Charged Functional Groups Research Articles

Positively Charged Nanoplastics Destruct the Structure of the PCK1 Enzyme, Promote the Aerobic Gycolysis Pathway, and Induce Hepatic Tumor Risks.

The production and weathering processes of nanoparticles (NPs) introduce charged functional groups on their surface. Previous studies have found that the surface charge properties of NPs play a critical role in their toxic effects and the mechanisms are generally attributed to their different accumulations and transmembrane potentials. Currently, we still lack sufficient knowledge about effects, owing to the unique structures of these polymers. In this study, positively charged NPs (PS-NH2, 50 nm) at 0.05-0.5 μg mL-1 promoted the proliferation of hepatic tumors in oncogenic KrasG12V zebrafish larvae and they also increased the viability of human hepatocellular carcinoma cells, whereas negatively charged NPs (PS-COOH, 50 nm) did not. We present evidence indicating that the potential carcinogenicity of PS-NH2 is related to the special polymer-molecular interactions caused by its positive surface charge. The affinity of PS-COOH chains for peptides typically enhances enzyme stability and upregulates its expression. However, PS-NH2 strongly competes with hydrogen bonds of the first rate-limiting enzyme PCK1 in gluconeogenesis, thus downregulating the expression of PCK1 and promoting the aerobic glycolysis pathway, which most tumor cells prefer. This study indicates that positive-charge modified NPs in the environment may bring additional carcinogenic risks.

A comprehensive study on pomegranate (Punicagranatum) peels as a low-cost biosorbent: adsorption mechanisms, application, regeneration, and cost analysis.

This study investigates the potential of utilizing pomegranate peel, a waste material, as an environmentally friendly adsorbent for the removal of methylene blue (MB) from wastewater. The novelty of this study lies in producing a competitive adsorbent (96% removal in a reasonably short contact time), very low cost, from a biowaste material and in providing cost analysis, regeneration method, application, and a mechanism based on a set of results that are in harmony with each other. Characterization of the purified pomegranate (Punicagranatum) peels (PP) inferred remarkable acidic sites. The MB removal was observed to increase with increasing dosages of adsorbent, contact time (93-94% removal took place in the first 30-40min), agitation speed (the amount of MB removed increased with increasing agitation speed up to 160 rpm), pH (increasing solution pH up to pH 8.0, the removal efficiency of MB by PP increased), and MB initial concentrations. The experimental results of MB adsorption on PP were best fitted to the Temkin isotherm model and the kinetic studies showed that the adsorption rate was best fitted to the pseudo-second-order (PSO) model showing a correlation coefficient R2 of 0.969-0.991. Thermodynamic investigations demonstrated that the removal of MB dye utilizing PP may be due to a spontaneous, electrostatic, chemical, and exothermic interaction with a heterogeneous adsorption mechanism. Adsorption is anticipated to begin with attraction between cationic MB and negatively charged active functional groups on adsorbent's surface, soon to be followed by multisite chemical interaction. The results (up to 96% removal) show that pomegranate peels could be used as a potential eco-friendly, cost-effective, and efficient biosorbent for dye removal from wastewaters. With an average removal effectiveness of 86.8%, PP were successfully utilized to remove MB from MB-spiked actual river water samples.

Dehydration-enhanced Ion Recognition of Triazine Covalent Organic Frameworks for High-resolution Li+/Mg2+ Separation.

The precise and rapid extraction of lithium from salt-lake brines is critical to meeting the global demand for lithium resources. However, it remains a major challenge to design ion-transport membranes with accurate recognition and fast transport path for the target ion. Here, we report a triazine covalent organic framework (COF) membrane with high resolution for Li+ and Mg2+ that enables fast Li+ transport while almost completely inhibiting Mg2+ permeation. The remarkably high rejection of Mg2+ by the COF membrane is achieved via imposed ion dehydration and the construction of the energy well. The proper hydrophilic environment of the COF channel promotes the dissociation of Li+ from the negatively charged functional groups, allowing Li+ for hopping transport supported by the sulfonate side-chains to shorten the diffusion path of Li+. Under high-salinity electrodialysis conditions, the COF membrane demonstrates robust Li+/Mg2+ separation performance (No Mg2+ were detected in the collected solution), achieving efficient lithium recovery and high product purity (Li2CO3: 99.3%). This membrane design strategy enables high energy efficiency and powerful lithium extraction in the electrodialysis lithium extraction process, and can be generalized to other energy and separation related membranes.

