Abstract
In this study, we utilized the surface freezing transition of mixed adsorbed films of cetyltrimethylammonium chloride (CTAC) and hexadecane at the isopropyl palmitate (IPP)–aqueous interface to encapsulate IPP in a stable oil-in-water (OW) emulsion droplets. IPP is a widely used emollient oil in cosmetic creams; however, as often seen in oily ingredients in cosmetics, it is also surface-active and adsorbs at the oil–water interface. Therefore, under normal experimental conditions, surfactant emulsifier and cosmetic oil form a mixed adsorbed film at the OW emulsion surfaces. However, such films typically do not enhance emulsion stability and for that purpose we used a 1:9 mixture of hexadecane and IPP as oil phase together with CTAC as surfactant. The interfacial tension of the oil phase against CTAC aqueous solution as a function of CTAC concentration and temperature shows three distinctive interfacial phases: disordered mixed adsorbed film of CTAC and IPP (surface liquid) and two surface frozen monolayers in which CTAC or IPP expelled the other and gives rise to a highly ordered and stiff hydrocarbon chain layer with incorporated hexadecane molecules. The compositional transition of the surface frozen monolayer of IPP and that of CTAC occurred as the CTAC concentration increased in the aqueous phase. Above the transition concentration, an enhanced OW emulsion stability was observed, whereas IPP surface frozen monolayer forms only kinetically unstable emulsions. From these findings, we suggest the potential use of surface frozen films of CTAC to encapsulate surface-active cosmetic oils stably in the OW emulsions, which in addition have the property that the stability can be controlled by temperature.
Graphical Abstract
Similar content being viewed by others
Data availability
The datasets generated and/or analyzed during the current study are available from the corresponding author on reasonable request.
References
Tokiwa Y, Ohtomi E, Takiue T, Aratono M, Bain CD, Matsubara H (2018) Effect of surface phase transition on OW emulsion stability. Langmuir 34:6205–6209
Lei Q, Bain CD (2004) Surfactant-induced surface freezing at the alkane−water interface. Phys Rev Lett 92:176103
Sloutskin E, Bain CD, Ocko BM, Deutsch M (2005) Surface freezing of chain molecules at the liquid−liquid and liquid−air interfaces. Faraday Discuss 129:339–352
Tamam L, Pontoni D, Sapir Z, Yefet S, Sloutskin E, Ocko BM, Reichert H, Deutsch M (2011) Modification of deeply buried hydrophobic interfaces by ionic surfactants. Proc Natl Acad Sci USA 108:5522–5525
Sakamoto H, Masunaga A, Takiue T, Tanida H, Uruga T, Nitta K, Prause A, Gradzielski M, Matsubara H (2020) Surface freezing of cetyltrimethylammonium chloride−hexadecanol mixed adsorbed film at dodecane−water interface. Langmuir 36:14811–14818
Tokiwa Y, Sakamoto H, Takiue T, Aratono M, Matsubara H (2015) Effect of alkane chain length and counterion on the freezing transition of cationic surfactant adsorbed film at alkane mixture-water interfaces. J Phys Chem B 119:6235–6241
Johnson DH (1977) The use of fatty acid derivatives in cosmetics and toiletries. JAOCS 55:438–443
Guo H, Liu Z, Li J, Nie S, Pan W (2006) Effects of isopropyl palmitate on the skin permeation of drugs. Biol Pharm Bull 29:2324–2326
Boonme P (2007) Applications of microemulsions in cosmetics. Journal of Cosmetics and Dermatology 6:223–228
Chen Y, Wei W, Zhu Y, Luo J, Liu R, Liu X (2020) Synthesis of temperature/pH dual-stimuli-response multicompartmental micro-capsules via Pickering emulsion for preprogrammable payload release. ACS Appl Mater Interfaces 12:4821–4832
Jagadeesan D, Nasimova I, Gourevich I, Starodubtsev S, Kumacheva E (2011) Microgels for the encapsulation and stimulus responsive release of molecules with distinct polarities. Macromol Biosci 11:889–896
Zhao X, Huang B, El-Aooiti M, Rousseau D (2018) Demulsification to control solute release from Pickering crystal-stabilized water-in-oil emulsions. J Colloid Interface Sci 509:360–368
