1 Introduction ................................................. 1
1.1 Objectives .............................................. 1
1.2 Synopsis of the work .................................... 4
2 Literature review ............................................ 5
2.1 Layered double hydroxides (LDH) ......................... 5
2.1.1 Synthesis of LDH ................................. 6
2.1.2 Modification of LDH ............................. 10
2.2 LDH/Polymer nanocomposites ............................. 14
2.2.1 Preparation methods of LDH/polymer
nanocomposites .................................. 15
2.2.2 Characteristics of LDH/polymer nanocomposites ... 19
2.3 Melt-spinning .......................................... 26
2.3.1 Principles of melt-spinning ..................... 26
2.3.2 Melt-spinning of nanocomposites ................. 27
2.4 Functionalized composites .............................. 29
2.4.1 v Stability of polymer nanocomposites ........... 29
2.4.2 Antimicrobiality of polymer nanocomposites ...... 30
3 Experimental ................................................ 33
3.1 Layered double hydroxide ............................... 33
3.1.1 Synthesis of LDH ................................ 33
3.1.2 Commercial LDHs ................................. 34
3.2 Modification of LDH .................................... 34
3.2.1 Chemicals used for modification of LDH .......... 34
3.2.2 LDH modification methods ........................ 35
3.3 Nanocomposite preparation .............................. 37
3.3.1 Polymers used for nanocomposite preparation ... 37
3.3.2 Small scale preparation ......................... 38
3.3.3 Large scale preparation ......................... 39
3.4 Compression molding of nanocomposites .................. 39
3.5 Melt-spinning of nanocomposites ........................ 40
3.5.1 Small-scale melt-spinning ....................... 40
3.5.2 Large-scale melt-spinning ....................... 40
3.6 Characterization of LDH and nanocomposites ............. 41
3.6.1 X-ray diffraction (XRD) analysis ................ 41
3.6.2 FTIR analysis ................................... 42
3.6.3 Elementary analysis ............................. 42
3.6.4 Thermal analysis ................................ 42
3.6.5 Mechanical tests ................................ 42
3.6.6 Electron microscopy ............................. 43
3.6.7 Rheology ........................................ 44
3.6.8 Microcalorimeter ................................ 44
3.6.9 UV/vis spectroscopy ............................. 45
3.6.10 Artificial aging ................................ 45
3.6.11 Antimicrobiality test ........................... 45
4 LDH modification and nanocomposite preparation .............. 47
4.1 LDH synthesis and modification ......................... 47
4.1.1 Synthesis conditions ............................ 47
4.1.2 Decarbonation of LDH ............................ 53
4.1.3 One-pot anion exchange intercalation of LDHs .... 55
4.1.4 Effect of intercalated molecule ................. 57
4.1.5 Intercalation of functional molecules ........... 60
4.1.6 Thermostability of nanofiller ................... 65
4.2 Nanocomposite preparation .............................. 71
4.2.1 Rheological characterization of prepared
nanocomposites .................................. 71
4.2.2 Morphological characterization .................. 74
4.3 Conclusion for nanocomposite preparation ............... 77
5 Melt-spinning of nanocomposites ............................. 79
5.1 Small-scale melt-spinning of nanocomposite fibers ...... 79
5.1.1 Mechanical properties of fibers ................. 79
5.1.2 Thermal behavior of the nanocomposites .......... 83
5.1.3 Rheological properties of nanocomposites ........ 84
5.1.4 Morphological characterization of the
nanocomposites .................................. 87
5.2 Up-scaling of melt-spun nanocomposite fibers ........... 89
5.2.1 Mechanical properties ........................... 89
5.2.2 FTIR characterization ........................... 91
5.2.3 Thermal behavior of the nanocomposites .......... 92
5.2.4 Rheological response of up-scaled
nanocomposites .................................. 94
5.2.5 Morphological characterization of
nanocomposites .................................. 96
5.3 Conclusion for melt spinning of nanocomposites ......... 98
6 Functionalized LDH/Polyolefin nanocomposites ................ 99
6.1 Stabilized nanocomposites .............................. 99
6.1.1 Polymer stability ............................... 99
6.1.2 Polymer stability under artificial aging ....... 101
6.1.3 Thermal stability/ Flame retardancy ............ 104
6.1.4 Electron Microscopy ............................ 106
6.1.5 Conclusion for dye integrated LDH
nanocomposites ................................. 106
6.2 Antimicrobial nanocomposites .......................... 108
6.2.1 Dispersion state of antimicrobial
nanocomposites ................................. 108
6.2.2 Antimicrobial activity of melt-spun fibers ..... 110
6.2.3 Durability of antimicrobial activity ........... 116
6.2.4 Conclusion for antimicrobial active
LDH-nanocomposites ............................. 120
7 Summary and Outlook ........................................ 121
References ................................................. 125
List of Figures ............................................... 143
List of Tables ................................................ 149
Appendix: Scientific Contributions ............................ 150
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