Enhancement Of Hydrophilicity Research Articles

Phosphorylation of MWCNTs/PPy/PDA-nZVI Catalyst for Boosted Catalytic Performance

Nano zero valent iron (nZVI) is widely studied for its efficient removal of recalcitrant organic contaminants. However, it is prone to oxidation and aggregation, and its structurally dense oxide shell seriously prevents mass and electron transport. Herein, a novel phosphorylated multi-wall carbonnanotubes/polypyrrole/polydopamine supported nZVI (P-MWCNTs/PPy/PDA-nZVI) was successfully fabricated. Induced by the circumferential stress from phosphate ions, a unique 2D agaric-like nanoflake morphology with ultrathin thickness (ca. 20nm) and inhibited dense oxide shell was formed. Impressively, the unprecedented modified kinetic rate constants (K-value) of 116.35 and 154.15 μmol·g-1·s-1 towards para-nitrophenol degradation were obtained in batch and continuous-flow reactors, far outperforming other reported catalysts (1-3 orders of magnitude) and non-P-doped MWCNTs/PPy/PDA-nZVI (1.53 and 10.5 folds). Phosphorylation-dependent enhancement in dispersity, conductivity and hydrophilicity rendered the catalyst with abundant active sites, accelerated electron transfer and boosted catalytic efficiency. The present encouraging findings might shed light on new ways to design high-performance nZVI in water decontamination.

Enhancing Microplastic Degradation through Synergistic Photocatalytic and Pretreatment Approaches.

Microplastics (MPs) pollution has emerged as a pressing environmental concern in recent years. Owing to their minute dimensions, conventional plastic remediation approaches are inadequate for addressing the challenges posed by MPs. Herein, spherical (BOC-S) and nanosheet (BOC-N) BiOCl photocatalysts were prepared and applied to the degradation of poly(ethylene terephthalate) (PET) MPs after hydrothermal pretreatment. The results indicated that the degradation efficiency of pretreated PET MPs using BOC-S and BOC-N photocatalysts was 8.8 and 6.9 times that of the unpretreated MPs under the same conditions. Comparative experiments confirmed the excellent performance of the photocatalysis-pretreatment system. The creation of pores on the surface of pretreated PET MPs facilitates the entry of active substances into the interior to cause damage, while the enhancement of hydrophilicity and specific surface area facilitates the contact between the catalyst and PET MPs, thus increasing the degradation efficiency. Free radical trapping experiments revealed that hydroxyl radicals (·OH) produced by photocatalysis had the greatest influence on the degradation performance of pretreated PET MPs. Finally, a possible photocatalytic degradation mechanism for PET MPs was proposed. This research offers a novel perspective on MPs degradation, providing valuable insights for advancing the efficacy of the process.

Surface Microstructure Study on Corona Discharge-Treated Polyethylene Using Positron Annihilation Spectroscopy.

The microstructure and chemical properties of the corona discharge process could provide an effective method for predicting the performance of high-voltage cable insulation materials. In this work, the depth profile of the microstructure and chemical characteristics of corona discharge-treated PE were extensively investigated using Doppler broadening of position annihilation spectroscopy accompanied with positron annihilation lifetime spectroscopy, attenuated total reflectance Fourier transform infrared spectra, Raman spectra and contact angle measurement. By increasing corona discharge duration, the oxygen-containing polar groups, including hydroxyl, carbonyl and ester groups, strongly contribute to the deterioration of hydrophobicity and the enhancement of hydrophilicity. And the mean free volume size, with a broadening distribution, decreases slightly. The line shape S parameter decreases because of the decrease in free volume elements and the appearance of oxygen-containing groups. Also, the thickness of the degradation layer, determined from the S parameter with positron injection depth, increases and diffuses into the PE matrix. A linear S-W plot within the degradation layer of different corona treatment duration samples indicates the defect type does not change. The S parameter decreases and the W parameter increases with an increasing corona duration. Using a slow positron beam, the nondestructive probe can be used to profile the microstructure and chemical environment across the corona discharge damage depth, which is beneficial for investigating the surface and interfacial insulation materials.

