Li, Ying; Du, Na; Song, Shue; Hou, Wanguo published the artcile< Adsorption of Cetylpyridinium Chloride at Silica Nanoparticle/Water Interfaces (I): Dependence of Adsorption Equilibrium on Particle Size>, SDS of cas: 123-03-5, the main research area is adsorption cetylpyridinium chloride silica nanoparticle size water interface equilibrium.
In the current work, a size-effect model was developed to describe the particle size-dependence of adsorption at solid/liquid interfaces. A parameter, ΔQad, was introduced, defined as the change of the product of the solid/liquid interfacial tension and the molar volume of solid surface components caused by adsorption. The model predicts that with a decrease in particle radius (r), the saturation adsorption amount per unit area (Γm, mol/m2) decreases, while the change of the adsorption equilibrium constant (Kad) is determined by the ΔQad, namely, it decreases if ΔQad > 0 but increases if ΔQad < 0. There exists a critical r at which the saturation adsorption amount per unit mass (Γmg, mol/g) attains a maximum In addition, the adsorption of cetylpyridinium chloride (CPyCl), a cationic surfactant, on silica nanoparticles with different r (ca. 6-61 nm) values was determined at 298 K and pH 9, showing an obvious size-dependence. With a decrease in r, Kad and Γm decrease, indicating a decrease in the affinity of silica particles toward CPyCl. The size-dependent adsorption data can be well described using our model. Adsorption can affect the molar volume of the solid surface phase, which plays an important role in the size-dependence of adsorption. This work provides a better understanding of the size-dependent adsorption phenomenon at solid/liquid interfaces. Langmuir published new progress about Adsorption. 123-03-5 belongs to class pyridine-derivatives, and the molecular formula is C21H38ClN, SDS of cas: 123-03-5.