Search

The isomerization of n-alkanes through hydrogenation is a crucial process for producing high-quality, clean oil products. The development of high-performance and cost-effective hydroisomerization catalysts is pivotal to this process. In this work, by leveraging the spatial steric effect of SAPO-11, a highly efficient Ni/SAPO-11 catalyst was prepared through a one-step solid-phase synthesis method to enhance isomerization activity. As well as its physicochemical properties, the effects of the aluminum source, template agent, silicon–aluminum ratio, crystallization temperature, crystallization time and nickel–aluminum ratio on the preparation of Ni/SAPO-11 catalyst were investigated. Utilizing pseudo-boehmite, phosphoric acid, silica sol, dipropylamine and nickel nitrate at the molar ratio of 1.0 Al2O3 : 1.0 P2O5 : 0.4 SiO2 : 2.0 DPA : 0.2 NiO under crystallization at 200 °C for 24 h obtained a Ni/SAPO-11 catalyst with suitable acid properties for the isomerization process. Three forms of Ni species were obtained by using a Ni/SAPO-11 catalyst: NiO with hydrogenation ability after reduction, framework nickel with acidic sites, and nickel–aluminum spinels. More importantly, achieving a balance between the dispersion of hydrogenation active sites and suitable acid properties with isomerization active sites was essential for highly effective hydroisomerization. In the hydroisomerization of n-hexane, optimizing the relationship between the catalyst metal sites and acidic sites resulted in a 70.9% conversion of n-hexane with a selectivity for isohexane of 93.0% over the Ni/SAPO-11 catalyst. [ABSTRACT FROM AUTHOR]

Rechargeable aqueous batteries using zinc as the anode have attracted more and more attention. However, the uncontrolled dendrite growth and hydrogen evolution reaction seriously hinder the performance of zinc anodes. In this work, a two-dimensional (2D) zinc-based MOF (ZHPCA) was synthesized by a simple solvothermal method, which is a Zn(II) coordination polymer with mixed ligands of nitrogen and oxygen donors (H-PCA). Using this MOF as the interface modification layer of the Zn electrode, the ZHPCA@UZn anode was prepared. The N-functional groups in ZHPCA can be used as binding sites for zinc ion deposition and promote their uniform deposition on zinc anodes. The modified layer also effectively inhibited hydrogen evolution and corrosion. It can be observed that the 40 μm ZHPCA@UZn (ZHPCA@UZn) has the longest cycle life exceeding 650 h with a low overpotential of about 46 mV. The zinc ion capacitor assembled by matching the ZHPCA@UZn anode with an activated carbon cathode maintained a specific capacity of 85 mA h g−1 after 1000 cycles at 1 A g−1. In conclusion, ZHPCA, the MOF selected in this work, can effectively protect the zinc anode, which provides certain inspiration for the selection of zinc anode coating materials in the future. [ABSTRACT FROM AUTHOR]

Interestingly, the metal–support interaction (MSI) influence of different metal phosphides on catalytic stability might be different in dry reforming of methane (DRM). After being supported on Al2O3, there was a rise, decline and no change in the catalytic stability of CoMoP, MoP and Co2P, respectively. This was probably because the MSI can tune the structural stability, methane dissociation ability and oxidation resistance ability of metal phosphides, which were the key factors that determined their catalytic stability. [ABSTRACT FROM AUTHOR]

