Stepan is Presenting at AOCS 2025!
April 7, 2025
Members of Stepan's Research and Development team are headed to Portland, Oregon for the 2025 AOCS Annual Meeting and Expo. This event is considered to be the premier international science and business forum on fats, oils, surfactants, proteins, and related materials.Our team looks forward to connecting with other industry experts and and sharing more about how Stepan's robust product portfolio can help deliver innovative, market-ready solutions.
This year, we also hope that you join our team for their technical presentations occurring throughout the Expo.
Explore full presentation details and abstracts here:
Enhancing Microbial Formulations: Improved Suspension and Bio-compatibility Between Microbial Spores and Surfactants
Monday, April 28, 2025 10:35 AM – 10:55 AM PST Room: B110-112
Presenting Author(s) - Sangwook Lim, PhD (he/him/his), Senior Research Chemist Lead, Stepan Company, Northfield, Illinois, United States
Co-Author(s) - Ron A. Masters, Research Fellow, Stepan Company, Northfield, Illinois, United States and Alexander Nikoloff, Senior Microbiologist, Stepan Company, United States
Abstract:
In recent years, formulations combining microbial spores and surfactants have gained popularity in various markets, including agriculture, consumer products, fermentation, bioremediation, and oil-field, due to the enhanced performance expected from microbial activity. Specifically, microbial enhanced formulations (MEFs) containing microbial spores have demonstrated long-lasting and sustainable performance by digesting undesired chemicals or organic materials, delivering desired outcomes (e.g., microbial enhanced cleaners). However, the use of microbial spores with surfactants is often limited due to the potential inhibition of spores in the presence of surfactants and issues related to sedimentation over time. This study introduces a formulation approach to overcome these challenges, ensuring compatibility, improving stability of MEFs, and driving a synergy between surfactants and biologics. Detailed studies reveal a novel method to overcome the incompatibility between various surfactants and microbial spores, rheological approach to ensure the physical stability of MEFs, and practical evaluation of the enhanced performance. Several case studies demonstrating the successful integration of surfactants and microbial spores are presented. The findings highlight the importance of surfactant self-assembly in MEFs and demonstrate the superior performance of MEFs compared to traditional formulations. This research paves the way for the development of more effective and sustainable products in agriculture and consumer markets.
Optimizing Amino Acid Surfactant Formulations: A Systematic Approach
Tuesday, April 29, 2025 4:35 PM – 4:55 PM PST Room: B113
Presenting Author(s) - Rachel Lang, Functional Chemist, Stepan Company, Northfield, Illinois, United States
Co-Author(s) - Sangwook Lim, PhD (he/him/his), Senior Research Chemist Lead, Stepan Company, Northfield, Illinois, United States
Abstract:
Amino acid surfactants (AAS) have emerged as environmentally friendly alternatives to traditional petroleum-based surfactants. In the consumer industry, formulators are rapidly adopting AAS to replace Sodium Lauryl Ether Sulfate (SLES) in response to market trends and shifting consumer behavior. However, AAS cannot simply replace SLES due to challenges in achieving the desired viscosity, as they do not respond well to salts like sodium chloride (NaCl) and are sensitive to pH changes.
Recent studies suggest that formulating at the pKa of AAS and adding nonionic co-surfactants (such as fatty alcohols and fatty acids) can help overcome these challenges. Despite this, there remains a need for a comprehensive understanding and systematic approach to determine the factors that influence the viscosity of AAS-based formulations across various applications.
In this research, we systematically study the effects of various nonionic dialkyl and dialkene amides as additives in AAS-based formulations. We focus on the impact of structural factors, including double bonds, branching, and chain length, on the viscosity response of AAS-based formulations. This study includes the different responses of several AAS, such as sodium lauroyl sarcosinate, sodium cocoyl glutamate, and sodium cocoyl methyl taurate, to these nonionic additives.
These findings highlight the critical role of structural factors in understanding the viscosity responses of AAS-based formulations. Our research provides formulators with practical guidelines for future product development, ensuring that their formulations meet desired performance parameters.
Application of HLD Framework to the pH-Dependent Behavior of Amino Acid Surfactants
Tuesday, April 29, 2025 10:55 AM – 11:15 AM PST Room: B10-112
Presenting Author(s) - Gregory P. Dado, PhD (he/him/his), Technical Director, Stepan Company, Northfield, Illinois, United States
Co-Author(s) - Rachel Lang, Functional Chemist, Stepan Company, United States
Abstract:
With consumer demands for cleansing products that are safe and effective, together with preferences for products free of label ingredients such as sulfates, amino acid-derived surfactants play an important role in the personal care product formulator’s toolbox. One of the challenges of effectively formulating with these surfactants is their strong pH-dependent behavior, a consequence of surfactant head group equilibration between ionized (anionic) and protonated (nonionic) forms. In this presentation, we report on our efforts to apply the HLD framework to the description and characterization of pH-dependent viscosity in aqueous amino acid surfactant formulations. Using n-alkane as a proxy for the hydrophobic interior of low-curvature aggregated states, acid-base titration of surfactant-oil-water (SOW) systems has been conducted to identify system HLD = 0 conditions via phase inversion (O/W → W/O emulsions) and microemulsion formation. In the case of sodium lauroyl sarcosinate in 1% aqueous NaCl and n-octane, phase inversion has been found to occur at about 67 mol% acidulation of COO-Na+, corresponding to an approximately 2:1 molar ratio of nonionic to anionic form of the sarcosinate surfactant. SOW phase inversion endpoints have been observed to shift toward increasing mole fraction of acidified form (COOH) with increasing oil EACN. The addition of cetyl betaine or cocamidopropyl hydroxysultaine co-surfactant has been found to have no significant effect on phase inversion endpoint, indicating that these amphoteric surfactants have comparable hydrophobicity to each other and to the state of sarcosinate surfactant at HLD = 0. This conclusion is further supported by observations for surfactant-water (SW) systems without added oil, where lauroyl sarcosinate formulations with and without added amphoteric surfactant display comparable evolution of phase behavior and rheological properties over the course of titration. This methodology has been extended to additional co-surfactants to map the effects of surfactant hydrophobicity on pH-dependent formulation viscosity.