Search

Carbon materials hold the great promise for application in energy storage devices owing to their low cost, high thermal/chemical stability, and high electrical conductivity. However, it remains challenging to synthesize high-performance carbon electrodes in a simple, scalable and sustainable way. Here, we report a facile method for scalable synthesis of porous carbon anode by using cheap and easily accessible zeolitic imidazolate framework-8 as a template and polyvinylpyrrolidone as an additional carbon source. The obtained porous carbon shows the macroscopic sheet-like morphology, which has the highly disordered structure, expanded interlayer spacing, abundant pore structure, and nitrogen doping properties. This porous carbon anode is demonstrated to have the excellent K+ charge storage properties in specific capacity, rate capability, and cycling stability. A potassium-ion capacitor assembled by using this porous carbon as the anode, delivers a maximum energy density of 85.12 Wh/kg and power density of 11860 W/kg as well as long cycle life exceeding 3000 cycles. This represents a critical advance in the design of low cost and scalable carbon material for applications in energy storage devices.

In this brief, we reported the improved break-down reliability and endurance in 10-nm Hf $_{0.5}$ Zr $_{0.5}$ O₂(HZO) using grain boundary interruption. By inserting an amorphous Al₂O₃ layer in the middle of polycrystalline HZO, grain boundaries penetrating between the electrodes were interrupted. Compared with single-layer HZO [metal-ferroelectric-metal (MFM)] and HZO/Al₂O₃ [metal-ferroelectric-insulator-metal (MFIM)], the ferroelectric/insulator/ferroelectric [metal-ferroelectric-insulator-ferroelectric-metal (MFIFM)] structure exhibited 9x reduction of leakage current, 0.85-V increase of breakdown (BD) voltage ( $T_{BD}$ ), and 0.97-V increase of voltage for 10-year time-dependent dielectric breakdown (TDDB) lifetime. Furthermore, >10¹⁰ endurance was achieved in MFIFM capacitor, which has more than three orders of magnitude improvement than MFM and MFIM capacitor. This work provides an effective way to enhance the reliability of HZO-based ferroelectric devices.

The aqueous Zinc-base batteries such as the Zn-air battery and the Zn-ion battery, featured with low-cost, high safety, high specific capacity and environmental-friendliness, have attracted intensive attention for energy storage. For high performance Zinc-base batteries, the electrocatalysts with good conductivity, convenient mass transfer path and adequate accessible active sites are demanded. Herein, we have fabricated transition-metal/nitrogen co-doped honeycomb-like carbon materials with hierarchical porous structure through a freeze-drying and one-step pyrolysis method. The as-prepared FeZnN-C are used as cathode materials of Zinc-air battery, the Zinc-air battery displays high peak power density of 257 mW cm-2, superior discharging voltage platform around 1.36 V and large specific capacity of 785 mAh gZn-1. Meanwhile, the prepared Zn/ZnN-C was used as anode of a Zinc-ion battery which exhibits great cycle stability and high charging/discharge rate. Our work provides a novel and facile method to construct highly efficient electrocatalysts with hierarchical macro-meso-micro-porous structure and multi-active sites for application in the aqueous Zinc-base batteries.

Flexible memory devices are promising for information storage and data processing applications in portable, wearable, and smart electronics operating under curved conditions. In this work, we realized high-performance flexible ferroelectric capacitors based on Hf0.5Zr0.5O2 (HZO) thin film by depositing a buffer layer of Al2O3 on polyimide (PI) substrates using atomic layer deposition (ALD). The flexible ferroelectric HZO films exhibit high remnant polarization (Pr) of 21 µC/cm2. Furthermore, deterioration of polarization, retention, and endurance performance was not observed even at a bending radius of 2 mm after 5,000 bending cycles. This work marks a critical step in the development of high-performance flexible HfO2-based ferroelectric memories for next-generation wearable electronic devices.

Green plums were dried at 50, 60, 70, and 80 ℃ to study the dynamic changes of internal moisture during the drying process. Low-field nuclear magnetic resonance (LF-NMR) was used to study the dynamic changes across the T2 relaxation spectrum, while magnetic resonance imaging (MRI) provided visualization of the plums throughout the process. The results indicate a negative linear relationship between the lost moisture of the plums (p < 0.05) as drying time increased. Relaxation times T21 , T22, and T23 , and the peak areas of A21 and A23 decreased significantly during the drying process. The MRI results also show that the brightness of the images decreased as the drying time increased, indicating that the higher the temperature, the greater the water loss inside the plums. Color measurements demonstrated that the high temperature dried plums had better sensory quality. Correlation analysis implies a strong positive relationship between A23 and Atotal and water content, with coefficients of 0.958 and 0.936, respectively. Principal component analysis results show that the drying temperature has a significant effect on the sample's internal moisture release. LF-NMR is a fast, convenient, and feasible technique for monitoring the moisture variation of green plums during the drying process. PRACTICAL APPLICATION: Low-field nuclear magnetic resonance (LF-NMR) was used to study the moisture dynamic changes of green plums across the T2 relaxation spectrum, while magnetic resonance imaging (MRI) provided visualization of plums throughout the process. The drying temperature has a significant effect on the green plum's internal moisture release and may affect the quality of the plums. LF-NMR might be a complementary technique in monitoring the moisture variation of green plums during the drying process.

