Cotton as Precursor for the Preparation of Porous Cellulose Adsorbers

Abstract

Natural biopolymer‐based porous spherical adsorbers from cellulose have good efficiency for removal of metal ion pollutants from aqueous media. However, high purity celluloses, most commonly used as precursors for preparation of the adsorber spheres, require complex synthesis processes, which consume energy and chemicals, and may thus lead to other types of pollution. In this work, the possibility to prepare cellulose‐based porous spherical adsorbers directly from cotton, using an ionic liquid‐based platform is analyzed in detail. The dissolution of microcrystalline cellulose (MCC), as reference, and of cotton in ionic liquid‐based solvents and the properties of the obtained polymer solutions are investigated in order to evaluate their processability toward porous macrospheres using the drop shaping cum non‐solvent induced phase separation process. The properties of the prepared spheres are assessed. The dissolution of cotton is more difficult than the dissolution of MCC and the formed cotton‐based solutions are considerably more viscous, which makes their processability possible only after careful adjustment of the cotton solution concentration. The maximum adsorption capacities toward Cu2+ are ≈110 and ≈72 mg/g for the porous cotton‐based spheres prepared from 1‐ethyl‐3‐methylimidazolium acetate ([Emim][OAc]):dimethylsulfoxide (DMSO) = 2:1 and 1‐butyl‐3‐methylimidazolium acetate ([Bmim][OAc]):DMSO = 2:1 solutions, respectively.

Preparation of Hydrogels Based Radix Isatidis Residue Grafted with Acrylic Acid and Acrylamide for the Removal of Heavy Metals

“…At present, biosorbents from natural by-product materials (such as cellulose [19], chitosan [20], keratin [21,22], zeolite and clay [23]), are potential options because of their widely avaiable resources, eco-friendliness, biocompatibility, and low cost. Cellulose, a natural macromolecular compound and one of the most abundant renewable resources in nature, mainly comes from plants sources such as Chinese herbal residue [24], bamboo [25], cotton straw [26][27][28], sawdust [29], nutshell [30], and Napier grass [31], which has the characteristics of high toughness, biocompatibility, biodegradability [32], and excellent adsorptivity for heavy metals. Furthermore, several studies have reported the excellent performance of biosorbents-based cellulose for the removal of heavy metal ions (such as mercury, lead, cadmium, and copper) in wastewater [6,10,15].…”

Antioxidant activity and controlled‐release feature of Quercetin loaded amines‐functionalized magnetically porous cellulose

“…Transformation of cellulose fiber into porous cellulose (PC) microstructure is also an interesting strategy to improve its physicochemical as well as textural properties as a potential drug carrier. Synthesis of PC can be achieved by a soft‐templating method, generally using a surfactant in a water/oil system as reported elsewhere 34–36 . Fundamentally, the cellulose solution was converted into beads or spherical particles by precipitation or introducing a cross‐linking agent on the water/oil system to interconnect the cellulose polymer chains which generated amorphous and porous structures.…”

“…Synthesis of PC can be achieved by a soft-templating method, generally using a surfactant in a water/oil system as reported elsewhere. [34][35][36] Fundamentally, the cellulose solution was converted into beads or spherical particles by precipitation or introducing a crosslinking agent on the water/oil system to interconnect the cellulose polymer chains which generated amorphous and porous structures. In this regards, Du and co-worker successfully prepared PC through a cross-link reaction of cellulose solution mediated by epichlorohydrin which produced spherical particles with BET surface area (S BET ) of 42.79 m 2 /g.…”