Designing Nanofluidic Channels of Boron Nitride Nanosheets/Aramid Nanofibers/Covalent Organic Frameworks Nanofiltration Membrane for Ultrafast Mass Transport.

2D lamellar nanofiltration membrane is considered to be a promising approach for desalinating seawater/brackish water and recycling sewage. However, its practical feasibility is severely constrained by the lack of durability and stability. Herein, a ternary nanofiltration membrane via a mixed-dimensional assembly of 2D boron nitride nanosheets (BNNS) is fabricated, 1D aramid nanofibers (ANF), and 2D covalent organic frameworks (COF). The abundant 2D and 1D nanofluid channels endow the BNNS/ANF/COF membrane with a high flux of 194 L·m‒2·h‒1. By the synergies of the size sieving and Donnan effect, the BNNS/ANF/COF membrane demonstrates high rejection (among 98%) for those dyes whose size exceeds 1.0 nm. Moreover, the BNNS/ANF/COF membrane also exhibits remarkable durability and mechanical stability, which are attributed to the strong adhesion and interactions between BNNS, ANF, and COF, as well as the superior mechanical robustness of ANF. This work provides a novel strategy to develop robust and durable 2D lamellar nanofiltration membranes with high permeance and selectivity simultaneously.

Formation Mechanisms of Hexagonal Boron Nitride Nanosheets in Solvothermal Exfoliation.

Solvothermal techniques are widely used to exfoliate many two-dimensional materials, but the formation mechanisms of these nanomaterials have not been clearly revealed. Herein, we discovered the dissociation of hexagonal boron nitride (h-BN) in solvothermal exfoliation evidenced by the formation of B(OH)3, NH4B5O8·4H2O, and (NH4)2B10O16·8H2O. In the selected solvents, the lateral sizes of the formed boron nitride nanosheets (BNNSs) are increased in the order of N-methyl-2-pyrrolidone (NMP), N,N-dimethylformamide (DMF), acetonitrile (MeCN), and isopropanol (IPA), suggesting the decreased dissolving abilities of these solvents to h-BN in turn. The dissociation behaviors are the properties of solvents themselves, but the inclusion of lithium chloride (LiCl) and cetyltrimethylammonium bromide (CTAB) can elevate the dissociation degree and yield BNNSs with smaller lateral sizes due to the intercalating effects. The cation-π interactions make CTAB more effective in obtaining uniform BNNSs than using the neutral halogenated hydrocarbons as assistant reagents. The dissociation abilities of the solvents have strong relationships with the surface tension, Hansen solubility parameters distances (Ra), and polarities, whereas there is little relevance with the pressures. Meanwhile, we also observed the cracking of CTAB and the polymerization of MeCN in these reactions. Our findings indicate that the impurities are prone to be attached to the BNNSs exfoliated by the solvothermal route.

Contrasting liquid imbibition into uncoated versus pigment coated paper enables a description of imbibition into new-generation surface-filled paper.

The transport of print fluids into paper is directly dependent on the imbibition characteristic of the paper including both the z-, x- and y-directions. As the measurement of free liquid imbibition into the paper thickness (z-direction) is difficult experimentally, due to the thin nature of paper, in this paper we resort to imbibition along the y-direction of paper to analyse and explore the possibility of understanding the mechanistic differences between wicking into uncoated unfilled paper versus that of controllable pigment-filled paper and paper coating. Considering the classical imbibition dynamic, the measured imbibition was characterised firstly with respect to [Formula: see text] and secondly with respect to linear t. It is shown that the wicking behaviour of uncoated unfilled paper follows neither the classical viscous drag balance model of Lucas-Washburn ([Formula: see text]) nor the more comprehensive inertia-included imbibition described by Bosanquet. However, by increasing the filler load into the surface layer of the paper, the imbibition dynamic is seen to revert to the Bosanquet model. Thus, when using highly filled papers, the imbibition dynamic for printing liquid shows a fast imbibition at the initial stages dominated by inertial plug flow, and then transits to the Lucas-Washburn viscosity-dominated imbibition component over longer time.