In order to study the flow-induced vibration characteristics of the natural gas vent pipeline under the internal flow field, taking the gas transmission station pipeline as an example, the ANSYS Workbench software was used to establish models under two working conditions, uncoupling and fluid-solid coupling, for modal analysis, and analyze and compare the calculation results and propose a structural improvement plan. The results show that the maximum amplitude of the first three modes under the two working conditions is concentrated on the riser mouth, and the amplitude under the fluid-solid coupling condition is slightly larger than that of no coupling; the inner diameter of the pipe elbow is large and the pressure is small, and the outside diameter is small and the pressure is small. Large, this instability will increase the air pulsation of the flow field. In the improved scheme, adding a restriction on the top to increase the rigidity of the pipeline can significantly reduce the maximum amplitude of the gas pipeline; adding an orifice to eliminate air flow pulsation has a certain effect on reducing the maximum amplitude and natural frequency, and the combination of the two can make the pipeline more stable. The research results of this paper can provide improved ideas for vibration reduction at the natural gas venting operation site.

The characterization of ferroelectricity in ultra-thin ferroelectric (FE) films is highly challenging due to enlarged leakage current and resistive switching (RS) effect. In this study, we investigated the polarization switching properties of 1.5-nm thick Hf0.5Zr0.5O2 (HZO) films via direct hysteresis remnant polarization/voltage (P–V) loop measurement. To reduce the leakage current and eliminate the RS effect, positive-up–negative-down (PUND) measurement was implemented on back-to-back connected complementary cells. Rational hysteresis loops, with remnant polarization of approximately $2~\mu \text{C}$ /cm2, were successfully obtained by directly measuring the polarization switching currents. In this study, we provide direct evidence of the stable ferroelectric property in 1.5-nm thick HZO films, and thereby show a potential prospect of ultimate scalability of HZO films.

The laser powder bed fusion (L-PBF) method of additive manufacturing (AM) is increasingly used in various industrial manufacturing fields due to its high material utilization and design freedom of parts. However, the parts produced by L-PBF usually contain such defects as crack and porosity because of the technological characteristics of L-PBF, which affect the quality of the product. Laser ultrasonic testing (LUT) is a potential technology for on-line testing of the L-PBF process. It is a non-contact and non-destructive approach based on signals from abundant waveforms with a wide frequency-band. In this study, a method of LUT for on-line inspection of L-PBF process was proposed, and a system of LUT was established approaching the actual environment of on-line detection to evaluate the method applicability for defects detection of L-PBF parts. The detection results of near-surface defects in L-PBF 316L stainless steel parts show that the crack-type defects with a sub-millimeter level within 0.5 mm depth can be identified, and accordingly, the positions and dimensions information can be acquired. The results were verified by X-ray computed tomography, which indicates that the present method exhibits great potential for on-line inspection of AM processes.

Phototherapeutic approaches, including photothermal therapy (PTT) and photodynamic therapy (PDT), have become a promising strategy to combat microbial pathogens and tackle the crisis brought about by antibiotic-resistant strains. Herein, porous gold nanoparticles (AuPNs) were synthesized as photothermal agents and loaded with indocyanine green (ICG), a common photosensitizer for PDT, to fabricate a nanosystem presenting near-infrared (NIR) light-triggered synchronous PTT and PDT effects. The AuPNs can not only convert NIR light into heat with a high photothermal conversion efficiency (50.6-68.5%), but also provide a porous structure to facilely load ICG molecules. The adsorption of ICG onto AuPNs was mainly driven by electrostatic and hydrophobic interactions with the surfactant layer of AuPNs, and the aggregate state of ICG significantly enhanced its generation of reactive oxygen species. Moreover, taking advantage of its synergistic PTT and PDT effect, the hybrid nanocomposites displayed a remarkable antibacterial effect to the gram-positive pathogen

The rapid and effective removal of organic micropollutants (OMPs) from water remains a huge challenge for traditional water treatment techniques. Compared with powder adsorbents such as polymers and nanomaterials, the free-standing adsorptive membrane is possible for large-scale applications and shows promise in removing OMPs. Herein, inspired by aquatic plants, a novel free-standing adsorptive membrane (NPPM) with high water flux, strong adsorption affinity, and excellent reproducibility was prepared by one-step UV surface grafting. N-Vinylformamide (NVF) was employed to introduce multiple hydrophilic and hydrogen bonding sites on the surface of commercial polypropylene fiber membranes (PPM). The NPPM exhibits excellent water permeability and ultrahigh water flux (up to 40 000 L/(m2 h)) and could continuously remove a broad spectrum of OMPs from water. Its adsorption performance is 5-100 times higher than that of PPM and commercial membranes. Even in natural water sources such as tap water and river water, the NPPM shows unchanged adsorption performance and high OMPs removal efficiency (>95%). Notably, the NPPM has excellent regeneration performance and can be regenerated by hot water elution, which provides an environmentally friendly regeneration method without involving any organic solvent. Moreover, the synergy between hydrogen bonding and hydrophobic interaction is revealed, and the hydrophobic interaction provided by the hydrophobic substrate is proved to play a fundamental role in OMPs adsorption. The strong hydrogen bonds between the grafts and the OMPs are demonstrated by variable-temperature FTIR spectroscopy (vt-FTIR), 13C nuclear magnetic resonance spectroscopy (13C NMR), and simulation calculations. The strong hydrogen bonds could increase the enthalpy change and enhance the adsorption affinity, so the NPPM has a strong adsorption affinity, which is 100 times that of similar adsorption membranes. This study not only presents an adsorptive membrane with great commercial potential in the rapid remediation of a water source but also opens a pathway to develop an adsorptive membrane with high water flux and strong adsorption affinity.

