High Efficiency of Formaldehyde Removal and Anti-bacterial Capability Realized by a Multi-Scale Micro-Nano Channel Structure in Hybrid Hydrogel Coating Cross-Linked on Microfiber-Based Polyurethane

Molecule self-assembly of hydrangea-shaped hollow O, Cl -codoped graphite-phase carbon nitride microspheres for efficient N-(1,3-dimethyl butyl)-N'-phenyl-p-phenylenediamine quinone photodegradation and bacteria disinfection

6PPD-quinone (6PPD-Q) as a derivative of the rubber antioxidant N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine (6PPD), is attracting intensive attention due to the significant hazard to ecosystems. However, the effective management of this type of contaminant has been scarcely reported. Hydrangea-like hollow O, Cl-codoped graphite-phase carbon nitride microspheres (HHCN), featuring open pores were readily prepared by molecular self-assembly and utilized to address 6PPD-Q in an aqueous system for the first time. More than 90 % of 6PPD-Q is efficiently photodegraded within 1 h on the as-prepared HHCN, which is 2.5 times more than that on bulk g-C3N4. Moreover, the as-synthesized HHCN demonstrates prominent photocatalytic activities for the degradation of doxycycline and tetracycline and the inactivation of Staphylococcus aureus (S. aureus) in an aqueous environment. The distinct hydrangea-like hollow structure imparts a large surface area and an abundance of active sites. In addition, the inclusion of Cl-3p orbitals also contributes to a reduction in the bandgap (2.01 eV) and facilitates carrier separation and transport. These combined characteristics synergistically enhance the remarkable photocatalytic performance of HHCN, which induces a more than 2 times higher degradation rate than bulk g-C3N4. This work offers a prospective route for template-free designing porous functional materials with improved properties and efficiently treating emerging pollutants such as 6PPD-Q, pathogenic bacteria, and antibiotic residues.

Efficient Oxidative Removal of Indoor Formaldehyde Using Functionalized Activated Alumina

Formaldehyde (HCHO) has become a significant indoor air pollutant, arising from the widespread use of decorative and construction materials. Adsorption is the most convenient method for HCHO removal. However, the current adsorption is limited by the current low adsorption capacity and desorption. Herein, activated alumina (γ-Al2O3) loaded with permanganate was proposed for the efficient oxidative removal of indoor HCHO. The results demonstrate that the permanganate-containing alumina-based pellets (PAP) with 75% of alumina (PAP-75) displayed the highest adsorption capacity of 10,800 μg g-1. This high adsorption capacity is mainly attributed to the presence of numerous pore structures within the pellets, good dispersion of permanganate on the surface and inside the spheres, abundant surface-active sites, and high porosity. The adsorption kinetics explains that the chemisorption, intraparticle diffusion, and film diffusion are the primary rate-controlling steps. This study provides an effective strategy for further improving alumina-based adsorption materials for HCHO removal.

Anisotropically Conductive Hydrogels with Directionally Aligned PEDOT:PSS in a PVA Matrix

Electrical anisotropy, which is characterized by the efficient transmission of electrical signals in specific directions, is prevalent in both natural and engineered systems. However, traditional anisotropically conductive materials are often rigid and dry, thus limiting their utility in applications aiming for the seamless integration of various technologies with biological tissues. In the present study, we introduce a method for precisely controlling the microstructures of conductive and insulating polymers to create highly anisotropically conductive composite hydrogels. Our methodology involves combining aligned poly(vinyl alcohol) microfibrils, infused poly(3,4-ethylenedioxythiophene) polystyrenesulfonate, and sodium citrate precipitation to form dense, aligned conductive paths. This significantly enhances the electrical conductivity anisotropy (σ∥/σ⊥ ≈ 60.8) within these composite hydrogels.

Gum Arabic-based three-dimensional printed hydrogel for customizable sensors

Most three-dimensional (3D) printed hydrogel exhibit non-idealized rheological properties in the process of direct ink writing and complicated curing. Therefore, accurate writability and convenient curing for 3D printed hydrogel remain a challenge. In this paper, we developed a typical 3D printed hydrogel which realized direct ink writing (DIW) at temperatures similar to human body. Silicon dioxide (SiO2) and Gum Arabic (GA) formed the Bingham fluid to ensure shape stability. The rapid initiation system of potassium persulfat (KPS) and N,N,N',N' -tetramethylethylenediamine (TMEDA) allowed the 3D printed hydrogel precursor solution to transiently form a hydrophobic conjoined cross-linking network structure of acrylamide (AAM) and lauryl methacrylate (LMA) after printing, resulting in preferable mechanical properties. Hydrogel precursor solution showed better rheological properties with the nature of Bingham fluids, and achieved transient cross-linking at 30 °C for 10 s in the rheological test. A variety of 3D printed hydrogel with individual strain sensing properties are prepared as customizable sensor that could monitor significant strain signals within 0-20 % strain with high sensitivity. Moreover, they were discovered excellent temperature sensitivity over a wide operating range (0-80 °C). The 3D printing hydrogel sensors were expected to have broad application prospects in flexible wearable devices and medical monitoring.