Fluffy Structure Research Articles

A Wearable Triboelectric Nanogenerator Based on Polyester-Paper Cloth for Mechanical Energy Harvesting and Running Motion Sensing.

Paper-based triboelectric nanogenerators (P-TENGs) have recently garnered significant attention in wearable electronics. However, traditional P-TENGs are constrained by the inherent strength limitations of paper. Hence, we reported a novel polyester-paper cloth-based triboelectric nanogenerator (PP-TENG) designed for mechanical energy harvesting and running motion monitoring. Compared to paper, polyester-paper cloth has higher durability and tear resistance. The PP-TENG capitalizes on the unique fluffy internal structure of polyester-paper cloth, imparting high sensitivity to pressure variations. Experimental results demonstrate that the PP-TENG achieves an open-circuit voltage (Voc) of 466.64 V, a short-circuit current (Isc) of 48.73 μA, and a transfer charge (Qsc) of 90 nC. Its maximum output power reaches 930.26 μW when connected to a 40 MΩ load. These impressive metrics underscore the potential of PP-TENG in energy harvesting applications, particularly for wearable electronic devices. The device's integration into the soles of athletic socks showcases its practical utility, providing real-time monitoring of runners' gait and step count. This integration not only enhances the functionality of sportswear but also offers valuable data for performance analysis and injury prevention, marking a significant advancement in wearable technology and intelligent textiles. This research provide a promising path for self-powered wearable sensors and flexible electronics applications.

Heterostructured GCN Nanosheets/ZnO nanoflowers for enhanced TMO loading: From high-performance three electrode systems to printed flexible asymmetric supercapacitors

Transition metal oxides (TMOs) are widely used in the development of high-energy-density devices due to their multiple oxidation states and their frequent heterostructuring with carbon-based materials. However, the synthesis process often leads to severe nanoparticle agglomeration and weak synergistic effects with carbon-based templates, thereby limiting their application potential. In this study, we constructed graphitic carbon nitride (GCN) nanosheets/ZnO nanoflowers (NFs) structures with high TMOs loading by utilizing GCN nanosheets, which are rich in surface nitrogen content, as enriched templates for metal ions in conjunction with ultrasonic cavitation. Compared with GCN nanosheets/ZnO nanoparticles (NPs), the ZnO NFs exhibited vertical growth and a fluffy structure on a 2D material template, which resulted in high electronic conductivity, a large effective surface area, hierarchical pores, and strong synergistic interactions with GCNs, thus improving electrochemical performance. This structural enhancement enabled the GCN/ZnO NFs electrodes to achieve a high specific capacitance of 1524F g−1 at a current density of 1 A g−1 in a three-electrode supercapacitor system. Additionally, we formulated GCN/ZnO NFs into electronic inks and used them for the mass production of flexible supercapacitors with the aid of dispensing printing technology. These flexible supercapacitors retained 94% of their specific capacitance even under extreme conditions of 90° torsion. Our proposed strategy of modulating TMOs and 2D structures can create active electrode materials with higher loading capacities, thereby enabling comprehensive customization in material design and device preparation processes.

N, O-codoped carbon aerogel electrode improves capacitive deionization performance

Capacitive deionization (CDI) using porous carbon materials provides an environmentally friendly and sustainable solution to produce affordable fresh water. However, low salt adsorption rates significantly limit its practical application. In this study, N, O-codoped carbon aerogel (NOCA) was prepared by a simple sol–gel method using agar as the carbon framework, NaCl as the template, NH4HCO3 as the nitrogen source and self-blowing agent. The electrochemical and electrosorption properties of the NOCA electrode were significantly better than compared to commercial activated carbon (CAC) electrodes. The NOCA material had the following characteristics: (i) During the rapid freeze-drying process, NaCl crystals provide a three-dimensional network structure for effective dispersion of agar, reducing the agglomeration of particles. The volatile gas generated during the thermal decomposition of NH4HCO3 reduces the plugging of pores. (ii) The fluffy interconnecting network structure of the material enhances its electrical conductivity, providing sufficient channels and adsorption sites for the entry and exit of salt ions. (iii) The abundant hydroxyl and ether groups in the agar enhance the hydrophilicity of the material, whereas N doping further improves the electrical conductivity and reduces the ion transport resistance. The electrosorption capacity and adsorption rate of the NOCA material in 500 mg/L NaCl solution were 22.1 mg/g and 4.4 mg/(g·min), respectively. These values correspond to low energy consumption and high energy recovery efficiency in the electrosorption process. The adsorption capacity remained at 95.5 % after 50 adsorption/desorption cycles. These findings show that NOCA is a novel and potential electrode material for CDI applications.