Sandwiched film of graphene/silver nanowire conductive layer reinforced by hydroxyethyl cellulose bond layer.

Multilayer nanocomposite film made of different materials has multifunctional properties and is applied in the field of flexible electronic devices. Herein, hydroxyethyl cellulose (HEC) and boron nitride nanosheets (BNNS) were used as the matrix and thermal conductivity material of the HEC/BNNS (HB) insulation layer and were combined with conductive blade structure graphene/silver nanowires (GA) film to prepare a three-layer HB/GA20/HB film. Using the high mechanical properties of the HEC based film, the tensile strength of the three-layer film is increased to 22.0 MPa, 633 % higher than that of the pure conductive film. The sensor prepared by multilayer film has good bending sensing performance (1500 cycles) and electromagnetic shielding performance (29.3 dB). The heating temperature of HB/GA20/HB film heater is up to 107.9 °C at 20 V. In the HB/GA20/HB film, the external HB layer provides insulation, thermal conductivity and physical support, and the internal GA layer with good conductive and sensing properties is combined to build a multi-functional sensor, which can be applied as a mobile sensor, heater and electromagnetic shielding material in the flexible wearable field.

Superwettable cellulose acetate-based nanofiber membrane with spider-web structure for highly efficient oily water purification.

Electrospinning nanofibers membrane has received much attention to remove the insoluble oil from the sewage, while the poor mechanical strength and low oil/water separation efficiency of membranes limit their practical application. Here, we prepared a superwettable deacetylated cellulose acetate (d-CA)-based electrospinning nanofibers membrane simply dipped by bacterial cellulose (BC) and cross-linked with citric acid (CCA) to construct the spider-web structure spontaneously. Compared with the pristine d-CA membrane, the obtained d-CA/BC@CCA membrane exhibits the remarkable oil/water separation performance. The flux and separation efficiency of n-hexane/water emulsion without (SFE) and with (SSE) emulsifier for d-CA/BC@CCA membrane are 9364 L·m-2·h-1·bar-1, 98.34 % and 5479 L·m-2·h-1·bar-1, 99.39 %, respectively, which are mainly attributed to the improved hydrophilicity of its surface and the decreased pore sizes caused by the unique spider-web structure. In addition, d-CA/BC@CCA membrane also possesses the outstanding mechanical properties, the better cycle stability, as well as the excellent durability. This study provides a novel strategy for the construction of the high-performance oil/water separation membrane.

Predictive value of presepsin and acylcarnitines for severity and biliary drainage in acute cholangitis.

BACKGROUND: Bacteremia, which is a major cause of mortality in patients with acute cholangitis, induces hyperactive immune response and mitochondrial dysfunction. Presepsin is responsible for pathogen recognition by innate immunity. Acylcarnitines are established mitochondrial biomarkers. AIM: To clarify the early predictive value of presepsin and acylcarnitines as biomarkers of severity of acute cholangitis and the need for biliary drainage. METHODS: Of 280 patients with acute cholangitis were included and the severity was stratified according to the Tokyo Guidelines 2018. Blood presepsin and plasma acylcarnitines were tested at enrollment by chemiluminescent enzyme immunoassay and ultra-high-performance liquid chromatography-mass spectrometry, respectively. RESULTS: The concentrations of presepsin, procalcitonin, short- and medium-chain acylcarnitines increased, while long-chain acylcarnitines decreased with the severity of acute cholangitis. The areas under the receiver operating characteristic curves (AUC) of presepsin for diagnosing moderate/severe and severe cholangitis (0.823 and 0.801, respectively) were greater than those of conventional markers. The combination of presepsin, direct bilirubin, alanine aminotransferase, temperature, and butyryl-L-carnitine showed good predictive ability for biliary drainage (AUC: 0.723). Presepsin, procalcitonin, acetyl-L-carnitine, hydroxydodecenoyl-L-carnitine, and temperature were independent predictors of bloodstream infection. After adjusting for severity classification, acetyl-L-carnitine was the only acylcarnitine independently associated with 28-d mortality (hazard ratio 14.396; P < 0.001) (AUC: 0.880). Presepsin concentration showed positive correlation with direct bilirubin or acetyl-L-carnitine. CONCLUSION: Presepsin could serve as a specific biomarker to predict the severity of acute cholangitis and need for biliary drainage. Acetyl-L-carnitine is a potential prognostic factor for patients with acute cholangitis. Innate immune response was associated with mitochondrial metabolic dysfunction in acute cholangitis.