Electrostatically tuning radical addition and atom abstraction reactions with distonic radical ions.

Although electrostatic catalysis can enhance the kinetics and selectivity of reactions to produce greener synthetic processes, the highly directional nature of electrostatic interactions has limited widespread application. In this study, the influence of oriented electric fields (OEF) on radical addition and atom abstraction reactions are systematically explored with ion-trap mass spectrometry using structurally diverse distonic radical ions that maintain spatially separated charge and radical moieties. When installed on rigid molecular scaffolds, charged functional groups lock the magnitude and orientation of the internal electric field with respect to the radical site, creating an OEF which tunes the reactivity across the set of gas-phase carbon-centred radical reactions. In the first case, OEFs predictably accelerate and decelerate the rate of molecular oxygen addition to substituted phenyl, adamantyl, and cubyl radicals, depending on the polarity of the charged functional group and dipole orientation. In the second case, OEFs modulate competition between chlorine and hydrogen atom abstraction from chloroform based on interactions between charge polarity, dipole orientation, and radical polarizability. Importantly, this means the same charge polarity can induce different changes to reaction selectivity. Quantum chemical calculations of these reactions with DSD-PBEP86-D3(BJ)/aug-cc-pVTZ show correlations between the barrier heights and the experimentally determined reaction kinetics. Field effects are consistent between phenyl and cubyl scaffolds, pointing to through-space rather than through-bond field effects, congruent with computations showing that the same effects can be mimicked by point charges. These results experimentally demonstrate how internal OEFs generated by carefully placed charged functional groups can systematically control radical reactions.

Unraveling the mechanisms underlying AOM-induced deterioration of the settling performance of algal floc.

The influence of algal organic matter (AOM) on the settling performance of algal flocs remains poorly understood. To address this, we employed fractionation techniques based on molecular weight to isolate different AOM fractions and analyzed their effects on floc structure and settling performance. This involved comparing the concentrations, compositions, potentials, and functional groups of organic matter before and after coagulation-sedimentation. The results demonstrated that AOM significantly impacts floc characteristics, including size and compactness, ultimately hindering floc settling performance. Specifically, AOM fractions smaller than 100 kDa, such as humic substances, preferentially consumed coagulants without directly participating in floc formation, leading to smaller and slower-settling algal flocs. This was particularly evident for fractions with a molecular weight below 5 kDa, where only 25 % of the material participated in floc formation. In contrast, over 90 % of the AOM with a molecular weight exceeding 100 kDa, such as proteins, exhibited negatively charged functional groups (e.g., carboxyl groups) that interacted with coagulants via electrostatic forces to form larger complexes. These complexes enhance the coagulant's ability to capture and bridge algal cells, directly binding to the flocs, resulting in an increase of 20.3 % in the size and a 37.5 % faster settling velocity of the flocs formed by >100 kDa AOM compared to <5 kDa. This study elucidates the mechanisms by which AOM influences algal floc settling performance from the perspectives of AOM composition and its interactions with coagulants and algal cells. The findings provide a theoretical basis for a deeper understanding of algal flocculation mechanisms and for accelerating algal flocculation and sedimentation.

Bioinspired Synthesis of Silver Nanoparticles Using L. Reuteri: Antibacterial Efficacy, Molecular Docking Insights, and Cytotoxicity Assessment

