[en] A series of experiments were performed to simulate the environmental behavior and fate of graphene oxide nanoparticles (GONPs) involved in the surface environment relating to divalent cations, natural organic matter (NOM), and hydraulics. The electrokinetic properties and hydrodynamic diameters of GONPs was systematically determined to characterize GONPs stability and the results indicated Ca"2"+ (Mg"2"+) significantly destabilized GONPs with high aggregate strength factors (SF) and fractal dimension (FD), whereas NOM decreased aggregate SF with lower FD and improved GONPs stability primarily because of increasing steric repulsion and electrostatic repulsion. Furthermore, the GONPs resuspension from the sand bed into overlying water with shear flow confirmed that the release would be restricted by Ca"2"+ (Mg"2"+), however, enhanced by NOM. The interaction energy based on Derjaguin–Landau–Verwey–Overbeek theory verifies the aggregation and resuspension well. Overall, these experiments provide an innovative look and more details to study the behavior and fate of GONPs. - Highlights: • Aggregation and resuspension of GONPs relating to surface environment are presented. • Aggregate strength factors of GONPs aggregates are quantitated by breakage experiment. • Compactness of the aggregates is closely related to fractal dimension. • Models for GONPs aggregation and breakage are synthetically proposed. • Interaction energy based on DLVO theory could interpret aggregation and resuspension of GONPs. - Aggregation and resuspension of graphene oxide relating to divalent cations, natural organic matter (NOM), and hydraulics are investigated based on DLVO theory

[en] Poly(cyclotriphosphazene-co-4,4′-sulfonyldiphenol) (PZS) nanospheres were prepared by a simple precipitation polymerization method and used as an efficient and specific adsorbent for the removal of methylene blue (MB), a cationic dye from aqueous solution. The as-synthesized PZS nanospheres were characterized by scanning electron microscopy (SEM), transmission electron microscope (TEM), Fourier transform infrared (FTIR) spectroscopy, and X-ray photoelectron spectroscopy (XPS). The effects of initial solution pH, initial MB concentration, adsorbent dosage, and contact time on MB adsorption have been investigated. Results showed that the neutral and basic solutions benefited MB adsorption. The pseudo-second-order model could be better fit to the experimental data compared with the pseudo-first-order kinetic adsorption model. In addition, Weber's intraparticle diffusion model was used to further understand the adsorption process. The mechanism of efficient and specific adsorption possibly involved the presence of numerous electron-rich N, P and S atoms in PZS, the electrostatic attraction and π-π stacking interactions between PZS nanospheres and MB.

[en] Phase-selective synthesis of stable metallic 1T transition metal dichalcogenides (TMDs) is challenging. Herein, we in-situ synthesis of stable 1T cobalt-doped tungsten selenide/carbon nanotubes (Co-WSe₂/CNTs) by synergistic effect of mechanical strain and interfacial-chemical interaction by CNTs and Co. Our experimental results indicate that Co-doping is pivotal for conformal coating of 1T Co-WSe₂ nanosheets around the CNTs due to their strong interfacial-chemical interaction between Co and CNTs, which is prerequisite for 1T phase engineering with high-stability by mechanical curvature strain. More importantly, for the first time we can easily regulate the concentrations of 1T Co-WSe₂ from 67.2% to 82.9% by varying the CNTs curvatures due to the tunable mechanical strains. The single-walled CNTs (SWNTs) with the largest curvature strain induces the highest content of 1T phase in Co-WSe₂ (82.9%), and moreover the 1T phase still remains even after high temperature annealing. Further benefiting from the improved electronic properties, the 1T Co-WSe₂/SWNTs exhibits enhanced electrocatalytic hydrogen evolution reaction (HER) activity in both acidic and alkaline electrolytes. The present work highlights the important role of strain in the 1T phase formation, also sheds lights on how the 1T phase occurs and stabilizes.

[en] Entanglement transfer from the superposition states of the pair coherent states or the SU(1,1) coherent states to two initially separable qubits is investigated. The entropy of the superposition states has a novel property: there exists a maximum value when the phase difference between the two 2-mode coherent states is π. In the process of entanglement transfer from these superposition states to qubits, it is found that the qubits have the largest possible entanglement at the maximum of the entropy of the initial field, which shows a relationship between the entanglement of the initial field and that of the qubits. The concurrence of the qubits can periodically approach unity when the parameters of the initial field are properly chosen and the two qubits are initially at the ground states.