Effect of buckwheat hulls at cell-scale on physiochemical and textural properties of steamed rice cake

Buckwheat hull (BWH) is a source of insoluble dietary fiber (IDF), which can be added to starch-based foods to increase their nutritional characteristics. The influence mechanism of different amounts (10, 20, 30 g/hg) of BWH at cell-scale (CBH, 10–50 μm) and tissue-scale (TBH,100–500 μm) on the physiochemical and textural properties of steamed rice cake was analyzed. With the decrease of BWH particle size and the increase of addition amount, the water retention capacity of rice flour-BWH mixture significantly (P < 0.05) increased. Compared with TBH, the addition of CBH significantly (P < 0.05) increased the viscosity of rice cake batter. The 20 g/hg and 30 g/hg addition of TBH significantly (P < 0.05) decreased the specific volume of rice cake, while that of CBH reversed the negative effects on the specific volume. Texture properties showed that the hardness of cake added with CBH was significantly (P < 0.05) lower than TBH. CBH with higher water affinity and stronger physical support enhanced the interactions of water-starch-IDF and the starch gel network of cake, thus leading to an open and fluffy cake structure. Therefore, milling the IDF to cell-scale might be a promising alternative for developing dietary fiber-enriched starch-based products.

High‐efficiency electrothermal and electromagnetic interference shielding performance of expanded graphite/silicone film

AbstractExpanded graphite (EG) is a desired filler for electrothermal and electromagnetic interference (EMI) shielding because of its easy access, low‐cost, lightweight, high conductivity, and heat sensitivity. Herein, fluffy EG was prepared from natural flake graphite (NFG) by a simple expansive technology and subsequently heat treatment at 800°C for 2.0 h in 5% Ar/H2 atmosphere. EG/silicone films with a filling ratio of 15 wt% were obtained via hot‐pressing, which exhibited sensitive electrothermal and excellent EMI shielding performances. When the applied voltages were 5.0, 10.0, and 15.0 V, the steady‐state temperatures were 54.0, 136.5, and 237.8°C in the 30s, respectively. Meanwhile, their average EMI shielding efficiency was greater than 20 dB in 2–18 GHz at 0.84 mm, which was 6.3 times as much as NFG/silicone film. Therefore, this study offers a simple and effective strategy for preparing excellent electrothermal‐EMI shielding materials.Highlights Fluffy EG is prepared by a simple expansive method and treatment at 800°C. EG/silicone films exhibit good electrothermal and EMI shielding performances. Steady temperatures of 55.0/136.5/237.8°C are gotten at 5/10/15 V in 30 s. The EMI shielding efficiency is greater than 20 dB at 0.84 mm. Good properties are due to the EG with high conductivity and fluffy structure.

A novel 3D hierarchical NiFe-LDH/graphitic porous carbon composite as multifunctional adsorbent for efficient removal of cationic/anionic dyes and heavy metal ions

