Interfacial Affinity Research Articles

Boosted performance of thin-film nanocomposite membranes based on phytic acid functionalized Zr-MOF for nanofiltration

Endowed with designable pore structure and intrinsically interconnected channels, metal-organic frameworks (MOFs) offer immense potential as functional nanofillers to boost the performance of nanocomposite membranes. However, achieving optimal pore size matching between MOFs and the polymer matrix while maintaining robust interfacial affinity remains a significant challenge in fabricating high-performance nanocomposite membranes. Herein, natural organic polyphosphate phytic acid was utilized to functionalize PCN-224 to narrow its pore size and enhance the polymer affinity. Thin-film nanocomposites containing mPCN-224 were afterward synthesized on the polysulfone support through a combined approach of anodic electrophoretic deposition (EPD) and vacuum filtration-assisted interfacial polymerization (VF-IP). The incorporation of mPCN-224 nanoparticles not only enhanced the hydrophilicity and electronegativity of the polyamide film but also led to a substantial reduction in film thickness. This is likely attributed to lessened piperazine supply at the interface, related to its limited diffusion at the presence of negatively charged mPCN-224. The additional nanochannels provided by mPCN-224, coupled with the loose PA layer, resulted in a substantial 56.3 % increase in the water permeance of the TFN-mPCN-224 membrane, reaching 20.0 L m−2 h−1 bar−1. Additionally, the post-synthesis modification with phytic acid led to an improved Cl−/SO42− selectivity coefficient of 44, substantially higher than that of the TFN-PCN-224 membrane. This improvement was primarily attributed to the narrowed pore size of mPCN-224 and the enhanced surface electronegativity. This study introduces a pathway for developing high-performance TFN membranes based on post-synthetic modification of MOF nanofillers with phytic acid molecules.

Thermal conductivity of epoxy/multilayered graphene composites prepared with different curing agents

Epoxy/multilayer graphene (ML-graphene) composites were prepared using different curing agents to control the graphene dispersion by changing the curing reactivity. With increasing initial reactivity, the aggregation size of the ML-graphene decreased and their thermal conductivity increased. In particular, the thermal conductivity of the composite prepared with p-phenylenediamine showed a maximum value of 1.46 W/(m·K) at 25 wt% ML-graphene loading because of the highest initial curing reactivity. The application of a magnetic field led to graphene alignment along the applied field, resulting in two times higher thermal conductivity than that of the corresponding system without magnetic field. The relationship between the interfacial affinity for epoxy/graphene and thermal conductivity was also investigated. As a result, resulting in a biphenyl epoxy composite showed higher thermal conductivity (6.17 W/(m·K)) than that of the bisphenol-A epoxy composite. This is derived that the π-conjugated and planar structure of biphenyl epoxy can easily interact with the surface of graphene.

High internal phase Pickering emulsions stabilized by Zein-hyaluronic acid conjugate particles and their application in active substances protection

In recent years, active substances have been extensively applied in the fields of food, cosmetics, and pharmaceuticals. However, their preservation and transportation have posed challenges due to issues such as oxidation and photodegradation. This study proposes a method for synthesizing Zein-Hyaluronic Acid (Zein-HA) conjugate particles via the Schiff base reaction, utilizing these conjugate particles to encapsulate and protect active substances within a stable emulsion system. Compared to zein, the modified conjugate particles exhibit significantly improved dispersibility, amphiphilicity, interfacial affinity, and emulsifying properties. Consequently, these particles are capable of stabilizing high internal phase Pickering emulsions with an oil phase volume fraction of up to 80 (v/v)%, thereby enabling the carriage of a higher load of active components. Furthermore, the prepared emulsions demonstrate excellent storage stability, resistance to ionic strength (250–2000 mM NaCl), and outstanding antioxidative characteristics. Moreover, after 8 h of UV light exposure, the retention rates of the active substances (curcumin, astaxanthin, and resveratrol) exceed 60 %. Therefore, these emulsions hold substantial potential to be applied as a carrier system in the food, cosmetics, and pharmaceutical industries.

