Programable sewage-cleaning technology: Regenerating chitosan biofilms with anti-bacterial capacity via self-purification of water pollutants.

In this paper, a novel programable sewage-cleaning technology for the regeneration of antibacterial nanocomposites via the removal of wastewater pollutants is presented. Montmorillonite (MMT) was encapsulated in poly(vinyl alcohol) (PVA)-enhanced chitosan (CTS) hydrogels to form MMT-loaded nanocomposite biofilms (PCM). The PCM nanocomposite biofilms exhibited increased breaking strength and elongation at break, by factors of approximately 1.38 and 1.40, respectively, compared with those of the pure PVA/CTS biofilms. The maximum adsorption capacity of the PCM nanocomposite biofilms toward tetracycline and Ag(I) is 275.0 and 567.0 mg/g, respectively. The adsorbed nanocomposite biofilms exhibited excellent antibacterial properties against Staphylococcus aureus and Escherichia coli. Meanwhile, the nanocomposite also showed an effective adsorption capacity toward other toxic components, where the highest adsorption capacity is 2748.0 mg/g (for methyl blue). The simulation results indicated that the adsorption behaviors of the malachite green, neutral red, methyl blue, tetracycline, Cu(II), Zn(II), and Ag(I) by the PCM nanocomposite biofilms followed pseudo-second-order kinetic and Freundlich isotherm models. Furthermore, the PCM nanocomposite biofilms are stable in PBS solution but degradable in lysozyme-containing PBS solution, suggesting their potential application in the wastewater treatment as well as antibacterial fields.

Constructing triple-network cellulose nanofiber hydrogels with excellent strength, toughness and conductivity for real-time monitoring of human movements.

In recent years, there has been a lot of interest in developing composite hydrogels with superior mechanical and conductive properties. In this study, triple-network (TN) cellulose nanofiber hydrogels were prepared by using cellulose nanofiber as the first network, isotropic poly(acrylamide-co-acrylic acid) as the second network, and polyvinyl alcohol as the third network via a cyclic freezing-thawing process. The strong (9.43 ± 0.14 MPa tensile strength, (445.5 ± 7.0)% elongation-at-break), tough (15.12 ± 0.14 MJ/m3 toughness), and conductive (0.0297 ± 0.00021 S/cm ionic conductivity) TN cellulose nanofiber hydrogels were effectively created after being pre-stretched in an external force field, cross-linked by Fe3+ and added Li+. The produced composite TN cellulose nanofiber hydrogels were successfully used as a flexible sensor for real-time monitoring and detecting human movements, highlighting their potential for wearable electronics, medical technology, and human-machine interaction. CHEMICAL COMPOUNDS STUDIED IN THIS ARTICLE: Acrylamide (PubChem CID: 6579); Acrylic acid (PubChem CID: 6581); Ammonium persulfate (PubChem CID: 6579); N, N'-methylene bisacrylamide (PubChem CID: 17956053); Sodium bromide (PubChem CID: 253881); Sodium hydroxide (PubChem CID: 14798); Sodium hypochlorite (PubChem CID: 23665760); Sodium chlorite (PubChem CID: 23668197); 2,2,6,6-tetramethylpiperidinyl-1-oxide (PubChem CID: 2724126); Polyvinyl alcohol (PubChem CID: 11199); Lithium chloride (PubChem CID: 433294); Iron nitrate nonahydrate (PubChem CID: 129774236).