TY - JOUR

T1 - Solubilization of Nile Red in Micelles and Protomicelles of Sodium Dodecyl Sulfate

AU - Rusanov, Anatoly I.

AU - Movchan, T. G.

AU - Plotnikova, E.V.

N1 - Rusanov, A.I.; Movchan, T.G.; Plotnikova, E.V. Solubilization of Nile Red in Micelles and Protomicelles of Sodium Dodecyl Sulfate. Molecules 2022, 27, 7667. https://doi.org/10.3390/molecules27227667

PY - 2022

Y1 - 2022

N2 - A spectrophotometric study of the solubilization and aggregation of the Nile red dye (NR) in premicellar and micellar aqueous solutions of sodium dodecyl sulfate (SDS) was carried out. The experiments were conducted both with saturated solutions of NR under conditions of thermodynamic equilibrium of the solution with a dye precipitate, and at a constant concentration of NR in a homogeneous solution. In the first case, it was proved theoretically and verified experimentally that with an increase in the SDS concentration, the NR concentration always increases, and at the limit of low concentrations, the dependence is linear. In both cases, the concentration of NR dimers as a function passes through a maximum in the premicellar region. There are no dimers in the micellar region. The extinction coefficients of NR monomers in SDS solutions were determined both below and above the critical micelle concentration (CMC) of SDS. A solubilization curve with branches for the premicellar and micellar regions was constructed, the intersection of which was used to find the CMC value in the system under study. The state of deep supersaturation of the NR solution in the metastable state upon dilution of the micellar system with water was studied. It was found that, in addition to dimers, molecular aggregates of higher orders were also formed.

AB - A spectrophotometric study of the solubilization and aggregation of the Nile red dye (NR) in premicellar and micellar aqueous solutions of sodium dodecyl sulfate (SDS) was carried out. The experiments were conducted both with saturated solutions of NR under conditions of thermodynamic equilibrium of the solution with a dye precipitate, and at a constant concentration of NR in a homogeneous solution. In the first case, it was proved theoretically and verified experimentally that with an increase in the SDS concentration, the NR concentration always increases, and at the limit of low concentrations, the dependence is linear. In both cases, the concentration of NR dimers as a function passes through a maximum in the premicellar region. There are no dimers in the micellar region. The extinction coefficients of NR monomers in SDS solutions were determined both below and above the critical micelle concentration (CMC) of SDS. A solubilization curve with branches for the premicellar and micellar regions was constructed, the intersection of which was used to find the CMC value in the system under study. The state of deep supersaturation of the NR solution in the metastable state upon dilution of the micellar system with water was studied. It was found that, in addition to dimers, molecular aggregates of higher orders were also formed.

KW - Sodium dodecyl sulfate

KW - Nile red

KW - Solubilization

KW - adsorption

KW - surfactants

KW - Hydrophobic effect

KW - micelles

KW - protomicelles

KW - Nano-adsorbent

KW - MOLECULAR AGGREGATION

UR - https://www.mdpi.com/1420-3049/27/22/7667

M3 - Article

VL - 27

SP - 7667

JO - Molecules

JF - Molecules

SN - 1420-3049

IS - 22

ER -