Affinity characteristics of neutral and anion exchange polymer resin adsorbents for main components in a simulated biomass hydrolysate

An interpenetrating polymer networks based on polydivinylbenzene/aminated polyglycidyl methacrylate with better decolorization performance toward reducing sugar solution

The separation of valuable sugar components from a xylose mother liquor (XML) requires a pre-decolorization over a resin, however the market-available resins show a low performance. To overcome this drawback, an interpenetrating polymer network (IPN) resin was designed for efficiently removing the non-sugar impurities from an XML. The prepared IPN resin showed good decolorization performance for the XML, and the decolorization effect of the XML on the resin modified with a short-chain amination reagent was better. The adsorption capacity of the resin for phenols was significantly improved after an amination-modification, but that for furfural remained constant. The theoretical study confirmed that good decolorization effect of the XML on that resin was mainly ascribed to the synergistic action of adsorption forces, such as π-π stacking and hydrogen bonding.

Preparation of boronic acid and carboxyl-modified molecularly imprinted polymer and application in a novel chromatography mediated hollow fiber membrane to selectively extract glucose from cellulose hydrolysis

A novel boronic acid and carboxyl-modified glucose molecularly imprinted polymer (glucose-MIP) was prepared through suspension polymerization, which is based on 1.0 mmol glucose as a template, 1.2 mmol methacrylamidophenylboronic acid, and 6.8 mmol methacrylic acid as monomers, 19 mmol ethyleneglycol dimethacrylate, and 1 mmol methylene-bis-acrylamide as crosslinkers. The prepared glucose-MIP had a particle size of 25-70 μm, and was thermally stable below 215°C, with a specific surface area of 174.82 m^2. g^-1 and average pore size of 9.48 nm. The best selectivity between glucose and fructose was 2.71 and the maximum adsorption capacity of glucose-MIP was up to 236.32 mg^. g^-1 which was consistent with the Langmuir adsorption model. The similar adsorption abilities in 6 successive runs and the good desorption rate (99.4%) verified glucose-MIP could be reused. It was successfully used for extracting glucose from cellulose hydrolysis. The adsorption amount of glucose was 2.61 mg^. mL^-1 and selectivity between glucose and xylose reached 4.12. A newly established chromatography (glucose-MIP) mediated hollow fiber membrane method in time separated pure glucose from cellulose hydrolysates on a large-scale, and purified glucose solution with a concentration of 3.84 mg^. mL^-1 was obtained, which offered a feasible way for the industrial production of glucose from cellulose hydrolysates. This article is protected by copyright. All rights reserved.

Enhanced removal of Cr(VI) by cation functionalized bamboo hydrochar

Chemical modification on hydrochars can significantly improve their ability of removing heavy metal ions from wastewater, but so far no research has focused on the chemical modification through free radical reaction. In this work, a cation functionalized hydrochar (CFHC) bearing - N⁺H₂R was synthesized by grafting-polymerization of glycidyl methacrylate (GMA) onto bamboo hydrochar under initiation by benzoyl peroxide, followed by the amination with the introduced epoxy group and diethylenetriamine and a subsequent hydrochloric acid treatment. The resulted CFHC exhibited a superior removal capacity of 424.09 mg·g^-1 for Cr(VI), and the highest sorption occurred at pH of 2. Combining a series of characterizations and tests, it was concluded that the sorption conformed to the pseudo-second-order and Freundlich equations, indicating a multilayer chemisorption process that mainly driven by electrostatic reaction, reduction, and surface complexation. This research proved that a free radical polymerization treatment could effectively transform hydrochars into super adsorbents for wastewater treatment.