Table of contents
0.
Introduction ... 1
1.
Literature review ... 3
1.1 Microencapsulation ... 3 1.1.1 Introduction ... 3 1.1.2 Microencapsulation techniques ... 4 1.1.3 Controlled release ... 14 1.1.4 Coating materials ... 21 1.2 Silica ... 27 1.3 Toothpaste ... 31 1.3.1 Introduction ... 31 1.3.2 Chemical composition ... 312.
Market research ... 35
2.1 Toothpaste market ... 352.2 Toothpaste history and future trends ... 38
2.3 Microencapsulation market overview ... 40
2.4 Biocides market overview ... 41
3.
Experimental equipment and materials ... 45
3.1 Equipments ... 45
3.2 Chemicals ... 46
3.3 Methods ... 47
3.3.1 Inductively coupled plasma mass spectroscopy ... 47
3.3.2 Mass spectroscopy ... 48
3.3.2 Atomic emission spectroscopy ... 49
3.3.3 Gas chromatography... 50
4.
Experimental preparations ... 52
4.1 Introduction ... 52
4.3 Process to evaluate the amount of A on the beads ... 53
4.4 Preparation of alginate-containing silica... 55
4.5 Release tests ... 59
4.6 Preparation of C-containing silica... 60
4.7 Release of C ... 63
4.8 Biological tests ... 64
4.9 Preparation of the toothpaste... 65
5.
Results and discussion ... 67
5.1 Release of A from the alginate beads ... 67
5.2 Mass balance on A ... 70
5.3 Content of A on silica ... 76
5.4 Results of the release tests ... 79
5.5 Examination of the C-containing silica ... 85
5.6 Results of the biological tests... 87
5.7 Compatibility of the particles in the toothpaste formulation ... 90
