Modification Approach Research Articles

Engineered alginate-polyethyleneimine and sludge-aluminosilicate biochar composites for greywater treatment: Performance evaluation and models for designing pilot-scale systems.

Greywater, originating from kitchen sinks and toilets, constitutes 75-80 % of the domestic wastewater produced in homes and can be reclaimed for non-potable uses. This study synthesized novel sludge-derived aluminosilicates and alginate-polyethyleneimine (PEI) biochar composites. The aluminosilicates offer a sustainable approach to sludge management, while alginate-polyethyleneimine presents a green biochar modification approach. Their performance in fixed bed columns for treating greywater was compared with zinc chloride, calcium alginate, and PEI-biochar composites. The CatBoost machine learning algorithm also predicted contaminant removal efficiency and breakthrough parameters. The morphological and chemical analyses showed that the modification techniques improved the physiochemical properties of the biochar, which in turn influenced contaminant removal efficiency. With its enhanced surface area and pore structure, zinc chloride-biochar demonstrated notable effectiveness in removing organic matter (highest COD removal efficiency 96.1 %). PEI-biochar exhibited a high removal efficiency for nitrates (highest value of 95.5 %), attributed to the positive amine groups. Aluminosilicate-biochar was the most effective at removing ammonium due to its high cation exchange capacity. The CatBoost algorithm successfully stimulated E. coli, total nitrogen, COD removal efficiencies, and breakthrough parameters from greywater using biochar (R2 > 0.7). Future research should conduct a pilot-scale study for this technology, explore the use of modified biochar arranged in multilayers for treating greywater, use of biochar for removing emerging contaminants in greywater, and optimize predictive models for greywater treatment. The insights from our study provide valuable guidance for effective and sustainable greywater treatment.

Synergetic Interface and Bulk Defects Modification with Identical Organic Molecule for Efficient Inverted Perovskite Solar Cells.

Recent progress in inverted perovskite solar cells (IPSCs) mainly focused on NiOx modification and perovskite (PVK) regulation to enhance efficiency and stability. However, most works address only monofunctional modifications, and identical molecules with the ability to simultaneously optimize NiOx interface and perovskite bulk phase have been rarely reported. This work proposes a dual modification approach using 4-amino-3,5-dichlorobenzotrifluoride (DCTM) to optimize both NiOx upper interfaces and reduction of bulk defects in perovskite. Amino group in DCTM increases the Ni3+/Ni2+ ratio in NiOx, thereby increasing the conductivity and optimizing the energy alignment. Additionally, DCTM fills Pb2+ and I- vacancies in perovskite, which improves the vertical orientation of perovskite grains and subsequently reduces nonradiative recombination, thereby achieving the increased carrier lifetime. PVK modified by DCTM exhibits enhanced energy level alignment with the electron transport layer, while femtosecond transient absorption (TA) spectroscopy confirms that DCTM facilitates efficient carrier transport, leading to high-performance IPSCs. The optimized IPSCs achieve a maximum efficiency of 22.8% with a reduced hysteresis (0.7%). Moreover, the unencapsulated device preserves over 80% of its initial power conversion efficiency (PCE) after 1000 h stored in air at 30% relative humidity. This dual modification strategy of monomolecular offers a straightforward solution for interface optimization and provides new insights into selecting aniline-derived molecules for high-performance IPSCs.

Nanostructured TiO2 Surface Enriched with CeO2 over Ti Metal for Enhanced Cytocompatibility and Osseointegration for Biomedical Applications.

