Adsorption最新文献

With increasing industrialization, the pollution of water resources by heavy metal ions has become an increasingly serious problem. In this study, dopamine-modified silk fibroin powder was used for the adsorption of heavy metal ions in water. A series of tests, including L value, visible light absorption, X-ray photoelectron spectroscopy, scanning electron microscopy, and particle size analysis, were performed on the modified silk fibroin powder. The results showed that the adsorption of heavy metal ions was most effective at pH = 6, and the adsorption effects of Cu²⁺, Cd²⁺, and Ni²⁺ were 115.8, 60, and 60 mg/g, respectively. The adsorption of Cu²⁺ by the modified silk fibroin powder conformed to Langmuir-type adsorption isotherm model and pseudo-second-order kinetic model. This study provides new insight for the application of natural silk fibroin powder for the adsorption of heavy metal ions in water.

Graphical abstract

In this work, we report Na-Fe(III) coordination polymer, Na[Fe(C₁₀H₁₂N₂O₈)(H₂O)]·2H₂O (1), derived from Ethylenediaminetetraacetic acid (EDTA) and the compound exhibits distorted octahedral coordination geometry. The polymeric structure is generated when octahedral sodium is connected with five oxygens comes from five EDTA molecules and one water molecule. The specific surface area (S_BET) of the compound was measured by Brunauer-Emmett-Teller (BET) which is 1036.9653 m²/g that value is consider as impressive. Further, thermal stability, sorption properties of nitrogen, water and benzene were also examined. In addition, electrical conductivity, the amount of ions and Hirshfeld surface analysis were also studied. The N₂ adsorption isotherm displays two distinct stages at low relative pressures (P/P₀ = 0-0.02), indicating the presence of two distinct types of nanopores within the material structure. In case of adsorption of water molecules, the adsorption capacity, reaching nearly 29 mol/kg, and achieves saturation at water vapor pressure while the benzene primarily adsorbs onto the outer surface of the sorbent material at 1.38 mol/kg but its adsorption capacity is lower in comparsion to water. This observation indicates that delineating the adsorption texture of the adsorbent material. The cleavage of certain bonds between the polymerized metal and the ligand in the coordination compound is confirmed through electrical conductivity and the amount of ions. The Hirshfeld surface analysis provided information about various types of surfaces interactions in this compound.

A new approach for understanding the mechanism of monolayer adsorption is proposed. The Langmuir model, which does not take into account sorbate-sorbate bonds, is the most common one for interpreting monolayer adsorption.When using it, the assumption about the absence of sorbate-sorbate interactions between the sorbate molecules of the first layer is never checked. However, the sorbate-sorbate interactions can make an important contribution to the adsorption energy at physical adsorption. In this case, the formation of sorbate clusters in first layer is an energetically preferable process compared to the process of individual molecules adsorption. The monolayer cluster adsorption model, which takes into account sorbate-sorbate interactions, was introduced in our previous works. In present work, based on the experimental isotherms analysis, a criterion for the mechanism of monolayer adsorption (cluster or adsorption of individual molecules) is proposed. Examples are given of the this criterion application to the study of the mechanism of carbon dioxide adsorption by IRMOF-6, IRMOF-11 and IRMOF-1, ethane by highly activated carbon Saran and methane by mica. This work develops a new approach to the interpretation of monolayer adsorption mechanism.

