Porous materials fabricated from Pickering foams stabilized by natural plant of Angelica sinensis for removal of Cd (II) and Cu (II)

Fabrication of porous adsorbents from eco-friendly aqueous foam for high-efficient removal of cationic dyes and sustainable utilization assessment

Porous materials applied in environmental remediation have received researchers' extensive attention recently, but the related green and convenient preparation method is rarely reported. Here, we recommended a green and convenient strategy for the fabrication of porous material via aqueous foam templates, which was synergistically stabilized by Codonopsis pilosula (CP) and clay minerals of attapulgite (APT). The characterization results revealed that the APT was modified by organic molecules leached from CP and anchored at the air-water interface, which improved the foam stability significantly. The novel porous material of polyacrylamide/Codonopsis pilosula/attapulgite (PAM/CP/APT) templated from the aqueous foam via a polymerization reaction had excellent adsorption capacity for the cationic dyes methyl violet (MV) and methylene blue (MB), and the adsorption capacity can reach 755.85 mg/g and 557.64 mg/g, respectively. More importantly, the adsorption capacity of spent adsorbent material was still over 200 mg/g after being recycled five times through a simple carbonization process, and then it was added to the plant pot, the total biomass was increased by about 86.42%. This study provided a green and sustainable pathway for the preparation, application and subsequent processing of porous materials.

Liquid foams: Properties, structures, prevailing phenomena and their applications in chemical/biochemical processes

Liquid foams are gas-liquid dispersions with flexible structures that provide high gas-liquid interfaces. This property nominates liquid foams as excellent gas-liquid contactors, systems that are widely used in the chemical and biochemical industries. However, challenges such as a lack of comprehensive understanding and foam instability have historically hindered their widespread industrial use in most applications. It was not until the recent development of nanofluidics, nanotechnology, surface science, and other related fields that the understanding, analysis, and control of foam phenomena improved. This led to the development of innovative stabilization techniques and foam-based unit operations in chemical and biochemical processes, each of which requires in-depth and exclusive reviews to fully comprehend their potential and limitations and to identify areas for further improvement and innovation. This paper reviews the foams, the common phenomena in them, the characteristics that make them suitable for chemical/biochemical engineering, reports on their current applications and recent developments in this field.

Porous superabsorbent composites prepared from aqueous foam template and application evaluation

Rapid water absorption is very important for the application of superabsorbent polymers under dry or semi-dry conditions, but there are currently few relevant studies. In this context, a novel porous superabsorbent of chitosan-grafted acrylic copolymer-2-acrylamido-2-methylpropanesulfonic acid/sapindus mukorossi pericarp/calcined oil shale semi-coke (CS-g-P(AA-co-AMPS)/SMP/COSSC) was prepared by a green and convenient foam template method, which was triggered by redox polymerization. The rich pore structure of the porous superabsorbent was conducive to accelerating the water absorption rate. It only took 15 min to reach a swelling capacity of 650 g g-1 in distilled water. Soil experiments show that even with the addition of 0.5 wt% porous superabsorbent, the soil water retention time can be extended to 7 days. Finally, it was applied to the growth of cabbage seeds and it was found that the growth was significantly improved. Based on these excellent properties, we expect to provide a valuable reference for the preparation of fast-absorbing materials through the green water-based foam template method, contributing to sustainable agriculture.

Preparation of robust silicone superhydrophobic and antibacterial textiles using the Pickering emulsion method

This study aimed to prepare textiles with superhydrophobic and antibacterial properties using the Pickering emulsion impregnation method. Cellulose nanocrystals were synergistically employed with dimethyloctadecyl[3-(trimethoxysilyl)-propyl] ammonium chloride as the solid surfactant, and hydrogenated (PHMS) and hydroxyl (MSDS) polysiloxane were used as the oil phase for emulsification. The emulsions were mixed and diluted in specific proportions, and the superhydrophobic and antibacterial textiles were prepared through fabric impregnation-drying strategies. The study optimised factors such as emulsion ratio and surfactant dosage. Results demonstrated that the nanoscale rough structure prepared using Pickering emulsion exhibited remarkable superhydrophobicity with contact and rolling angles of 163.1° ± 0.5° and 7.2° ± 0.2°, respectively. This effect was achieved when the ratio of PHMS emulsion to MSDS emulsion was maintained at 1:2 and the surfactant dosage was set at 2 %. The superhydrophobicity of textiles was maintained even after three washing cycles and 50 abrasion cycles, demonstrating excellent mechanical durability. The developed textiles also exhibited excellent oil/water separation ability, reliable recyclability and stability. Moreover, they demonstrated excellent self-cleaning and antibacterial capabilities. Thus, these valuable functionalities hold the potential to considerably improve the practical feasibility of superhydrophobic textiles in various application scenarios.