Improving osteogenic properties of zirconia ceramic via glow discharge plasma-enhanced deposition of amine organic compound

Background/purposeOsseointegration potential is greatly depended on the interaction between bone cells and dental implant surface. Since zirconia ceramic has a bioinert surface, functionalization of the surface with an organic compound allylamine was conducted to overcome its drawback of minimal interaction with the surrounding bone. Materials and methodsThe zirconia surface was initially treated with argon glow discharge plasma (GDP), then combined with amine plasma at three different conditions of 50-W, 75-W and 85-W, to prepare the final samples. The surface characteristics and cell biocompatibility were then evaluated. ResultsSurface morphology analysis revealed a bulbous pattern on allylamine-treated sample groups. The aromatic C–H, C–O, N–H, C ˆ C, and C–H stretching and functional groups have been identified. Surface roughness increased, and hydrophilicity improved after surface modification. Cell viability analysis showed the highest result for the allylamine 50-W (A50) group. Alkaline phosphatase (ALP) assay indicated the A50 group had the highest activity, subsequently promoting late-stage mineralization at day 21. The reverse transcription-quantitative polymerase chain reaction (RT-qPCR) data demonstrated a significant upregulation of osteogenic gene expressions from day 1 to day 21. ConclusionThe allylamine-treated surface demonstrates immense enhancement in the surface hydrophilicity as well as in the viability, differentiation, and osteogenic properties of osteoblast-like cells. This makes it a promising candidate for future dental implant applications.

Integrating Multipolar Structures and Carboxyl Groups in sp2‐Carbon Conjugated Covalent Organic Frameworks for Overall Photocatalytic Hydrogen Peroxide Production

The direct production of hydrogen peroxide (H2O2) through photocatalytic reaction via H2O and O2 is considered as an ideal approach. However, the efficiency of H2O2 generation is generally limited by insufficient charge and mass transfer. Covalent organic framework (COFs) offer a promising platform as metal‐free photocatalyst for H2O2 production due to their potential for rational design at the molecular level. Herein, we integrated the multipolar structures and carboxyl groups into COFs to enhance the efficiency of photocatalytic H2O2 production in pure water without any sacrificial agents. The introduction of octupolar and quadrupolar structures, along with an increase of molecular planarity, created efficient oxygen reduction reaction (ORR) sites. Meanwhile, carboxyl groups could not only boost O2 and H2O2 movement via enhancement of pore hydrophilicity, but also promote proton conduction, enabling the conversion to H2O2 from ·O2‐, which is the crucial intermediate product in H2O2 photocatalysis. Overall, we demonstrate that TACOF‐1‐COOH, consisting of optimal octupolar and quadrupolar structures, along with enrichment sites (carboxyl groups), exhibited a H2O2 yield rate of 3542 μmol h‐1 g‐1 and a solar‐to‐chemical (SCC) efficiency of 0.55%. This work provides valuable insights for designing metal‐free photocatalysts for efficient H2O2 production.

Integrating Multipolar Structures and Carboxyl Groups in sp2-Carbon Conjugated Covalent Organic Frameworks for Overall Photocatalytic Hydrogen Peroxide Production.

The direct production of hydrogen peroxide (H2O2) through photocatalytic reaction via H2O and O2 is considered as an ideal approach. However, the efficiency of H2O2 generation is generally limited by insufficient charge and mass transfer. Covalent organic framework (COFs) offer a promising platform as metal-free photocatalyst for H2O2 production due to their potential for rational design at the molecular level. Herein, we integrated the multipolar structures and carboxyl groups into COFs to enhance the efficiency of photocatalytic H2O2 production in pure water without any sacrificial agents. The introduction of octupolar and quadrupolar structures, along with an increase of molecular planarity, created efficient oxygen reduction reaction (ORR) sites. Meanwhile, carboxyl groups could not only boost O2 and H2O2 movement via enhancement of pore hydrophilicity, but also promote proton conduction, enabling the conversion to H2O2 from ⋅O2 -, which is the crucial intermediate product in H2O2 photocatalysis. Overall, we demonstrate that TACOF-1-COOH, consisting of optimal octupolar and quadrupolar structures, along with enrichment sites (carboxyl groups), exhibited a H2O2 yield rate of 3542 μmol h- 1 g-1 and a solar-to-chemical (SCC) efficiency of 0.55 %. This work provides valuable insights for designing metal-free photocatalysts for efficient H2O2 production.