In Situ Loading of Polypyrrole onto Aramid Nanofiber and Carbon Nanotube Aerogel Fibers as Physiology and Motion Sensors.

Nanocomposite conductive fiber has been newly developed as a lightweight material with high flexibility and strong weavability, which can meet the requirements of flexible wearable devices. Herein, lightweight porous aramid nanofibers (ANF) and carbon nanotube (CNT) aerogel fibers coated with polypyrrole (PPy) layers are prepared by a wet spinning method for motion detection and information transmission. The ANF/CNT/PPy aerogel fiber with low density (56.3 mg/cm3), conductivity (6.43 S/m), and tensile strength (2.88 MPa) were used as motion sensors with high sensitivity (0.12) and long life (1000 cycles). At the same time, the differential conductivity of aerogel fibers is utilized to reduce the information transmission time (up to 46%). High- and low-temperature-resistant (-196 to 100 °C) aerogel fibers are also available as a quick heater and ionic solution detector. In summary, the prepared ANF/CNT/PPy aerogel fiber can be used as a multifunctional sensor for human-health detection and motion monitoring.

Diminazene aceturate mitigates cardiomyopathy by interfering with renin-angiotensin system in a septic rat model.

BACKGROUND: There were limited studies investigating treatments of septic cardiomyopathy (SCM), which is a common complication during sepsis. A septic rat model created by cecal ligation and puncture (CLP) was used to investigate the effects of diminazene aceturate (DIZE) in SCM. METHODS: A total of 151 Wistar rats were randomly assigned into the sham, CLP, or CLP + DIZE group. Data evaluated postoperatively at 6, 12, 24, and 48 hours included: cardiac function; plasma concentrations of tumor necrosis factor-alpha (TNF-α), interleukin-6, angiotensin-(1-7) [Ang-(1-7)], angiotensin II (AngII), troponin I, and brain natriuretic peptide; expression levels of myocardial Ang-(1-7), angiotensin-converting enzyme (ACE), ACE2, and angiotensin type 1 and Mas receptors; and histological changes. RESULTS: We found that the CLP + DIZE group had a lower mortality compared to the CLP group (38.5% versus 61.5%) within 48 h postoperatively, although without statistical significance. In contrast to the sham group, the CLP group had decreased cardiac functions, increased myocardial injuries, and higher TNF-α levels, which were ameliorated in the CLP + DIZE group. Furthermore, administration of DIZE could reverse the decreases of myocardial Ang-(1-7) and ACE2 expressions in the CLP group, which finally minimized the myocardial microstructure disruptions. CONCLUSIONS: It was concluded that DIZE could mitigate the development of SCM and preserve cardiac function during sepsis possibly by interfering with the renin-angiotensin system through promoting myocardial ACE2 expression and restoring local Ang-(1-7) levels.

Optimal timing of biliary drainage based on the severity of acute cholangitis: A single-center retrospective cohort study.

