INFORM February 2026

26 INFORM FEBRUARY 2026 , VOL. 37, NO. 2

formation. As a result, S8 assembles into shorter, less connected crystallites. Optical microscopy and XRD further support these distinctions. Under polarized light, M8 gels display dense, micrometer-scale fibrous networks, whereas S8 shows dispersed needle-like microcrystals. XRD analysis reveals that M8 exhibits larger layer spacing (around 2.9 nanometers) compared with S8 (about 2.4 nanometers), indicating different packing periodicities within the crystalline domains. Thus, a stereochemical difference of the hydroxyl group at one carbon influenced the self-assembly of the molecules. Understanding these differences is crucial for selecting appropriate stereoisomers to structure or solidify oils to obtain desired properties. OIL-IN-WATER EMULSION Emulsions are part of our everyday life, found in products such as milk, salad dressings, ice cream, mayonnaise, creams, and lotions. Emulsions are a mixture of two immiscible liquids in which one liquid, the dispersed phase, is broken into tiny droplets and distributed throughout the other liquid, the continuous phase. Emulsions are generally categorized into two types: oil-in water (O/W) emulsion (milk and

mayonnaise) and water-in-oil (W/O) emulsion (butter and margarine). To form stable emulsions, where the droplets resist coalescence and phase separation, emulsifiers (or stabilizers) are essential. An emulsifier typically contains both hydrophilic and lipophilic regions, allowing it to sit at the oil-water interface and prevent droplet coalescence. By lowering the interfacial The comparative study of the two sugar-based stereoisomeric gelators, M8 and S8, highlights the profound influence of stereochemistry on molecular self-assembly and material behavior. tension and forming a protective barrier around droplets, they prevent merging and help maintain long-term stability. By employing S8 and M8, we investigated their emulsification efficiency. Water-in-oil emulsions were prepared by first dissolving the required amount of gelator (M8 or S8) in the oil by heating. Once fully dissolved and the solution became clear, a measured volume of water was slowly added to the oil while stirring. Upon cooling to room temperature, the dissolved M8 or S8 molecules began to aggregate through hydrogen bonding and

van der Waals interactions and self-assembled into nanofibers or microcrystals at the oil-water interface. Both M8 and S8 successfully produced W/O emulsions that remained stable for weeks to months. However, their efficiencies differed markedly. M8 could only emulsify up to 30 percent water by volume, with emulsions stable for few weeks. In contrast, S8

accommodated nearly 60 percent water, forming emulsions that remained stable for several months. Optical microscope images of these emulsions revealed that in S8 stabilized emulsions, shorter, hair-like fibers densely

coated the droplet surfaces, forming a continuous shell (see page 25 image). This behavior can be attributed to the intramolecular hydrogen bonding between the hydroxyl groups of C2 and C4 leading to the formation of short fibers due to the competition between intra- and inter-molecular hydrogen bonding. In M8, since the orientation of the hydroxyl group at C2 does not facilitate the intramolecular hydrogen bonding, long, rigid fibers tended to remain in the oil bulk, creating a 3D network rather than wrapping individual water droplets. This explains M8’s lower emulsification capacity and shorter stability. Understanding these interactions and