The present study aims to analyze the thermal regulation of the Ce3+/Ce4+ ratio on the nanonetwork titania layer over the titanium (Ti) surface developed by the alkali-mediated surface modification approach. The effect of sequential heat treatment from 200 to 800 °C was evaluated for its surface characteristics such as morphology, phase formation, roughness, hardness, hydrophilicity, etc. Surface oxidation by temperatures up to 600 °C demonstrated a progressive increase in the Ce4+ (CeO2) content with a rutile TiO2 network layer over the Ti surface. In contrast, a bulk reduction with increased Ce3+ (Ce2O3) content was observed at 800 °C. Heat treatment at 800 °C was also characterized by an improved nanohardness and roughness with a distorted surface network layer. The coexistence of Ce4+/Ce3+ (CeO2/Ce2O3) on a porous titania layer displayed a noticeable enhancement in antibacterial activity, which was evaluated against Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria. The surface-modified sample heat-treated at 600 °C and enriched with a high Ce4+/Ce3+ ratio revealed enhanced cell compatibility toward MG-63 in terms of cell adhesion, noncytotoxicity, and mitochondrial membrane potential with higher extracellular matrix mineralization. Further, in vivo bone defect investigations in a rat model using additively manufactured cancellous Ti scaffolds functionalized with surface incorporation of Ce ions heat-treated at 600 °C demonstrated significant enhancement in the osseointegration potential observed from histological and micro-computed tomography analyses. The upregulation of osteogenic marker genes (ALP, OCN, OPN, OSX, and RUNX2) at the implantation site evaluated by reverse transcription polymerase chain reaction confirmed the osteogenic potential of ceria surface functionalization. Hence, the Ce-incorporated nanostructured titania layer predominantly possessing a high Ce4+/Ce3+ ratio or CeO2 content on Ti metal is expected to reduce the risk of implant-related infections and improve cellular responses in orthopedic applications.

High‐Density Polyethylene Janus Fibrous Membrane with Enhanced Breathability and Moisture Permeability via PDA Assisted Hydrophilic Modification

AbstractFunctional fibrous membranes with high mechanical properties are intensively developed for different application fields. In this study, to enhance moisture and air permeability without compromising mechanical strength, a facile float‐surface modification strategy is employed to fabricate Janus fibrous membranes with distinct hydrophobicity/hydrophilicity using the high‐density polyethylene (HDPE) fibrous membranes. By coating one side of the HDPE fibrous membranes with polydopamine (PDA) and a superhydrophilic polyelectrolyte, the obtained Janus HDPE fibrous membranes demonstrate an excellent water transmission rate (577.61 ± 72.66 g m−2 h−1), water vapor transmission rate (WVTR, 131.62 ± 24.34 g m−2 h−1) and gas permeability (17,496 ± 235 m3 m−2 h−1 bar−1), which are much better than those commercial membranes (Tyvek with water transmission rate 518.93 ± 23.20 g m−2 h−1, WVTR 53.09 ± 6.19 g m−2 h−1, and gas permeability 2,871 ± 145 m3 m−2 h−1 bar−1). Further, the Janus HDPE fibrous membranes keep outstanding mechanical strength (17.00 ± 4.26 MPa of tensile strength, 45.49 ± 8.75% of strain at break), and exhibit an asymmetric wettability on each side which is demonstrated by the separation experiments with various oil‐water mixtures. This simple modification approach not only improves the serviceability of HDPE fibrous membranes but also offers scalable potential for apparel applications and other industrial applications.

Advances in composite anion-exchange membranes for fuel cells: Modification approaches and synthesis strategies

Advances in composite anion-exchange membranes for fuel cells: Modification approaches and synthesis strategies

Improving the mechanical and dynamic properties of Al-Zn-Mg-Cu- based aluminum alloy: A combined approach of microstructural modification and heat treatment

Improving the mechanical and dynamic properties of Al-Zn-Mg-Cu- based aluminum alloy: A combined approach of microstructural modification and heat treatment

A shape-reconfigurable electronic composite for stimulus customizable detection via neutral plane shifting.