Harnessing Ion‐Dipole Interactions for Water‐Lean Solvation Chemistry: Achieving High‐Stability Zn Anodes in Aqueous Zinc‐Ion Batteries

AbstractThe reversibility and stability of aqueous zinc‐ion batteries (AZIBs) are largely limited by water‐induced interfacial parasitic reactions. Here, dimethyl(3,3‐difluoro‐2‐oxoheptyl)phosphonate (DP) is introduced to tailor primary solvation sheath and inner‐Helmholtz configurations for robust zinc anode. Informed by theoretical guidance on solvation process, DP with high permanent dipole moments can effectively substitute the coordination of H2O with charge carriers through relatively strong ion‐dipolar interactions, resulting in a water‐lean environment of solvated Zn2+. Thus, interfacial side reactions can be suppressed through a shielding effect. Meanwhile, lone‐pair electrons of oxygen and fluorinated features of DP also reinforce the interfacial affinity of metallic zinc, associated with exclusion of neighboring water to facilitate reversible zinc planarized deposition. Thus, these merits endow the Zn anode with a high‐stability performance exceeds 3800 hours at 0.5 mA cm−2 and 0.5 mAh cm−2 for Zn||Zn batteries and a high average Coulombic efficiency of 99.8 % at 4 mA cm−2 and 1 mAh cm−2 for Zn||Cu batteries. Benefiting from the stable zinc anode, the Zn||NH4V4O10 cell maintains 80.3 % of initial discharge capacity after 3000 cycles at 5 A g−1 and exhibits a high retention rate of 99.4 % against to the initial capacity during the self‐discharge characterizations.

Fully Recycled Polyolefin Elastomer-Based Vitrimers with Ultra-High, Universal, Stable, and Switchable Adhesion.

Achieving both robust adhesion to arbitrary surfaces and thermal-switchable/recyclable properties has proven challenging, particularly for commodity polyolefins. Herein, a simple and effective route is reported to transform polyolefins elastomer (POE) into a fully recycled epoxy-functionalized POE vitrimers (E-POE vit) with ultra-high, universal, stable, and switchable adhesion via facile free radical grafting and dynamic cross-linking. The resultant E-POE vit exhibits increase in adhesion strength on glass exceeding three to ten times compared to those commonly used polymers, due to the synergy of dense hydrogen (H)-bonds and strong interfacial affinity. In addition, E-POE vit also displays strong adhesion on diverse surfaces ranging from inorganic to organic while maintaining good stability in various harsh environments. More importantly, temperature-sensitive H-bonds allow E-POE vit to switch between attachment-detachment at alternating temperatures, resulting in reversible adhesion without adhesion loss, even after 10 cycles. Moreover, E-POE vit is able to be fully recycled and reused more than ten times via thermo-activated transesterification reactions with negligible change in structure and performance. This work may unlock strategies to fabricate high-performance commercial polymer-based adhesives with adhesion and recyclable features for intelligent and sustainable applications.

A Highly Stable, Multifunctional Janus Dressing for Treating Infected Wounds.

The limited and unstable absorption of excess exudate is a major challenge during the healing of infected wounds. In this study, a highly stable, multifunctional Janus dressing with unidirectional exudate transfer capacity is fabricated based on a single poly(lactide caprolactone) (PLCL). The success of this method relies on an acid hydrolysis reaction that transforms PLCL fibers from hydrophobic to hydrophilic in situ. The resulting interfacial affinity between the hydrophilic/phobic PLCL fibers endows the Janus structure with excellent unidirectional liquid transfer and high structural stability against repeated stretching, bending, and twisting. Various other functions, including wound status detection, antibacterial, antioxidant, and anti-inflammatory properties, are also integrated into the dressing by incorporating phenol red and epigallocatechin gallate. An in vivo methicillin-resistant Staphylococcus aureus-infected wound model confirms that the Janus dressing, with the capability to remove exudate from the infected site, not only facilitates epithelialization and collagen deposition, but also ensures low inflammation and high angiogenesis, thus reaching an ideal closure rate up to 98.4% on day 14. The simple structure, multiple functions, and easy fabrication of the dressing may offer a promising strategy for treating chronic wounds, rooted in the challenges of bacterial infection, excessive exudate, and persistent inflammation.