AbstractThis study reports the green synthesis of silver nanoparticles (AgNps) by using Lactobacillus reuteri. Characterized AgNps exhibited near‐spherical morphology with an average size of 86.54 nm, as revealed by SEM (scanning electron microscopy), TEM (transmission electron microscopy), and AFM (atomic force microscopy) analyses. The nanoparticles displayed a slightly rough surface, with some particles exhibiting surface protrusions and sharp edges. The zeta potential measurement of −30.16 mV and electrophoretic mobility of −2.36 cm2/Vs that indicated the presence of negatively charged functional groups on the AgNps surface, suggesting stabilizing biomolecules that prevent nanoparticle aggregation in solution. The hydrodynamic size of the AgNps was determined to be 140.3 nm, and XRD (X‐ray diffraction) analysis revealed a crystallinity of 76.89% with an average crystal size of 8.35 nm and an interplanar distance of 0.233 nm. AgNps demonstrated crystallinity and potent antibacterial activity against Pseudomonas aeruginosa (92.9% killing efficiency) and an ATCC reference strain (76.8%). Molecular docking revealed moderate interactions between an optimized Ag3 cluster and key amino acid residues (Arg277, Gln279, Trp280, Asp273, and Val276) in the P. aeruginosa protein. These interactions, with binding energies ranging from −1.89 to −3.68 kcal/mol, suggested a potential mechanism for the observed antibacterial activity. A charge transfer interaction involving Asp273, contributing a stabilization energy of 3.66 kcal/mol, was identified as a key factor in the Ag‐protein complex formation.

Ultrasound-triggered drug release and cytotoxicity of microbubbles with diverse drug attributes

Ultrasound (US)-triggered cavitation of drug-loaded microbubbles (MBs) represents a promising approach for targeted drug delivery, with substantial benefits attainable through precise control over drug release dosage and form. This study investigates Camptothecin-loaded MBs (CPT-MBs) and Doxorubicin-loaded MBs (DOX-MBs), focusing on how properties such as hydrophilicity, hydrophobicity, and charged functional groups affect their interaction with the lipid surfaces of MBs, thereby influencing the fundamental characteristics and acoustic properties of the drug-loaded MBs. In comparison to DOX-MBs, CPT-MBs showed larger MB size (2.2 ± 0.3 and 1.4 ± 0.1 μm, respectively), a 2-fold increase in drug loading, and an 18 % reduction in leakage after 2 h at 37℃. Under 1 MHz US with a 100 ms pulse repetition interval (PRI), 1000 cycles, 5-minute duration, and 550 kPa acoustic pressure, CPT-MBs undergo inertial cavitation, while DOX-MBs undergo stable cavitation. Drug particles released from these MBs under US-induced cavitation were analyzed using dynamic light scattering, NanoSight, cryo-electron microscopy, and density gradient ultracentrifugation. Results showed that CPT-MBs mainly release free CPT, while DOX-MBs release multilayered DOX-lipid aggregates. The cytotoxicity to C6 cells induced by US-triggered cavitation of these two types of MBs also differed. DOX-lipid aggregates delayed initial uptake, leading to less pronounced short-term (2 h) effects compared to the rapid release of free CPT from CPT-MBs. These findings underscore the need to optimize drug delivery strategies by fine-tuning MB composition and US parameters to control drug release kinetics and achieve the best tumoricidal outcomes.

Diameter and Morphology of Colloidal-Silica-Abrasives Depending on Surfactant Concentration with Amine-Functional Group

As the design rule of logic semiconductors has been scaled down to 5, 3, 2.1, 1.5, and 1.0 nm, the line width of Cu film used as interconnect lines in logic semiconductors has also been rapidly reduced to 36, 32, 24, 20, and 16 nm. The CMP (Chemical Mechanical Planarization) of these Cu lines is a crucial fabrication process, posing challenges in achieving E.O.E (Edge Over Erosion), as well as minimizing dishing and erosion during the CMP of Cu films. Specifically, the E.O.E in the CMP of Cu films is primarily influenced by the diameter and morphology of colloidal silica abrasives in the CMP slurry. In a conventional synthesis method synthesis of colloidal-silica-abrasives, the diameter of colloidal-silica-abrasives could be obtained by adjusting the precursor concentrations such as TEOS, alcohol, and alkali catalyst. It has been reported that the effect of precursor concentration and the presence of a carboxylic acid-functionalized surfactant, specifically ethylene-diamine-tetraacetic acid (EDTA), on the morphology of colloidal silica abrasives.Therefore, in our study, we designed a novel synthesis method for colloidal silica abrasives by incorporating a charged functional group surfactant into the conventional synthesis process of colloidal silica abrasives. The effect of the surfactant having the positive charged amine functional group (i.e. Triethanolamine: Tri-ETA, Ethylenediamine: EDA, Diethylenetriamine: DETA, Triethylenetetramine: TETA) were estimated as function of the number of amine functional group in the surfactant, as shown in Fig. 1. When the number of positive charged amine functional groups increased 0 to 4, the diameter of colloidal-silica-abrasives increased from 67.2 to 143.86 nm and the solid loading of colloidal-silica-abrasives increased from 2.0 to 2.2 wt%. In addition, the synthesis with positive charged amine functional group was transformed from cocoon shape to spherical shape. We will present the changes in colloidal silica abrasive morphology as the concentration of amine functional groups, as well as the distinctions between amine and carboxyl funtuonal group. Moreover, we intend to provide a thorough investigation into the mechanisms underlying each synthesis. Acknowledgement This research was supported by the MOTIE(Ministry of Trade, Industry & Energy (1415180388) and KSRC(Korea Semiconductor Research Consortium) (20019474) support program for the development of the future semiconductor device, and by the Brain Korea 21 PLUS Program and the Samsung Electronics’ University R&D program. Figure 1