Endowing MXene-based electromagnetic wave-shielding aerogels with superior hydrophobicity and reversible compressibility is crucial, yet challenging to support their adaptability to humid surroundings and reliability. From an economic and environmental perspective, it is highly desired to devise a practical method to fabricate such aerogels derived from MXenes and biomass. Herein, methyltrimethoxysilane (MTMS)-treated bacterial cellulose (BC) and Ti3C2Tx MXene suspensions are unidirectionally freeze-dried to prepare silylated BC/MXene aerogels. The hybrid aerogel with 84 wt% MXene integrates superior hydrophobicity (water contact angle of 128°), high elasticity (residual height of 87.5% after 100 compression cycles), and high electrical conductivity of 132 S m−1. Silylation treatment can boost electromagnetic interference (EMI) shielding efficiency (SE) by ∼25%. The specific electromagnetic interference (EMI) shielding effectiveness (SE) of the aerogel reaches 66 943.8 dB cm2 g−1, significantly outperforming that of other shielding materials. An increasing silylated BC (S@BC) content enables a significant enhancement in the hydrophobicity, aerogel elasticity, and compressive strength. When the S@BC loading was up to 50%, the mechanically robust and highly elastic aerogel exhibited superhydrophobic behavior while offering 99.6% shielding of electromagnetic waves (23 dB). The silylation treatment also enriches the diversity of the aerogel applications such as self-cleaning, strong adsorption of organic solvents and oils, efficient thermal insulation, and sensitive strain–electrical signal response. [ABSTRACT FROM AUTHOR]

Two-dimensional (2D) organometallic halide perovskites (OHPs) are promising optoelectronic materials because of their excellent stability and tunable band gaps. Herein, we report the optical and elastic properties of a newly synthesized 2D lead halide perovskite, (C9H14ON)2PbI4 (C9H14ON+ = 4-methoxyphenethylammonium), by a combined experimental and theoretical approach. Our experiments demonstrate that (C9H14ON)2PbI4 shows a strong green emission under ambient conditions which is ascribed to its band gap of 2.4 eV. Moreover, our temperature-dependent photoluminescence (PL) experiments in the temperature range of 143–283 K reveal that the green emission red-shifts with increasing temperature, which is primarily attributed to the synergistic effect of thermal expansion and electron–phonon interactions. The elastic properties, obtained from density functional theory calculations, reveal that (C9H14ON)2PbI4 has relatively low modulus and anisotropy compared with other 2D materials. [ABSTRACT FROM AUTHOR]

For reliable downstream molecular analysis, it is crucially important to recover circulating tumor cells (CTCs) from clinical blood samples with high purity and viability. Herein, magnetic nanoparticles coated with an antifouling hydrogel layer based on the polymerization method were developed to realize cell-friendly and efficient CTC capture and recovery. Particularly, the hydrogel layer was fabricated by zwitterionic sulfobetaine methacrylate (SBMA) and methacrylic acid (MAA) cross-linked with N,N-bis(acryloyl)cystamine (BACy), which could not only resist nonspecific adhesion but also gently recover the captured cells by glutathione (GSH) responsiveness. Moreover, the anti-epithelial cell adhesion molecule (anti-EpCAM) antibody was modified onto the surface of the hydrogel to provide high specificity for CTC capture. As a result, 96% of target cells were captured in the mimic clinical blood samples with 5–100 CTCs per mL in 25 min of incubation time. After the GSH treatment, about 96% of the obtained cells were recovered with good viability. Notably, the hydrogel-coated magnetic nanoparticles were also usefully applied to isolate CTCs from the blood samples of cancer patients. The favorable results indicate that the hydrogel-modified magnetic nanoparticles may have a promising opportunity to capture and recover CTCs for subsequent research. [ABSTRACT FROM AUTHOR]

Perovskite solar cells (PSCs) have reached their highest efficiency with the state-of-the-art hole-transporting material (HTM) spiro-OMeTAD. However, the relatively low conductivity and high cost of this material significantly limit the commercialization of this promising technology. In this work, a low-cost, asymmetric HTM containing a carbazole core and peripheral triphenylamine moieties, named Cz-3OMeTAD, was designed and synthesized via a facile three-step synthetic procedure and employed successfully in planar CH3NH3PbI3 PSCs. The optical and electrochemical data of the asymmetric HTM Cz-3OMeTAD exhibited appropriate energy levels for efficient interfacial charge transfer with the perovskite. The asymmetric propeller-shaped Cz-3OMeTAD has a relatively high mobility value of 1.42 × 10−3 cm2 V−1 s−1, beneficial for the PSC performance. Moreover, steady-state PL and time-resolved PL measurements indicate successful hole extraction properties of Cz-3OMeTAD from the perovskite at the perovskite/HTM interface. Consequently, the Cz-3OMeTAD-based devices achieved a high efficiency of 16.36% in PSCs under 1 sun conditions, comparable with the efficiency obtained for the reference cell using spiro-OMeTAD. Thus, our result demonstrated the asymmetric carbazole-based material as a new class of HTM for highly efficient PSCs. [ABSTRACT FROM AUTHOR]