Hydroxychloroquine (HCQ) is a very substantial drug active substance that was approved for emergency use by the FDA during the peak of the COVID-19 pandemic due to its potent antiviral properties. In this study, adsorption and desorption of hydroxychloroquine on sulfur (S)-doped graphene powders were investigated. While the adsorption experiments were carried out in the environment of distilled water (pH 5.0-6.0), HEPES buffer (pH 7.6), and Tris.HCl buffer (pH 8.0) the desorption studies were performed in distilled water. The HCQ adsorbed S-doped graphene powders were characterized by UV-Vis, FT-IR, XRD, BET and TEM techniques. According to UV-Vis measurements, the adsorption efficiency in the HEPES buffer medium at pH 7.6 was the highest (68.72% for H3 (HCQ adsorption with SGr3 graphene in HEPES medium)). FT-IR and XRD analyses confirmed the presence of HCQ on the graphene powders’ surface. While morphological changes on the surfaces of graphene powders were imaged by TEM, BET surface area changes proved the HCQ adsorption. The in vitro toxicity of the developed H3 was found to be lower than that of HCQ alone on the L929 cell line. These fundamental findings of the surface interaction between HCQ and graphene are precious for the design and optimization of a targeted drug based on this molecule and material. The adsorption/desorption features of HCQ onto graphene-based carrier systems which in particular doped with sulfur from functional metals have been investigated for the first time.

Analysis of physicochemical properties and treatment of water via modified natural adsorbent material is vital to the ecosystem. The purpose of this study is to analyze physicochemical parameters and synthesize polyaniline (PANI)/moringa oliefera (MO) nano-composite adsorbent material via in situ polymerization techniques. Physicochemical parameters of the sample show, a strong and moderate correlation between all parameters while a weak correlation of turbidity. The synthesized materials were also characterized using powder XRD, FT-IR, UV-VIS spectroscopy, SEM, and conductometer. The physical characterization shows the amorphous nature of MO and the crystallinity of polyaniline and composite material. The existence of skeletal interaction, electronic transition, and porous and granular morphology was confirmed using FT-IR, UV-VIS spectroscopy, and SEM, respectively. After physical characterization, the adsorption performance of as-synthesized material was tested using the batch method. The maximum adsorption capacity (q_max) of Cu²⁺ and Pb²⁺ ions by PANI/MO was 10.01 mg/g and 23.01 mg/g, respectively. When all parameters were optimized (pH at 5, contact time at 30 min, temperature at 25⁰C, and 2 grams of PANI/MO) adsorption efficiency for Pb²⁺ is 99%, and Cu²⁺ ions is 97.77%. The Freundlich isotherm data for Cu²⁺ and Pb²⁺ have a good fit with the experimental data (R² = 0.99 and 0.98), and Langmuir isotherm data for Cu²⁺ and Pb²⁺ is R_L=0.18 & 0.19, respectively. The pseudo-second-order kinetic isothermal was more fit with physisorption at R² = 0.99 for Cu²⁺ and R² = 1 for Pb²⁺. Therefore, the novel PANI/MO composite remarkably outperformed MO and can be a promising candidate to adsorb Cu²⁺ and Pb²⁺ from wastewater.

Glioma tumors are the most common form of central nervous system tumors, and there is a pressing need for innovative methods that can precisely target cancer cells while leaving healthy tissues unharmed. In this study, progressing in the field of Catalytic Nanomedicine, we investigated the cytotoxic effects of a novel class of bionanocatalysts on glioma cancer cells. These bionanocatalysts were constructed from a catalytic matrix of oxides with evenly dispersed superficial copper-coating nanoparticles. This design optimizes both the inherent catalytic characteristics of the matrix and instills cytotoxic properties. The bionanocatalysts coated with copper demonstrated a significant reduction in cancer cell viability when compared to reference bionanocatalysts without the transition metal. We also observed structural damage to the cytoskeleton and alterations in mitochondrial activity. These findings suggest that these pathways are integral to the mechanisms through which these nanostructures execute their bionanocatalytic activities, particularly in breaking chemical bonds. Importantly, our physicochemical analyses verified that the coating with copper species, primarily CuO, did not disrupt the individual structure of the bionanocatalysts: instead, it enhanced their catalytic cytotoxic potential. This research aims to deepen our understanding of the mechanisms underlying this promising antineoplastic treatment and underscore the effectiveness of superficial copper-coating nanoparticles as agents for amplifying the inherent properties of bionanocatalysts through nanocatalysis.