A Novel Hydrate Form of Sodium Dodecyl Sulfate and Its Crystallization Process

Abstract

A novel hydrate form of sodium dodecyl sulfate (SDS) was firstly discovered through a hydrate screening with the use of organic solvents, while SDS is generally prepared solely in aqueous media. Surprisingly, a novel SDS hydrate form with needle-shaped crystals produced by adding acetonitrile to a 20 wt % SDS aqueous solution at a ratio of 3:1 (v/v) and further cooling to around 5 °C could be found with a trace amount in one of the two purchased SDS products that we examined. After comprehensive solid-state characterizations by powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA), Fourier transform infrared (FTIR), Raman spectroscopy, dynamic vapor sorption (DVS), and elemental analysis (EA), it is also successfully made directly from the synthesis of SDS through esterification and saponification. Four times the equal proportion of acetone was added into the reaction solution at an interval of 5 min to separate the side product, sodium sulfate, from the mother liquor. The desired novel hydrate form of SDS was then obtained by cooling the filtered mother liquor to 5 °C and aged for 8 h for a preferential growth.

Effect of sodium dodecyl sulfate on shape‐memory properties of side‐chain crystalline hydrogel via micellar copolymerization

“…In a given region or composition, those forms could interconvert from one another depending on the stability of thermodynamic. 23,24 In a low temperature, for SDS, some significant peaks were detected at the position of q = 1.64, 3.26, 4.90 nm À1 and 2θ = 20.2, 20.4, 21.5 , these values implied that SDS presented a 1/8H 2 O hydrated crystal structure. When the temperature exceeded 80 C, there was a change of SDS in structure, as shown in the Figure 7.…”

“…It had several hydrate forms, such as anhydrous form, 1/8 hydrate, hemihydrate, monohydrate and dihydrate depending on the different temperature and concentration. In a given region or composition, those forms could interconvert from one another depending on the stability of thermodynamic 23,24 . In a low temperature, for SDS, some significant peaks were detected at the position of q = 1.64, 3.26, 4.90 nm −1 and 2 θ = 20.2, 20.4, 21.5°, these values implied that SDS presented a 1/8H 2 O hydrated crystal structure.…”

“…It could occur several hydrate forms, such as anhydrous form, 1/8 hydrate, hemihydrate, monohydrate and dihydrate depending on the different temperature and concentration. In a given region or composition, those forms could interconvert from one another depending on the stability of thermodynamic 23,24 . At the same time, its hydrophobic group had similar structures with the hydrophobic monomer such as octadecyl acrylate used in the micellar copolymerization, so it was unknown that whether SDS crystalline structure will have an effect on shape‐memory properties of hydrogels.…”

Green and Strategic Approach for Chiral Resolution by Diastereomeric Salt Formation: The Study of Racemic Ibuprofen

“…Recrystallization is usually performed right after forming diastereomeric salt solids having an inadequate or unqualified %de. As temperature cooling and antisolvent addition are two preferred methods for solution crystallization, , they are, respectively, suitable for situations where significant differences in the solubility of two diastereomers exist in a certain temperature range and in different solvent compositions (mixed solvents). Besides, solvent properties, handling/disposal after use, and impacts on the environment should be taken into account.…”

Crystallization of Form II Paracetamol with the Assistance of Carboxylic Acids toward Batch and Continuous Processes

“…Polymorphism is a common phenomenon in which a substance exists in multiple ordered structures with different packing or conformational arrangements [ 1 , 2 ]. The diversity in molecular arrangements gives rise to various physicochemical properties, such as solubility, dissolution rate, stability [ 3 ], hygroscopicity [ 4 ], morphology [ 5 ], color [ 6 ], and taste [ 7 ]. Those properties are associated with the process and product performance.…”