Cellulose triacetate-based mixed matrix membranes for concurrent removal of arsenate and arsenite from groundwater

Arsenic is one of the most dangerous groundwater contaminants whose effective removal is a major challenge for environmental scientists. Herein, several cellulose triacetate-based hybrid membranes are synthesized by adding different dosages (10, 30, and 50 wt%) of chitosan or chitosan-stabilized iron nanosheets. The fabricated membranes are characterized by advanced analytical tools such as AFM, SEM, FTIR, BET, TGA, zeta potential, and XRD. The enhancement in hydrophilicity and improved antifouling are evaluated by porosity, water uptake, contact angle, permeability tests, and bovine serum albumin (BSA) studies. At neutral pH, the cellulose triacetate-chitosan 50 % (CTA-CH 50 %) removed 85.13 % As(III) and 87.20 % As(V) at 67.23 L.m−2.h−1 permeability. On the other hand, cellulose triacetate-chitosan iron nanosheets 50 % (CTA-CIN 50 %) removed 91.30 % As(III) and 84.24 % As(V) at 62.35 L.m−2.h−1 permeability. The synthesized membranes efficiently removed arsenic from real groundwater taken from different Pakistani cities. The membranes are synthesized through a low-cost and scalable method, making it convenient for industrial-level applications.

Enhanced brackish water desalination in capacitive deionization with composite Zn-BTC MOF-incorporated electrodes

In this study, composite electrodes with metal–organic framework (MOF) for brackish water desalination via capacitive deionization (CDI) were developed. The electrodes contained activated carbon (AC), polyvinylidene fluoride (PVDF), and zinc-benzene tricarboxylic acid (Zn-BTC) MOF in varying proportions, improving their electrochemical performance. Among them, the E4 electrode with 6% Zn-BTC MOF exhibited the best performance in terms of CV and EIS analyses, with a specific capacity of 88 F g−1 and low ion charge transfer resistance of 4.9 Ω. The E4 electrode showed a 46.7% increase in specific capacitance compared to the E1 electrode, which did not include the MOF. Physicochemical analyses, including XRD, FTIR, FESEM, BET, EDS, elemental mapping, and contact angle measurements, verified the superior properties of the E4 electrode compared to E1, showcasing successful MOF synthesis, desirable pore size, elemental and particle-size distribution of materials, and the superior hydrophilicity enhancement. By evaluating salt removal capacity (SRC) in various setups using an initially 100.0 mg L−1 NaCl feed solution, the asymmetric arrangement of E1 and E4 electrodes outperformed symmetric arrangements, achieving a 21.1% increase in SRC to 6.3 mg g−1. This study demonstrates the potential of MOF-incorporated electrodes for efficient CDI desalination processes.

Deposition of a polymer thin film on a silver surface for surface plasmon sensing

We report a deposition method of a polymer thin film on the silver surface of a surface plasmon sensor for preventing sensitivity degradation in refractive index measurements due to the poor chemical stability of the silver. The deposition of a poly(methyl methacrylate) thin film with a ∼15 nm thickness was conducted by employing a spin coating technique along with a hydrophilicity enhancement of the silver surface using an atmospheric low-temperature plasma treatment. We experimentally verified the thickness by measuring the propagation constant of the surface plasmon. The measured propagation constants that showed the standard deviation at the order of 10−4 indicated microscopical uniformity. Furthermore, the reproducibility of thickness was experimentally verified.

Improving Hemocompatibility of Polysulfone Membrane by UV-Assisted Grafting of Sulfonated Chitosan.

