A pH-sensitive composite hydrogel based on sodium alginate and medical stone: Synthesis, swelling, and heavy metal ions adsorption properties

Abstract

New pH-sensitive composite hydrogels were synthesized by free-radical graft copolymerization among sodium alginate (NaAlg), sodium acrylate (NaA), and medical stone (MS). Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM), tronsmission electron microscopy (TEM), and thermogravimetric analysis (TGA) analyses confirmed that NaA was grafted onto the NaAlg chains and MS participate in polymerization by its active silanol groups, and the surface morphologies and thermal stability was clearly improved after incorporating MS. The swelling capacity and rate of the hydrogel were clearly enhanced by introducing MS, and the intriguing deswelling in gelatin solution and "overflowing" behaviors in dimethyl sulfoxide (DMSO) and glycerin solutions were observed. In addition, the composite hydrogels exhibited excellent adsorption capacity on heavy metal ions, which enhanced the adsorption of Ni 2+ , Cu 2+ , Zn 2+ and Cd 2+ ions by 10.4, 8.0, 23.0, and 14.3 fold compared to active carbon (AC), and by 17.3, 16.0, 38.3 and 23.8 fold compared to MS, respectively. The biopolymer-based composite hydrogel can be used as a potential water-saving material and candidate of AC for heavy metal removal.

Nanocomposite Hydrogels and Their Applications in Drug Delivery and Tissue Engineering

“…Natural polymers, i.e., alginate and methyl cellulose, have been used for the preparation of clay NC gels. 16 poly(ethylene oxide)-block-poly(propylene oxide)-blockpoly(ethylene oxide), 18 and poly(trimethylene carbonate) -block-PEG-block-poly(trimethylene carbonate), 19 NC gels with good biocompatibility and enhanced mechanical properties can be fabricated without sacrificing their biocompatibility. In addition, the incorporated clay nanoparticles might also act as drug reservoirs, 20 21 which released drug in stomach and intestine with reduced/no burst release in initial period.…”

Adsorption and heat‐energy‐aid desorption of cationic dye on a new thermo‐sensitive adsorbent: Methyl cellulose/calcium alginate beads

“…Among these biopolymers, polysaccharide type biopolymers, such as cellulose, chitosan, cyclodextrin, and sodium alginate (SA), have been received more attention. SA is a naturally occurring polysaccharide composed of two types of monomer units, i.e., β‐ d ‐mannuronic acid and α ‐ l ‐guluronic acid . SA can be extracted from abundant natural resources, including brown seaweeds.…”

Adsorption characteristics of Cr (III) onto starch‐graft‐poly(acrylic acid)/organo‐modifed zeolite 4A composite: A novel path to the adsorption mechanisms

“…Additionally, many acrylic series superabsorbent have been observed to have a significant decrease in water absorbency when immersed in metal ion solutions . Here, we found the trivalent chromium needs a number of carboxyl groups nearby, up to 4, to complete the adsorption as shown in Fig.…”