Developing effective adsorbents for wastewater purification is crucial, as excessive emissions of toxic dyes and heavy metal ions have been proven harmful to ecosystems and human health. A NiFe-layered double hydroxide/graphitic porous carbon (NiFe-LDH/GPC) composite was fabricated by introducing NiFe-LDH nanosheets into GPC via a simple hydrothermal method to utilize the advantages of both materials fully, and thus ultimately obtain a composite adsorbent with improved adsorption properties. The samples obtained were comprehensively characterized by various characterization means, and the effects of several critical influential factors on the pollutant uptake capability of the NiFe-LDH/GPC were also studied through batch experiments. The results show that the as-synthesized NiFe-LDH/GPC exhibits a three-dimensional (3D) fluffy ultrathin-wall hierarchical porous structure, which possesses a high specific surface area and pore volume separately up to 506.74 m2/g and 0.22 cm3 g−1 as well as a relatively narrow pore size distribution. These characteristics bring advantages to enhance the adsorption ability of the NiFe-LDH/GPC for cationic/anionic dyes and heavy metal ions such as congo red (CR), malachite green (MG) and hexavalent chrome (Cr(VI), which reached the maximum adsorption capacity of 1726.51 mg/g, 1157.11 mg/g and 155.72 mg/g under the optimum conditions, respectively. Meanwhile, the adsorption behavior can be well described by the pseudo-second-order kinetic model and Langmuir isotherm model, reflecting that the sorption process mainly occurred chemically in the adsorbent monolayer. Furthermore, the NiFe-LDH/GPC maintained relatively high adsorption performance after multicycle testing, manifesting its good recyclability and stability.

Using polycaprolactone and sodium alginate to prepare self-pumping/super-absorbent/transportable drug dressings for stage 3–4 pressure ulcer treatment

Pressure ulcer dressings with different functions can enhance wound healing ability to varying degrees; however, pressure ulcer dressings that integrate various functions and break the resistance of bacteria to traditional antibiotics have not been widely studied. We proposed a self-pumping/super-absorbent/transportable drug dressing (PLD-SLD), polycaprolactone (PCL)/sodium alginate (SA) was used to load platelet-derived growth factor (PDGF) and lidocaine hydrochloride (LID) by Janus electrospinning and self-assembly technology, and Ɛ-polylysine was used as a biological bacteriostatic agent to prepare a multi-layer dressing. SEM showed that the dressing had a fluffy structure. The dressing can pump the exudate to the SA layer away from the skin. The swelling ratio reached 1378.667 ± 44.752 %. Coagulate blood in 5 min. On the 8th day, the unclosed area rate of the PLD-SLD dressing group was 16.112 ± 0.088 % lower than that of the model group. Importantly, the dressing can induce the expression of CD31, VEGF, α-SMA, and reduce the expression of CD68, thereby giving priority to wound healing. There was no scar formation after healing. In this study, a new dressing preparation method was proposed for the problems of exudate management, infection control, pain relief and healing promotion of stage 3–4 pressure ulcer healing.

Petroleum residue-based ultrathin-wall graphitized mesoporous carbon and its high-efficiency adsorption mechanism

Creating petroleum residue-based new functional materials are vital for the sustainable development of petroleum residues. This study developed a method to prepare a petroleum residue-based ultrathin-wall graphitized mesoporous carbon (PGMC) with high specific surface area by the carbonization of a composite of the petroleum residue uniformly mixed with aluminium isopropoxide. Results show that the PGMC possesses a highly fluffy ultrathin-wall mesoporous structure with a high degree of graphitization. It had a high specific surface area of 1174 m2 g−1 with a high pore volume of 4.57 cm3 g−1 and a narrow pore size distribution at 8.09 nm. These unique features endow the PGMC with excellent adsorption properties for Congo red, Malachite green, and Methylene blue removal. The experimental data were better described with Freundlich isotherm and Quasi-second-order kinetic models. Thermodynamic analysis indicated a spontaneous and endothermic adsorption process. The adsorption mechanisms proposed that pore-filling effect, π-π conjugation, and electrostatic interaction were the main interactions between the PGMC and dyestuff, followed by functional groups and hydrogen bonding. Moreover, the PGMC could maintain good adsorption rates after five cycles, proving that it is an effective adsorbent with good adsorption ability and cycling stability.

