Fabrication of Cellulose Nanocrystal-g-Poly(Acrylic Acid-Co-Acrylamide) Aerogels for Efficient Pb(II) Removal

Abstract

In this work, cellulose nanocrystals (CNCs) obtained by the acid hydrolysis of waste bamboo powder were used to synthesize cellulose nanocrystal-g-poly(acrylic acid-co-acrylamide) (CNC-g-P(AA/AM)) aerogels via graft copolymerization followed by freeze-drying. The structure and morphology of the resulting aerogels were characterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM), and the CNC-g-P(AA/AM) aerogels exhibited excellent absorbent properties and adsorption capacities. Subsequent Pb(II) adsorption studies showed that the kinetic data followed the pseudo-second-order equation, while the adsorption isotherms were best described using the Langmuir model. The maximum Pb(II) adsorption capacity calculated by the Langmuir model reached up to 366.3 mg/g, which is a capacity that outperformed that of the pure CNC aerogel. The CNC-g-P (AA/AM) aerogels become structurally stable through chemical cross-linking, which enabled them to be easily regenerated in HCl solution and retain the adsorption capacity after repeated use. The aerogels were found to maintain 81.3% removal efficiency after five consecutive adsorption–desorption cycles. Therefore, this study demonstrated an effective method for the fabrication of an aerogel adsorbent with an excellent reusability in the effective removal of Pb(II) from aqueous solutions.

Irreversible and Self-Healing Electrically Conductive Hydrogels Made of Bio-Based Polymers

“…Bagheri et.al [ 69 ] first prepared hydrogel by the polymerization of acrylic acid in the presence of carboxymethyl cellulose (CMC), a small amount of a cross-linker, and ammonium persulfate (APS) as an initiator ( Figure 10 ). Since the formed sulfate anion radicals can trap the hydrogen from the hydroxyl groups of the CMC, grafting of the acrylic acid onto CMC can occur as well during the polymerization and, thus, it is directly chemically incorporated into the hydrogel structure [ 21 ]. The CMC hydrogel was immersed into aniline solution which was polymerized by ammonium persulfate and doped by hydrochloric acid.…”

“…Accordingly, hydrogels can absorb water up to as much as 1000 times of its dry weight owing to the hydrophilic functional groups in the polymer, but do not dissolve owing to the cross-links between the polymer chains [ 18 ]. Synthetic polymers such as poly(vinyl alcohol) [ 19 ], poly(ethylene oxide) [ 20 ], poly(ethylene glycol), and poly(acrylamide) [ 21 ] can form hydrogels as well with higher mechanical strength than that of natural polymers. However, natural polymers are still preferred due to their biocompatibility and biodegradability.…”

Wood‐Derived Functional Polymeric Materials

“…The balance between the modification and native self‐assembly ability of CNCs needs to be considered when designing more complex structures. In terms of polymeric modification, [ 90 ] although controlled/living polymerization has been used to functionalize CNCs, [ 91 ] there are few studies to utilize the obtained CNCs to prepare aerogels. [ 92 ] This may provide a new way to fabricate CNCs aerogels when structures, properties and functional groups of grafted polymers are carefully decided.…”

The New Approach to the Preparation of Polyacrylamide-Based Hydrogels: Initiation of Polymerization of Acrylamide with 1,3-Dimethylimidazolium (Phosphonooxy-)Oligosulphanide under Drying Aqueous Solutions

“…Linear and crosslinked polyacrylamide, as well as acrylamide copolymers, are of significant applied interest and are used in water treatment [ 1 , 2 , 3 ], enhanced oil recovery (EOR) technologies [ 3 , 4 , 5 , 6 ], stabilization of nanoparticles [ 7 , 8 , 9 ], electrophoresis-induced separation and purification of substances [ 10 ], and adsorption removal of Pb 2+ ions from aqueous solutions [ 11 ]. The biocompatibility and hydrophilicity of polyacrylamide have ensured its wide application in biomedical fields [ 12 ], including in systems of pharmacologically active substance delivery [ 13 ] and the binding of toxins [ 14 ].…”