Determining the status of epidermal growth factor receptor (EGFR) T790M mutation is crucial for guiding further treatment intervention in advanced non-small cell lung cancer (NSCLC) patients who develop acquired resistance to initial EGFR tyrosine kinase inhibitor (TKI) treatment. Circulating tumor cells (CTCs) which contain plentiful copies of well-preserved RNA offer an ideal source for noninvasive detection of T790M mutation in NSCLC. We developed a CTC-based digital assay which synergistically integrates NanoVelcro Chips for enriching NSCLC CTCs and reverse-transcription droplet digital PCR (RT-ddPCR) for quantifying T790M transcripts in the enriched CTCs. We collected 46 peripheral arterial and venous blood samples from 27 advanced NSCLC patients for testing this CTC-based digital assay. The results showed that the T790M mutational status observed by the CTC-based digital assay matched with those observed by tissue-based diagnostic methods. Furthermore, higher copy numbers of T790M transcripts were observed in peripheral arterial blood than those detected in the matched peripheral venous blood. In short, our results demonstrated the potential of the NanoVelcro CTC-digital assay for noninvasive detection of the T790M mutation in NSCLC, and suggested that peripheral arterial blood sampling may offer a more abundant CTC source than peripheral venous blood in advanced NSCLC patients. [ABSTRACT FROM AUTHOR]

Analysis of circulating tumor cells (CTCs) can provide significant clinical information for tumors, which has proven to be helpful for cancer diagnosis, prognosis monitoring, treatment efficacy, and personalized therapy. However, CTCs are an extremely rare cell population, which challenges the isolation of CTCs from patient blood. Over the last few decades, many strategies for CTC detection have been developed based on the physical and biological properties of CTCs. Among them, nanostructured interfaces have been widely applied as CTC detection platforms to overcome the current limitations associated with CTC capture. Furthermore, aptamers have attracted significant attention in the detection of CTCs due to their advantages, including good affinity, low cost, easy modification, excellent stability, and low immunogenicity. In addition, effective and nondestructive release of CTCs can be achieved by aptamer-mediated methods that are used under mild conditions. Herein, we review some progress in the detection and release of CTCs through aptamer-functionalized nanostructured interfaces. [ABSTRACT FROM AUTHOR]

Single-tailed and gemini-type supra-gelators were facilely fabricated via the conjugation of the D - or L -enantiomeric dihydrazide TDH with single-tailed achiral aldehyde C12BAD through dynamic acylhydrazone bonding. Chirality transfer from small molecules to supramolecules was successfully achieved via the spontaneous assembly of the formed supra-gelators into supramolecular chiral hydrogels. [ABSTRACT FROM AUTHOR]

Ultra-fast self-healing organogels based on dynamic covalent chemistry for dye adsorption were prepared from polyvinyl alcohol (PVA), 4-formylphenylboronic acid (FPBA), and tartaric acid dihydrazide (TDH) by an effective in situ reaction approach. The relative xerogels can adsorb methylene blue selectively with high efficiency. The boronate ester bonds and acylhydrazone bonds endow organogels with a very fast self-healing property. What's more, the chirality can be transferred from TDH to the organogels. The organogels obtained from l-TDH and d-TDH show opposite chirality according to the circular dichroism spectra. [ABSTRACT FROM AUTHOR]