Ultralight, superelastic, and antibacterial micro/nanofibrous sponges with dual-network interwoven structure for warmth retention

Developing ultralight warmth retention materials with desirable mechanical properties and antibacterial abilities is urgently demanded to cope with extreme cold weather. Here, we propose a humidity-induced electrospinning strategy to prepare micro/nanofibrous sponges (MNFSs) with dual-network interwoven structures. The resulted MNFS exhibits a three-dimensional (3D) fluffy structure, an ultralight characteristic with a porosity of 99.7 % and a volume density of 4.1 mg cm−3. Thanks to these well-designed structures, the obtained MNFSs display a low thermal conductivity of 25.4 mW m−1 K−1. Moreover, the dual-network interwoven structure consisting of microfiber frames and nanofibers endows the MNFSs with excellent mechanical properties. Thus, the MNFSs showed an elastic recovery rate of more than 90 % after 100 cycles of fatigue testing. Furthermore, the introduction of graphene oxide (GO) enables MNFSs with a high antibacterial rate of 94.6 %. This work presents a fresh perspective for the advancement of ultralight, superelastic, and antibacterial materials for warmth retention.

Full micro-nanofiber aerogel with three-dimensional fluffy network structure for rapid liquid absorption and uniform liquid retention in diapers

Diapers are essential for infants and patients with urinary incontinence. The super-absorbent polymer (SAP) in the core layer of diapers suffers from slow liquid absorption, fault formation, and reverse osmosis. Therefore, it is desirable to construct a core layer that can integrate rapid liquid absorption, uniform retention, and anti-seepage qualities. In this study, a diaper core layer and a three-dimensional fluffy network structure with a wetting gradient was constructed via one-step solution blow spinning (SBS). By regulating the content of the glutaraldehyde (GA) cross-linking agent, absorbent and insoluble fibers could be obtained. The ratio of super-absorbent fibers (SAF) to PAN-PVP micro-/nano fibers in the three-layer fiber structure and the gram weight of the core layer were adjusted. A wetting gradient was established when the weight of the adjusted gradient core layer was 2/3 that of the commercial core layer. The amount of reverse osmosis was reduced by 0.25 g, and the liquid absorption and retention were 30 times and 28.5 times, respectively, two and 3.5 times higher than those of commercial diapers. The SAF prepared by SBS could improve the core layer's liquid absorption rate, retention ratio, and comfort. The fibers are applicable in diapers, sanitary napkins, and other disposable products.

Novel highly utilized PdNi bimetallic-loaded N-doped carbon catalysts prepared from MOF for Suzuki coupling reaction and hydro reduction of nitroaromatics

The usage of palladium-based catalysts in numerous chemical reactions has been increased significantly; in particular, the synthesis of heterogeneous catalysts by attaching palladium atoms to carriers has expanded rapidly. Therefore, the selection of nitrogen-doped carbon materials for carriers has become a popular research subject. In this study, Ni-Ni PMOF was first created, then Ni nanoparticles (NPs) modified nitrogen-doped mesoporous carbon materials were synthesized through pyrolysis. Subsequently, Pd atoms were successfully deposited onto the surface of Ni NPs as Pd2+ is capable of being reduced by metal Ni. The structure of the prepared carriers was verified by FT-IR, XRD, SEM, TEM, XPS and other characterizations, and was found to have a fluffy and porous structure that increases the number of active sites of PdNi NPs. This material was found to be effective in catalyzing the Suzuki coupling reaction (TOF = 1019 h) and the reduction reaction of p-nitrophenol (Kapp = 4.34 × 10−2 s−1), and its catalytic activity remained stable even after 10 uses, showing good recoverability and recyclability. This study thus provides a novel approach for the preparation of N-doped porous carbon materials, which can enable green chemistry by making efficient and full use of precious metals.