Three-dimensional (3D) sensors selectively measure the applied force in a particular direction through the designed shape. However, such a fixed sensor design incurs a relatively low sensitivity and narrow measurement range to forces applied from other directions. Here, we report a shape-reconfigurable electronic composite based on a stiffness-tunable polymer and a crack-based strain sensor. The stiffness-tunable polymer allows a high degree of freedom (DOF) in modifying the shape of the electronic composite in its flexible state, enabling the formation of various 3D structures. This modification involves shifting the neutral plane toward the electrode to prevent fractures in the embedded sensors. After modifying the shape of the soft and flexible electronic composite, the dramatically increased stiffness of the stiffness-tunable polymer enables the maintenance of the reconfigured shape of the electronic composite and amplifies the mechanical signal from the external force of the targeted direction by returning the neutral plane to the original position. We validated the reversible modification of the shape of the electronic composite by demonstrating the increase in sensitivity and measured range for targeted external forces (bending, pressing, and stretching) via sequential changes in the designed shapes (wire, spiral, and spring) compared to the initial shape. This facile approach for shape modification will provide an opportunity to realize versatile shape changes in rigid electronics for user purpose.

Achievements and Difficulties with Batch and Optimization Investigations of Heavy Metal Adsorptive Removal Utilizing Enhanced Biomass-based Adsorption Materials

: Surface enhancement improves the porousness and surface area (SSA) of biomass materials, which boosts their adsorption capability. This work investigates recent advances in surface modification technologies of biomass-based materials for heavy metal adsorption, including Pb, As, Cr, Fe, Cd, Mn, Cu, Co, Hg, Ni, Zn, and their ions in waters/wastewaters. The chemical structure and surface properties of biomass were examined in connection with various surface modification approaches and their effects on the adsorption process. In addition, adsorption performance we assessed using various operating conditions, isotherms, kinetics, and computational and artificial intelligence methodologies. This study found that acid-activated Posidonia oceanica had the highest adsorption effectiveness of 631.13 mg/g to eliminate Pb2+, whereas H3PO4/furnace-modified oil palm biomass had the lowest (0.1576 mg/g) for removing Cd2+. Important insights into knowledge gaps for changing these materials for extremely effective adsorption performance were emphasized to improve the area.

Unlocking the neuroprotective potential of Ziziphora clinopodioides flavonoids in combating neurodegenerative diseases and other brain injuries.

Ziziphora clinopodioides Lam. (Z. clinopodioides) is a traditional Chinese and ethnic medicine in Xinjiang, China with various therapeutic effects. It is primarily used for conditions such as heart disease, fever with chills, palpitations, and insomnia. Flavonoids are the main medicinal components of Z. clinopodioides, Interestingly, current research has increasingly focused on its neuroprotective effects. This study provides a comprehensive overview of the potential therapeutic applications of Z. clinopodioides and its constituents in central nervous system disorders such as Alzheimer's disease, Parkinson's disease, Huntington's disease, and cerebral ischemia-reperfusion injury. At present, about 25 flavonoids have been isolated and identified from various organs of Z. clinopodioides, including linarin, acacetin, hyperoside, quercetin, apigenin, luteolin, chrysin, kaempferol, baicalein, rutin and others. Modern pharmacological studies have revealed that Z. clinopodioides and its constituents exhibits neuroprotective effects in vitro and in vivo, and the mechanism of action is related to anti-apoptosis, anti-inflammatory, antioxidant, autophagy, endoplasmic reticulum stress and so on. Currently, there is limited research on the extracts of Z. clinopodioides and their potential mechanisms of action in these neurological disorders. It is also important to prioritize research on biosynthetic pathways and chemical modification approaches to fully explore and improve the neuroprotective potential of Z. clinopodioides and its flavonoids and establish a strong foundation for its clinical applications.

Secure state constraints control design for uncertain nonlinear systems via a unified boundary modification approach

This paper investigates the tracking control problem of uncertain nonlinear systems under secure full-state constraints. Existing results implicitly assume that the constraints are reasonable and feasible control strategy capable of maintaining such constraints exists, which is unrealistic, especially for uncertain nonlinear systems, pre-determining the controllable attractor domain poses a challenge. In this paper, we present a unified boundary modification approach, which addresses the incompatibility problem between state constraints and ensures the secure operation of the system. First, we complete the direct constraints on the states using nonlinear state-dependent functions, where constraints comprise two components: (1) user-specified boundaries and (2) dynamic modification part. Then, we construct detection variables to determine whether the system loses control due to incompatible constraints. When the system enters the collision avoidance region, the dynamic adjustment function automatically corrects the constraints to ensure controllability and stability. The dynamic adjustment function remains inactive when the system operates within the safe region. Thus, existing state constraint results are a special case of ours. Moreover, we introduce a novel transformation so that the initial conditions of virtual controller are not restricted by the barrier function. The solution is more flexible in design and implementation, and the tracking error is confined within the specified performance envelope. Finally, numerical simulations validate the effectiveness of the approach.