Gold nanocluster (AuNC) decorated hydrogels have attracted considerable attention as versatile biomaterials. To date AuNCs and hydrogels have mainly been mixed as independent components. Here, we report the use of AuNCs as reactive monomers in the polymerization of hydrogels. We used a free radical polymerization to copolymerize AuNCs with acrylamide and N-acryloyl glycinamide to prepare stimuli-responsive smart hydrogels. Multiple C═C bonds were decorated on the surface of the AuNCs as active sites for polymerization. These C═C bonds not only protected the structure of the AuNCs from oxidation by free radicals during polymerization but also covalently connected the AuNCs with the polymer chains. This structure ensured good photothermal performance of the AuNCs while preserving the thermoresponsive hydrogen bonds of polymers. Moreover, the copolymerized AuNCs acted as cross-linkers, which improved the mechanical properties of the hydrogels. These smart hydrogels had good stability, efficient photothermal conversion, and a sensitive thermoresponsive. We examined their potential for capture of MDA-MB-231 cells with hyaluronic acid as target molecules. The captured cells were released under 660 nm irradiation. This process of targeted capture and light-controlled remote release could be repeatedly applied. These results suggest that systems based on AuNCs copolymerized with hydrogels have great potential for biomedical applications.

Polylactide-b-poly(N-isopropylacrylamide)-b-polystyrene (PLA-b-PNIPAM-b-PS) triblock copolymers (tri-BCPs) with various chemical compositions (block ratio) were prepared from the combination of ring-opening polymerization and reversible addition-fragmentation chain transfer polymerization. Subsequently, the self-assembling behaviors of these tri-BCP films obtained from spin-coating were investigated by annealing them under different solvent atmosphere. We found that these films could self-assemble into various morphologies due to the microphase separation of incompatible copolymer blocks. Atomic force microscopy confirmed the perpendicular cylindrical morphology self-assembled from PLA4.5k-b-PNIPAM5.2k-b-PS22.4k tri-BCP film under mixed solvent atmosphere of toluene/acetone (7:3, v/v). Self-assembled PLA cylinders are evenly distributed among the PS matrix and perpendicular to the film surface, with PNIPAM component taking place at the PLA/PS interphase. Furthermore, by etching the degradable PLA component, porous PS film decorated with PNIPAM “brushes” hoisting channels were generated. This work provides a facile method and detailed protocol for fabricating stimuli-responsive porous films which are promising for thermoresponsive “smart” separation technologies.

Piezoelectric semiconductor-based piezocatalysis has emerged as a promising approach for converting mechanical energy into chemical energy for renewable hydrogen generation and wastewater treatment under the action of mechanical vibration. Similar to photocatalysis, piezocatalysis is triggered by the separation, transfer, and consumption of piezo-generated electrons and holes. Inspired by this, herein, we report that the cocatalyst, which is widely used in photocatalysis, can also improve the semiconductor-based piezocatalytic properties. In the proof-of-concept design, well-defined Pd as a model cocatalyst has been deposited on the surface of piezoelectric BiFeO3 nanosheets, which not only facilitates the separation of charge carriers by accepting the piezoelectrons from BiFeO3 but also lowers the activation energy/overpotential through supplying highly active sites for the proton reduction reaction. Consequently, the as-obtained hybrid piezocatalyst delivers a high H2 evolution rate of 11.4 μmol h-1 (10 mg of catalyst), 19.0 times as high as that of bare BiFeO3. The band tilting induced by the piezoelectric potential is proposed to lower or eliminate the Schottky barrier and smooth the electron transfer from BiFeO3 to Pd, while the exposed facet, domain size, and loading amount of Pd cocatalyst are proved to be the key parameters determining the ultimate piezocatalytic activity. Our work provides some enlightenment on advancing the design and fabrication of more efficient piezocatalysts for H2 evolution based on rational engineering on the cocatalyst.