Iwata N, Neves MA, Watanabe J, Sato S, Ichikawa S (2014) Stability control of large oil droplets by layer-by-layer deposition using polyelectrolyte dietary fibers. Colloids Surf A 440:2–9
Zhang Y, Feng Y (2020) Stimuli-responsive microemulsions: state-of-the-art and future prospects. Adv Colloid Interface Sci 49:27–41
Sakamoto H, Murao A, Hayami Y (2002) Real-time measurement of interfacial tension by image processing. J Inst Image Inf Telev Eng 56:1643–1650
Drude P (1959) The theory of optics. Dover, New York
Casson BD, Bain CD (1997) Determination of the optical properties of monolayers on water. Langmuir 13:5465–5469
Motomura K, Iyota H, Ikeda N, Aratono M (1988) Thermodynamic studies on adsorption at interfaces. VI. Interface between cyclohexane-benzene mixture and water. J Colloid Interface Sci 126:26–36
Dinh H, Santanach-Carreras E, Lalanne-Aulet M, Schmitt V, Panizza P, Lequeux F (2021) Effect of a surfactant mixture on coalescence occurring in concentrated emulsions: the Hole Nucleation Theory revisited. Langmuir 37:8726–8737
Narayan S, Metaxas AE, Bachnak R, Neumiller T, Dutcher CS (2020) Zooming in on the role of surfactants in droplet coalescence at the macroscale and microscale. Curr Opin Colloid Interface Sci 50:101385
Ivanov IB, Kralchevsky PA (1997) Stability of emulsions under equilibrium and dynamic conditions. Colloids Surfaces A 128:155–175
Heunemann P, Prévost S, Grillo I, Marino CM, Meyer J, Gradzielski M (2011) Formation and structure of slightly anionically charged nanoemulsions obtained by the phase inversion concentration (PIC) method. Soft Matter 7:5697–5710
Guttman S, Sapir Z, Schultz M, Butenko AV, Ocko BM, Deutsch M, Sloutskin E (2016) How faceted liquid droplets grow tails. Proc Natl Acad Sci USA 113:493–496
Guttman S, Sapir Z, Ocko BM, Deutsch M, Sloutskin E (2017) Temperature-tuned faceting and shape changes in liquid alkane droplets. Langmuir 33:1305–1314
García-Aguilar I, Fonda P, Sloutskin E, Giomi L (2021) Faceting and flattening of emulsion droplets. Phys Rev Lett 126:038001
Marin O, Alesker M, Guttman S, Gershinsky G, Edri E, Shpaisman H, Guerra RE, Zitoun D, Deutsch M, Sloutskin E (2019) Self-faceting of emulsion droplets as a route to solid icosahedra and other polyhedral. J Colloid Interface Sci 538:541–545
Denkov N, Cholakova D, Tchokakova S, Smoukov SK (2016) On the mechanism of drop self-shaping in cooled emulsions. Langmuir 32:7985–7991
Denkov N, Tcholakova S, Lesov I, Cholakova D, Smoukov SK (2015) Self-shaping of oil droplets via the formation of intermediate rotator phases upon cooling. Nature 528:392–395
Cholakova D, Denkov ND, Tcholakova S, Lesov I, Smoukov SK (2016) Control of drop shape transformations in cooled emulsions. Adv Colloid Interface Sci 235:90–107
Cholakova D, Valkova Z, Tcholakova S, Denkov N, Smoukov SK (2017) ”Self-shaping” of multicomponent drops. Langmuir 33:5696–5706
National Center for Biotechnology Information (2023) PubChem Compound Summary for CID 8907, Isopropyl Palmitate. Retrieved April 28, 2023 from https://pubchem.ncbi.nlm.nih.gov/compound/Isopropyl-Palmitate
Funding
This work was supported by DAAD and JSPS under the Germany-Japan Research Cooperative Program (DAAD: Project-ID 57402195, JSPS: Project-ID 18035821–000146) and by JSPS KAKENHI Grant Number 22K03551.
Author information
Authors and Affiliations
Corresponding author
Ethics declarations
Conflict of interest
The authors declare no competing financial interest. However, one of the authors (M.G.) is guest editor of the special issue “100 Years Colloid Society / Colloid Science—as Modern as Ever.”
Additional information
Publisher's Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Rights and permissions
Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.
About this article
Cite this article
Matsubara, H., Sakamoto, H., Prause, A. et al. Surface freezing of CTAC-hexadecane mixed adsorbed film at the isopropyl palmitate–water interface: a way to stabilize emulsions. Colloid Polym Sci 301, 745–752 (2023). https://doi.org/10.1007/s00396-023-05113-1
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00396-023-05113-1