Constructing interfacial chemical interaction of dual-carbon protected cobalt diselenide anode for sodium storage

Transition metal selenides are attracting enormous attention due to their high theoretical capacity and appropriate working potential for sodium storage, while their intrinsic low electronic conductivity and large volume expansion during the cycling processes inevitably result in inadequate rate performance and inferior cycling stability. Herein, cobalt diselenide-based hollow sugarloaf-like self-supporting fiber membranes with strong interfacial chemical (Co-C) bonds have been reported for sodium-ion batteries (SIBs) via the dual-carbon protection strategy. Based on X-ray photoelectron spectroscopy (XPS) and X-ray absorption spectroscopy (XAS) combined with density functional theory (DFT), A built-in electric field is generated at the interface between CoSe2/C and CNFs, which provides a strong driving force for electron transfer and ion migration, making the optimal CoSe2/C−0.3@CNFs anode over 67.8 % of capacity retention from 0.1 to 5 A/g and maintained about 269.5 mAh/g of discharge capacity at 5 A/g. The strong interfacial Co-C bonds in CoSe2/C@CNFs enhance the interfacial affinity between CoSe2/C and CNFs, making it easier for CoSe2/C to trap sodium ions and effectively resist the volume expansion during cycling, thus showing excellent cyclic stability with a reversible capacity of 247.6 mA h g−1 at 1.0 A/g after 2600 cycles. The sodium storage mechanism of CoSe2/C−0.3@CNFs electrode in SIBs is systematically analyzed via in-situ XRD and in-situ Raman spectra. This study provides an effective approach to constructing heterostructured composites with strong chemical bonds and built-in electric field characteristics for high-rate capability and long-cycle stability SIBs. Moreover, the sodium ion diffusion kinetics in the CoSe2/C−0.3@CNFs anode is also revealed.

Synergetic sludge conditioning by US enhanced Fe2+ activated sodium persulfate: Physicochemical properties and mechanisms

Efficient dewatering of sewage sludge is an energy- and carbon-saving procedure for sludge treatment in wastewater treatment facilities. The ultrasound-coupled divalent iron ion activated persulfate process can effectively promote sludge dewatering and improve organic substance content. Under the action of ultrasound (US 50 w/L), divalent iron ions (Fe2+) 200 mg/g (TS), and persulfate (PDS) 200 mg/g (TS) for 60 min, the capillary suction time (CST) was reduced by 79.74%, and the moisture content of the dewatered sludge cake reached 56.51 wt%. The organic carbon content of treated sludge was also four times higher than the original sludge and types were richer in short-chain volatile species in US/Fe2+/PDS. Moreover, the correlation analysis found that the relationship of between CST and SV30, Zeta and lactate dehydrogenase (LDH) were positive correlation, and the relationship of SCOD and TC were positively correlated with the PN (SB-EPS). Mechanistic studies showed that the US/Fe2+/PDS system could produce oxygen activators by US coupling Fe2+ to strengthen the effect of activated PDS strongly, while the sulfate radicals (SO4·-) radical was a dominant role. The cracking mechanism is divided into two pathways effectively degraded the macromolecule EPS into a small-molecule acid and further reduced the water-holding interfacial affinity as follow: (1) the radical path dominated by hydroxyl radicals (·OH), SO4·-, and superoxide radical (O2·-); (2) the non-radicals dominated by monoclinic oxygen (1O2). Afterwards, the electrostatic force and interfacial free energy were reduced, resulting in enhanced self-flocculation and mobility to enhanced dewaterability. These findings demonstrated the US/Fe2+/PDS system had significant advantages in sludge cracking and provided theoretical support for its practical application.

Molecular recognition on the surface of concentrated hydrochloric acid: Hydration configuration-driven preferential recognition of Rh (III) anions with inner-coordinated water molecules