Aqueous Zn-ion batteries (ZIBs) have acquired the researchers' curiosity owing to their harmlessness, cost effectiveness and high theoretical capacity of Zn anode. However, desirable cathode materials with high-capacity and high-rate are still scarce. In this work, the formation of carbon quantum dots induced vanadium pentoxide nanobelts was demonstrated via a facile one-step hydrothermal method for ZIBs. It exhibited an excellent Zn ion storage capacity of 460 mA h g-1 at 0.1 A g-1 , superior rate capability and stable cycling performance (above 85 % capacity retention over 1500 cycles at 4 A g-1 ). The electrochemical kinetics and zinc ion storage mechanism were also considered. An efficient architecture-coupled valence engineering in the hybrid cathode was proposed to improve the electric conductivity, Zn ion diffusion rate, and cycling stability for ZIBs. This work may be a great motivation for further research on V2 O5 or other vanadium-based materials for high-performance ZIBs.

Nitrogen-doped carbon nanotubes (N-CNTs) were synthesized via a hydrothermal method and further modified with magnetic Co0.5Cu0.5Fe2O4 nanoparticles following a one-pot solvothermal method. The characterization data show that the distribution of the magnetic materials and the adsorption characteristics of the CNTs can be tailored as a function of the N doping amount. The N-CNT adsorption isotherms as a function of N content and chlorophenol uptake show that a N doping level of 6% is optimum. After loading the N-CNTs with the magnetic Co0.5Cu0.5Fe2O4 nanoparticles (M-N-CNTs), the resulting materials were easily dispersed in aqueous media with specific surface area reaching 95.64 m2/g. The M-N-CNTs exhibit high affinities toward the adsorption of different chlorophenols following the order: Pentachlorophenol (PCP) > 2,4,6-trichlorophenol (2,4,6-TCP) > 2,4-dichlorophenol (2,4-DCP) > 2,4-dichlorophenoxyacetic acid (2,4-D) > phenol. Additionally, the M-N-CNTs exhibit good microwave absorption performance and can be regenerated by microwave irradiation with high efficiencies (> 90%) maintained with high stabilities.

Investigations on the structural transition and property of the intermediate structures are significant to understand the gas adsorption and separation performance in flexible metal–organic frameworks (MOFs). Herein, theoretical investigations were conducted to track CO2/N2 adsorption and separation in the flexible bridged phenyl MOF 1. Results showed the closed pore form 1B expanded and exhibited the intermediate states of 1B_x (x = 9.8, 10.34, 11.3, 12.5, and 14.1) with the adsorption of CO2. The adsorption performance–structure–pressure relationship was built based on the adsorption isotherms, and 1B_9.8, 1B_10.34, 1B_11.3, 1B_12.5, and 1B_14.1 were the structures of 1B with adsorbed CO2 at 26.3, 29.2, 29.5, 33.7, and 37.1 bar at 298 K, respectively. The CO2/N2 selectivity was plotted based on the structure–pressure relationship. The interaction and gas distribution analyses demonstrated that the adsorption site changed during the structural transition in the adsorption process, which played a significant role in CO2 adsorption and separation. This work provided significant guidelines for elucidating the gas adsorption and separation in flexible adsorbent materials. Changing processes in CO2 adsorption and separation over N2 were traced along structural transition of the flexible MOF framework, and the synergistic effect of adsorption site and pore volume was elucidated via systematic analyses on pore characteristics, CO2/N2 adsorption capacity, selectivity, interaction, and gas distribution.

Sodium ion batteries (SIBs) are regarded as a promising alternative to lithium ion batteries, while their application is hindered by the lack of good anode materials. Integrating morphology, struct...

In order to improve the ductilityof cement-based materials, rubber is often added to cement-based materials. But the rubber-cement interface will introduce more initial defects, and make the three dimensional images obtained by the X-ray micro-computed tomography (X-ray μCT) technology more complex, and finally,which leads to the full threshold method no longer applicable to analysis of the internal three-dimensional cracks.This paper presents an improved image processing method, which can accurately identify mesoscopic cracks and achieve the separation of pores and cracks. In order to verify this method, X-ray computed tomography (XCT) in-situ observation technology is used to obtain the crack formation of rubber mortar with different replacement ratios. Pores and cracks are well identified and separated by this method. Quantitative analysis shows that the new method has higher accuracy and better identification of mesoscopic cracks than traditional methods. Due to the incorporation of rubber, there are more initial cracks in the rubber mortar, but the rubber will improve the overall absorption of the input energy of the sample, resulting in a decrease in the number of large cracks and the total crack volume when the specimen is failure.Compared with the sample without rubber content, the total crack volume of the sample with 5% and 10% mass fraction of rubber decreases by 30% and 45%, respectively.

The mesoporous nanostructures of cobalt-doped (Co-doped) manganese oxides (MnOx) with controllable compositions are successfully synthesized by a facile inverse micelle sol-gel method. It can be found that with the addition of cobalt ions, the Mn-Co two-element spinel structure oxide is formed. Moreover, as the amount of cobalt ions increases, the shape of the agglomeration changes from rod to approximately spherical particles, and its average pore size decreases gradually, which is conducive to improve the specific surface area of the as-prepared product. The electrochemical measurements show that the specific capacitance of as-prepared mesoporous samples increases with the rise of Co-doped content. In particular, when the molar ratio of Mn/Co is 10:5, the synthesized mesoporous CoMn2O4 nanoparticles exhibit a high specific capacitance of 614.8 F g−1 at 1 A g−1. The final capacitance can still maintain 82.4% of the initial capacitance at 5 A g−1 after 5000 cycles. Furthermore, asymmetric supercapacitor assembled by CoMn2O4 and activated carbon also exhibits high energy density (29.5 Wh kg−1 at 799.7 W kg−1), high power density (8.0 kW kg−1 at 3.2 Wh kg−1) and excellent cycle stability (84.3% capacitance retention rate after 5000 cycles). The mesoporous CoMn2O4 with superior electrochemical performance has great potential in the application of high-performance supercapacitors.