The most prevalent type of hemodialysis membrane is polysulfone (PSf). However, due to inadequate biocompatibility, it significantly compromises the safety of dialysis for patients. In this study, we modify the surface of the PSf membrane with 2,4-dihydroxybenzophenone (DBPh) groups to serve as anchoring sites during UV irradiation. Subsequently, a tailored sulfonated dihydroxy propyl chitosan (SDHPCS) is grafted onto the modified PSf membrane to compensate for the deficiencies in hydrophilic additives. The modified PSf membrane exhibits outstanding hydrophilicity and stability, as demonstrated by its characterization and evaluation. This paper focuses on investigating the interaction between platelet membrane formation, protein adsorption, and anticoagulant activity. The results show that the modified PSf membrane exhibits remarkable enhancement in surface hydrophilicity, leading to a significant reduction in protein and platelet adsorption as well as adhesion.

Biological activity of tantalum oxide coating doped with calcium and strontium by micro-arc oxidation under osteoimmunomodulation

Tantalum is widely used in clinics due to its excellent properties. However, its high density and elastic modulus constrain its application as a large implant. The new porous tantalum material addresses the issue of incompatibility between the implant and the human body. Nevertheless, it still exhibits biological inertia and limited bone-bonding ability; therefore, it is necessary to modify its surface. At present, some surface modification methods have inconsistent results in vitro and in vivo. To solve this problem, this study described the preparation of a ceramic coating with a "trabeculae-like" structure on the surface of pure tantalum using micro-arc oxidation (MAO). Calcium and strontium ions were introduced by adding acetate to the electrolyte. The effects of incorporating bioactive ions Ca2+ and Sr2+ into the electrolyte on the coating's morphology, coating thickness, phase composition, roughness, hydrophilicity, and the activity of MC3T3-E1 osteoblast cells under osteoimmunomodulation were investigated. The results demonstrated that the introduction of bioactive ions did not change the porous morphology of the coating; instead, it led to an increase in coating thickness, enhancement of surface roughness and hydrophilicity, as well as promotion of osteoblast spreading, proliferation, and ALP activity. Moreover, it regulated the phenotypic polarization of RAW264.7 macrophages to augment osteoblast proliferation, spreading, and ALP activity, implying that the coating has superior osteogenic potential under osteoimmunomodulation.

A CO-releasing coating based on carboxymethyl chitosan-functionalized graphene oxide for improving the anticorrosion and biocompatibility of magnesium alloy stent materials

Due to its biofunctions similar to NO, the CO gas signaling molecule has gradually shown great potential in cardiovascular biomaterials for regulating the in vivo performances after the implantation and has received increasing attention. To construct a bioactive surface with CO-releasing properties on the surface of magnesium-based alloy to augment the anticorrosion and biocompatibility, graphene oxide (GO) was firstly modified using carboxymethyl chitosan (CS), and then CO-releasing molecules (CORM401) were introduced to synthesize a novel biocompatible nanomaterial (GOCS-CO) that can release CO in the physiological environments. The GOCS-CO was further immobilized on the magnesium alloy surface modified by polydopamine coating with Zn2+ (PDA/Zn) to create a bioactive surface capable of releasing CO in the physiological environment. The outcomes showed that the CO-releasing coating can not only significantly enhance the anticorrosion and abate the corrosion degradation rate of the magnesium alloy in a simulated physiological environment, but also endow it with good hydrophilicity and a certain ability to adsorb albumin selectively. Owing to the significant enhancement of anticorrosion and hydrophilicity, coupled with the bioactivity of GOCS, the modified sample not only showed excellent ability to prevent platelet adhesion and activation and reduce hemolysis rate but also can promote endothelial cell (EC) adhesion, proliferation as well as the expression of nitric oxide (NO) and vascular endothelial growth factor (VEGF). In the case of CO release, the hemocompatibility and EC growth behaviors were further significantly improved, suggesting that CO molecules released from the surface can significantly improve the hemocompatibility and EC growth. Consequently, the present study provides a novel surface modification method that can simultaneously augment the anticorrosion and biocompatibility of magnesium-based alloys, which will strongly promote the research and application of CO-releasing bioactive coatings for surface functionalization of cardiovascular biomaterials and devices.

