….…23
3.4 Capillary Forces..........................................................................…….……25
3.5 Applications of SMFS................................................................…………..27
3.5.1. Intra and Intermolecular Forces.......................................………..27
3.5.2. Stretching of Single Polymer Chains..............................………...28
3.6 Molecule Specific Force Spectroscopy........................................………...29
3.7 Fly-fishing Mode....................................................................………….….30
3.8 Polymer Models from Statistical Mechanics..……………………..…….30
3.9 Stiff Chains.....................................................................................….….…31
3.10 References.....................................................................................……….33

CHAPTER 4

MATERIALS INSTRUMENTS AND PREPARATIONS......………...........……36

4.1 Instruments......................................................................................……..36
4.2 Substrates.........................................................................................…….36
4.3 Spin Caster....................................................................................……....37
4.4 AFM Cantilevers and Spring Constant Measurement................……..38
4.6 References.....................................................................................…….....39

CHAPTER 5

VISUALIZATION OF CYLINDRICAL POLYMER BRUSH
MOLECULES ..............................................................................................…….….40
5.1 Introduction to Single Molecule AFM Imaging............................…….40
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5.2 Poly (2-vinylpyridine) Cylindrical Polymer Brushes............…..………..40
5.3 Micelles Formed by Cylindrical Brush-Coil Block Polymers….………..43
5.4 Thermally Responsive Cylindrical Brush Polymers..................………....47
5.4.1. AFM Characterization of thermally responsive cylindrical brush
molecules.....……..…….....................................................…………………....48
5.4.2. Cylinder-globule-cylinder reentrant transition observed by AFM………57
5.5 Conclusions...........................................................................................…….62
5.6 References............................................................................................……..62

CHAPTER 6

PERSISTENCE LENGTH OF CYLINDRICAL BRUSH MOLECULES
MEASURED BY ATOMIC FORCE MICROSCOPY...........……...................…….64

6.1 Introduction..................................................................................……….……64
6.2 Experimental.........…....................................................................……………65
6.3 Results and Discussion........................................................……....…………..66
6.4 Conclusions....................................................................................……………83
6.5 References….......…..........................................................................………….83

CHAPTER 7

STRETCHING CYLINDRICAL BRUSHES UNDER POOR SOLVENT
CONDITIONS BY ATOMIC FORCE MICROSCOPE............................……….86
7.1 Introduction........................................................................……………….86
7.2 Experimental….…....................................................................…….…….87
7.3 Results and Discussion.......................................................…..…………..88
7.3.1 Qualitative analysis of stretching of individual collapsed
cylindrical brushes ....................................................………………. ..88
7.3.2 Quantitative analysis of stretching of individual collapsed
cylindrical brushes.....…………............................................................93
7.4 Molecule Specific Force Spectroscopy................................................….95
7.5 Conclusions…...........................................................................................101
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7.6 References..............................................................................................101

CHAPTER 8

GLOBULECYLINDER TRANSITION OBSERVED BY FORCE
SPECTROSCOPY..............……………….................................................103

8.1 Introduction....……..........................................................................103
8.2 Experimental..…...............................................................................105
8.3 Results and Discussion.….................................................................105
8.4 Scaling Theory...................................................................................109
8.5 Conclusions.............................................................…………...........113
8.6 References…......................................................................................114

CHAPTER 9

CONFORMATION AND ELASTICITY OF POLYLYSINE
CYLINDRICAL BRUSHES BY AFM.......................…………...............116

9.1 Introduction..………........................................................................116
9.2 Experimental...........................................................….....................117
9.3 Results and Discussion....................................................................118
9.3.1 AFM imaging............................................................................119
9.3.2 Qualitative analysis of desorption of individual polylysine
cylindrical brus