Phase behaviour of polymer emulsions during the phase inversion process in the presence of non-ionic surfactants

Zerfa, M.; Sajjadi, Shahriar; Brooks, Brian W.

doi:10.1016/s0927-7757(00)00728-7

Cited by 42 publications

(34 citation statements)

References 8 publications

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“…The current literature has extensively reported the appearance of these abnormal multiple emulsions. [27][28][29][30][31][32][33][34] However, these multiple emulsions have been described as transitory or temporary systems that appear only during the phase inversion process. Recently, our group has reported the formation of stable multiple emulsions and reported a one-step method for the preparation of such multiple emulsions using different oil phases and nonionic surfactant blends.…”

Section: Introductionmentioning

confidence: 99%

Influence of Phase Inversion on the Formation and Stability of One-Step Multiple Emulsions

2009

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A novel method of preparation of water-in-oil-in-micelle-containing water (W/O/W(m)) multiple emulsions using the one-step emulsification method is reported. These multiple emulsions were normal (not temporary) and stable over a 60 day test period. Previously, reported multiple emulsion by the one-step method were abnormal systems that formed at the inversion point of simple emulsion (where there is an incompatibility in the Ostwald and Bancroft theories, and typically these are O/W/O systems). Pseudoternary phase diagrams and bidimensional process-composition (phase inversion) maps were constructed to assist in process and composition optimization. The surfactants used were PEG40 hydrogenated castor oil and sorbitan oleate, and mineral and vegetables oils were investigated. Physicochemical characterization studies showed experimentally, for the first time, the significance of the ultralow surface tension point on multiple emulsion formation by one-step via phase inversion processes. Although the significance of ultralow surface tension has been speculated previously, to the best of our knowledge, this is the first experimental confirmation. The multiple emulsion system reported here was dependent not only upon the emulsification temperature, but also upon the component ratios, therefore both the emulsion phase inversion and the phase inversion temperature were considered to fully explain their formation. Accordingly, it is hypothesized that the formation of these normal multiple emulsions is not a result of a temporary incompatibility (at the inversion point) during simple emulsion preparation, as previously reported. Rather, these normal W/O/W(m) emulsions are a result of the simultaneous occurrence of catastrophic and transitional phase inversion processes. The formation of the primary emulsions (W/O) is in accordance with the Ostwald theory ,and the formation of the multiple emulsions (W/O/W(m)) is in agreement with the Bancroft theory.

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Section: Introductionmentioning

confidence: 99%

Influence of Phase Inversion on the Formation and Stability of One-Step Multiple Emulsions

2009

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“…This type of inversion is irreversible and can occur over a wide range of volume fractions. The term catastrophic means a sudden change in behavior of a system and occurs as a result of gradual changes in process conditions [36][37][38]. The phase inversion in this case is triggered by the change of the water/oil ratio when the volume fraction of the dispersed phase increases.…”

Section: <Table 2>mentioning

confidence: 99%

Opportunities and Challenges for the Nasal Administration of Nanoemulsions

Comfort¹,

Garrastazu²,

Pozzoli³

et al. 2015

CTMC

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18Nasal delivery has become a growing area of interest for drug administration as a consequence of several 19 practical advantages, such as ease of administration and non-invasiveness. Moreover, the avoidance of hepatic 20 first-pass metabolism and rapid and efficient absorption across the permeable nasal mucosa offer a promising 21 alternative to other traditional administration routes, such as oral or parenteral delivery. In fact, nasal delivery 22 has been proposed for a number of applications, including local, systemic, direct nose-to-brain and mucosal 23 vaccine delivery. Nanoemulsions, due to their stability, small droplet size and optimal solubilization properties,

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“…One of these processes is phase inversion, also known as the low-energy method of producing emulsions. This method relies on the internal energy of the micelles by changing the properties of the medium in which they are found (Izquierdo et al 2002;Sajjadi, Zerfa, and Brooks 2003;Zerfa, Sajjadi, and Brooks 2001).…”

Section: Introductionmentioning

confidence: 99%

Determination of the Phase Inversion Temperature of Orange Oil/Water Emulsions by Rheology and Microcalorimetry

Souza¹,

Spinelli²,

González

et al. 2009

Analytical Letters

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In low-energy emulsification processes, phase inversion occurs when the phases of a dispersion exchange, because of changes in the medium's properties. This paper reports experiments to determine the phase inversion temperature (PIT) of orange oil=water emulsions stabilized by nonionic surfactants. Two techniques were employed: rheology, which is already commonly used to obtain the PIT, and microcalorimetry, which has been proposed as a new technique. Continuous monitoring of the emulsions' viscosity permitted identifying different phenomena that occur while the temperature varies. For all the dispersions prepared, the rheological curves obtained showed two peaks, one attributed to the phase separation process and the other to the phase inversion phenomenon. The microcalorimetry technique showed two endothermic transitions as the dispersion's temperature increased. The initial temperatures were comparable to those obtained by rheology. The influence of the surfactant concentration and the hydrophilic-lipophilic balance (HLB) of the mixture of surfactants and the reduction in volume of the phases at the phase inversion temperature were also evaluated. In general, both methods used to evaluate the phase inversion of the orange oil=water systems (rheology and microcalorimetry) presented concordant results, both for the phase separation process and the phase inversion temperature.

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Phase behaviour of polymer emulsions during the phase inversion process in the presence of non-ionic surfactants

Cited by 42 publications

References 8 publications

Influence of Phase Inversion on the Formation and Stability of One-Step Multiple Emulsions

Influence of Phase Inversion on the Formation and Stability of One-Step Multiple Emulsions

Opportunities and Challenges for the Nasal Administration of Nanoemulsions

Determination of the Phase Inversion Temperature of Orange Oil/Water Emulsions by Rheology and Microcalorimetry

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