Charge-Selective Electrochemical Detection through Electrolyte Adsorption on Indium Tin Oxide Electrodes

In the field of electroanalytical methods, selective sensing of target analytes is as crucial as sensitive detections, as interfering substances coexist in real samples. Therefore, various strategies have been developed to enhance the selectivity of electrochemical sensors, including molecularly imprinted polymers, enzymes, or nanostructured electrodes. Modifying the charge of electrode have been also developed, which leads to charge-based discrimination, and eventually resulting in selective electrochemical sensing of charged species. For example, the introduction of negatively charged functional groups (e.g., carboxyl groups) on electrodes has shown selective detection towards positively charged species (e.g., dopamine). However, such approaches require complex materials that are customized for specific target redox species, which limits their wide applicability. In this work, we utilized the adsorption of electrolyte anions on bare indium tin oxide (ITO) electrodes to control the surface charge of the electrode and thus enable charge-based discrimination of redox species. By using polyprotic acid anions as electrolytes and varying the solution pH to determine their protonation states, we could systematically assess the electrochemical response of adsorbed charge density towards negative, positive, and neutral redox species. Furthermore, the anion effect was applied to the selective detection of dopamine in the presence of the two representative interfering species in blood, ascorbic acid and uric acid. We expect that the electrolyte-derived surface charging of the ITO electrode could be a widely applicable strategy for the selective detection of charged analytes.

Composite of Hydrolyzed PAN and β-Cyclodextrin Forms a Nanofiber Membrane with an Excellent Removal Effect on Various Cationic Dyes and Copper Ions.

The presence of dyes and heavy metals in wastewater represents a significant environmental and public health hazard, necessitating the development of efficient materials for their removal. In this study, we modified hydrolyzed polyacrylonitrile (PAN-H) and combined it with β-cyclodextrin (β-CD) by using an electrostatic spinning technique to fabricate composite nanofibrous membranes for water treatment applications. The resulting PAN-H/β-CD nanofiber membranes exhibit spindle-shaped fibers and porous structures with a high density of charged functional groups, which significantly enhance their selective adsorption capacity compared to pure PAN fibers. Furthermore, post-treatment with a sodium bicarbonate solution further improved this capacity, resulting in the membranes demonstrating a remarkable adsorption efficiency for cationic dyes. The adsorption process conformed to the Langmuir and pseudo-second-order kinetic models, with maximum adsorption capacities of 216.94 mg/g for methylene blue (MB), 471.59 mg/g for malachite green (MG), 299 mg/g for crystal violet (CV), and 43.95 mg/g for copper ions. The selective adsorption of these positively charged contaminants, particularly cationic dyes and metallic copper, indicates that PAN-H/β-CD membranes have significant potential for the treatment of wastewater containing similar pollutants.