Green Modification Approach Using Novel Viscosity Stabilizer for Inhibiting Storage Hardening of Natural Rubber

Green Modification Approach Using Novel Viscosity Stabilizer for Inhibiting Storage Hardening of Natural Rubber

Strategy To Enhance Interfacial Properties: Preparation of Porous Polytetrafluoroethylene Fibers and the Adsorption of Initiators/Curing Agents.

Polytetrafluoroethylene (PTFE) fibers exhibit high inertness and demonstrate limited interfacial bonding capabilities with other materials. To overcome this limitation, PTFE@ZnO fibers were developed by depositing the porous ZnO layer onto PTFE fibers via a hydrothermal reaction, and porous fibers were adsorbed curing agents or initiators. The interfacial shear strength (ILSS) of the composites demonstrated a significant improvement, particularly in the case of composites containing PTFE/initiator fibers, where the ILSS increased by 104.8% compared to PTFE alone (from 8.3 to 17.0 MPa). The digital image correlation (DIC) method revealed a more uniform stress distribution in the modified fiber composites at the point of fracture. Additionally, nanoscratch tests indicated a significant enhancement in the interfacial bonding between the modified fibers and the resin. The porous structures facilitated mechanical interlocking between the modified fibers and the resin. Furthermore, the presence of an adsorbed initiator/curing agent within the porous structure served as the initiation site for the free radical polymerization of vinyl ester resin 901, thereby enhancing the interfacial bonding between the modified fibers and the resin. The novel strategy presents a general and viable approach for the extensive modification of PTFE fibers, focusing on achieving exceptional interfacial bonding properties.

Hierarchical Tough Hydrogel with Enhanced Rigidity and Extensibility for Strain Sensing, Posture Guide, and Injury‐Prevention

AbstractHydrogels, as valuable biomaterials, have limited applications owing to their mechanical fragility. This study presents a structural modification approach to strengthen hydrogels mechanically. First, the precursor hydrogel undergoes deformation through stretching and twisting, resulting in a helical polymer structure and a deformation gradient. This deformed structure is then stabilized by densification and additional crosslinking. The twisted hydrogel shows improved extensibility and toughness owing to enhanced stress transfer in its unique structure. Additionally, multiple hydrogel strands are assembled hierarchically into ropes and cables, exhibiting advantageous mechanical properties such as high energy dissipation and durability. These reinforced mechanical features lead to considerable performance improvements in applications such as strain sensing and impact absorption. Furthermore, practical utility is demonstrated in areas including posture correction and injury prevention. The hydrogel reinforced by this method has the potential to be used in various fields where both mechanical properties and biocompatibility are crucial.

Improved non‐cascaded continuous‐set model‐free predictive control scheme for PMSM drives

AbstractThis article presents an improved multiple‐step model‐free predictive control (MS‐MFPC) method for permanent magnet synchronous motor (PMSM) drives. Specifically, a reduced‐order MS‐MFPC based on an ultra‐local model, which employs only the input and output of the plant without addressing any motor parameters, is developed to enhance the robustness and reliability of the non‐cascaded PMSM system in the presence of parametric uncertainties. Meanwhile, the decoupled form of algebraic ultra‐local model is derived to extend the prediction horizon to multiple steps without increasing the computational burden. Besides, in order to improve the dynamic performance, an online adaptive modification approach is embedded into this suggested design to enhance the cost function calculation for the first time. Compared with the conventional continuous control set‐model predictive control (CCS‐MPC) method, our development not only achieves the smaller overshoot, settling time and steady‐state error, but also attenuates the inherent issue of system uncertainties in widely existing industrial application. Finally, the proposed MS‐MFPC methodology is experimentally assessed for a PMSM test bench, where steady‐state and transient‐state performance tests confirm the interest of the proposal.

