Adsorption of Sodium Dodecyl Sulfonate from Aqueous Solution by Polyvinyl Butyral: Kinetics and Thermodynamics

Abstract

During the synthesis of polyvinyl butyral (PVB), sodium dodecyl sulfonate (SDS) is generally added in appropriate amounts, which prevents PVB from agglomeration but also causes PVB to turn yellow. The removal of SDS and its final residue in PVB are closely related to the adsorption performance of SDS on PVB. In this study, PVB with a high acetal degree (81.96 mol %) was synthesized by polyvinyl alcohol and butyraldehyde and was characterized by 1H NMR, Fourier transform infrared spectroscopy, scanning electron microscopyenergy-dispersive X-ray spectroscopy, and other methods. The adsorption properties of SDS on PVB were investigated under different initial pHs, PVB doses, PVB particle sizes, contact times, initial SDS concentrations, and temperatures. The adsorption kinetic data were analyzed using pseudo-first-order, pseudo-second-order, Elovich, and intraparticle diffusion models. The results showed that the pseudo-second-order model fitted the adsorption data well, and the intraparticle diffusion was not the only control mechanism for PVB adsorption. The equilibrium data were analyzed with Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich models. The results showed that the adsorption data conformed to the Langmuir model, and the maximum adsorption capacity of PVB for SDS was 40.5168 mg/g at 290.15 K. Moreover, the Dubinin–Radushkevich model illustrated that the adsorption process was chemisorption at low SDS concentrations and physical adsorption otherwise. The thermodynamic parameters showed that the adsorption of SDS on PVB was spontaneous and exothermic. In conclusion, the research results provide some basis for the PVB purification plant equipment.

Chaotropic Salt Dispersion Enables Room-Temperature Synthesis of High-Purity Polyvinyl Butyral

“…For purposes of comparative analysis, we also synthesized PVB powder by replacing NaSCN with conventional surfactants, exemplified by sodium dodecyl benzene sulfonate (SDBS), as a dispersant. Detailed information pertaining to this approach can be found in the “PVB Synthesis with Sodium Dodecyl Benzene Sulfonate” SI section, along with Video S1, in accordance with prior literature references. , The produced PVB is labeled as SDBS-B. Note that we designed the synthesis protocol using SDBS to compare it with that using NaSCN.…”

“…However, these surfactants can become permanently entrapped or entangled within the PVB granules. 21 The residual surfactants undermine hydrophobic interactions, leading to a decline in the strength and cohesion of the PVB membranes. Consequently, a massive volume of water is required for PVB rinsing (1 ton of PVB resins consumes 100 tons of water or even more), 18 resulting in the generation of significant waste emissions.…”

“…Detailed information pertaining to this approach can be found in the "PVB Synthesis with Sodium Dodecyl Benzene Sulfonate" SI section, along with Video S1, in accordance with prior literature references. 21,27 The produced PVB is labeled as SDBS-B. Note that we designed the synthesis protocol using SDBS to compare it with that using NaSCN.…”

“…Surfactants (such as sodium dodecyl benzene sulfonate or SDBS) are routinely introduced to emulsify the reaction system. However, these surfactants can become permanently entrapped or entangled within the PVB granules . The residual surfactants undermine hydrophobic interactions, leading to a decline in the strength and cohesion of the PVB membranes.…”