[en] Highlights: • Nanoplatform for combined photothermal therapy, chemotherapy, and NO gas therapy was developed. • Nanoplatform shows controllable NO gas release by NIR-II laser stimulus on demand. • Inhibition of P-gp experssion by the released NO gas molecules. • The combination therapeutic nanoplatform is expected to be a potentially effective strategy against MDR tumors and may reveal new insights for other NO gas-relevant medical applications. Multi-drug resistance (MDR) in tumor therapy often leads to relatively low efficiency of the current chemotherapeutics, attributing to the overexpression of P-glycoprotein (P-gp) increases the efflux of anticancer drugs out of the cells. To address this obstacle, herein, a photothermal-triggered nitric oxide (NO) gas releasing nanosystem was designed for reversing drug resistance in MDR cells based on mesoporous core–shell structured nanocomposites (MCSN) of Cu_2-xSe@SiO₂. The mesoporous shell provided the modification and encapsulation capacity for the NO donor—S-nitrosothiol (SNO) and doxorubicin (DOX) loading. Besides, the heat generated from the photothermal conversion of Cu_2-xSe could trigger NO gas generation and enhance DOX release in the acid microenvironment of cancer cells. The released NO gas in the cytoplasm could induce mitochondrial dysfunction to block adenosine triphosphate (ATP) synthesis and ATP-dependent drug efflux, thereby overcoming MDR. Therefore, this novel gas/chemo/photothermal triple-combination therapeutic nanoplatform is expected to be a potentially effective strategy against MDR and may reveal new insights for other NO gas-relevant medical applications.

[en] Highlights: • Economic analysis on using FSP to produce cathode materials of Li-ion batteries. • The FSP process has lower electricity consumption and no Na₂SO₄ emission. • MCSP of the new process is $19.1/kg, which is 83% of that of the carbonate pathway. • When all the material prices are decreased by 20%, NMC333 is $16.8/kg. • NMC811 produced by FSP has the best potential to reach the battery price of $125/kWh. The cost of cathode materials contributes approximately 32.7% of the total cell construction cost of lithium-ion batteries, significantly affecting the price of battery packs. To reduce the cathode material manufacturing cost, a flame-assisted spray pyrolysis (FSP) method has been developed to utilize a sustainable solvent of glycerol to manufacture the LiNi_1/3Mn_1/3Co_1/3O₂ (NMC333) cathode materials. The objective of this study is to evaluate the minimum cathode material selling price (MCSP) of the FSP processes compared with a traditional carbonate co-precipitation pathway. Results show that the MCSP of the FSP is $19.1/kg that is 17% lower than the traditional carbonate co-precipitation pathway as a result of lower fixed operating cost and variable overhead. Sensitivity analysis shows that when the new process is integrated with in-situ sintering and processing, the MCSP can be as low as $15.6/kg. When all the material prices are decreased by 20%, the FSP process can synthesize NMC333 at a price of $2.3/kg lower. According to the simulation result, LiNi_0·8Mn_0·1Co_0·1O₂ (NMC811) has the best potential to meet the U.S. Department of Energy battery price target of $125/kWh, demonstrating that the FSP process is an attractive manufacturing technology for NMC cathode powder material production.

[en] Metal phosphates have many applications in catalysis, separation, and proton conduction, but their small surface areas and/or constrained pore structures limit their utilization. Here, we report two new methods for the liquid-phase grafting of titanium phosphate onto mesoporous silica (SBA-15) surfaces: (1) alternate grafting of Ti(OPri)4 and then POCl3 and (2) one-pot grafting of titanium phosphate formed in situ by employing Ti(OPri)4 (a base) and POCl3 (an acid) as an appropriate acid-base pair . Both the size of mesopores and the content of titanium phosphate can be changed by increasing the number of modification cycles in a stepwise (or layer-by-layer) fashion. The obtained products were characterized by inductively coupled plasma optical emission spectroscopy, X-ray diffraction, N2 adsorption desorption, transmission electron microscopy, 31P and 29Si magic-angle spinning NMR, and NH3 temperature programmed desorption, and their performance in acid catalysis and metal ion adsorption was investigated. This work provides new methodologies for the general synthesis of supported metal phosphates with large surface areas, ordered nanoporous structures, and acid properties.