Functionalized Modification of Conjugated Porous Polymers for Full Reaction Photosynthesis of H2O2

AbstractModulating the molecular structure to achieve the full reaction including oxygen reduction reaction and water oxidation reaction is a promising strategy for efficient photosynthesis of hydrogen peroxide (H2O2) but remains a challenge. Herein, a triphenylamine and naphthalimide‐based conjugated porous polymers are synthesized with photo oxidation‐reduction structures, then sulfonate (─SO3H) and quaternary ammonium groups are introduced via a post‐modification strategy to produce two photocatalysts named NI‐TPA‐NI‐SO3H and NI‐TPA‐NI‐N, respectively. Introducing charged functional groups has improved the hydrophilicity and oxygen (O2) adsorption, beyond that, the ─SO3H further stabilizes the adsorbed O2 via hydrogen bonding as well as accelerates the photogenerated carrier separation and electron/proton transport that enables full reaction photosynthesis of H2O2. Therefore, motivated by efficient charge separation, stabilized O2 adsorption, and boosted proton‐coupled electron transfer, NI‐TPA‐NI‐SO3H exhibits the highest light‐driven H2O2 production rate among the three photocatalysts, reaching 3.40 mmol g−1 h−1, which is 4.9‐fold of NI‐TPA‐NI. Remarkably, in the presence of ethylenediaminetetraacetic acid disodium salt, its rate significantly enhances to 14.5 mmol g−1 h−1, superior to most reported organic photocatalysts to the best of the knowledge.

In situ growth of Cd0.6Zn0.4S on graphene guided by ion anchoring for boosting hydrogen production

Owing to its large specific surface area and high conductivity, reduced graphene oxide (RGO) serves as an ideal platform for electron transfer. In this study, in situ growth of sulfides on RGO was attributed to metal ion anchoring on graphene oxide nanosheets by electrostatic attraction between negatively charged functional groups and metal ions. Tight binding between sulfides and RGO caused by in situ nucleation and growth can promote direct electron transfer and electron-hole separation, which is a more effective way to enhance hydrogen evolution activity. Cd0.6Zn0.4S/graphene (CZS/RGO) composite photocatalysts with different graphene ratios were prepared and exhibited high photocatalytic activity due to the improved dispersion of CZS and increased electronhole separation. The hydrogen production rate of CZS-0.8/RGO reached 52.50 mmol∙g–1∙h–1, and after nine cycles for 27 h, the hydrogen production efficiency remained at 86.4 %.

Copper removal with chemically reinforced Leptolyngbya sp. GUEco 1015

Leptolyngbya sp. GUEco 1015, an autochthonous cyanobacterial strains isolated from copper rich hydrocarbon contaminated waterbodies of Assam (India), was subjected to different grades of two acids and one salt to retrieve their copper (Cu2+) removal efficacy. Pretreated Leptolyngbya biomass when considered as an alternative adsorbent showed better removal rate of toxic Cu2+in vitro. The experimental data confirmed that the strain could remove up to 96.77 %, 92.1 % and 88.14 % of Cu2+ with 0.3 mM HCl, 0.1 mM CaCl2, and 0.1 mM CH3COOH in pretreated in-vitro condition respectively from 0.1 ppm of initial Cu2+ concentration. A number of negatively charged functional groups (FG) like O-H, -NH, CO, diketones, C-O stretching and phenols are known to be involved in the adsorption events during the process. The study thus revealed that pretreated biomass of Leptolyngbya sp. GUEco 1015 with 0.3 mM HCl is obviously a feasible alternative as compared to CaCl2 and CH3COOH for Cu2+ removal.

Impact of organic matter constituents on phosphorus recovery from CPR sludges.

This study evaluated the influence of organic matter (OM) constituents on the potential for recovery of P from wastewaters when FeCl3 treatment is employed for P removal. The presence of OM constituents did not influence P release from Fe-P sludges when alkaline and ascorbic acid treatments were employed. However, the overall recovery of P from wastewater was impacted by the presence of selected OM constituents through the reduction of P uptake during coagulation. The presence of protein and humic matter showed remarkably low P removal values (3.0±0.4% and 23 ±1% respectively) when compared to an inorganic control recipe (62 ±2%). Elevated soluble Fe (SFe) residuals in the presence of proteins (87 ±5%) and humics (51 ±1%) indicated interactions between Fe(III) cations and negatively charged functional groups like hydroxyl, carboxyl, and phenolic groups available in these organics. Significant negative correlations between P removal and residual SFe were observed suggesting Fe solubilization by OM constituents was the mechanism responsible for reduced P removal. The findings of this study identify, for the first time, the impact of OM constituents on overall P recovery when Fe(III) salts are employed and provide insights into recoveries that can be expected when Fe is added to primary, secondary treated, and industrial wastewaters. PRACTITIONER POINTS: Low P removal values were observed for protein and humic dominated wastewater recipes. Iron(III) solubilization counted for P removal reduction by proteins and humic acids. There is no effect of OM on P release from Fe-P sludge at pH 10 and ascorbic acid treatments. OM and agent employed to release P from sludges affected overall recovery of P.

