Sustainable aerogels based on biobased poly (itaconic acid) for adsorption of cationic dyes

This work reports the synthesis of poly (itaconic acid) by thermal polymerization mediated by 2,2'-Azobis(2-methylpropionamidine) dihydrochloride. Furthermore, physical hydrogels were prepared by using high molecular weight poly (itaconic acid) characterized by low dispersity and laponite RD. The hydrogels presented porous 3D network structures, with a high-water penetration of almost 2000 g/g of swelling ratio, which can allow the adsorption sites of both poly (itaconic acid) and laponite RD to be easily exposed and facilitate the adsorption of dyes. The water adsorption followed Schott's pseudo-second-order model. The mechanism of the adsorption process was investigated using 1H and 31P NMR. The hydrogel is able to fast adsorb by a combination of electrostatic interactions and hydrogen bonding by the synergic effect of the clay and poly (itaconic acid). Moreover, the prepared aerogels exhibited a fast removal of Basic Fuchsin, with an adsorption capacity of 67.56 mg/g and a high removal efficiency (~99 %). The adsorption followed the pseudo-second-order kinetic model and Langmuir isotherm model. Furthermore, the thermodynamic parameters showed that the BF process of adsorption was spontaneous and feasible, endothermic, and followed physisorption. These results indicated that the PIA/laponite-based aerogel can be considered a promising adsorbent material in textile wastewater treatment.

High performance, cost-effective and ecofriendly flocculant synthesized by grafting carboxymethyl cellulose and alginate with itaconic acid

Natural polymer flocculant possesses an exciting prospect in water treatment due to its non-toxicity, wide source, low cost and biodegradability. In this work, we have successfully synthesized the anionic terpolymer of carboxymethyl cellulose-itaconic acid‑sodium alginate (CIS) by microwave-assisted copolymerization. By studying the flocculation properties towards cationic dye of crystal violet (CV), the optimum synthesis conditions were determined. The maximum removal rate of 100 mg/L CV simulated wastewater was 92.2 % with CIS concentration of 30 mg/L. The flocculation kinetic results showed the rapid dye removal rate and the dye decolorization ratio of 89.8 % could be obtained at 75 s. Moreover, the CIS flocculant showed excellent flocculation effects in ambient pH of 4-10, flocculation temperature of 10-40 °C, and various inorganic salts. In general, the anionic CIS flocculant shows excellent cost effectiveness, where the predicted operation cost of as-prepared CIS is about 60 % of conventional polyacrylamide flocculant. It also has the advantages of excellent ecofriendliness and rich raw material source, indicative its potential applications of wastewater treatment.

Highly Tough, Stretchable and Self-Healing Polyampholyte Elastomers with Dual Adhesiveness

A new type of polyampholyte with unique viscoelastic properties can be easily synthesized by the copolymerization of butyl acrylate with dimethylaminoethyl methacrylate and acid acrylate in one pot. The elastic modulus of the as-prepared polyampholyte can be easily tuned by adjusting the ratio between the butyl acrylate and ionic monomers. The polyampholyte synthesized by a low proportion of ionic monomer showed low tensile strength and high stretchability, resulting in good conformal compliance with the biological tissues and potent energy dissipation. Due to the existence of high-intensity reversible ionic bonds in the polymer matrix, excellent self-recovery and self-healing properties were achieved on the as-prepared polyampholytes. By combining the high Coulombic interaction and interfacial energy dissipation, tough adhesiveness was obtained for the polyampholyte on various substrates. This new type of polyampholyte may have important applications in adhesives, packaging and tissue engineering.

Insight into the aqueous Laponite® nanodispersions for self-assembled poly(itaconic acid) nanocomposite hydrogels: The effect of multivalent phosphate dispersants

HYPOTHESIS

We hypothesize, that physical network between Laponite® nanoparticles and high molecular weight polyelectrolyte formed by mixing of Laponite® nanodispersion (containing multivalent phosphate dispersant) and polyelectrolyte solution is strongly influenced by the type and content of dispersant, which forms electric double layer (EDL) closely to the Laponite® edges. Thus, optimum dispersant concentration is necessary to overcome clay-clay interactions (excellent clay delamination), but should not be exceeded, what would result in the EDL compression and weakening of attractions forming clay-polyelectrolyte network. Thus, deeper investigation of Laponite® nanodispersions is highly demanded since it would enable to better design the self-assembled clay-polyelectrolyte hydrogels.

EXPERIMENTS

To study clay interparticle interactions in the presence of various multivalent phosphates, complementary methods providing wide nanodispersion characterization have been applied: zeta potential measurement and SAXS technique (electrostatic interactions), oscillatory rheology (nanodispersion physical state) and NMR experiments (ion immobilization degree).

FINDINGS

It was found that multivalent phosphates induce and tune strength of clay-polyelectrolyte interactions forming hydrogel network in terms of varying EDL on the Laponite® edges. Moreover, phosphate dispersing efficiency depends on the molecular size, chemical structure, and valence of the anion; its potential as efficient dispersant for hydrogel preparation can be evaluated by estimation of anion charge density.

Incorporation of Poly(Itaconic Acid) with Quaternized Thiazole Groups on Gelatin-Based Films for Antimicrobial-Active Food Packaging

Poly(itaconic acid) (PIA) was synthesized via conventional radical polymerization. Then, functionalization of PIA was carried out by an esterification reaction with the heterocyclic groups of 1,3-thiazole and posterior quaternization by N-alkylation reaction with iodomethane. The modifications were confirmed by Fourier transform infrared (FTIR) and proton nuclear magnetic resonance (1H-NMR), as well as ζ-potential measurements. Their antimicrobial activity was tested against different Gram-negative and Gram-positive bacteria. After characterization, the resulting polymers were incorporated into gelatin with oxidized starch and glycerol as film adjuvants, and dopamine as crosslinking agent, to develop antimicrobial-active films. The addition of quaternized polymers not only improved the mechanical properties of gelatin formulations, but also decreased the solution absorption capacity during the swelling process. However, the incorporation of synthesized polymers increased the deformation at break values and the water vapor permeability of films. The antioxidant capacity of films was confirmed by radical scavenging ability and, additionally, those films exhibited antimicrobial activity. Therefore, these films can be considered as good candidates for active packaging, ensuring a constant concentration of the active compound on the surface of the food, increasing products' shelf-life and reducing the environmental impact generated by plastics of petrochemical origin.

Novel Biobased Self-Healing Ionomers Derived from Itaconic Acid Derivates

This article presents novel biobased ionomers featuring self-healing abilities. These smart materials are synthesized from itaconic acid derivates. Large quantities of itaconic acid can be produced from diverse biomass like corn, rice, and others. This study presents a comprehensive investigation of their thermal and mechanical properties via differential scanning calorimetry (DSC), thermo gravimetric analysis (TGA), and FT-Raman and FT-IR measurements as well as dynamic mechanic analysis. Within all these measurements, different kinds of structure-property relationships could be derived from these measurements. For example, the proportion of ionic groups enormously influences the self-healing efficiency. The investigation of the self-healing abilities reveals healing efficiencies up to 99% in 2 h at 90 °C for the itaconic acid based ionomer with the lowest ionic content.