A fast method to prepare highly isotropic and optically adjustable transparent wood-based composites based on interface optimization

The production design of transparent materials using wood flour as the substrate aims to improve the value-added utilization rate of waste wood, and explore the preparation process of energy-saving building materials. This paper reports a rapid method for the preparation of transparent wood-based composites (TW-OTS) with high isotropy and optical adjustability, which changes the high energy consumption of bleaching wood flour in the past. Using the fluffy and porous structure of wood flour, the wood flour was bleached by hydrogen peroxide drop coating method assisted with ultraviolet light, and then hydrophobicized and impregnated with epoxy resin. The interfacial bonding and optimization mechanism of organic polymer Octadecyl trichlorosilane (OTS), wood fiber and resin at the micro scale were systematically studied in order to improve the optical parameters, mechanical strength and thermal properties of the composites, so as to balance the relationship between the structure and properties. TW-OTS based on interface optimization has excellent transmittance (80.1 %), thermal insulation performance, mechanical strength, and biocompatibility. If 1 % chitosan is added to the resin, the antibacterial properties of the sample can be added. This material can be used in energy-saving building windows, medical equipment, ecological home products, and other fields.

Fuzzy Based Expert System For Test Case Generation On Web Graphical User Interface For Usability Test Improvement

The Ease of Use Test (UT) method is used to evaluate a website's or its point of interaction's usability without involving the site's actual users. UT can be carried out manually or with the use of a machine. Currently, a lot of software testers manually test their program, which leads to issues like lengthier test times, uneven testing, and the requirement for human intervention to complete every test. The ease of use test manual is an expensive and time-consuming process. Analyzers are additional resources needed for manual labor, and there is a great chance that these results will conflict. The goal of this investigation is to improve the reliability and skill of the Test Case (TC) age experiments; the test system is delivered using test instruments that have been programmed. The purpose of this examination's efficient writing audit was to identify any gaps in the current AT and create a mess in the TC era. The evaluation was also focused on identifying the primary issues raised by alternate neighborhood analysts throughout the physical creation of TC. According to the selected plausible experiments, TC was created using the fluffy rationale master structure. Non-probabilistic, vulnerability-related, and multi-esteemed reasoning can all be emphasized in fluffy reasoning. The purpose of the information inquiry was to obtain access to the login page and to create experiments about Graphic User Interface events using a lighthearted justification. The framework separated the conditions, traits, and watchwords from the information examination code, and the outcomes were displayed as experiments. A close examination of behavioral test system age processes was conducted using the master framework for evaluation based on fluff. The evaluation results obtained through quantifiable analysis demonstrated that the provided framework is significantly more productive and reliable for conducting experiments than the manual framework.

A wearable flexible triboelectric nanogenerator for bio-mechanical energy harvesting and badminton monitoring

Recently, textile materials used for wearable flexible sensors have received much attention. Wearable textile based triboelectric nanogenerator (TENG) not only has unique advantages in mechanical energy harvesting, but also has application value in the direction of motion sensing. Here, we proposed a non-woven fabric triboelectric nanogenerator (NW-TENG) for mechanical energy harvesting and badminton monitoring. The non-woven fabric play the role of positive triboelectric, and the fluffy fiber structure endows NW-TENG with a sensitive response to pressure. The pressure sensing sensitivity of NW-TENG sensor can reach 1.22 V N−1 (Pressure range: 0–7 N) and 0.18 V N−1 (Pressure range: 8 N–55 N). Furthermore, the NW-TENG can be installed on the body joints of badminton players for analyzing joint movements, thereby achieving data-driven badminton training and facilitating the evaluation of training effectiveness. This research provide a new path to promote TENG to the badminton monitoring field.

Heterocyclic polymerization modified g-C3N4 nanotube with advanced charge separation for solar light driven degradation of ciprofloxacin