In this brief, the contact etch stop layer (CESL) stressor is introduced to improve the performance of n-type lateral double-diffused MOSFET (nLDMOSFET) with various operating voltages. Three groups of nLDMOSFETs were studied to demonstrate the effects of the CESL stressor. The electrical properties were carefully characterized, and the tip-enhanced Raman spectroscopy measurements were carried out to examine the process-induced strain directly. It is found that nLDMOSFETs with the strained SiN CESL have larger output current, transconductance ( ${g} _{m}$ ), and higher breakdown voltage (BV). The strained SiN CESL introduces tensile strain in the device and results in the performance boosts, which are verified by negative Raman peak shift mappings and TCAD simulations. The strained SiN CESL could effectively decrease the specific ON-resistance ( ${R} _{\text {on}}$ ) and improve the BV of the nLDMOSFET, due to the mobility enhancement.

The electrocatalytic CO2 reduction reaction (CO2RR) on copper-based catalysts is a promising method to produce valuable chemicals, but its selectivity is much lower than expected largely due to insufficient research on the structure of new materials. Herein, the antimony-doped Cu/Cu2O (Cu/Cu2O–Sb) catalyst is developed for a highly selective CO2RR to CO. The synthesized Cu/Cu2O–Sb exhibits intensive suppression of hydrogen evolution, a low overpotential and high faradaic efficiency (FE) towards CO. The CO selectivity is as high as ∼95% with a partial current density of ∼6.3 mA cm−2 at −0.9 V and maintains over 90% in a broad range of potentials. DFT calculations reveal that the doping of antimony achieves the distinct activation of CO2 and suppression of hydrogen evolution. Meanwhile, the pre-adsorbed *CO significantly promotes the desorption of the neighboring *CO, which is the key for high selectivity of CO2RR to CO. This work will provide a new consideration for the origin of high selectivity during the CO2RR and pave the way toward design of highly selective CO2 reduction catalysts.

CdS has been regarded as a promising visible-light-response photocatalyst in H2 production while its practical application is often limited by low photoactivity and serious photocorrosion. To tackle these problems, traditional CdS based core–shell and supported photocatalysts have been widely developed but they also suffer from intrinsic structural drawbacks. Herein, a novel stacked nanostructure with CdS embedded at interfaces between graphene supports and metallic MoS2 overlayers has been designed to eliminate the shortages and achieve outstanding photocatalytic performance, which reaches an optimum H2 production rate of 14.4 mmol gcat−1 h−1 and realizes an apparent quantum efficiency of 23.7% at 420 nm without obvious deterioration of activity in 20 h cyclic testing, far exceeding that of pure CdS by a factor of 17.9 times. The enhanced photocatalytic performance is mainly ascribed to the synergistic effects of MoS2 and graphene: (1) the intimate contact between the CdS core and MoS2 shell with a large interfacial area favors the transfer of photogenerated electrons to MoS2 cocatalysts, while a high-percentage 1T-phase provides an excellent electron mobility in the MoS2 cocatalysts and a high density of active sites for H2 evolution; (2) CdS cores are protected by MoS2 and graphene from photocorrosion, in which photogenerated holes are quickly transferred to the MoS2 shell and isolated from the sulfide surface, while excessive electrons in CdS are shuttled to adjacent MoS2 outer layers by graphene supports for H2 evolution in reducing their recombination with holes in the MoS2 shell and increasing the number of MoS2 sites available for the proton reduction reaction. The stacking design can be extended to the fabrication of other highly efficient photocatalytic systems.

BODIPY dyes have recently been used for photothermal and photodynamic therapy of tumors. However, complex multi-material systems, multiple excitation wavelengths and the unclear relationship between BODIPY structures and their PTT/PDT efficiency are still major issues. In our study, nine novel BODIPY near-infrared dyes were designed and successfully synthesized and then, the relationships between BODIPY structures and their PTT/PDT efficiency were investigated in detail. The results showed that modifications at position 3,5 of the BODIPY core with conjugated structures have better effects on photothermal and photodynamic efficiency than the modifications at position 2,6 with halogen atoms. Density functional theory (DFT) calculations showed that this is mainly due to the extension of the conjugated chain and the photoinduced electron transfer (PET) effect. By encapsulating BDPX-M with amphiphilic DSPE-PEG2000-RGD and lecithin, the obtained NPs not only show good water solubility and biological stability, but also could act as superior agents for photothermal and photodynamic synergistic therapy of tumors. Finally, we obtained BODIPY NPs that exhibited excellent photothermal and photodynamic effects at the same time under single irradiation with an 808 nm laser (photothermal conversion efficiency: 42.76%, A/A0: ∼0.05). In conclusion, this work provides a direction to design and construct phototherapeutic nanoparticles based on BODIPY dyes for tumor treatment.