BACKGROUND: Biliary decompression is well known to greatly decrease the risks of mortality in acute cholangitis (AC). Although early biliary drainage is recommended by the treatment guidelines for AC, the best time for performing this procedure is yet to be established. Furthermore, since the clinical outcomes of patients with severe AC vary dramatically, screening for patients that could benefit the most from early drainage would be more beneficial than the drainage performed based on the severity grade criteria. AIM: To investigate the optimal drainage timing for AC patients with each disease severity grade and organ dysfunction. METHODS: In this retrospective monocenter cohort analysis, we reviewed 1305 patients who were diagnosed with AC according to the Tokyo guidelines 2018 at a Chinese tertiary hospital between July 2016 and December 2020. Demographic characteristics including age and sex, clinical and laboratory characteristics, and imaging findings of each patient were obtained from electronic medical records. We investigated the all-cause in-hospital mortality (IHM), hospital length of stay (LOS), and hospitalization costs associated with the timing of biliary drainage according to the severity grading and different dysfunctioning organs and predictors [age, white blood cell (WBC) count, total bilirubin, albumin, lactate, malignant obstruction, and Charlton comorbidity index (CCI)]. RESULTS: Biliary drainage within 24 or 48 h in Grade III AC patients could dramatically decrease IHM (3.9% vs 9.0%, P = 0.041; 4% vs 9.9%, P = 0.018, respectively), while increasing LOS and hospitalization costs. Multivariate logistic analysis revealed that neurological, respiratory, renal, and cardiovascular dysfunctions, hypoalbuminemia, and malignant obstruction were significantly associated with IHM (odds ratio = 5.32, 2.541, 6.356, 4.021, 5.655, and 7.522; P < 0.001, P = 0.016, P < 0.001, P = 0.012, P < 0.001, and P < 0.001; respectively). Biliary decompression performed within 12 h of admission significantly decreased the IHM in AC patients with neurological dysfunction (0% vs 17.3%, P = 0.041) or with serum lactate > 2 mmol/L (0% vs 5.4%, P = 0.016). In the subgroup of AC patients with renal dysfunction, abnormal WBC count, hyperbilirubinemia, or hypoalbuminemia, early drainage (< 24 h) reduced the IHM (3.6% vs 33.3%, P = 0.004; 1.9% vs 5.8%, P = 0.031; 1.7% vs 5.0%, P = 0.019; 0% vs 27%, P = 0.026; respectively). The IHM was lower in patients with AC combined with hepatic dysfunction, malignant obstruction, or a CCI > 3 who had undergone biliary drainage within 48 h (2.6% vs 20.5%, P = 0.016; 3.0% vs 13.5%, P = 0.006; 3.4% vs 9.6%, P = 0.021; respectively). CONCLUSION: Biliary drainage within 12 h is beneficial for AC patients with neurological or cardiovascular dysfunction, while complete biliary decompression within 24 h of admission is recommended for treating patients with Grade III AC.

Polyvinyl alcohol-mediated splitting of Kevlar fibers and superior mechanical performances of the subsequently assembled nanopapers.

In this work, a composite of aramid nanofibers (ANFs) and polyvinyl alcohol (PVA) was prepared by PVA-assisted splitting of macro Kevlar fibers, which assures the uniform wrapping of PVA chains on the surface of ANFs, thus leading to an enhanced interfacial bonding strength between ANFs and PVA. The morphological characterizations manifest the enhanced diameters of the ANFs after PVA wrapping. The subsequently assembled ANFs/PVA paper shows a strength of 283.25 MPa and a toughness of 32.41 MJ m-3, which are increased by 57% and 152% compared to the pure ANF paper, respectively. The superior mechanical properties are attributed to the strong interfacial bonding strength, enhanced hydrogen bonding interactions, the densification of the materials, and curved fracture paths. Meanwhile, the ANFs/PVA paper also shows robust UV shielding and visible transparency properties, as well as excellent environmental stabilities, especially at high and low temperatures.

Highly compressible, heat-insulating and self-extinguishing cellulose nanofiber/aramid nanofiber nanocomposite foams.