A novel heterocyclic polymerized g-C3N4 nanotube was prepared by thermal polycondensation using urea and 2,4,6-triaminopyrimidine (TAP). The TAP-polymerized g-C3N4 composite with 0.5 wt% TAP content showed the highest photocatalytic activity for ciprofloxacin (CIP) degradation under solar irradiation. The optimal composite derived from urea achieved ∼ 10.8 and ∼ 7.5 time of CIP degradation activity when compared with TAP-polymerized g-C3N4 derived from melamine and thiourea. The copolymerization of TAP molecules reduces the π electron defects in the g-C3N4 conjugated system thus accelerates the migration of photogenerated carriers. The doping of TAP in g-C3N4 reduces its band gap, which enhances the light absorption capacity and improves the utilization efficiency of visible light. The fluffy porous nanotube structure of the material endows it with unique surface morphology and excellent photoelectric characteristic. Electron spin resonance (ESR) and probe technology were used for qualitative or quantitative detection of free radicals in this work. Superoxide radicals (O2·-) played the major roles in the photodegradation of CIP. Recycling experiments displayed the high stability and activity of the modified materials, which is potentially applicable in practical engineering. Moreover, the photodegradation pathways and mechanisms of CIP were proposed and its toxicity evolution was assessed in this study. This work revealed the specific application of heterocyclic polymerization in modifying g-C3N4 material and provided unique insights for its application in photocatalytic degradation of antibiotic.

Enhancing solar-driven atmospheric water harvesting by a bilayer macroporous hydrogel

The adsorption-based atmospheric water harvesting technique has shown great potential in providing clean water. An ideal device for atmospheric water harvesting should enable the massive and quick release of water after it is rapidly absorbed by the moisture adsorbent. At present, however, the moisture adsorbent still experiences issues such as a slow water absorption rate, hampered adsorption–desorption kinetics, and a low total water yield. In this paper, a bilayer moisture adsorbent (BMA), which glues a hydrophilic macroporous layer for rapid water adsorption and a carbonized sunlight-absorbing layer for both water harvesting and desorption acceleration, is introduced. Further evidence suggests that it is the stable, fluffy, and rough porous structure of the BMA that helps to harvest atmospheric water efficiently. The fully carbonized BMA exhibits a water absorption capacity of up to 396% at a relative humidity of 90%, which is 20% higher than a monolayer sample. More importantly, the desorption efficiency of the half-carbonized BMA reaches 98% under 1 sun illumination. These results jointly demonstrate that the BMA can play the dual role of absorbing moisture and light, allowing for rapid atmospheric water harvesting, massive water storage, and efficient desorption under the light.

FeCoNiMgB high-entropy boride powder with a fluffy cotton structure and enhanced activity in the oxygen evolution reaction

Exploring efficient, low-cost electrocatalysts is critical for improving the efficiency of water splitting reactions. Noble-metal-based oxides exhibit high activities in the oxygen evolution reaction (OER). However, their high cost and the lack of natural resources hinder their practical application. Therefore, in this study, we successfully synthesized an FeCoNiMgB high-entropy boride powder via a facile chemical reduction method for use as an OER catalyst in an alkaline medium. The FeCoNiMgB powder, with an ultrathin fluffy cotton structure, exhibited an excellent OER catalytic performance, affording an overpotential of 268 mV at a current density of 10 mA/cm2 and a low Tafel slope of 42.9 mV/dec; this performance was superior to those of FeCoNiB, FeNiMgB, CoNiMgB, FeCoMgB, and commercial RuO2. The FeCoNiMgB powder also displayed remarkably stable catalytic properties for >72 h with no clear evidence of degradation. Finally, using theoretical calculations, the excellent OER performance of FeCoNiMgB was verified in terms of its adsorption and charge transfer energies and covalence. The performance and stability of FeCoNiMgB were equivalent or superior to those of several nanostructured catalysts, and thus, this study provided valuable insight into the design of efficient high-entropy boride materials.

A three-dimensional hierarchical porous graphene aerogel as a fiber coating for headspace solid-phase microextraction: Enhancing the enrichment and detection of polychlorinated naphthalenes in fish