Herein, we report the first oxygen (O2) and carbon dioxide (CO2) dual gas-switchable thermoresponsive polymers based on a newly synthesized monomer N-(2-fluoroethyl amide)-N-(2-(diethylamino)ethyl) acrylamide, that is, AM(F1EA-DEAE), which bears both O2-switchable fluorinated ethyl amide (F1EA) and CO2-switchable N,N-diethylamino ethyl (DEAE) moieties on its side chain. PolyAM(F1EA-DEAE) samples prepared from reversible addition–fragmentation chain transfer (RAFT) polymerization exhibited good temperature-responsive properties. Their inherent low critical solution temperature (LCST) could be reversibly tuned to different levels by respectively purging O2 or CO2 into its aqueous solution. The O2-treatment shifted LCST to a higher temperature, while the CO2-treatment made the polymer fully water-soluble. The polymer could be readily recovered to its initial state by washing off the trigger gas with an inert gas such as nitrogen. This work provides an effective monomer design approach for the preparation of ...

Poly(ester-b-carbonate)s are successfully synthesized for the first time through the metal-free copolymerization of cyclohexene oxide (CHO), propylene oxide (PO), phthalic anhydride (PA), and CO2 i...

The associated impurity phases derived from the introduction of vanadium ions in yttrium gallium garnet (YGG) were investigated in detail. The XRPD data indicate that β-Ga2O3 is contained in all synthesized samples and YVO4 can be identified when the V-doped concentration above 0.5 at. %. The existence of β-Ga2O3 is related to the antisite defects usually contained in the garnet host, and the generation of YVO4 is mainly derived from its lower formation temperature in comparison to the garnet phase. The micro-area composition analysis further verifies the existence of impurity phases, and the X-ray computed tomography survey provides a more visualized spatial distribution of the YVO4 phase. Moreover, the fluorescence analysis manifests a more sensitive phase identification than the XRPD technique, and the YVO4 impurity phase can be detected even if the V-doped content is reduced to 0.2 at. %. Additionally, the evaluated V/(V + Y + Ga) ratios from structure refinement coincide well with the theoretical value in the low-doping section, and the slight deviation in the high doping part is mainly attributed to the volatilization of vanadium oxides. What discussed in this study offers a comprehensive analysis strategy for the detection of impurity phases originating from ion doping.

Background Starch-based Pickering emulsions have been the focus of considerable research on emulsion-based delivery systems during the past decade. The performance of starch particles at the interface is vital for emulsion stability. The unique gelatinization characteristics and various modifications of starch endow the interface with controllable tuning strategies. However, information regarding the properties of starch-based emulsions from the interface perspective remains limited. Scope and approach This review provides detailed insight into the interfacial properties of starch-based Pickering emulsions. We discuss the interface formation and present the impacts of interfacial properties on the physical stability and gastrointestinal fate of emulsions. Strategies for tuning interfacial behavior are also highlighted. Key findings and conclusions The emulsion interface formation usually involves the complex adsorption behavior of starch particles. Differences in particle shape, roughness, hydrophobicity, and size strongly influence the adsorption stability. The external environment generally affects the destabilization of emulsions by changing the packing density, thickness, mechanical strength, and electrical characteristics of the interface. The protective effect of the starch-based particle laden interface enables the retardation of lipid digestion and drug release. Various methods including the modification of starch particles, co-stabilization with other biopolymers, and pH/ionic strength adjustment are utilized to control interfacial performance and thus improve emulsion properties. The information presented in this review may be used to inform future emulsion studies.

Zirconia are widely employed as a bone-substitute material for surgical implants due to its biocompatible and mechanical properties. However, implants introduced into the human undergo detachment from the host tissue due to poor biological performance. The laser-texturing can enhance the biological performance of the surface by altering surface properties and maintaining the bulk properties of the zirconia. In this work, laser-texturing microstructure features on zirconia are carried out to modify surface characteristics. Wettability are evaluated through water contact angles (WCAs) measurements. To characterize the influence of laser-texturing on pattern morphology, the produced surfaces are measured by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). Micro cracks with melted material flowing along the scanning tracks in the untreated areas were observed from SEM. XRD results, in turn, show that the tetragonal → monoclinic phase transformation leads to many tiny cracks around the transformed particles. Wettability can be attributed to the modifications of the surface's microstructure depending on laser parameters and chemical composition. The stability tests prove that the super-hydrophobic surfaces produced by laser-texturing possess good abrasion resistance. This work may provide a simple method for producing zirconia surfaces with controlled wettability with the proper choice of laser parameter for extremely extensive industrial applications.