Foam as a kind of burgeoning materials with laminated porous 3D structure was realized multifunctional application in diversified fields. In this work, we aimed to prepare a highly compressible and self-extinguishing multifunctional nanocomposite foam with anisotropic porous 3D structure through a green aqueous freeze-drying method. In order to address the inflammable property and brittleness issue of high-loading cellulose nanofiber foam, aramid nanofiber was incorporated into cellulose nanofiber framework, forming the multicomponent and multilevel honeycomb structure of the nanocomposite foam. Herein, the compression cycle properties of the nanocomposite foam could be significantly improved by adding 50 wt.% aramid nanofiber and at 20% stress recovered by 100 % even if cyclically compressed 200 times. The total heat release of the nanocomposite foam was as low as 2.12 MJ/m2 which also had low thermal conductivity about 28.8 mW/m ·â€¯K. The ANF improved the flame retardancy of the composite foam.

Presepsin as a biomarker for risk stratification for acute cholangitis in emergency department: A single-center study.

BACKGROUND: Acute cholangitis is caused by bacterial infection and has high morbidity and mortality risk. The grade of cholangitis can guide clinical treatment from single antibiotic treatment to biliary drainage. With the introduction of white blood cell (WBC) count, C-reactive protein (CRP), and total bilirubin (T-Bil) into the diagnostic criteria and severity grading for acute cholangitis, the diagnosis rate and grading have significantly improved. However, early risk stratification assessments are challenging in the emergency department. Therefore, we hope to find an ideal predictive biomarker for cholangitis grade. Presepsin is a promising biomarker for the early diagnosis, severity, and prognosis of acute bacterial infections. AIM: To assess the grading value of presepsin in patients with acute cholangitis. METHODS: This clinical study was conducted at the Beijing Friendship Hospital, a 2000-bed teaching hospital with approximately 200000 emergency admissions per year. In this prospective observational study, 336 patients with acute cholangitis meeting the Tokyo Guidelines 2018 diagnostic criteria in the emergency department from May 2019 to December 2020 were analyzed. WBC count, CRP, procalcitonin (PCT), presepsin, T-Bil, and blood culture results were collected. The values were compared using the Pearson χ 2 test, Fisher's exact test, or Mann-Whitney U test. The area under the receiver operating characteristic curve (AUC) of the value was examined using the Delong test. The correlations among the key research indicators were determined using Pearson correlation. RESULTS: In total, 336 patients were examined, which included 107, 106, and 123 patients classified as having mild, moderate, and severe cholangitis, respectively. WBC count, CRP, PCT, presepsin, T-Bil, direct bilirubin, and sequential organ failure assessment scores of moderate and severe cholangitis patients were higher than those of mild cholangitis patients (P = 0.000). The AUC of presepsin in predicting moderate acute cholangitis was 0.728, which was higher than that of CRP (0.631, P = 0.043) and PCT (0.585, P = 0.002), and same as that of WBC count (0.746, P = 0.713) and T-Bil (0.686, P = 0.361). The AUC of presepsin in predicting severe acute cholangitis was 0.715, which was higher than that of WBC count (0.571, P = 0.008), CRP (0.590, P = 0.009), PCT (0.618, P = 0.024), and T-Bil (0.559, P = 0.006). The presepsin levels in the positive blood culture group were higher (2830.8pg/mLvs1987.8pg/mL, P = 0.000), and the AUC of presepsin (0.688) proved that it was a good biomarker for predicting positive bacterial culture. CONCLUSION: Presepsin can predict positive blood culture in patients with acute cholangitis. It is superior to WBC count, CRP, PCT, and T-Bil for the risk stratification of acute cholangitis.

Improved mechanical and ultraviolet shielding performances of hydroxyethyl cellulose film by using aramid nanofibers as additives.