Comprehension of selective recognition of anions is confined to a phenomenological list of solvents, hardly surpassing Pedersen’s empirical observations of cationic-crown ether binding. In this work, a novel strategy employing thin-layer oil membrane extraction (TOMX) on the surface of concentrated hydrochloric acid is proposed for controllable recognition and separation of anions with different hydration configurations. Four typical chloric-complexing anions, RhCl63−, PdCl42−, PtCl62− and FeCl4−, usually coexisting in the concentrated hydrochloric acid leaching solutions of precious metal concentrates were focused. A surprising phenomenon was noticed that the octahedral RhCl5(H2O)2− anions with inner-coordinated water molecules were preferentially recognized by 18C6 macrocyclic molecule. However, the planar quadrilateral Pd (II) chloric-complexing anions with a hydration configuration via water molecules attacking the central Pd (II) atoms along the Z-axis direction can be separated subsequently. The Pt (IV) and Fe (III) chloric-complexing anions respectively with an octahedral and tetrahedral outer-coordinated hydration shell configuration were the last to be recognized. Such an order in extracting Rh (III) > Pd (II) > Pt (IV) > Fe (III) anions depends on their hydration capacity and the preferential affinity towards the interface, which is almost impossible during the conventional stirring and oil droplet dispersed extraction. Because of a lower concentration of dissociated hydrogen ions on the surface of concentrated hydrochloric acid compared to its bulk concentrations, the hydration of those chloric-complexing anions was enhanced. The Rh (III) anions with inner-coordinated water molecules exhibit a higher interfacial affinity than other anions. The water molecules entering the inner coordination layer of Rh (III) chloric-complexing anions, cooperating with its outer-coordinated hydration shell, act as a hydrogen bond “water bridge” to interact with 18C6 molecules, which makes it easier to feel the influence from the aqueous laminar shear flow under the thin-layer oil membrane, thereby driving the preferential recognition of easily hydrated Rh (III) anions at the interface. The controllable “water bridge” interactions driven by shear flow can be activated or deactivated on the surface of concentrated hydrochloric acid by adjusting the shear flow rate. This work lays a foundation for the future development of a controllable flexible molecular recognition technology at liquid–liquid interfaces.

A Janus membrane with electro-induced multi-affinity interfaces for high-efficiency water purification.

Drinking water with micropollutants is a notable environmental concern worldwide. Membrane separation is one of the few methods capable of removing micropollutants from water. However, existing membranes face challenges in the simultaneous and efficient treatment of small-molecular and ionic contaminants because of their limited permselectivity. Here, we propose a high-efficiency water purification method using a low-pressure Janus membrane with electro-induced multi-affinity. By virtue of hydrophobic and electrostatic interactions between the functional interfaces and contaminants, the Janus membrane achieves simultaneous separation of diverse types of organics and heavy metals from water via single-pass filtration, with an approximately 100% removal efficiency, high water flux (>680 liters m-2 hour-1), and 98% lower energy consumption compared with commercial nanofiltration membranes. The electro-induced switching of interfacial affinity enables 100% regeneration of membrane performance; thus, our work paves a sustainable avenue for drinking water purification by regulating the interfacial affinity of membranes.

A novel approach for sludge deep-dewatering via flowing-out enhancement but not relying on cell lysis and bound water release

Effective deep-dewatering is crucial for wastewater sludge management. Currently, the dominant methods focus on promoting cell lysis to release intracellular water, but these techniques often lead to secondary pollution and require stringent conditions, limiting their practical use. This study explores an innovative method using a commercially available complex quaternary ammonium salt surfactant, known as G-agent. This agent remarkably reduces the sludge water content from 98.6 % to 56.8 % with a low dosage (50 mg/g DS) and under neutral pH conditions. This approach surpasses Fenton oxidation in terms of dewatering efficiency and avoids the necessity for cell lysis and bound water release, thereby reducing the risk of secondary pollution in the filtrate, including heavy metals, nitrogen, phosphorus, and other contaminants. The G-agent plays a significant role in destabilizing flocs and enhancing flocculation during the conditioning and initial dewatering stages, effectively reducing the solid-liquid interfacial affinity of the sludge. In the compression filtration stage, the agent's solidification effect is crucial in forming a robust skeleton that improves pore connectivity within the filter cake, leading to increased water permeability, drainage performance and water flow-out efficiency. This facilitates deep dewatering of sludge without cell lysis. The study reveals that the G-agent primarily improves water flow-out efficiency rather than water flowability, indicating that cell lysis and bound water release are not indispensable prerequisites for sludge deep-dewatering. Furthermore, it presents an encouraging prospect for overcoming the limitations associated with conventional sludge deep-dewatering processes.

Self-Sorting of Interfacial Compatibility in MOF-Based Mixed Matrix Membranes.

