A series of alkyl β‐d‐galactopyranosides were prepared by the trichloroacetimidate method with d‐galactose and alcohols with different chain lengths as raw materials. Their solubility, surface tension, emulsification, foaming, wettability, thermotropic liquid crystalline properties, and thermal stability were investigated. Alkyl β‐d‐galactopyranosides are soluble in water and ethanol, and the solubility decreases with increasing alkyl chain length. Decyl β‐d‐galactopyranoside was insoluble in water, but soluble in ethanol. Dissolution of alkyl β‐d‐galactopyranoside in water is an endothermic process with dissolution enthalpies greater than zero. Nonyl β‐d‐galactopyranoside had an excellent emulsifying property, better foaming ability and the best foam stability. The CMC values of alkyl β‐d‐galactopyranosides decrease with increasing of alkyl chain length. Alkyl β‐d‐galactopyranosides are thermally stable up to 270 °C. Alkyl β‐d‐galactopyranosides show the distinctive optical texture of a thermotropic liquid crystal smectic A type phase. Decyl β‐d‐galactopyranoside showed the strongest wettability.

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Alkyl β‐D‐maltosides are an important class of sugar‐based nonionic surfactants and have been widely studied. Nevertheless, it is still necessary to investigate further their amphiphilic structure‐surface property relationships. In this article, we reported a series of properties of synthetic alkyl β‐D‐maltosides (6a–6i, n = 6–18) including their hydrophilic–lipophilic balance (HLB) number, water solubility, hygroscopicity, moisture‐retention capacity, foaming ability, surface tension, thermotropic phase behavior, and skin irritation. Their HLB number and water solubility decreased with increasing alkyl chain length. Hexyl β‐D‐maltoside exhibited the strongest hygroscopicity and moisture‐retention capacity. Decyl β‐D‐maltoside and dodecyl β‐D‐maltoside possessed excellent foaming power and foaming stability. Furthermore, the critical micelle concentration (CMC) of alkyl β‐D‐maltoside (6a–6g, n = 6–14) and their surface tension at CMC decreased with increasing alkyl chain length. At last, alkyl β‐D‐maltosides (6a–6g) should be considered as safe surfactants by the skin irritation assessment.