Two regio-asymmetric polymers PR2F and PR1F with three repeat units A–D–A, π–D–A, and π–D–π along the polymer backbone were obtained by polymerizing different fluorinated benzothiadiazole–thiophene units, FBT-T and 2FBT-T units (A–π), with a benzodithiophene unit (D), respectively. Here, the new regio-asymmetric polymers were different from traditional polymers featuring a D–A or D–π–A–π backbone. Both the regio-asymmetric polymers showed a low lying HOMO energy level in relation to that of the PC61BM acceptor and then a high open-circuit voltage of ∼1 V was observed in both PR2F and PR1F devices. Bulk-heterojunction devices based on PR2F with difluorinated BT exhibited an appreciable power conversion efficiency (PCE) of 4.73% due to the relatively high and balanced charge carrier mobilities, while the mono-fluorinated BT polymer PR1F-based devices showed a lower PCE of 2.92%. These results indicate that the regio-asymmetric conjugated polymers are a promising class of materials for polymer solar cell applications, and it is significant to further understand the influence of the polymer structure on the optoelectronic properties. [ABSTRACT FROM AUTHOR]

In this study, a novel anode material of SnS hollow nanofibers (SnS HNFs) was rationally synthesized by a facile process and demonstrated to be a promising anode candidate for sodium-ion batteries. The synergetic effect of unique hollow and porous microstructures of SnS HNFs led to high capacity and ultra-long cycling stability. [ABSTRACT FROM AUTHOR]

To deliver siRNA efficiently, prevailing conventional lipid or polymer encapsulation often needs multi-step compounding methods, which may inevitably introduce cationic or other components and may lead to cytotoxicity or an immune response. Herein, we present a novel enzymatic synthetic approach to produce tumor-targetable RNAi nanoflowers. The RNAi nanoflowers are mainly composed of multiple tandem copies of siRNA precursors by rolling circle transcription (RCT), and produce large amounts of siRNA to silence Bcl-2 gene expression after cellular uptake, which can overcome the problem of low loading capacity. In particular, the RNAi microspheres (RNAi-MS) were condensed into nanosized complexes (RNAi nanospheres, RNAi-NS) by cholesterol-modified DNA strands without the assistance of polycationic agents. RNAi-NS are entirely composed of nucleic acid, giving them lower cytotoxicity and immunogenicity, which can be caused by synthetic polycationic reagents. In addition, the RNAi nanoflowers can also integrate DNA aptamers that bind specifically to target membrane proteins for cell-targeting. Therefore, thousands of copies of siRNA will be delivered to cells specifically, and this RNAi nanoflower system will have great potential for siRNA delivery and biomedical applications. [ABSTRACT FROM AUTHOR]

A novel luminescent probe based on a Tb3+/Cu2+ heterometallic metal–organic framework (MOF) was first designed for beamed monitoring of urinary sarcosine, a differential metabolite that can indicate the progression of prostate cancer (PCa). The fluorescent probe presented high selectivity towards sarcosine in urine. It also displayed good sensitivity with a comparatively low detection limit and a fast response to sarcosine within 5 min. Moreover, such high selectivity and sensitivity towards sarcosine is not subject to interference from other coexisting species in urine. At the same time, this fluorescent material also demonstrated the possibility for recycling. The excellent sensing performance of this Ln-MOF (lanthanide MOF) enables it to be further employed as a serviceable tool for PCa diagnosis and monitoring. [ABSTRACT FROM AUTHOR]