Recently, aramid nanofibers (ANFs) have drawn the attention of scientist due to the high mechanical strength, high-temperature resistance, and high electrical and thermal insulation properties. In this work, we aimed at improving the mechanical and ultraviolet shielding properties of hydroxyethyl cellulose (HEC) film by using ANFs as additives. Mechanical results show that the 1.0 % ANFs could improve the tensile strength of pure HEC film by 176.6 %. Meanwhile, the ANFs additives can also enable the HEC film excellent ultraviolet (UV) shielding and visible light transmittance, as well as high UV radiation resistance ability. It is believed that the high mechanical strength of the HEC/ANFs composites is derived from the rearrangement of HEC chains along the tensile direction after the addition of hard ANFs and the enhanced hydrogen bonds between HEC and ANFs.

Multiple hydrogen bonding self-assembly tailored electrospun polyimide hybrid filter for efficient air pollution control.

Air pollutions are extremely serious threats to human health and the functional hybrid filter is able to remove complicated pollutants with great potential. However, the stable structure design of hybrid filter to provide efficient filtration and adsorption performance for high temperature applications still remains a challenge. In this study, electrospun polyimide (PI) based hybrid filter was fabricated via multiple hydrogen bonding self-assembly for high-temperature air purification. In particular, Octa(amino-propylsilsesquioxane) (POSS-NH2) was utilized as "bridge" for the surface activation of PI fiber, and then amino-functionalized Zeolitic Imidazolate Framework-8 (NH2-ZIF-8) nanocrystals were anchored on the fiber surface through hydrogen bonding. On account of the synergistic effect of the interception effect of fibers and the electrostatic interaction of NH2-ZIF-8 nanocrystals, the as-obtained PI-POSS@ZIF hybrid filter possessed excellent filtration performance with a high PM0.3 removal efficiency of 99.28% and a low pressure drop of 49.21 Pa at high temperature of 280 °C. Moreover, due to the massive micropore structure, rich open metal sites and functional groups of NH2-ZIF-8, the hybrid filter exhibited prominent VOCs adsorption performance with adsorption capability of 89.95 mg/g for formaldehyde.

Electrospun Wrinkled Porous Polyimide Nanofiber-Based Filter via Thermally Induced Phase Separation for Efficient High-Temperature PMs Capture.

Benefiting from its superior thermal stability, polyimide (PI) fiber-based composites have attracted wide attention in the field of high-temperature filtration and separation. However, the trade-off between filtration efficiency and pressure drop of traditional PI filters with single morphology and structure still remains challenging. Herein, the electrospun PI high-temperature-resistant air filter was fabricated via thermal-induced phase separation (TIPS), employing polyacrylonitrile (PAN) as a template. The PI nanofibers exhibited special wrinkled porous structure, and the filter possessed a high specific surface area of 304.77 m2/g. The removal of PAN changed the chemical composition of the fiber and induced PI molecules to form complex folds on the surface of the fiber, thus forming the wrinkled porous structure. Additionally, the wrinkled porous PI nanofiber filter displayed a high PM0.3 removal efficiency of 99.99% with a low pressure drop of 43.35 Pa at room temperature, and the filtration efficiency was still over 97% after being used for long time. Moreover, the efficiency of the filter could even reach 95.55% at a high temperature of 280 °C. The excellent filtration performance was attributed to the special wrinkled porous surface, which could limit the Brownian motion of PMs and reinforce the mechanical interception effect to capture the particulate matters (PMs) on the surface of the filter. Therefore, this work provided a novel strategy for the fabrication of filters with special morphology to cope with increasingly serious air pollution in the industrial field.

Toward high-performance nanofibrillated cellulose/aramid fibrid paper-based composites via polyethyleneimine-assisted decoration of silica nanoparticle onto aramid fibrid.