Metal-organic framework (MOF)-based mixed matrix membranes (MMMs) have shown great promises to overcome the performance upper limit of polymeric membranes for various gas separation processes. However, the gas separation properties of the MMMs largely depend on the MOF-polymer interfacial compatibility which is a metric difficult to quantify. In most cases, whether a MOF filler and a polymer matrix make a good pair is not revealed until the gas transport experiments are performed. This is because there is a lack of characterization techniques to directly probe the MOF-polymer interfacial compatibility. In this work, we demonstrate a self-sorting method to rank the interface compatibility among several MOF-polymer pairs. By mixing one MOF with two polymers in an MMM, the demixing of two polymers will form two polymer domains. The MOF particles will preferably partition into the "preferred" polymer domain due to their higher interfacial affinity. By scanning different polymer pairs, a rank of MOF-polymer interfacial compatibility from high to low can be obtained. Moreover, based on this ranking, it was also found that a highly compatible MOF-polymer pair suggested by this method also corresponds to a more predictable MMM gas separation performance.

Self‐Sorting of Interfacial Compatibility in MOF‐Based Mixed Matrix Membranes

AbstractMetal–organic framework (MOF)‐based mixed matrix membranes (MMMs) have shown great promises to overcome the performance upper limit of polymeric membranes for various gas separation processes. However, the gas separation properties of the MMMs largely depend on the MOF‐polymer interfacial compatibility which is a metric difficult to quantify. In most cases, whether a MOF filler and a polymer matrix make a good pair is not revealed until the gas transport experiments are performed. This is because there is a lack of characterization techniques to directly probe the MOF‐polymer interfacial compatibility. In this work, we demonstrate a self‐sorting method to rank the interface compatibility among several MOF‐polymer pairs. By mixing one MOF with two polymers in an MMM, the demixing of two polymers will form two polymer domains. The MOF particles will preferably partition into the “preferred” polymer domain due to their higher interfacial affinity. By scanning different polymer pairs, a rank of MOF‐polymer interfacial compatibility from high to low can be obtained. Moreover, based on this ranking, it was also found that a highly compatible MOF‐polymer pair suggested by this method also corresponds to a more predictable MMM gas separation performance.

Phospholipid Membrane Interactions of Model Ac-WL-X-LL-OH Peptides Investigated by Solid-State Nuclear Magnetic Resonance.

The role of aromatic amino acids in peripheral protein membrane binding has been reported to involve cation-π interactions with choline lipids. In this study, we have investigated the interactions of the model pentapeptide Ac-WL-X-LL-OH (where X = L, Y, F, or W) with the phospholipid membrane using solid-state NMR. The effect of guest residue X on the peptide-lipid interactome was complementary to the seminal report on the interfacial hydrophobicity scale by Wimley and White. We found that the phospholipids retained a lamellar phase in the presence of each of the peptides with an aromatic X residue, whereas the Leu peptide perturbed the bilayer to an extent where an additional isotropic phase was observed. The solid-state NMR 13C and 31P data provide additional information on the influence of these short peptides on the membrane that has not been previously reported. The magnitude of membrane perturbation was in the order of guest residue X = L > Y~F > W, which is consistent with the relative amino acid interfacial affinity reported by Wimley and White. Further work is, however, required to uncover the behavior of the peptide and localization in the membrane domain due to ambiguity of the 13C NMR data. We have launched efforts in this regard for the objective of better understanding the role of aromatic amino acids in peripheral membrane protein binding.

Enhancing permeability and mechanical properties of rubber cement-based materials through surface modification of waste tire rubber powder

In this study, the authors present a detailed investigation into the surface mineralization of recycled rubber powder (RP) to enhance its performance in cement mortars. A modified rubber, referred to as RTC, is produced by employing a straightforward and efficient method involving the deposition of tannic acid (TA) and calcium carbonate (CaCO3, <5 μm) on the surface of RP. The main objective of this research is to elucidate the impact of RTC on the impermeability, mechanical properties, and pore structure of rubberized mortar. Through a comprehensive set of characterizations and tests, we demonstrate the successful deposition of TA and CaCO3 on the RP surface, resulting in RTC with excellent chemical activity and hydrophilicity, while also providing nucleation sites for hydration products. This modification process facilitated improved interfacial affinity with cement paste, enhancing bonding between rubber and cement paste. Remarkably, the incorporation of rubber into mortars with markedly enhanced resistance to permeation, with RTC mortars demonstrating particularly noticeable improvement. The marginal decrease in density in comparison to conventional mortars arises from the rubber's lightweight properties. Moreover, rubber exerts a minor adverse influence on hydration kinetics, yet this detrimental impact is alleviated in mortars incorporating RTC. Notably, the study elucidates the nuanced changes in porosity induced by rubber incorporation, underscoring its influence on the mechanical performance of rubberized cement mortars. The RTC5 mortar with a 5% content demonstrates the most remarkable enhancement compared to RP5 mortar. Overall, this study highlights the potential of surface mineralization of RP as a promising approach for improving the performance of rubberized cement mortars.

