ABSTRACT Polysulfone (PSF) nanofiltration membranes incorporating L‐lysine‐functionalized boehmite nanoparticles (Lys‐BM) were developed to improve dye and salt removal from water. Lysine functionalization enhanced nanoparticle dispersion and compatibility within the PSF matrix. Membranes containing 0–1 wt.% Lys‐BM were fabricated by phase inversion and characterized using XRD, FT‐IR, TGA, and SEM. The membranes exhibited an asymmetric structure with a dense skin layer, porous sublayer, and finger‐like pores. The 0.5 wt.% Lys‐BM membrane showed the best overall performance, while higher loading (1 wt.%) caused minor agglomeration and reduced efficiency. Lys‐BM incorporation significantly enhanced membrane hydrophilicity, reducing the contact angle from 65.06° to 50.31°, while increasing porosity and approximately doubling pure water flux. Antifouling properties also improved substantially, with flux recovery ratio increasing from 52.85% for pristine PSF to 92.32%. The modified membranes achieved >95% Methylene Blue rejection and >90% MgSO4 and MgCl2 rejection. Zeta‐potential analysis confirmed surface charge reversal following Lys‐BM incorporation, supporting improved separation performance. Moreover, long‐term cross‐flow filtration showed that the optimized membrane retained 88–90% of its initial flux, compared with approximately 60% for pristine PSF. Overall, Lys‐BM modification provides an effective strategy for producing high‐performance and operationally stable nanofiltration membranes for advanced water treatment.
ABSTRACT In this study, we treated ground tire rubber (GTR) with electron‐beam irradiation in an aqueous medium and investigated its application in natural rubber (NR)‐based compounds. We characterized the changes in the internal chemical structure using Soxhlet extraction and swelling tests. Based on the results, it can be stated that both the sol content and the crosslink density changed only slightly (1%–2%), indicating that the energy imparted during electron irradiation was primarily consumed by the radiolysis of water. We used the irradiated GTR in NR‐based compounds and then examined their properties. The tensile strength of the vulcanizates increased by 30%, while their elongation at break increased by 28% compared to the reference, even at an absorbed dose of 10 kGy. The tear strength reached its maximum at 40 kGy, where it increased by 42% compared to the reference. Based on the dynamic mechanical properties, it can be concluded that radiation treatment resulted in stronger adhesion between the phases, as evidenced by a decrease in the Payne effect. The results demonstrate that the water‐radiolysis‐assisted surface activation concept previously developed using gamma irradiation can be successfully transferred to electron‐beam processing, providing a faster and more economically attractive route for industrial GTR recycling.
ABSTRACT Electrospun nanofibrous membranes are promising candidates for air decontamination because of their high surface‐to‐volume ratio, tunable pore structure, and low basis weight. However, the rapid screening of membrane performance before full filtration testing remains challenging. In this study, polyacrylonitrile (PAN)‐based nanofibrous membranes were fabricated by electrospinning using pristine PAN and PAN modified with halloysite nanotubes (HNTs), polyamidoamine (PAMAM) dendrimers, and their hybrid combination. The effects of these additives on fiber morphology, viscosity, surface topography, packing density, mechanical response, thermal behavior, and particulate filtration performance were systematically evaluated. The incorporation of nanoparticles significantly impacted the membrane structure, resulting in a 20%–55% reduction in nanofiber diameter, which directly altered the packing density and surface properties. An empirical structural descriptor, termed the structural quality factor (QFS), was evaluated by combining packing density with the absolute value of surface skewness. The descriptor showed a preliminary correlation with the experimental filtration quality factor, suggesting its potential use for preliminary screening of electrospun filter media.
ABSTRACT The infrared luminescence is easily quenched by polar groups or compounds in the vicinity domain around emitting centers. Thus, natural cotton fibers (NCFs) were thought as unavailable to be substrate for this purpose due to their rich hydroxyl groups. To address this critical problem, this article focused on Yb3+‐complexes as the infrared‐emitting central element to reconstruct the surficial layer of natural cotton fibers for obtaining strong infrared (IR) luminescent cotton fibers. Thus, the excellent IR property of NCFs can be used as invisible photon information fiber materials. In this work, Yb3+ with its light‐energy antenna compounds (i.e., ligands) is as penetrant as to disperse in swollen cotton fibers and to be anchored at/in the surficial layer through drying‐caused shrinkage. The obtained hybrid fibers of Yb(HDNM)3bath have high luminescence intensity at a relative value of 1 200 000 a.u., high photon quantum yield at 1.43%, and a high lifetime of 8 µs. Thus, this work explored a new generation of infrared luminescence fibers that will potentially be applied for the hidden photon information fiber materials.