Morphological evolution of nano-droplets impinging on cylindrical wall: A molecular dynamics study

The impact of droplets on solid walls is the primary behavior in spray cooling, seawater desalination, self-cleaning, and other technological processes. Based on the molecular dynamics (MD) method, the morphological evolution characteristics of nanodroplets impinging on the copper cylinder wall are studied. The effects of droplet size, initial velocity, impact position, and wall wettability on nanodroplet dynamics are analyzed. The results indicate that a single nanodroplet impacting on a nanocylinder exhibits four distinct impact modes: spread-partially wrapped-deposition (SPD), spread-completely wrapped-deposition (SCD), spread-completely wrapped-splitting-deposition (SCSD), and spreading-partially wrapped-splitting-deposition (SPSD). The trend of the influence of initial velocity and droplet size on the impact mode is similar. As the initial velocity and droplet size increase, the droplet’s kinetic energy and inertia force increase, successively exhibiting the SPD, SCD, and SCSD modes. The trend of the influence of impact position and wall wettability on the droplet impact mode is similar. When the impact eccentricity distance is small, and the wall is highly hydrophilic, it exhibits the SCD mode. With increasing impact eccentricity and enhanced wall hydrophobicity, the adhesion force between the droplet and the cylinder wall decreases, making the droplet less likely to be captured and more prone to splitting, exhibiting the SPSD mode. The change in droplet centroid height and mean square displacement could predict whether the droplet undergoes a splitting mode, and its influence is most significant at the impact position. Constrained by the cylindrical wall, the droplet impacts radially and spreads primarily in that direction. With the enhancement of wall hydrophilicity, the migration region of the three-phase contact line expands, and the droplet spreading transforms into synchronous development along the radial and axial directions. The research results can enrich the dynamic mechanism of micro-nano scale droplet impact and provide potential guidance for optimizing relevant technologies.

Hydrophilic Modification of Polytetrafluoroethylene (PTFE) Capillary Membranes with Chemical Resistance by Constructing Three-Dimensional Hydrophilic Networks.

Polytetrafluoroethylene (PTFE) capillary membranes, known for the great chemical resistance and thermal stability, are commonly used in membrane separation technologies. However, the strong hydrophobic property of PTFE limits its application in water filtration. This study introduces a method whereby acrylamide (AM), N, N-methylene bisacrylamide (MBA), and vinyltriethoxysilane (VTES) undergo free radical copolymerization, followed by the hydrolysis-condensation of silane bonds, resulting in the formation of hydrophilic three-dimensional networks physically intertwined with the PTFE capillary membranes. The modified PTFE capillary membranes prepared through this method exhibit excellent hydrophilic properties, whose water contact angles are decreased by 24.3-61.2%, and increasing pure water flux from 0 to 1732.7-2666.0 L/m2·h. The enhancement in hydrophilicity of the modified PTFE capillary membranes is attributed to the introduction of hydrophilic groups such as amide bonds and siloxane bonds, along with an increase in surface roughness. Moreover, the modified PTFE capillary membranes exhibit chemical resistance, maintaining the hydrophilicity even after immersion in strong acidic (3 wt% HCl), alkaline (3 wt% NaOH), and oxidative (3 wt% NaClO) solutions for 2 weeks. In conclusion, this promising method yields modified PTFE capillary membranes with great hydrophilicity and chemical resistance, presenting substantial potential for applications in the field of water filtration.

Antifouling and Antioxidant Properties of PVDF Membrane Modified with Polyethylene Glycol Methacrylate and Propyl Gallate.

In this study, molecules of propyl gallate (PG) and polyethylene glycol methacrylate (PEGMA) were covalently bonded via a transesterification reaction and subsequently grafted onto polyvinylidene fluoride substrates using a homogeneous radiation grafting technique. The enhancement of the membranes' hydrophilicity with the increment of the grafting rate was corroborated by scanning electron microscopy imaging and measurements of the water contact angle. At a grafting degree of 10.1% and after a duration of 4 min, the water contact angle could decrease to as low as 40.1°. Cyclic flux testing demonstrated that the membranes modified in this manner consistently achieved a flux recovery rate exceeding 90% across varying degrees of grafting, indicating robust anti-fouling capabilities. Furthermore, these modified membranes exhibited significant antioxidant ability while maintaining antifouling performance over 30 days. The ability of the modified membranes to scavenge 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS+) free radicals remained nearly unchanged after being stored in pure water for 30 days, and the flux recovery rate remained above 95% after immersion in sodium hypochlorite solution for 30 days. Among the tested membranes, the PVDF-g-PEGMAG modified membrane with a grafting degree of 7.2% showed the best antioxidant effect.

