Sepawa Congress
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SEPAWA Congress Stanimirova Rumyana P
Dr. Rumyana Stanimirova

Department of Chemical & Pharmaceutical Engineering, Faculty of Chemistry & Pharmacy, Sofia University “St. Kliment Ohridski” | Centre of Competence “Smart Mechatronics, Eco- and Energy Saving Systems and Technologies”, Sofia, Bulgaria

Researcher R2

stanimirova@gmail.com

Current lectures/posters

16.10.2026

10:45

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11:00

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Room 12+13

Aqueous Solutions of Oil-Soluble Polyglycerol Esters: Structuring and Emulsifying Abilities

Forum for Innovation

| Personal Care: “Future Trends for Personal Care Ingredients and Formulations”

, R/G/S (Rheology Modifier/Gelling Agent/Silicone Alternatives)

Dr. Rumyana Stanimirova (Department of Chemical & Pharmaceutical Engineering, Faculty of Chemistry & Pharmacy, Sofia University “St. Kliment Ohridski” | Centre of Competence “Smart Mechatronics, Eco- and Energy Saving Systems and Technologies”, Sofia, Bulgaria)
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(available in the SOFW media library after the congress)

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Lecture Language: English

Polyglycerol esters (PGEs) of fatty acids exhibit a broad range of HLB values and are widely used across various industries, including pharmaceuticals and cosmetics. While the physicochemical properties of oil-soluble PGEs in oil phases have been extensively studied, there is still a lack of information regarding their structuring in aqueous phases and their emulsifying capabilities [1]. In this study, rheological measurements, differential scanning calorimetry (DSC), and microscopic observations are combined to investigate how the structuring of oil-soluble PGEs in aqueous phases depends on their concentration, the homogenization temperature, and respective molecular structure. A strong correlation is found between the significant changes in the solution viscosity and the temperatures corresponding to the endothermic and exothermic peaks in the DSC thermograms.
Single-tail PGE molecules with a higher number of polyglycerol units tend to form more organized network structures, resulting in higher viscosities of their aqueous solutions compared to their double-tail counterparts. Additionally, the PGEs demonstrate good emulsifying properties, and the viscosity of the resulting emulsions at room temperature can vary by orders of magnitude depending on the emulsification temperature. These findings highlight the potential of oil-soluble PGEs to broaden their range of practical applications.

Acknowledgements:
The support of the CoC “Smart Mechatronics, Eco- and Energy Saving Systems and Technologies”, project BG16RFPR002-1.014-0005, funded by the Program “Research, Innovation, and Digitization for Smart Transformation” 2021–2027, co-funded by the EU, and the support of the National Science Fund of Bulgaria, Grant No. KP-06-N 79/4/2023, are greatly acknowledged.

References
[1] Stanimirova, R.D.; Georgiev, M. T.; Danov, K.D.; Petkov, J.T. Aqueous Solutions of Oil-Soluble Polyglycerol Esters: Structuring and Emulsifying Abilities. Molecules 2025, 30(23), 4507

Hall Europa

Dr. Rumyana Stanimirova (Department of Chemical & Pharmaceutical Engineering, Faculty of Chemistry & Pharmacy, Sofia University “St. Kliment Ohridski” | Centre of Competence “Smart Mechatronics, Eco- and Energy Saving Systems and Technologies”, Sofia, Bulgaria)

31 | Interfacial and Bulk Properties of Volatile Amphiphiles and Sodium Dodecyl Sulfate Mixtures

Scientific Conference (SEPAWA)

| Fragrance (SEPAWA)

, "Perfume Design, Society & Economical Value"

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The volatile amphiphiles (fragrances) present in perfume compositions, cosmetics, and home-care products are volatile organic compounds with low water solubility, good solubility in alcohols and ethers, partial solubility in oils, and a wide range of vapor pressure at room temperature. They are often combined with various perfume molecules and surfactants (detergents, softeners, cleaning products), which can affect the system properties. Therefore, understanding their molecular characteristics and interactions with surfactants is essential.
In previous studies [1,2], the surface tension properties of several volatile amphiphiles (linalool, citronellol, benzyl acetate, geraniol, and (-) menthol) were investigated. The surface tension isotherms at different VAs – sodium dodecyl sulfate (SDS) ratios were measured and analyzed using appropriate theoretical models that provide quantitative information on both bulk and interfacial properties. All surface tension isotherms were described by the van der Waals model for a two-component adsorption layer, considering counterion binding in the Stern layer, with one adjustable parameter (interfacial pair interaction energy). Based on the obtained model parameters, various properties of the adsorption layers were computed, including the adsorption of different components, occupancy of the Stern layer, and the interfacial electrostatic potential. Experimental solubility data were fitted using the regular solution theory to obtain the bulk pair interaction parameter. The mixing behavior of SDS with: i) benzyl acetate and citronellol is antagonistic; ii) linalool and geraniol is synergistic; iii) menthol is ideal. These findings support the practical application of VA–SDS mixtures.

References
[1] Danov et al., Colloids Surf. A 625 (2021) 126931
[2] Uzunova et al., JCIS Open 18 (2025) 100133

Acknowledgments
The authors are grateful for the financial support from the Project #KP-06-H79/4–05.12.2023 of BG FNI – MON. This research was funded by the European Regional Development Fund under the Operational Program “Scientific Research, Innovation, and Digitization for Smart Transformation 2021-2027”, Project BG16RFPR002-1.014-0005.

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