Flexible paper-based nanocomposites dielectrics are of crucial importance in electrical insulation and advanced electrical power systems. In this work, a novel nanofibrillated cellulose/aramid fibrid (NFC/AF) composite was fabricated by vacuum-assisted filtration process. In order to improve the dielectric property of the composites, carboxylated nano-SiO2 was chemically coated onto aramid fibrid via molecular self-assembly with the aid of phosphoric acid (PA) pretreatment and subsequent polyethyleneimine (PEI) functionalization. It was found that composites prepared by NFC and (PEI/SiO2)-modified AF (after crosslinking) ((PEI/SiO2)-AF) showed dense structure, which was mainly due to enhanced interfacial interaction between AF and NFC. Consequently, NFC/(PEI/SiO2)-AF paper-based composites showed better tensile toughness (∼6 % elongation at break) and mechanical strength (∼36.28 MPa), in comparison with NFC/AF. More importantly, the electrical insulation performance and thermal stability of the composites were significantly improved. Accordingly, this work provides a facile approach to fabricate high-performance dielectric composites especially for high-temperature electrical insulation applications.

All cellulose composites prepared by hydroxyethyl cellulose and cellulose nanocrystals through the crosslink of polyisocyanate.

In this work, all cellulose composite (ACC) films were prepared through a blocked polyisocyanate (BPIC) induced cross-linking of hydroxyethyl cellulose (HEC) and cellulose nanocrystals (CNC). The chemical characterization indicates that the covalent bonds have been formed between HEC and CNC. Mechanical test shows that the addition of 4 % CNC into the HEC matrix improves the tensile strength by 120.2 % compared to the neat HEC film. The further incorporation of 10 % BPIC into the above ACC film can enhance the tensile strength by 280.2 %. The water contact angles of the ACC film that constituted by 4 % CNC and 10 % BPIC is increased to 100.1° while the thermal decomposition temperature is up to 210 °C. The morphological analysis suggests that the CNC is beneficial to the dispersion of the cross-linked HEC, which increases the elongation at break and maintains the excellent tensile strength meanwhile.

Ultrathin MXene/aramid nanofiber composite paper with excellent mechanical properties for efficient electromagnetic interference shielding.

MXenes, new two-dimensional compounds with hydrophilic surfaces and high metallic conductivity, have attracted significant interest in the electromagnetic interference shielding field in recent years. Nevertheless, poor mechanical properties and brittle nature are bottlenecks for their commercial application. Herein, one-dimensional ANFs were designed as the intermolecular cross-linker between d-Ti3C2Tx flakes and MXene (d-Ti3C2Tx)/aramid nanofiber (ANF) composite paper with a multi-layered structure was fabricated via the vacuum-assisted filtration approach. Further investigation revealed that the ANFs and MXene displayed good combination by hydrogen bonding, and MXene/ANF composite papers exhibited excellent mechanical properties and superior electrical conductivity. The MXene/ANF composite paper possessed a favorable shielding effectiveness (SE) which reached ∼28 dB in 8.2-12.4 GHz (X band) with an ultra-thin thickness ∼17 µm and showed potential application prospects as an advanced composite in sensitive electronic products.

Comparative study of aramid nanofiber (ANF) and cellulose nanofiber (CNF).

Cellulose nanofiber (CNF) has faced challenges toward advanced applications due to the poor water resistance, wet strength, and poor thermal stability. The fabrication methods, morphologies and dispersibility between CNF and aramid nanofiber (ANF) were compared. Then the mechanical strength, especially the retention of wet strength (RWS), optical property, UV shielding, wettability and thermal stability of CNF and ANF nanopapers were further investigated. The results show that ANF and ANF nanopaper have significant advantages in dispersibility, water resistance, wet strength, thermal stability and UV-blocking ability over the CNF and CNF nanopaper. Especially the RWS of ANF nanopaper reached ˜82.5%, which notably exceeded the CNF nanopaper of 1.1%. This work demonstrates that the ANF could be an ideal alternative to CNF for advanced nanocomposites. Transparent, flexible, ultra-strong ANF nanopaper with favorable water resistance and wet strength, as well as good UV-blocking property shows great potential in variety of advanced applications.