Glutathione (GSH) exhibits many cellular functions in human pathologies. A sensitive and simple method capable of assaying GSH would be useful to understand the mechanism of GSH-related diseases. In this study, a new colorimetric and fluorescent off–on probe, 3-oxo-3H-phenoxazin-7-ylthiophene-2-carboxylate, is constructed, synthesized and applied to determine fluctuations in intracellular GSH levels selectively and sensitively. The latent fluorescent probe is designed by reacting resorufin with thiophenecarboxylate and shows high sensitivity (LOD 8.9 × 10−7 M) and off–on fluorescent response to GSH over other different physiological species in pH 7.4 buffer solutions. A new reaction mechanism based on the cut-through of thiophenecarboxylate in the probe by GSH is confirmed via the HPLC (high performance liquid chromatography) and MS (mass spectrometry) analytical methods. Moreover, the probe is successfully applied to image GSH in A549 cells and indicates fluctuations in GSH levels under the stimulation of chemicals and drugs, which is verified by the investigation of the cell lysate with a commonly used commercial assay kit. As a result, it is feasible to monitor the levels of GSH in biosamples. [ABSTRACT FROM AUTHOR]

In the development of nanotechnology, the creation of new nanomaterials consistently feeds back into efforts to design and fabricate novel macroscopic materials with specific properties. Despite recent progress in preparing numerous types of nanomaterials, it remains a prodigious challenge to assemble tiny building blocks into functional macroscale architectures suitable for practical applications. Herein, we report a facile strategy suitable for common nanomaterials, in which ice-templated assembly and liquid nitrogen-assisted rotation are coupled, for fast processing of uniform spongy millispheres with tunable microstructures. Such spheres possess a hierarchical structure with an interpenetrating, open-porous, urchin-like network and abundant external voids, which can be continuously fabricated on a large scale by employing an automatic propeller. To demonstrate the great potential of the unique three-dimensional network in the energy and environmental field, boron nitride plates and graphene based spheres are fabricated to be utilized in oil/solvent adsorption and supercapacitors, respectively. With such useful features, we believe that this strategy may serve as a valuable tool for the assembly of nanomaterials for various applications. [ABSTRACT FROM AUTHOR]

Exploitation of high capacity and long-life anode materials is essential for the development of lithium-ion batteries (LIBs) with high energy density. Metal sulfides have shown great potential as anode materials for LIBs due to their high theoretical specific capacity and excellent electronic properties and therefore they are considered as excellent candidates for anode materials. However, structural degradation during cycling and polysulfide dissolution has limited their practical application. In this work, we design a unique 0D/1D heterostructure of carbon coated iron–nickel sulfide nanodots/carbon nanorod through simultaneous decomposition and sulfidation of a bi-metal organic framework template. The resultant nanodots/nanorod heterostructure allows for fast ion/electron transport kinetics, suppresses polysulfide dissolution and ensures structural integrity during the lithiation/delithiation process. Consequently, this carbon coated iron–nickel sulfide nanodots/carbon nanorod structure exhibits a high specific capacity (851.3 mA h g−1 at 0.5C after 200 cycles) and an excellent cycling stability (484.7 mA h g−1 after 1000 cycles at a high rate of 4C). [ABSTRACT FROM AUTHOR]

Conventional chemotherapy drugs such as paclitaxel (PTX) can effectively inhibit tumor growth by killing the majority of the proliferating cancer cells; however, it also results in multi-drug resistance (MDR) and facilitates the conversion of non-cancer stem cells (non-CSCs) to cancer stem cells (CSCs), which are considered the reason for chemotherapy resistance, relapse, and metastasis. Thus, exploring combination therapy with multiple chemotherapeutics is considered as a promising approach for simultaneously eliminating CSCs and non-CSCs. Here, we fabricated a bCSC (breast cancer stem cell)-targeting co-delivery system (HA-hybrid NPs) by attaching a lipoid (HA-HDA) to the surface of hydrophobic PLGA nanoparticles to co-deliver the widely used chemotherapy agent, PTX, and the selective inhibitor of CSCs, curcumin (CUR). This co-delivery system was capable of targeting bCSCs via an interaction between HA and the CD44 receptor on the membrane of bCSCs, and it could efficiently eliminate the bCSC population, decrease the mammosphere formation of bCSCs, and inhibit the migration of bCSCs. Most importantly, HA-hybrid co-delivered NPs exhibited enhanced anti-tumor efficacy by synergistically inhibiting the growth of both non-bCSCs and bCSCs on MCF7 xenografted tumor models. Taken together, the results of this study demonstrate that this bCSC-targeted HA-hybrid NP provides a potential strategy for enhancing breast cancer therapeutic efficiency. [ABSTRACT FROM AUTHOR]

