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Herein, poly (allylamine hydrochloride) (PAH)/ poly (styrene sulfonic acid) sodium salt (PSS) microcapsules of (PAH/PSS)2PAH (P2P MCs) and (PAH/PSS)2 (P2 MCs) were obtained by a layer-by-layer method. The P2 MCs show high adsorption capacity for Rhodamine B (642.26 mg/g) and methylene blue (909.25 mg/g), with an extremely low equilibrium adsorption time (~20 min). The P2P MCs exhibited high adsorption capacities of reactive orange K-G (ROKG) and direct yellow 5G (DY5G) which were 404.79 and 451.56 mg/g. Adsorption processes of all dyes onto microcapsules were best described by the Langmuir isotherm model and a pseudo-second-order kinetic model. In addition, the P2P MCs loaded with reactive dyes (P2P–ROKG), could further adsorb rhodamine B (RhB) dye, and P2 MCs that had adsorbed cationic MB dyes could also be used for secondary adsorption treatment of direct dye waste-water, respectively. The present work confirmed that P2P and P2 MCs were expected to become an excellent adsorbent in the water treatment industry.

Polyester/polyamide 6 hollow segmented pie bicomponent spunbond hydro-entangled microfiber nonwovens (PET/PA6) with a microfilament structure have recently emerged in many markets around the world due to their green, high-strength, and lightweight properties. However, PET/PA6 is highly hydrophobic, which inhibits its large-scale application at present. In order to enhance the hydrophilic performance of PET/PA6, many methods have been applied, but the effects are not obvious. Ultraviolet (UV) irradiation treatment has proven to be an effective method to improve the hydrophilicity of fabrics. Herein, the aim of this paper was to investigate hydrophilic modification of PET/PA6 by UV/TiO2/H2O2. The effect of H2O2, nano-TiO2, and UV irradiation time on the morphology, elemental composition, hydrophilic properties, and mechanical properties of PET/PA6 were systematically investigated. The results showed that the modified microfibers were coated with a layer of granular material on the surface. It was found that the C 1s peak could be deconvoluted into six components (C–C–C, C–C–O, O–C=O, N–C=O, N–C–C, and C–C=O), and a suitable mechanism was proposed. Moreover, the water contact angle of PET/PA6 modified by 90 min irradiation with UV/TiO2/H2O2 decreased to zero in 0.015 s, leading to the water vapor transmission rate and the water absorption reaching 5567.49 g/(m2·24 h) and 438.81%, respectively. In addition, the modified PET/PA6 had an excellent liquid wicking height of 141.87 mm and liquid wicking rate of 28.37 mm/min.

In order to improve the photocatalytic performance of g-C3N4, the g-C3N4/Ti3C2/Ag3PO4 S-type heterojunction catalyst was prepared by electrostatic assembly method, and then the g-C3N4/Ti3C2/Ag3PO4/PAN composite nanofiber membrane was prepared by electrospinning technology. The morphology and chemical properties of the nanofiber membrane were characterized by SEM, FTIR, and XRD, and the photocatalytic degradation of tetracycline hydrochloride (TC) in water by the nanofiber membrane was investigated. The results showed that g-C3N4/Ti3C2/Ag3PO4 could be successfully loaded on PAN and uniformly distributed on the surface of composite nanofiber membrane by electrospinning technology. Increasing the amount of loading and catalyst, lowering the pH value and TC concentration of the system were conducive to the oxidation and degradation of TC. The nano-fiber catalytic membrane had been recycled five times and found to have excellent photocatalytic stability and reusability. The study of catalytic mechanism showed that h+, •OH and •O2− were produced and participated in the oxidation degradation reaction of TC, and •O2− plays a major role in catalysis. Therefore, this work provides a new insight into the construction of high-performance and high-stability photocatalytic system by electrospinning technology.