Stabilisation of water-in-oil emulsions to improve - eTheses ...

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5.4 Emulsion Stability 5.4.1 Coalescence and Droplet Evolution All of the samples showed some degree of droplet coalescence over the entire 127 day period, albeit initially after the first 30 days (Figure 5.4), with PGPR showing the highest degree of stability overall with an increase of 11% for volume-weighted mean droplet diameter D3.3 compared to the blends of Span 80 with Tween 80 which showed an increase of 19%, with Span 80 being the least stable showing a 45% increase. Not only did PGPR exhibit greater stability by way of droplet size, but also, the breadth of the distribution remained much smaller throughout compared to the blend of Span 80 with Tween 80 and Span 80 alone (Figures 5.25, 5.26 & 5.27), indicating less coalescence throughout for both the smaller and larger droplets. D 3.3 Droplet Diameter (µm) 20 18 16 14 12 10 8 6 4 2 Emulsion Stability for 40% H 2 O; 1% Emulsifiers 40% H 2 O; 1% Span 80 with Tween 80 (HLB = 5) 40% H 2 O; 1% Span 80 (HLB = 4.3) 40% H 2 O; 1% PGPR (HLB = 1.5 ± 0.5) 0 20 40 60 80 100 120 140 Time Period (Days) Fig. 5.24. Stability (evolution) of the volume-weighted mean droplet diameter D3.3, for 40 wt% water content and 1 wt% emulsifier over a period of 127 days. 83
Relative frequency Emulsion Stability for 40% H 2 O; 1% Span 80 with Tween 80 (HLB = 5) 100 80 60 40 20 40% H2O; 1% Span/Tween80 (HLB = 5) at 0 days 40% H2O; 1% Span/Tween80 (HLB = 5) at 127 days 0 0 20 40 60 80 100 120 Mean droplet size diameter D 3.3 (µm) Fig. 5.25. Stability (evolution) of the volume-weighted mean droplet diameter D3.3 frequency distributions for 40 wt% water content, 1 wt% Span 80 with Tween 80 (HLB = 5) at 0 and 127days. Relative frequency 100 80 60 40 20 Emulsion Stability for 40% H 2 O; 1% Span 80 (HLB = 4.3) 40% H 2 O; 1% Span 80 (HLB = 4.3) at 0 days 40% H 2 O; 1% Span 80 (HLB = 4.3) at 127 days 0 0 10 20 30 40 50 60 70 Mean droplet size diameter D 3.3 (µm) Fig. 5.26. Stability (evolution) of the volume-weighted mean droplet diameter D3.3 frequency distributions for 40 wt% water content, 1 wt% Span 80 (HLB = 4.3) at 0 and 127days. 84
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Stabilisation of water-in-oil emuls
Page 3 and 4:
Abstract The stabilisation of water
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Contents 1 Introduction ...........
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4.7.1 Penetrometer Test ...........
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Figures Fig. 1.1. The global cosmet
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Fig. 5.18. DSC Thermograms for the
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Fig. 5.36. Changes in the viscoelas
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Table. 5.6. Emulsion based Lipstick
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Symbols α Alpha β Beta β’ Beta
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provide additional moisture for the
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1.1 Layout of the Thesis This Thesi
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more than 2 to 3 applications daily
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O HO O C H 3 CH 3 O OH O O O Molecu
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C H 3 HO O OH Molecular Formula = C
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C H 3 C H 3 Molecular Formula = C 6
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the long chains. Due to its structu
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and subsequent infections. This can
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In order to attain a state of minim
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which there is an excess of opposit
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By applying the HLB system, one wil
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2.7 Emulsion stability & instabilit
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(Voorhees, 1992; Dickinson, Ritzoul
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chains are in free rotation and pre
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(a) (b) (c) Fig. 2.7. Double chain
Page 49 and 50: prevented by the addition of crysta
Page 51 and 52: 2.9 Microbial stability & Origin of
Page 53 and 54: There are a number of important fac
Page 55 and 56: which of course is an important con
Page 57 and 58: ideal for assessing not only the de
Page 59 and 60: 3 Materials 3.1 Waxes & Emulsifiers
Page 61 and 62: With the continuous phase being oil
Page 63 and 64: melting point range in order to mai
Page 65 and 66: The moulds were then placed in a fr
Page 67 and 68: Table. 4.2. IFT Procedure settings
Page 69 and 70: 4.4 Emulsion Lipstick Preparation F
Page 71 and 72: The water was transferred directly
Page 73 and 74: emulsions were taken in triplicate
Page 75 and 76: d0,0; number-weighted mean (e.g. NM
Page 77 and 78: 4.7 Texture Profile Analysis - TA T
Page 79 and 80: 4.7.2 Compression Test The second m
Page 81 and 82: 4.7.3 Rheology Rheological non-dest
Page 83 and 84: critical micelle concentration (CMC
Page 85 and 86: Interfacial Tension (mN/m) 10 CMC -
Page 87 and 88: Sorbitan Hydrophilic portion (Water
Page 89 and 90: HO O O O O Water droplet O O O O HO
Page 91 and 92: 5.3.2 Wax selection for Simplified
Page 93 and 94: 5.3.3 Thermo-physical Characteristi
Page 95 and 96: Heat Flow Endo/Exo (mW) 2% PGPR DSC
Page 97 and 98: Heat Flow Endo/Exo (mW) 2% Span 80
Page 99: Table. 5.3. Thermo-physical charact
Page 103 and 104: drainage and rupture. In spite of t
Page 105 and 106: Table. 5.4. Emulsion based Lipstick
Page 111 and 112: the emulsification process along wi
Page 113 and 114: Fig. 5.29. 30 wt% water content wit
Page 115 and 116: Fig. 5.33. Cryo-SEM micrograph of H
Page 117 and 118: no doubt give rise to a much denser
Page 119 and 120: Table. 5.9. Texture profile penetro
Page 121 and 122: Table. 5.10. Compression firmness d
Page 123 and 124: Although no emulsions were prepared
Page 125 and 126: G' & G'' (Pa) x 10 5 Viscoelastic p
Page 127 and 128: Table. 5.11. Viscoelastic moduli, G
Page 129 and 130: potentially reduce microbial spoila
Page 131 and 132: Appendix The following Figures; 5.9
Page 133 and 134: Heat Flow Endo/Exo (mW) 5 4 3 2 1 0
Page 135 and 136: Heat Flow Endo/Exo (mW) 2.0 1.5 1.0
Page 137 and 138: References Adamczyk, S., Lázaro, R
Page 139 and 140: Dweck, A. C., & Burnham, C. A. M. (
Page 141 and 142: Kobayashi, H., & Tagami, H. (2004).
Page 143 and 144: Pourreza, N., & Rastegarzadeh, S. (
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