Enhanced selective adsorption of cation organic dyes on polyvinyl alcohol/agar/maltodextrin water‐resistance biomembrane

Abstract

In this study, we designed a novel hydrogel composite membrane based on the combination of polyvinyl alcohol (PVA), agar, and maltodextrin through a facile solution‐casting router. From Fourier‐transform infrared spectroscopy, contact angle, scanning electron microscopy, and swelling analyses, the formation of hydrogen bonds between surface functional groups of PVA, agar, and maltodextrin was confirmed. As a result, the PVA/agar/maltodextrin membranes exhibited a more hydrophobic nature compared with pure PVA. The thermal stability and integrity of such obtained composite membranes were also elucidated by the evaluation of thermogravimetric analysis and mechanical behavior. Besides, the composite membrane exhibited high selective adsorption for cationic dyes, namely 20.2 mg g−1 for methylene blue and 19.17 mg g−1 for crystal violet at initial dye concentration of 100 mg/L, an adsorbent dosage of 0.1 g, contact time of 180 min, and solution pH 7, while anionic dyes such as congo red and methyl orange are approximately zero. The adsorption kinetics and isotherm of the as‐prepared composite membranes were well fitted to the pseudo‐second‐order and Temkin model. The effect of factors, including contact time, solution pH, PVA content, and initial dye concentration on the adsorption capacity of the as‐prepared composite membrane was also investigated in detail. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 137, 48904.

Agar-reduced graphene oxide selectively adsorbs organic dyes and strengthens double-network hydrogels

“…The signal intensity assigned to RhoB attenuated by 90% aer 12 h whereas the signal intensity assigned to MO remained relatively constant. Adsorbed RhoB was later recovered by soaking the loaded ArGO paper in ethanol for 1 h. The selectivity may stem from charge complementarity as the cationic (ammonium) groups in RhoB should exhibit a stronger attraction to the anionic (carboxylate) groups present in the ArGO, 35,51 particularly when compared to the anionic (sulfonate) groups found in MO. The RhoB adsorption capacity of the ArGO lm was measured to be 39.6 mg g À1 .…”

Theoretical and Experimental Optimization of the Graft Density of Functionalized Anti-Biofouling Surfaces by Cationic Brushes

“…Grafting PU with cationic brushes resulted in a significantly reduced WCA. Therefore, grafted PU became hydrophilic because of the presence of hydrophilic functional groups on the ends of the molecules of the cationic brushes [ 48 ]. Additionally, the WCA decreased as the grafting degree increased.…”

Facile preparation of agaraldehyde chitosan‐based composite beads as effectual adsorbent especially towards amido black

“…27 These findings encourage us to synthesize functional agar derivative with anionic moieties suitable for electrostatic interaction with cationic molecules/ polymers such as CHI. In literature, many agar-based composite or hybrid adsorbents such as polyvinyl zeolitic imidazolate/carbon nitride/agar composite, 28 alcohol/agar/maltodextrin composite, 29 agar/monometallic or bimetallic nanoparticle composite, 30 g-C3N4/agar composite, 31 and agar-carrageenan 32 were prepared and utilized for the dye removal from water. On other hand, no agar and its anionic derivatives are utilized for the preparation of beads with CHI as adsorbent to remove the dyes from water.…”