Removal of dyes through adsorption from wastewater has gained substantial interest in recent years, especially in development of hydrogel based adsorbents, owing to their easy use and economical nature. The aim of the present study was to design a super-adsorbent hydrogel based on sodium styrenesulfonate (NaSS) monomer for removal of dyes like methylene blue (MB). NaSS displays both an aromatic ring and strongly ionic group in its monomer structure that can enhance adsorption capacity. Poly(sodium styrenesulfonate-co-dimethylacrylamide) hydrogels were prepared by solution free radical polymerization using gelatin methacryloyl (GelMA) as crosslinker, creating a highly porous, three-dimensionally crosslinked polymer network contributing to higher swelling ratios of up to 27,500%. These super-adsorbent hydrogels exhibited high adsorption capacity of 1270 mg/g for MB adsorption with above 98% removal efficiency. This is the first report for such a high adsorption capacity for dye absorbance for NaSS-based hydrogels. Additionally, the adsorption kinetics using a pseudo-first-order and the Freundlich adsorption isotherm models for multilayer, heterogeneous adsorption processes has been reported. The adsorbents’ reusability was confirmed through 4 repeated cycles of desorption-adsorption. The results discussed herein illustrate that NaSS based chemistries can be used as an efficient option for removal of organic dyes from contaminated wastewater.

Epoxy–clay nanocomposites derived from renewable soybean oils and organo modified montmorillonite clay were prepared. Improved efficiency and performance were achieved through application of new, low viscosity, glycidyl esters of epoxidized fatty acids (EGS) as the epoxy monomer and 4-methyl-1,2-cyclohexanedicarboxylic anhydride as the comonomer. Tensile testing showed that 1 wt% of clay improved nanocomposite strength and modulus by 22% and 13%, respectively, compared to neat polymer. Tensile modulus could be increased up to 34% by nanocomposite clay without any sacrifice of strength. Three types of dispersion techniques, mechanical stirring, high speed shearing, and ultrasonication, were carried out to disperse the clay directly into the epoxy or anhydride portion of the thermoset system without the need of additional solvent. Dispersion of the clay particles into monomer was assessed by means of solubility parameters and optical and scanning electron microscopies, and quality of dispersion further confirmed by small angle X-ray scattering and transmission electron microscopy. Sonication dispersion of clay into the epoxy portion was needed to optimize the dispersion and exfoliation of clay and the higher mechanical and thermal strength of the nanocomposites. The nanocomposites’ morphologies were a mix of intercalated and exfoliated structures, dependent on the dispersion technique. The optimum tensile strength and glass transition temperatures of the nanocomposites were a function of clay concentration and dispersion morphology.

Interfacial covalent bonding is an effective approach to increase the electrical resistance of a polymer–particle composite to charge flow and dielectric breakdown. A bifunctional tether reagent bo...

Conformance problems often exist in natural gas-related activities, resulting in excessive water production from natural gas production wells and/or excessive natural gas production from oil production wells. Several mechanical and chemical solutions were reported in the literature to mitigate the conformance problems. Among the chemical solutions, two classes of materials, namely polymer gels and water-soluble polymers, have been mostly reported. These systems have been mainly reviewed in several studies for their applications as water shutoff treatments for oil production wells. Natural gas production wells exhibit different characteristics and have different properties which could impact the performance of the chemical solutions. However, there has not been any work done on reviewing the applications of these systems for the challenging natural gas-related shutoff treatments. This study provides a comprehensive review of the laboratory evaluation and field applications of these systems used for water control in natural gas production wells and gas shutoff in oil production wells, respectively. The first part of the paper reviews the in-situ polymer gel systems, where both organically and inorganically crosslinked systems are discussed. The second part presents the water-soluble polymers with a focus on their disproportionate permeability reduction feature for controlling water in gas production wells. The review paper provides insights into the reservoir conditions, treatment design and intervention, and the success rate of the systems applied. Furthermore, the outcomes of the paper will provide knowledge regarding the limitations of the existing technologies, current challenges, and potential paths forwards.