Study on the Effect of Residual Polymer Superplasticizer on the Properties of Graphene-Cement Composites.

Graphene, renowned for its exceptional mechanical, thermal, and electrical properties, is being explored as a cement nanofiller in the construction field. However, the limited water dispersibility of graphene requires the use of polymer superplasticizers, such as polycarboxylate ether (PCE). Previous studies have investigated the mechanisms by which PCE facilitates the dispersion of graphene within cement nanocomposites. However, such studies have made minimal progress, indicating a lack of understanding of the effect of residual PCE (rPCE) remaining in aqueous solution without binding to graphene. In this study, the effects of rPCE on the dispersion of graphene and the mechanical properties of graphene-cement composites (GCCs) were systematically analyzed. For this purpose, the content of rPCE was accurately measured through the centrifugation process and thermal analysis of graphene dispersion with PCE, and the result was 78.0 wt.% compared to graphene. The optical microscopy, particle size analysis, and contact angle measurement of the graphene dispersions with and without rPCE confirmed that rPCE is crucial for the dispersion of graphene and the enhancement of the interfacial affinity between graphene and cement. Additionally, the compressive strength of GCC with rPCE exhibited a substantial enhancement of approximately 10% (68.36 MPa) compared to plain cement (62.33 MPa). The effectiveness of rPCE in enhancing compressive strength correlated with the uniform dispersion of graphene within GCC and the promotion of cement hydration, as evidenced by field emission scanning electron microscopy and X-ray diffraction, respectively.

Facile synthesis of Pd loaded g-C3N4/TiO2 heterojunction catalyst with enhanced photothermal catalytic performance in Suzuki coupling under moderate condition

Photothermal synergistic catalysis of Suzuki-Miyaura coupling reaction not only utilizes the solar energy efficiently, but also reduces the energy consumption. It is a green organic synthesis method for constructing C–C bonds, which has a wide application. In this work, we constructed a PdO/g-C3N4/TiO2 bilayer tubular structure material with a heterojunction structure by a simple and effective method. The catalyst exhibited efficient photothermal synergistic catalytic performance in Suzuki coupling reaction under visible light irradiation. The influence of the catalyst’s structure, morphology, composition, and photothermal response on the Suzuki coupling reaction were discussed based on a series of characterizations and activity test of the catalyst. The results showed that the PdO/g-C3N4/TiO2 catalyst contained an effective g-C3N4/TiO2 heterojunction structure. Under visible illumination, the differences in interfacial charge concentration and electron affinity between these two different types of semiconductors lead to charge rearrangement and transfer, which greatly improves the carrier separation efficiency. Meanwhile, palladium metal exhibits excellent electron deposition effects, both as an active metal center for SMC reactions and as an electron acceptor for facilitating photoelectron transfer. Electron-rich palladium atoms play an important role in C–C bond formation reactions, improving catalytic efficiency. The PdO/g-C3N4/TiO2 catalyst has excellent catalytic activity and can catalyze the SMC reaction under visible light and at 0 ℃, the yield reached 85.6%, which is comparable to the activity of thermal catalysis for 15 minutes. Furthermore, after five cycles, the PdO/g-C3N4/TiO2 catalyst still maintained an 83.1% yield, demonstrating excellent cycle stability. This article offers an effective strategy for preparing heterojunction catalyst with visible light response for photothermal reaction and presents the potential of these catalysts as a way to improve the efficiency and sustainability of Suzuki coupling reactions.