A poly(glycidyl methacrylate) (PGMA) grafted bentonite (Bent) was prepared by surface-initiated atom transfer radical polymerization (SI-ATRP), followed by modification with tetraethylenepentamine (TEPA) through a ring-opening reaction of the epoxy groups in PGMA to form polyamine grafted bentonite (Bent–PGMA–TEPA). The as-prepared novel material was characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and thermal gravimetric analysis (TGA). The ability of Bent–PGMA–TEPA to adsorb Orange I (OI), a negatively charged dye, was tested. The effects of pH, initial concentration, contact time and temperature were investigated. The equilibrium adsorption isotherm and adsorption kinetics fitted well with the Langmuir model and the pseudo-second-order kinetic model respectively. [ABSTRACT FROM AUTHOR]

Recently, sodium-ion batteries (SIBs) have attracted increasing attention as an important supplement or alternative to lithium ion batteries (LIBs) due to the abundance of sodium resources and its much lower cost. A critical issue and great challenge in current battery research for the extensive application of SIBs is the development of earth-abundant and high-performance electrode materials. In various studies of these electrode materials, Sn-based nanocomposites have been identified as promising anodes for SIBs. In this study, Sn nanoparticles on nitrogen-doped carbon nanofiber composites (Sn@NCNFs) have been synthesized by an electrostatic spinning technique and used as anodes for SIBs. Morphological and structural characterizations indicate that the Sn nanoparticles adhere uniformly on the surface of the nitrogen-doped carbon nanofibers. The corresponding specific capacity can reach over 600 mA h g−1 at 0.1C after 200 cycles. Additionally, these Sn@NCNFs also show excellent high-rate cycling performance and can maintain a capacity of up to 390 mA h g−1 even at an extremely high rate of 1C for over 1000 cycles. The results demonstrate that this Sn@NCNFs composite is a promising anode material with good reversible capacity and cycling performance for SIBs. [ABSTRACT FROM AUTHOR]

The co-organization of polymerizable imidazolium-based ionic liquids and p-xylene led to the formation of a bicontinuous cubic phase with a primitive-type periodic minimal surface, and for the first time an anion exchange membrane preserving 3D interconnected ionic nano-channels was fabricated through in-phase photopolymerization of bicontinuous cubic liquid crystals. [ABSTRACT FROM AUTHOR]

We report a specific light-up fluorescent probe for i-motif DNA for the first time. Compared with the previously reported probes, neutral red could selectively interact with an i-motif and show a significant increase in its fluorescence. This feature makes it advantageous for designing label-free fluorescent sensing systems. [ABSTRACT FROM AUTHOR]

In this study, we present a facile method to construct highly ordered and well-defined ionic channels in anion-exchange membranes (AEMs) through in-phase photopolymerization of liquid crystals (LCs). Hexagonal and lamellar LC samples were prepared by the self-organization of polymerizable amphiphilic imidazolium-based ionic liquids. The preservation of LC nanostructures in the obtained polymeric membranes was confirmed by the combination of small-angle X-ray scattering (SAXS), polarized optical microscope (POM), and scanning electronic microscopy (SEM) measurements. Phase separations of LCs at the molecular level provided highly ordered and well-defined ionic channels for efficient anion conduction and meanwhile maintained a strong hydrophobic domain to suppress the swelling degree. The membranes synthesized in the present work provide a promising model system for understanding the idea of constructing ionic highways in AEMs through self-organization. [ABSTRACT FROM AUTHOR]