Encapsulation of triclosan within 2-hydroxypropyl–β–cyclodextrin cavity and its application in the chemisorption of rhodamine B dye

Presence of organic micro-pollutants in aquatic ecosystems is a major concern in public health. Designing effective strategies to remove organic pollutants are subject of intense research interests. Rhodamine B (Rb), a widely used stain in textile, food industries and biomedical laboratories, is highly cytotoxic and induce oxidative stress, hormonal imbalance and apoptosis. Thus devising an effective strategy for Rb removal from aquatic environment is an urgent need. Present study demonstrates the applicability of triclosan (TR)-2-hydroxypropyl–β–cyclodextrin (HP–β–CD) inclusion complex to effectively adsorb rhodamine B (Rb) from aqueous solution. Triclosan readily incorporates into HP–β–CD cavity and the calculated binding constant is 230.5 M−1. Both solid and solution state complexes have been prepared and detailed characterization have been carried out using fluorescence spectroscopy, MALDI–TOF, FT–IR, 1H NMR, XRD, FT-Raman and SEM methods. The TR:HP–β–CD complex exhibits excellent ability to remove Rb from aqueous solutions with maximum adsorption efficiency of 261.78 mg/g. The adsorption process is a pseudo-second order reaction. Adsorption isotherm analysis reveals that the isotherm data are well fitted to the Langmuir adsorption model. Details of the isotherm analysis reveal that the adsorption take place at specific homogeneous sites where the adsorbent forming monolayer coverage of Rb at the surface of the TR:HP–β–CD complex.