Dietary diversity and nutritional status of children with and without autism spectrum disorder: a comparative cross-sectional study in Bangladesh

ObjectivesThe objective of our study was to compare the dietary diversity and nutritional status of children with autism spectrum disorders (ASD) and non-ASD.MethodsWe included a total of 344 children in this cross-sectional study; of them,172 non-ASD children from three public schools and 172 ASD children from six special schools in Dhaka, Bangladesh. We used a multinomial logistic regression model to assess the association of ASD with nutritional status and dietary diversity among children.ResultsThe mean age of the children was 7.9 years; 29.7% were female. ASD children were more likely to be overweight and obese compared to the non-ASD group (RRR: 2.85, 95% CI 1.28–6.34, p-value 0.011). ASD children had lower dietary diversity than non-ASD children (RRR: 18.57, 95% CI 4.49–76.77, p-value < 0.001). Children with ASD had a significantly lower daily frequency of intake of food from starchy roots, sugars, preserves and syrups, meat, fish and eggs, milk and milk products than non-ASD children (p-value < 0.05). However, consumption of cereals, vegetables and fruits, fats and oils, and beverages was almost similar for both groups of children.ConclusionsASD children had a higher risk of being overweight and obese and a lower dietary diversity. We recommend robust longitudinal studies to explore the role of tailored intervention approaches for dietary behavior modification and weight management.

Interface Issues of Layered Transition Metal Oxide Cathodes for Sodium-Ion Batteries: Current Status, Recent Advances, Strategies, and Prospects.

Sodium-ion batteries (SIBs) hold significant promise in energy storage devices due to their low cost and abundant resources. Layered transition metal oxide cathodes (NaxTMO2, TM = Ni, Mn, Fe, etc.), owing to their high theoretical capacities and straightforward synthesis procedures, are emerging as the most promising cathode materials for SIBs. However, the practical application of the NaxTMO2 cathode is hindered by an unstable interface, causing rapid capacity decay. This work reviewed the critical factors affecting the interfacial stability and degradation mechanisms of NaxTMO2, including air sensitivity and the migration and dissolution of TM ions, which are compounded by the loss of lattice oxygen. Furthermore, the mainstream interface modification approaches for improving electrochemical performance are summarized, including element doping, surface engineering, electrolyte optimization, and so on. Finally, the future developmental directions of these layered NaxTMO2 cathodes are concluded. This review is meant to shed light on the design of superior cathodes for high-performance SIBs.

Maximizing Nano-Silica Efficiency in Laboratory-Simulated Recycled Concrete Aggregate via Prior Accelerated Carbonation: An Effective Strategy to Up-Cycle Construction Wastes.

Herein, the study explores a composite modification approach to enhance the use of recycled concrete aggregate (RCA) in sustainable construction by combining accelerated carbonation (AC) and nano-silica immersion (NS). RCA, a major source of construction waste, faces challenges in achieving comparable properties to virgin aggregates. Nano-silica, a potent pozzolan, is added to fill micro-cracks and voids in RCA, improving its bonding and strength. AC pretreatment accelerates RCA's natural carbonation, forming calcium carbonate that strengthens the aggregate and reduces porosity. Due to the complexity of the original RCA, a laboratory-simulated RCA (LS-RCA) is used in this study for the mechanism analysis. Experimental trials employing the composite methodology have exhibited noteworthy enhancements, with the crushing index diminishing by approximately 23% and water absorption rates decreasing by up to 30%. Notably, the modification efficacy is more pronounced when applied to RCA derived from common-strength concrete (w/c of 0.5) as compared to high-strength concrete (w/c of 0.35). This disparity stems from the inherently looser structural framework and greater abundance of detrimental crystal structures in the former, which impede strength. Through a synergistic interaction, the calcium carbonate content undergoes a substantial increase, nearly doubling, while the proportion of calcium hydrate undergoes a concurrent reduction of approximately 30%. Furthermore, the combined modification effect leads to a 15% reduction in total porosity and a constriction of the average pore diameter by roughly 20%, ultimately resulting in pore refinement that equates the performance of samples with a water-to-cement ratio of 0.5 to those with a ratio of 0.35. This remarkable transformation underscores the profound modification potential of the combination approach. This study underscores the efficacy of harnessing accelerated carbonation in conjunction with nano-silica as a strategic approach to optimizing the utilization of RCA in concrete mixes, thereby bolstering their performance metrics and enhancing sustainability.