Electrophoresis of polyelectrolyte-adsorbed soft particle with hydrophobic inner core.

This article deals with the electrophoresis of hydrophobic colloids absorbed by a layer of polymers with an exponential distribution of the polymer segments. The functional groups present in the polymer layer further follow the exponential distribution. We made an extensive mathematical study of the electrophoresis of such core-shell structured soft particles considering the combined impact of heterogeneity in polymer segment distribution, ion steric effect, and hydrodynamic slippage of the inner core. The mathematical model is based on the flat-plate formalism and deduced numerical results for electrophoretic mobility are valid for weak to highly charged particles for which the particle size well exceeds the Debye-layer thickness. In addition, we have derived closed form analytical results for electrophoretic mobility of the particle under several electrohydrodynamic limits. We have further illustrated the results for electrophoretic mobility considering a charged and hydrophobic inner core coated with an uncharged polymer layer or a polymer layer that entraps either positive or negatively charged functional groups. The impact of pertinent parameters on the overall electrophoretic motion is furtherillustrated.

Polystyrene influence on Pb bioavailability and rhizosphere toxicity: Challenges for ramie (Boehmeria nivea L.) in soil phytoremediation

Microplastics (MPs) and heavy metals often coexist in soil, however their interactions and effects on the soil–plant system remain largely unclear. In this study, ramie (Boehmeria nivea L.) was exposed to soil contaminated with lead (Pb) and polystyrene (PS) of different sizes, dosages, and surface–charged functional groups. This design aimed to simulate the effects of MPs on phytoremediation. The experimental results revealed that PS exacerbated the damaging effects of Pb on ramie. Compared to the effect of Pb alone, PS–COOH had a greater influence on root vigor, leading to a 15.6 % reduction in the active absorption ratio. Laser scanning confocal microscope showed PS entered the roots. Adsorption/desorption experiments demonstrated that PS had a weaker adsorption capacity for Pb than soil but a greater desorption rate than soil when simulating rhizosphere secretion. Moreover, PS reduced soil pH and increased the reducible state of Pb by 6–12 %. After 100 days of phytoremediation, Pb content in the soil with PS–5 μm was 150 μg g−1 less than that in the soil without PS. These results demonstrated that PS improved Pb bioavailability and enhanced the efficiency of Pb uptake by ramie. The redundancy analysis demonstrated that PS mitigated the toxicity of Pb to rhizosphere microorganisms, potentially via its effects on metal chemical fractions, dehydrogenase activity (S–DHA), cation exchange capacity (CEC), and soil organic matter (SOM). This study indicates that the presence of PS could potentially enhance the phytoremediation efficiency of ramie in Pb–contaminated land by influencing soil microenvironmental properties. This study provides insights into the complex interactions of MPs with soil–plant–microbial systems during metal remediation, thereby enhancing our understanding of their environmental impacts.

Synthesis of succinate derivatives using a magnetically separable Fe3O4@gly@Furfural@Co(NO3)2 nanocatalyst at room temperature

A simple, one-pot synthesis of nine 3-(4-oxo-4,5-dihydro-thiazole-2-yl sulfanyl) succinate derivatives has been achieved in moderate to good yields via a three-component reaction of dialkyl acetylenedicarboxylates, phosphites, and rhodanine at room temperature conditions and a magnetically-separable Fe3O4@gly@Furfural@Co(NO3)2 nanocatalyst. The size, surface charge, superparamagnetic properties, crystalline structure, and surface functional groups of nanoparticles were characterized and carried out utilizing several techniques such as X-ray diffraction analysis (XRD), Field emission scanning electron microscopy (FESEM), and Value stream mapping (VSM).