In this study, a novel three-dimensional hierarchical porous deep eutectic solvents-modified graphene aerogel (3D DES-GA) was synthesized for use as a solid-phase microextraction (SPME) fiber coating. The SPME fiber was characterized by its fluffy and hierarchical porous structure, uniform thickness, and rapid mass transfer capabilities. This fiber demonstrated a lifetime (≥160 uses) and excellent precision (with relative standard deviations of 2.4–6.6% for single fiber and 6.0–9.8% for fiber-to-fiber repeatability). The SPME fiber also exhibited remarkable extraction performance for polycyclic aromatic hydrocarbons and polychlorinated biphenyls, which are common persistent organic pollutants in environmental samples. When combined with gas chromatography-tandem mass spectrometry, the method allowed for high-efficiency extraction (enrichment factors ranging from 1225 to 4652 folds) and sensitive determination (limit of detection ranging from 0.010 to 0.056 pg g−1) of polychlorinated naphthalenes (PCNs) in complex samples. To validate this method, we applied it to the determination of four PCNs in five types of fish tissues. The results revealed the presence of 1-chloronaphthalene at concentrations of 7.0 ± 2.9–34.8 ± 2.1 pg g−1 and 1,4-dichloronaphthalene at concentrations of 6.0 ± 0.3–10.9 ± 1.4 pg g−1 in three fish species. Compared with reported sample pretreatment methods reported in the literature, this proposed headspace SPME method offers additional advantages, including simplicity of operation and reduced sample and organic solvent consumption.

Evaluation and prediction of fibrous filters' operating performance in residential fresh air system

Fibrous filters play a crucial role in determining indoor air quality and protect people from bacteria, particulates, and viruses such as COVID-19. However, there is a lack of comprehensive research on methods for effectively evaluating and predicting the operating performance of these filters. In this study, we conducted laboratory and field tests on coarse (G4) and medium (F9 or F7) filters from four different brands to assess both their initial and operating performance. We discovered that a fluffy fiber structure in coarse filters could achieve an impressive threefold increase in dust holding capacity (DHC) compared to normal filters. Utilizing initial pressure drop, initial particle capture efficiency, and DHC, we introduced a new quality factor (QF) that integrates these parameters to evaluate the filter's long-term performance. This approach addresses the limitations of traditional quality factor, which neglects DHC and tends to underestimate the performance of filters with high DHC. Additionally, we proposed a simple method to predict the filter's operating pressure drop, using particle concentration data from weather report. This allows for convenient assessment of the fresh air system's operating status, offering potential integration into a user-friendly mobile application or computer software. These findings contribute innovative ideas for enhancing the intelligent and energy-efficient operation of fresh air systems.

Development of a three-dimensional porous ionic liquid-chitosan-graphene oxide aerogel for efficient extraction and detection of polyhalogenated carbazoles in sediment samples

The three-dimensional porous ionic liquid-chitosan-graphene oxide aerogel (IL–CS–GOA) monolithic adsorbent with a through-hole structure was prepared using natural chitosan (CS) as the skeletal framework, graphene oxide (GO) as the support to provide mechanical strength, and ionic liquid (IL) as the porogen and modifier. The resulting IL–CS–GOA demonstrated a fluffy and porous structure with various pore sizes and excellent regeneration capability (over six cycles). Its specific surface area exceeded that of CS-GOA and IL-GOA by more than 7 times, enhancing its polyhalogenated carbazoles (PHCZs) adsorption capacity. Within 5 min, IL–CS–GOA (1.0 mg) exhibited adsorption amounts of 539 ng mg−1 for 3-bromocarbazole (3-BCZ), 716 ng mg−1 for 2,7-dibromocarbazole (2,7-BCZ), and 798 ng mg−1 for 1,3,6,8-tetrabromocarbazole (1,3,6,8-BCZ), showcasing its rapid mass transfer and high adsorption capabilities. IL–CS–GOA was utilized as the adsorbent for glass dropper extraction (GDE) in conjunction with gas chromatography-mass spectrometry (GC-MS/MS), to develop a highly efficient and accurate method for determining PHCZs in sediments. Under optimal conditions, the established method exhibited a wide linear range (0.4–250 ng g−1, r ≥ 0.9990), low detection limits (0.04–0.24 ng g−1), and satisfactory recoveries (80.5 %–93.8 %), enabling the accurate and rapid detection of PHCZs in sediment samples. This study presents a novel approach for creating three-dimensional porous aerogels, introduces a new form of sample pretreatment using GDE with a monolithic adsorbent, and offers a new method for the determination of PHCZs in environmental matrices.