CO2 capture and separation over N2 in penta-graphene (PG) slit pores (PG-x, x = 7−12) were investigated by using grand canonical Monte Carlo (GCMC) and density functional theory (DFT) simulations. GCMC results showed that PG pores exhibit high-efficiency CO2 capture and separation over N2. The best performing PG-8 exhibited an extraordinary CO2 adsorption capacity of 8.11 mmol/g at 1 bar and 5.56 mmol/g at 0.15 bar, respectively, with a high CO2/N2 selectivity of 69 at 1 bar and 298 K. The relative concentration distribution analyses illustrated that gas molecules were mainly adsorbed nearby PG nanosheet at their equilibrium states. DFT results showed that CO2 had a higher adsorption energy than that of N2 on PG nanosheet, further demonstrating PG pore as a promising material for CO2 capture and separation.

We report a convenient method to synthesize O, N-codoped hierarchical porous carbon by one-step carbonization of the mixture of KHCO3, urea and alginic acid. Benefiting from KHCO3 and urea synergistic effect, the obtained O, N-codoped hierarchical porous carbon (NPC-700) material has a well-developed interconnected porous framework with ultrahigh specific surface area (2846 m2/g) and massive heteroatoms functional groups. Consequence, such porous carbon displays high specific capacitance (324 F/g at 1 A/g), excellent rate performance (212 F/g at 30 A/g) and good electrochemical stabilization in 6 mol/L KOH solution. More importantly, the assembled NPC-700//NPC-700 symmetrical supercapacitor can achieve a high energy density of 18.8 Wh/kg and good electrochemical stabilization in 1 mol/L Na2SO4 solution. This process opens up a new way to design heteroatoms-doped hierarchical porous carbon derived from biomass materials for supercapacitors.

Gold nanoclusters are promising optically functional materials because of their attractive optical properties, such as luminescence, two-photon absorption, photothermal conversion, and photodynamics. Regulating the optical functions of gold nanoclusters and improving their performance have attracted wide interest in biological applications. In this Review, we introduce the principles to manipulate both the intrinsic optical properties and the apparent optical performance of gold nanoclusters. Manipulating the surface ligands and compounding with other nanomaterials are facile and efficient strategies. Based on the regulated optical properties, the gold nanoclusters can be well applied in various biomedical applications from multimodal bioimaging toward theranostics. By correlating structures and optical properties, we expect a better utilization of the optical gold nanoclusters in the biological field.

Aim. To investigate the different effects on osteolysis between commercial pure Ti particles and TiAl6V4 particles obtained from prosthesis of patients with aseptic loosening. Method. Scanning electron microscope, energy dispersive X-ray spectrometry, and X-ray diffraction were used for the size test, chemical composition test, and phase analysis of two kinds of Ti particles. Microcomputed tomography (micro-CT) and 3-dimensional reconstruction analysis were applied to analyze the bone loss quantitatively and radiologically. Hematoxylin-eosin (HE) staining and tartrate-resistant acid phosphatase (TRAP) staining were used to assess the histologic difference. Result. TiAl6V4 particles were constituted by FeO, Al45V7, and Al3Ti while pure Ti particles were constituted by Ti, Ti3O, and C4H7NO3. Similar particle size of nanoscale was detected of two Ti particles. A TiAl6V4 osteolysis model had more severe bone loss when scanned with micro-CT and assessed by quantitative analysis. TiAl6V4 also presented deeper and wider calvarial bone loss in HE staining and more activated osteoclasts in TRAP staining. Conclusion. A mouse calvarial model is the most effective animal model for the primary in vivo research of aseptic loosening. Compared with commercial Ti particles, TiAl6V4 particles derived from prosthesis of an aseptic loosening patient had more severe bone loss and more activated osteoclast, which was more consistent with pathogenesis of aseptic loosening in vivo, had high success rate of establishment of a model, and was more desired in animal modeling.

CaSc2O4:Ce3+ is a well-known green emitting phosphor, but needs to match with suitable red emitting phosphors in practical white lighting. Herein, a site engineering strategy is proposed to modify the local coordination environment of Ce3+ by introducing Y3+ and Mg2+ ions into the CaSc2O4 crystal lattice. The obtained results indicate in the modified Ce3+-doped samples (CSO-YMg), Y3+ ions can occupy both Sc3+ and Ca2+ sites simultaneously, and the Y3+ ions tend to occupy Ca2+ sites in low-doped stage and enter into the Sc3+ sites in the high-doped stage. The introduction of Y3+ ions gives rise to the existence of MgO in as-prepared CSO-YMg samples, and it can be effectively washed through pickling. In the spectral aspect, with the increase of Y3+ and Mg2+ ions, the main emission peak is red-shifted from 512 nm to 530 nm upon excitation at 450 nm. However, the high-doped sample presents much stronger thermally induced fluorescence quenching than CaSc2O4:Ce3+. The lattice defects caused by doped ions (Y3+ and Mg2+) and the non-radiative energy transfer process between the Ca2+ (Ce3+) and Sc3+ (Ce3+ or Ce4+) sites should be responsible for such evident quenching phenomenon in CSO-YMg, which is obviously different from the emitting feature of CaSc2O4:Ce3+ (only at Ca2+ sites). Besides, utilizing the as-prepared CSO-5 phosphors and a blue LED (~450 nm), a WLED was successfully fabricated, yielding a comparable performance to those with commercial Y3Al5O12:Ce3+ phosphors. What discussed in this study would bring some inspirations in the exploration and understanding of Ce3+-based phosphors according to local structural modification.

