Modification Approaches to Enhance Dehydration Properties of Sodium Alginate-Based Pervaporation Membranes

Abstract

Transport characteristics of sodium alginate (SA) membranes cross-linked with CaCl2 and modified with fullerenol and fullerene derivative with L-arginine for pervaporation dehydration were improved applying various approaches, including the selection of a porous substrate for the creation of a thin selective SA-based layer, and the deposition of nano-sized polyelectrolyte (PEL) layers through the use of a layer-by-layer (Lbl) method. The impacts of commercial porous substrates made of polyacrylonitrile (PAN), regenerated cellulose, and aromatic polysulfone amide were investigated by scanning electron microscopy (SEM), atomic force microscopy (AFM), standard porosimetry method, and water filtration. The effects of PEL combinations (such as poly(sodium 4-styrene sulfonate) (PSS)/SA, PSS/chitosan, PSS/polyacrylic acid, PSS/poly(allylamine hydrochloride)) and the number of PEL bilayers deposited with the Lbl technique on the properties of the SA and SA/fullerene derivative membranes were studied by SEM, AFM, and contact angle measurements. The best characteristics were exhibited by a cross-linked PAN-supported SA/fullerenol (5%) membrane with five PSS/SA bilayers: permeation flux of 0.68–1.38 kg/(m2h), 0.18–1.55 kg/(m2h), and 0.50–1.15 kg/(m2h), and over 99.7, 99.0, and 89.0 wt.% water in the permeate for the pervaporation dehydration of isopropanol (12–70 wt.% water), ethanol (4–70 wt.% water), and tetrahydrofuran (5.7–70 wt.% water), respectively. It was demonstrated that the mutual application of bulk and surface modifications essentially improved the membrane’s characteristics in pervaporation dehydration.

Novel Mixed Matrix Membranes Based on Polyphenylene Oxide Modified with Graphene Oxide for Enhanced Pervaporation Dehydration of Ethylene Glycol

“…The data in Table 1 demonstrate that the PPO/GO (0.1%) and PPO/GO (0.3%) membranes have comparatively the same values of surface roughness within the margin of error, compared to the pristine PPO membrane due to a low GO content in the polymer matrix. Notably, the difference in the surface roughness values (Ra and Rq) of these membranes (PPO, PPO/GO (0.1%), and PPO/GO (0.3%)) did not exceed even 0.8 nm [53]. Only the introduction of GO above 0.5 wt.% significantly increased surface parameters, making it possible to clearly evaluate the contribution of the modification to the change in the membrane surface.…”

Recovery of Model Pharmaceutical Compounds from Water and Organic Solutions with Alginate-Based Composite Membranes

“…As a result, the membranes based on cross-linked sodium alginate were successfully utilized for separation of water and organic media including pervaporative dehydration of various solvents (alcohols, acetic acid, dioxane, tetrahydrofuran, etc.) [10,11,[17][18][19][20][21][22][23][24], as the electrolyte material in the methanol fuel cells [25][26][27], aqueous nanofiltration [28][29][30], and very recently for organic solvent nanofiltration [10,31]. The advantage of natural polymers over the synthetic polymers is their biodegradability which simplifies their utilization from an environmental point of view.…”

Novel Polyelectrolyte Complex Membranes Containing Carboxymethyl Cellulose–Gelatin for Pervaporation Dehydration of Azeotropic Bioethanol for Biofuel

“…To obtain the high value of water permeation and selectivity, it is necessary to use polymers with high sorptive centers capable of specific interactions with water [ 11 , 12 , 13 ]. Some of the polymers, such as poly (acrylic acid) [ 14 , 15 ], poly (vinyl alcohol) [ 16 , 17 ], sodium alginate [ 18 ], hydroxyethyl cellulose [ 19 ], chitosan [ 20 , 21 ], and NaCMC have been recently applied for the fabrication of PV membranes. Among these membrane materials, NaCMC is a highly significant cellulose derivative; it is safe, non-toxic, biocompatible, and biodegradable.…”