Ammonium persulfate-initiated polymerization of cationic starch-grafted-cationic polyacrylamide flocculant for the enhanced flocculation of oil sludge suspension

Synthesis, Characterization and Bioactivity Evaluation of a Novel Nano Bagasse Xylan/Andrographolide Grafted and Esterified Derivative

In the in-depth research that has been conducted on nanometer biomaterials, how to use the biomass resources with high activity and low toxicity to prepare nanomaterials for biomedical applications has attracted much attention. To realize efficient and comprehensive utilization of biomass, bagasse xylan/andrographolide (BX/AD) was ued as a raw material and glycyrrhetinic acid (GA) as an esterification agent to synthesize bagasse xylan/andrographolide esterified derivative (GA-BX/AD). Then, the bagasse xylan/andrographolide grafted and esterified derivative (GA-BX/AD-g-IA) was synthesized by the graft crosslinking reactions using itaconic acid (IA) as graft monomer. The better synthesis conditions were optimized by single factor experiments, the degree of esterification substitution (DS) was 0.43, and the grafting rate (G) of the product reached 42%. The structure and properties of the product were characterized by FTIR, XRD, DTG, SEM, and ¹H NMR. The results showed that the product morphology was significantly changed, and the nanoparticles were spherical with a particle size of about 100 nm. The anti-cancer activity of the product was measured. The molecular docking simulations revealed that the product had good docking activity with human glucocorticoid protein (6CFN) with a binding free energy of 14.38 kcal/mol. The MTT assay showed that the product had a strong inhibitory effect on the growth of human liver cancer cells (BEL-7407) and gastric cancer cells (MGC80-3), with inhibition ratio of 38.41 ± 5.32% and 32.69 ± 4.87%. Therefore, this nanomaterial is expected to be applied to the development and utilization of drug carriers and functional materials.

Research Progress on Typical Quaternary Ammonium Salt Polymers

Quaternary ammonium salt polymers, a kind of polyelectrolyte with a quaternary ammonium group, are widely used in traditional and emerging industries due to their good water-solubility, adjustable cationicity and molecular weight, high efficiency and nontoxicity. In this paper, firstly, the properties and several synthesis methods of typical quaternary ammonium salt monomers were introduced. Secondly, the research progress on the synthesis of polymers was summarized from the perspective of obtaining products with high molecular weight, narrow molecular weight distribution and high monomer conversion, and special functional polymers. Thirdly, the relationships between the structures and properties of the polymer were analyzed from the perspectives of molecular weight, charge density, structural stability, and microstructural regulation of the polymer chain unit. Fourthly, typical examples of quaternary ammonium salt polymers in the application fields of water treatment, daily chemicals, petroleum exploitation, papermaking, and textile printing and dyeing were listed. Finally, constructive suggestions were put forward on developing quaternary ammonium salt polymers with high molecular weights, strengthening the research on the relationships between the structures and their properties and pinpointing relevant application fields.