A Method for Preparing Surface Sub-Microstructures on Sapphire Surfaces Using Femtosecond Laser Processing Technology

Femtosecond laser processing technology is an advanced sub-micro-processing technique that enables the non-contact processing of various materials. This technology can be used to apply sub-micro structures for purposes such as hydrophilicity enhancement, optical transmittance improvement, and photonics detection. However, when it comes to processing micro/nanostructures on highly brittle materials using femtosecond lasers, there are challenges such as low processing efficiency, generation of debris, and microcracking. In this paper, we propose a method called the out-of-focus femtosecond laser direct writing technique combined with wet etching. This method offers simplicity, speed, and flexibility in preparing dense, large-area sub-microstructured surfaces on the brittle material sapphire. Our detailed investigation focuses on the impact of laser processing parameters (direct writing period, distance of focusing, direct writing speed, etc.) on the sub-microstructures of Al2O3 surfaces. The results demonstrate that this method successfully creates embedded sub-microstructures on the sapphire surface. The microholes, with a diameter of approximately 2.0 μm, contain sub-micro structures with a minimum width of 250 ± 20 nm. Additionally, we conducted experiments to assess the optical transmittance of sapphire nanostructures in the range of 350–1200 nm, which exhibited an average transmittance of approximately 77.0%. The water contact angle (CA) test yielded a result of 52 ± 2°, indicating an enhancement in the hydrophilicity of the sapphire nanostructures with only a slight reduction in optical transmittance. Our efficient fabrication of sub-microstructures on the sapphire surface of highly brittle materials offers a promising method for the production and application of brittle materials in the field of micro-optics.

A comprehensive review on the use of Ti3C2Tx MXene in membrane-based water treatment

Population growth, industrial activities, and the energy demands of water production intensify the global challenge of accessing clean water. Membrane-based water treatment processes have emerged as crucial solutions to address this crisis, these include microfiltration (MF), ultrafiltration (UF), nanofiltration (NF), forward osmosis (FO), reverse osmosis (RO), and membrane distillation (MD). This review summarizes the properties and use of Ti3C2Tx MXene, a material with notable chemical stability, specific surface area, hydrophilicity, thermal conductivity, and environmental compatibility. Ti3C2Tx fills in the class of two-dimensional materials, it is promising in various membrane processes by offering enhancement in hydrophilicity, permeability, and selectivity. In UF, Ti3C2Tx-based membranes have superior antifouling properties and high rejection rates of contaminants. Meanwhile, in NF, MXene nanosheets elevate the rejection of organics, dyes, and salts, and present valuable nanocomposite membranes. In desalination, incorporating Ti3C2Tx in RO membranes is found to increase water permeability while maintaining high salt rejection in desalination. Also, MXene-modified FO membranes had lower fouling and improved water flux compared with plain membranes, presenting a promising avenue for water purification. Additionally, Ti3C2Tx enhanced water vapor transport and resistance against wetting, which is favorable in MD.This review underscores the transformative potential of Ti3C2Tx MXene in revolutionizing membrane-based water treatment processes, providing innovative solutions to meet the escalating global demand for clean water. Future research directions should optimize MXene-based membrane designs and scale up their production for practical applications in water treatment, thereby contributing to a more sustainable water future.