Cationic Coordination Modification Drives Birefringence and Nonlinear Effect Double Lifting in Sulfate.

As nonlinear optical (NLO) crystals, sulfates have the superiority of transparency for ultraviolet (UV) light, but they are often troubled by small nonlinear coefficients and birefringence owing to the high symmetry of the [SO4]2- group. By introducing two neutral diethylenetriamine (DETA) molecules to replace the six coordinated water molecules of the [Zn(H2O)6]2+ complex cation in [Zn(H2O)6](SO4)(H2O), a new sulfate with an acentric structure, namely, [Zn(DETA)2](SO4)(H2O)3, has been designed and synthesized. Structural investigation reveals that the coordination modification of Zn2+ ion tremendously enhances its intraoctahedral distortion. The formed distorted [Zn(DETA)2]2+ cations and the [SO4]2- groups feature an optimized arrangement, endowing [Zn(DETA)2](SO4)(H2O)3 with enhancements in both second harmonic generation (SHG) intensity, from undetectable to 0.25 × KH2PO4 (KDP), and birefringence, from 0.014 to 0.042 at 1064 nm. Despite the slight compromise made in the light transmission range, [Zn(DETA)2](SO4)(H2O)3 still possesses a short absorption edge of 220 nm, retaining the majority of the light transmission range in the solar-blind region. Our work provides a novel and applicable approach of cationic coordination modification to improve the nonlinear optical coefficient and birefringence of sulfates.

Chemical engineering of CRISPR-Cas systems for therapeutic application.

Clustered regularly interspaced short palindromic repeats (CRISPR) technology has transformed molecular biology and the future of gene-targeted therapeutics. CRISPR systems comprise a CRISPR-associated (Cas) endonuclease and a guide RNA (gRNA) that can be programmed to guide sequence-specific binding, cleavage, or modification of complementary DNA or RNA. However, the application of CRISPR-based therapeutics is challenged by factors such as molecular size, prokaryotic or phage origins, and an essential gRNA cofactor requirement, which impact efficacy, delivery and safety. This Review focuses on chemical modification and engineering approaches for gRNAs to enhance or enable CRISPR-based therapeutics, emphasizing Cas9 and Cas12a as therapeutic paradigms. Issues that chemically modified gRNAs seek to address, including drug delivery, physiological stability, editing efficiency and off-target effects, as well as challenges that remain, are discussed.

The Importance of Catalytic Effects in Hot-Electron-Driven Chemical Reactions.

Hot electrons (HEs) represent out-of-equilibrium carriers that are capable of facilitating reactions which are inaccessible under conventional conditions. Despite the similarity of the HE process to catalysis, optimization strategies such as orbital alignment and adsorption kinetics have not received significant attention in enhancing the HE-driven reaction yield. Here, we investigate catalytic effects in HE-driven reactions using a compositional catalyst modification (CCM) approach. Through a top-down alloying process and systematic characterization, using electrochemical, photodegradation, and ultrafast spectroscopy, we are able to disentangle chemical effects from competing electronic phenomena. Correlation between reactant energetics and the HE reaction yield demonstrates the crucial role of orbital alignment in HE catalytic efficiency. Optimization of this parameter was found to enhance HE reaction efficiency 5-fold, paving the way for tailored design of HE-based catalysts for sustainable chemistry applications. Finally, our study unveils an emergent ordering effect in photocatalytic HE processes that imparts the catalyst with an unexpected polarization dependence.