Establishment of circular economy by utilising textile industry waste as an adsorbent for textile dye removal

This study explored the use of waste from the textile industry (silkworm byproducts) as a promising raw feedstock for the production of carbon-based adsorbents (biochar). The silk excreta biochar generated at 600 and 700 °C (referred to as SEB-600 and SEB-700, respectively) were evaluated in terms of their efficacy in adsorbing cationic (methylene blue) and anionic (Congo red) textile dyes. Although the functional groups on the surfaces of SEB-600 and SEB-700 were not significantly different, the specific surface area of SEB-700 was greater than that of SEB-600. The dye adsorption capacity of SEB-700 was higher than that of SEB-600. The adsorption of methylene blue and Congo red on SEB-700 followed Freundlich isotherms (R2 ≥ 0.963) and pseudo-second-order kinetics (R2 = 0.999), indicating chemisorption with multilayer characteristics. The mechanism for the adsorption of methylene blue on SEB-700 may involve interactions with the negatively charged functional groups on the surface and the mesopores of SEB-700. For the adsorption of Congo red, the mesopores in the biochar and the electrostatic interaction between biochar (positively charged because of the dye solution pH < pHzpc) and the anionic dye could affect adsorption. The maximum adsorption capacities of SEB-700 for methylene blue and Congo red were determined to be 168.23 and 185.32 mg g−1, respectively. Utilising the waste generated from the textile industry to remove pollutants will build a sustainable loop in the industry by minimising waste generation and pollutant emissions.

Novel visible-light activated photocatalytic ultrafiltration membrane for simultaneous separation and degradation of emerging contaminants

Emerging contaminants (ECs) in secondary effluent of wastewater treatment plants (WWTPs) have received increasing attention due to their adverse effects on aquatic ecosystems and human health. Herein, visible-light responsive photocatalyst TM (TiO2 @NH2-MIL-101(Fe)) and resultant photocatalytic ultrafiltration (PUF, PVDF/TM) membrane were prepared to remove 32 typical compounds of antibiotics, 296 compounds of antibiotic resistance genes (ARGs), and their corresponding bacterial hosts. The construction of heterojunction photocatalyst promoted the electron transfer from NH2-MIL-101(Fe) to TiO2 and the formation of N-TiO2, enhancing visible-light (λ ≥ 420 nm) photocatalytic activity. With highly-hydrophilic surface and delicately-regulated pore structure, the initial water permeance of optimal PUF membrane significantly increased to 3912.2 L/m2/h at 1.0 bar. Meanwhile, membrane retention (via adsorption, electrostatic interaction, and steric hindrance) was improved due to the narrowed pore size, highly-negative surface charge and abundant functional groups. Additionally, hydroxyl radical (•OH) was the dominant active reactive oxygen species (ROS) for ECs degradation, and the narrowed pore structure could serve as microreactors to increase ROS concentration and reduce migration distance. Consequently, the removal efficiencies of antibiotics, bacteria and ARGs were 86.5 %, 91.4 % and 91.8 %, respectively. Overall, this novel visible-light-activated PUF membrane expands membrane application, and has great potential in ECs treatment.

Ionic Twin Nanostructural Comparison: Propylammonium Butanoate vs. Butylammonium Propanoate and Their Interactions with Water.

This study investigates the nanostructure of two protic ionic liquids (PILs), [N0 0 0 3][C3CO2] and [N0 0 0 4][C2CO2], with similar polar head groups but varying alkyl chain lengths. An X-ray scattering technique and molecular dynamics simulations have been utilized to characterize the bulk and interfacial properties of these PILs. The findings suggest that the nanostructure of the PILs is primarily determined by the electrostatic forces between charged functional groups playing a dominant role. Despite differences in the alkyl chain lengths, the PILs possess remarkably similar nanostructures. Extending our investigation, we report the impact of water on the nanostructure. Our findings reveal that the addition of water disrupts interactions between cations and anions, weakening Coulombic forces. The disruptive behavior is attributed to the establishment of hydrogen bonds between water and ions. This comprehensive approach provides valuable insights into the nuanced factors shaping the nanostructure of these PILs, which are crucial for tailoring their applications in synthetic chemistry, catalysis, and beyond.