Long-term observation of polycaprolactone small-diameter vascular grafts with thickened outer layer and heparinized inner layer in rabbit carotid arteries

In our previous study, the pristine bilayer small-diameter in situ tissue engineered vascular grafts (pTEVGs) were electrospun from a heparinized polycaprolactone (PCL45k) as an inner layer and a non-heparinized PCL80k as an outer layer in the thickness of about 131 μm and 202 μm, respectively. However, the hydrophilic enhancement of inner layer stemmed from the heparinization accelerated the degradation of grafts leading to the early formation of arterial aneurysms in a period of 3 months, severely hindering the perennial observation of the neo-tissue regeneration, host cell infiltration and graft remodeling in those implanted pTEVGs. Herein to address this drawback, the thickness of the outer layers was increased with PCL80k to around 268 μm, while the inner layer remained unchangeable. The thickened TEVGs named as tTEVGs were evaluated in six rabbits via a carotid artery interpositional model for a period of 9 months. All the animals kept alive and the grafts remained patent until explantation except for one whose one side of arterial blood vessels was occluded after an aneurysm occurred at 6 months. Although a significant degradation was observed in the implanted grafts at 9 month, the occurrence of aneurysms was obviously delayed compared to pTEVGs. The tissue stainings indicated that the endothelial cell remodeling was substantially completed by 3 months, while the regeneration of elastin and collagen remained smaller and unevenly distributed in comparison to autologous vessels. Additionally, the proliferation of macrophages and smooth muscle cells reached the maximum by 3 months. These tTEVGs possessing a heparinized inner layer and a thickened outer layer exhibited good patency and significantly delayed onset time of aneurysms.

Ultrasensitive detecting of dopamine in complex components by field effect transistor sensor based on the synergistic enhancement effect and overcoming debye length limitations

Field effect transistor (FET) has attracted high attention in biomolecules detection. However, the sensitivity of FET-based biosensors is often limited by the charge screening effect. In addition, the facile and ultra-sensitive detection for small biomolecules, which possess weak charge or electroneutral, remains to be studied. Here, the self-assembled monolayer AuNPs/three-dimensional (3D) crumpled graphene FET is structured for a biosensor by shrinking flexible polystyrene (PS) films through heat treatment method and realized label-free and ultra-sensitive detection of dopamine (DA) using DA aptamer as probes immobilized on the AuNPs/3D crumpled graphene surface. The nanoscale deformation caused by thermal expansion effect of flexible graphene/PS can effectively reduce charge screening and the synergistic application of crumpled graphene and AuNPs can promote electron transfer and the graphene carrier concentration, leading to conductivity increase and hydrophilicity enhancement of 3D graphene. In addition, the binding of DA aptamer to DA will cause conformational changes of the aptamer molecule, which affects the charge transport properties of the sensor, thus improving its selectivity and stability. The biosensor can also easily distinguish interfering substances for DA detection in complex components (PBS, human urine, and fetal calf serum) with the detection limits as low as 60, 240 and 316 zM (10−19–10−11 M), respectively. DA released from exocytosis induced by K+ stimulation was selectively detected. The results show that the biosensor can be used as an excellent tool for ultrasensitive molecular recognition and detecting the effects of exogenous reagents on living cells, which is promising for clinical diagnosis and early disease prevention.

Polyamide nanofiltration membranes mediated by mesoporous silica nanosheet interlayers display substantial desalination performance enhancement

Recently, thin-film nanocomposite membranes with interlayered structures (TFNi) have demonstrated great promise for breaking the permeance-selectivity trade-off in nanofiltration (NF). Here, we first report the polyamide (PA) nanofiltration membranes mediated by mesoporous silica nanosheet (MSNS) interlayers. According to the characterizations and chemical analysis, it suggested that the inclusion of MSNS greatly affected the PA membrane surface topography and chemical structure, leading to an enhancement in surface roughness, hydrophilicity, and negative charge and a reduction in crosslinking degree and thickness of the PA layer. Ultimately, the fabricated optimal membrane displayed a favorable combination of high water permeance of 22.5 L m−2 h−1 bar−1 (2.5 times higher than pristine PA) and satisfactory Na2SO4 rejection of 97.8 %, superior to most of the TFNi membranes reported so far when compared by NaCl/Na2SO4 permeation selectivity versus water permeance. Additionally, the MSNS aided design endowed the TFNi membranes with drastically improved antifouling property and high operational stability. Also, the structural advantages of MSNS were highlighted by conducting a control experiment with zero-dimensional (0D) silica nanoparticles. This work is expected to stimulate the use of silica-based nanomaterials for preparing high-performance NF membranes for efficient desalination.