In bone tissue engineering, the structure of a scaffold is very important for cell growth and bone regeneration. It is better to make the scaffold resemble the native cancellous bone because natural cancellous bone can promote scaffold revascularization, which then accelerates cell proliferation. This study presents a parameterized design and fabrication method for cranial scaffold construction. A native human cranial sample was first scanned using micro computed tomography (CT), followed by 3D reconstruction, after which the internal structure of the bone trabecula was created. Based on an extracted negative bone trabecula model, the design components of “cavity”, “connecting pipe” and “spatial framework” were proposed to describe the scaffold model. Then, by using the parameterized component model and an assembly and deformation algorithm, the bionic scaffold was designed. Its porous distribution, connection, porosity and area size were easily controlled. Finally, a biomaterial scaffold case was fabricated using a gelcasting process, and cell culture testing was performed in vitro to verify the scaffold's biocompatibility. The results show that the scaffold can promote cell growth and that cells accumulate in the form of a mass within three days.

A series of heteroleptic copper­(I) complexes featuring a phosphonic acid anchor with asymmetric ligands has been studied using density functional theory (DFT) and time-dependent DFT (TD-DFT). Results showed that the absorption spectra of all copper­(I) complexes covered the visible light region with typical metal-to-ligand charge transfer characteristics. The modification of functionalized asymmetric ligands by introducing phenyl, anisole, N,N-diethyl-4-vinylaniline, and bromobenzene groups can reduce the energy gap (ΔH–L), form an effective charge-separated state, and lead to red-shifted absorption within the 350–650 nm range compared to the reference complex. The copper­(I) complexes with functionalized N,N-diethyl-4-vinylaniline ligands displayed the smallest ΔH–L and highest light-harvesting efficiency (LHE), exhibiting excellent light-harvesting capabilities. The introduction of isoquinoline ligands increased the excited singlet state lifetimes, the number of transferred electrons, and electron transfer distances. The electron injection time and driving force revealed efficient interfacial electron injection and regeneration of oxidized dyes. The photoelectronic properties of copper­(I) complexes featuring a pyridine ring with asymmetric ancillary ligands were superior to those of the reference complex. These copper­(I) complexes exhibited desirable electronic and spectral characteristics for future DSSC applications.

The effect of Cu(I) ions on the electrodeposition of zinc from ChCl-urea-ZnO deep eutectic solvent (DES) was investigated through electrochemical measurement and the deposit characterization. The cyclic voltammetry and cathodic polarization analyses demonstrated that Cu(I) ions obviously decreased the nucleation potential of Zn(II) and promoted the Zn(II) reduction reaction. The analysis of the chronoamperometric transients indicated that the nucleation and growth mode of Zn deposition changed from a three-dimensional progressive nucleation to three-dimensional instantaneous nucleation in the presence of Cu(I) ions. The addition of Cu(I) ions was observed to change the surface morphology, purity, and crystallographic orientation of the zinc deposits.

The homogeneous dispersion of graphene oxide (GO) in cementitious materials is critical to achieve its unique properties. In this study, based on the formation kinetic of GO aggregation and the pro...

Eu3+ lanthanide ion possesses abundant 4f-4f transition lines in the visible spectral region, and its spectroscopic changes can sensitively reflect the variation of local ligand environments. Here, Eu3+ ions are successfully introduced into Ca4Al6SO16 lattice, and the structural difference from orthorhombic (o-Ca4Al6SO16) to cubic (c-Ca4Al6SO16) phases is systematically analyzed. On that basis, the related influence on crystal-field splitting of Eu3+ ions is discussed in detail. The obtained results indicate that Eu:o-Ca4Al6SO16 and Eu:c-Ca4Al6SO16 have three and two non-degenerate 5D0→7F0 transition peaks, respectively. Through the theoretical analysis and low-temperature (78 K) luminescent investigation with changing the excitation wavelength, those non-equivalent Ca2+ sites are assigned as o-Ca(1) (~577.6 nm), o-Ca(3) (~579.6 nm), o-Ca(4) (~580.6 nm), c-Ca(1) (~578.7 nm), and c-Ca(2) (~580.2 nm), respectively. In addition, with the increase of c-Ca4Al6SO16 content in the sintered product, the fluorescence intensity ratios of I580.6/I613.7, I616.2/I613.7 and I621/I613.7 present a gradual decreasing tendency. And, the introduction of c-Ca4Al6SO16 into the as-prepared product is beneficial for increasing the decay lifetime of the 5D0 excited state and enhancing the resistance capability to thermally induced fluorescence quenching. What discussed in this work might provide some useful thoughts for multi-phase studies and broaden the application range of lanthanide fluorescent probes.

Most injectable hydrogels are prone to irreversible deformation or damage under sustained shear forces and exhibit low mechanical properties, which limit their practical applications in biological ...

Researches into non-noble cobalt-related electrocatalysts to produce H2 and O2 by water splitting have aroused much attention since the favorable adsorption of intermediates and low energy barriers...