Fabricating advanced MXene-based hybrid materials to elevate fire safety and mechanical strength in carbon fiber-reinforced bismaleimide resins

Bismaleimide (BMI) resin holds great significance to the aerospace field, however, the limited toughness and inadequate fire resistance impede its broader application area. The addition of carbon fiber (CF) can enhance the toughness of BMI resin, but fire safety and interfacial stability between CF and BMI matrix need to be further considered. Here, the carbon fiber-reinforced BMI resin laminate was designed to improve fire resistance, mechanical properties, and interfacial affinity based on a novel P, N, and Si surface-modified flame retardant (MX@HBET) and silane-modified CF. Upon addition of 1 wt% MX@HBET to BMI/CF composites, the total heat release and total smoke production respectively exhibited 10.73 % and 33.3 % reduction. Furthermore, the laminate exhibited significant fire resistance when exposed to butane flame (1500 °C) and the backplane temperature was maintained at approximately 430 °C for 20 min. In addition, the impact and tensile strengths of the laminate respectively reached 82.10 kJ/m2 and 466.6 MPa (pure BMI/CF corresponding to 63.52 kJ/m2 and 350.1 MPa). In brief, the flame resistance and mechanical performance enhanced greatly via the introduction of modified MXene and CF, providing promising prospects for the application of aviation materials in extreme conditions.

In-situ generation of iron activated percarbonate for sustainable sludge dewatering

Effective dewatering of sewage sludge could potentially address the issues of high energy consumption and large carbon footprint inherent in the sludge treatment process, advancing toward carbon neutrality in environmental remediation. Yet, the surface hydrophilic characteristics and water-holding interfacial affinity in sludge led to dwindled sludge-water separation performance. Here, the integration of in-situ generation of iron from zero-valent scrap iron (ZVSI) and sodium percarbonate (SPC) was attempted to attenuate the water-retaining interfacial affinity within sludge, thus achieving superior sludge dewatering performance. Results showed that under the optimal conditions, the ZVSI + SPC system led to a remarkable decline of 76.09 % in the specific resistance to filtration of the sludge, accompanied by a notable decline of 34.96 % in the water content. Moreover, the utilization of ZVSI + SPC system could be a viable alternative to the traditional strategies in terms of enhanced sludge dewaterability, offering application potential with stable operating performance, economic feasibility, and reduced carbon emissions. Investigation into dewatering mechanism revealed that ZVSI could maintain the Fe3+/Fe2+ in a stable dynamic cycle and continuously in-situ generate Fe2+, thereby efficaciously fostering the SPC activation for the ceaseless yield of reactive oxygen species. The predominant •OH and 1O2 efficiently decomposed the hydrophilic biopolymers, therefore minimizing the hydrophilic protein secondary structures, along with the hydrogen and disulfide bonds within proteins. Subsequently, the water-holding interfacial affinity was profoundly diminished, leading to intensified hydrophobicity, self-flocculation, and dewaterability. These findings have important implications for the advancement of efficacious ZVSI + SPC conditioning techniques toward sustainable energy and low-carbon prospects.

Dual nonionic photoacids synergistically enhanced photosensitivity for chemical amplified resists

In this paper, 4,5-dimethoxy-2-nitrobenzyl methacrylate (MONMA) was copolymerized with 2-hydroxyethyl methacrylate (HEMA) and tert-butyl methacrylate (TBMA) to obtain the terpolymer with dual sensitivity of ultraviolet (UV) light and acid, P(MONMA-HEMA-TBMA). The nonionic photosensitive ester, 4,5-dimethoxy-2-nitrobenzyl p-toluene sulfonate (MONS), is designed and synthesized as the prime photoacid generator (PAG) because of excellent photoacid generating capability of MONS and the similar substituted structure between MONS and MONMA. The ester groups in MONS PAG small molecules and the MONMA units of P(MONMA-HEMA-TBMA) disintegrate under UV irradiation to generate free diffused sulfonic acids and localized carboxylic acids, respectively. Both free and localized acids facilitate the subsequent acid-catalyzed hydrolysis of TBMA adjacent to MONMA units to induce exponential growth of carboxylic acids. Therefore, the hydrolyzed polymers containing high-content carboxylic acids become soluble in the alkaline developer. Hydrophilic HEMA is introduced to the photoresist resin to improve the interfacial affinity between the resist and the substrate. Dual synergy effect from free photoacid generator MONS and polymerized photoacid unit MONMA enhances photoacid generation and accelerates acid proliferation, which enables the decreased exposure dose and lower content of free photoacid generator MONS. A series of novel chemical amplification photoresists with various methacrylate monomer ratios are designed and synthesized to optimize the photolithographic effect of photoresist resin. The UV photolithography results demonstrate that the distinct exposed patterns are obtained at a low exposure dose using the photoresist formulation with P(MONMA50-HEMA19-TBMA31) and MONS of 9:1 w/w.