Green Electrospun Membranes Based on Chitosan/Amino-Functionalized Nanoclay Composite Fibers for Cationic Dye Removal: Synthesis and Kinetic Studies

Abstract

Chitosan/poly(vinyl alcohol)/amino-functionalized montmorillonite nanocomposite electrospun membranes with enhanced adsorption capacity and thermomechanical properties were fabricated and utilized for the removal of a model cationic dye (Basic Blue 41). Effects of nanofiller concentrations (up to 3.0 wt %) on the morphology and size of the nanofibers as well as the porosity and thermomechanical properties of the nanocomposite membranes are studied. It is shown that the incorporation of the nanoclay particles with ∼10 nm lateral sizes into the polymer increases the size of the pores by about 80%. To demonstrate the efficiency of the adsorbents, the dye removal rate is investigated as a function of pH, adsorbent dosage, dye concentration, and nanofiller loading. The highest and fastest dye removal occurs for the nanofibrous membranes containing 2 wt % nanofiller, where about 80% of the cationic dye is removed after 15 min. This performance is at least 20% better than the pristine chitosan/poly(vinyl alcohol) membrane. The thermal stability and compression resistance of the nanocomposite membranes are found to be higher than those of the pristine membrane. In addition, reusability studies show that the dye removal performance of this nanocomposite membrane reduces by only about 5% over four cycles. The adsorption kinetics is explained by the Langmuir isotherm model and is expressed by a pseudo-second-order kinetic mechanism that determines a spontaneous chemisorption process. The results of this study provide a valuable perspective on the fabrication of high-performance, reusable, and efficient electrospun fibrous nanocomposite adsorbents.

Hybridization of Nanoclay with a Chromium‐Based Metal‐Organic Framework for Boosting Adsorption of Organic Dyes from Wastewater

“…Evaluations of surface charge by zeta potential (Figure 3c) have determined that the Clay-MOF composite is positively charged at all pH values (3)(4)(5)(6)(7)(8)(9)(10)(11). The surface charge gradually decreased from + 10.2 mV at pH 5 down to + 0.93 mV at pH 11.…”

“…Therefore, surface modification and/or hybridization of clay‐based adsorbent are vital issues for efficient wastewater treatment. Several attempts have also been conducted on the preparation of functionalized and composite clay structures with different materials such as dendritic nanostructures, [6] calcium alginate, [5] chitosan, [7,8] and nanoparticles [9] …”

“…[5] Therefore, surface modification and/or hybridization of clay-based adsorbent are vital issues for efficient wastewater treatment. Several attempts have also been conducted on the preparation of functionalized and composite clay structures with different materials such as dendritic nanostructures, [6] calcium alginate, [5] chitosan, [7,8] and nanoparticles. [9] Despite the significant enhancement in adsorption performance of clay-based composites, further surface modification seems necessary to expand the specific surface area and active sites to accomplish fast and highly efficient organic dye removal.…”

Fabrication of a novel magnetic rubidium ion-imprinted polymer for selective separation

“…Reusability is one of the crucial economic indexes for evaluating the industrial application of adsorbents. 45 Therefore, the stability and regeneration performance of the synthesized MIIP were studied through adsorption-desorption cycle tests. Briefly, 20 mg MIIP was dispersed in 50 mL 20 mg L À1 Rb + solution (pH = 10), and when the adsorption process was at equilibrium, MIIP was separated using an external magnet.…”

Environmentally Friendly Polyvinyl Alcohol−Alginate/Bentonite Semi-Interpenetrating Polymer Network Nanocomposite Hydrogel Beads as an Efficient Adsorbent for the Removal of Methylene Blue from Aqueous Solution

“…Nanoparticles based on clay minerals, have received extensive attention due to their remarkably low-cost, large abundance, high specific surface area, and good intrinsic adsorption characteristics [11,23,31]. Because of the anionic nature of the clay nanoparticles in aqueous media, a number of studies have been reported the efficacy of clay minerals for removing cationic dyes from wastewater [41,42]. Bentonite (Bent) is a naturally occurring clay that is composed tetrahedral Si layer and octahedral Al layer which are interlinked and contain reactive -OH groups.…”