[en] Oxygen reduction reaction (ORR) occupies a pivotal position in fuel cell applications, and it is a challenge to obtain highly durable ORR catalysts. Herein, porous cobalt oxide microsphere growing at the surface of on nitrogen-doped graphitized-nano-diamond (CoO_x/N-GND) was prepared using hydrothermal and subsequent heat treatment process. Porous cobalt oxide of high specific surface area could expose more surface Co²⁺ that act as active sites than bulk one does. The doping of nitrogen also promotes the catalytic activity. Besides, nano-diamond (ND) of sp ³ hybrid structure was used as an electronic conduction carriers of ultrahigh stability to improve the durability of catalytic composite. Prepared CoO_x/N-GND shows a satisfactory half-wave potential of 0.82 V (versus RHE), which is close to that of Pt/C (0.85 V), an excellent methanol tolerance and a lower activity loss after 5000 cycles. These merits inspire the application of CoO_x/N-GND as the cathode of Zn-air battery and the battery performance was evaluated in this work. In general, this work highlights an innovate approach to design and prepare highly durable catalyst. (paper)

[en] Highlights: • Polyphosphazene nanotube as an adsorbent could be facilely synthesized. • The adsorbent owns numerous electron-rich N and P atoms and hydroxyl groups. • The adsorbent was an efficient and specific adsorbent for the removal of MB. • The pseudo-second-order model could be better to describe the adsorption of MB. • The MB adsorption onto PZS nanotubes was endothermic and spontaneous. - Abstract: Poly(cyclotriphosphazene-co-4,4′-sulfonyldiphenol) (PZS) nanotubes, an excellent adsorbent, were successfully synthesized by an in situ template method and used for the removal of methylene blue (MB) from aqueous solution. The morphology and structures of as-synthesized PZS nanotubes were characterized by scanning electron microscopy, transmission electron microscope, Fourier transform infrared spectroscopy and N₂ adsorption/desorption isotherms. The effects of temperature, concentration, pH and contact time on MB adsorption were studied. It was favorable for adsorption under the condition of basic and high temperature. The pseudo-first-order, pseudo-second-order and intraparticle diffusion models were used to fit adsorption data in the kinetic studies. And results showed that the adsorption kinetics were more accurately described by the pseudo-second-order model. The equilibrium isotherms were conducted using Freundlich and Langmuir models. It has been demonstrated that the better agreement was Langmuir isotherm with correlation coefficient of 0.9933, equilibrium absorption capacity of 69.16 mg/g and the corresponding contact time of 15 min. Thermodynamic analyses showed that MB adsorption onto the PZS nanotubes was endothermic and spontaneous and it was also a physisorption process

[en] Highlights: • A photocurable hybrid bioink composed of chitosan and AM is provided for DLP bioprinting. • Using DLP, the hybrid bioink can be processed into complex 3D hydrogel constructs. • The printed constructs are endowed with high-strength and good biocompatibility. Chitosan-based hydrogel has been widely used in the field of tissue engineering due to its favorable biocompatibility and good biodegradability. However, this kind of hydrogel generally exhibits poor mechanical stability, which greatly limits its application in the field of 3D bioprinting. In this study, we provided a hybrid bioink created from photocurable chitosan and acrylamide (AM) for digital light processing (DLP) based 3D bioprinting in tissue engineering applications. This hybrid bioink was facilely prepared by combining AM and chitosan modified with methacryloyl groups (CHIMA). The gelling point of the hybrid pre-hydrogel bioink was greatly dependent on the photoinitiators. Both the mechanical properties and cytocompatibility of the hydrogel formed by the bioink can be modulated by varying the AM contents. The hybridization of natural CHIMA and synthetic AM enables the hybrid hydrogels with desirable biological activity and mechanical properties. Utilizing the DLP based 3D printing, this hybrid bioink can be processed into complex 3D hydrogel constructs with high-strength and good biocompatibility. Therefore, the photocurable hybrid bioink composed of CHIMA and AM in proper proportion is well suitable for use in DLP based 3D bioprinting, which would play a promising role in constructing tissues and organs in the future.