Polyaniline-Based Infrared Dynamic Patterned Encoder with Multiple Thermal Radiation Characteristics.

A high-level infrared dynamic patterned encoder (IR-DPE) possesses prospective applications for energy-harvesting and information, but a simple and reliable method for fabrication remains challenging. Herein, we first report an IR-DPE with multiple thermal radiation characteristics based on polyaniline (PANI). Specifically, the electron-beam evaporation technique is introduced to obtain the divanadium pentoxide (V2O5) coating, and then the V2O5 film acts as an oxidant to drive in situ polymerization of the PANI film. During the process, we experimentally explore the relationship between the thickness of V2O5 and the emissivity of PANI to obtain up to six emissivity levels and achieve the IR pattern integrated into multiple thermal radiation characteristics. The device shows multiple thermal radiation characteristics at the oxidized state, realizing a pattern visible with the IR camera and the same thermal radiation properties at the reduced state, leading to the pattern concealed in the IR regime. In addition, the highest emissivity tunability of the device is to be tuned from 0.40 to 0.82 (Δε = 0.42) at 2.5-25 µm. Meanwhile, the device exhibits a maximum temperature control of up to 5.9 °C. The results show the enormous potential of IR-DPEs for IR information transfer and thermal management.

Microbial response behavior to powdered activated carbon in high-solids anaerobic digestion of kitchen waste: Metabolism and functional prediction analysis.

Anaerobic digestion (AD) can not only treat organic waste, but also recycle energy. However, high-solids AD of kitchen waste usually failed due to excessive acidification. In this study, the effect of activated carbon (AC) on kitchen waste AD performance was investigated under high-solids conditions (total solids contents = 15%). The results showed that efficiencies of acidogenesis and methanogenesis were promoted in presence of moderate concentration (50 g/L > AC >5 g/L), but high concentration (AC >70 g/L) weakened AD performance. Moreover, AC addition enhanced the methane production rate from 66.0 mL/g VS to 231.50 mL/g VS, i.e., up to 250.7%. High-throughput sequencing results demonstrated that the abundance of electroactive DMER64 increased from less than 1%-29.7% (20 g/L AC). As AC gradually increased，aceticlastic methanogenesis changed to hydrogenotrophic pathway. Predicted functional analysis indicated that AC can enhance abundances of energy and inorganic ion metabolism, resulting in high methane production.

Alleviating acid inhibition via bentonite supplementation during acidulated swine manure anaerobic digestion: Performance enhancement and microbial mechanism analysis.

Swine manure is usually transmitted by the "collection-storage-transport" mode of the biogas project. However, this particular application pattern results in high volatile fatty acids (VFAs) concentration due to the long transition time in the "collection-storage-transport" process. In this work, acidulated swine manure anaerobic digestion (AD) with bentonite supplementation was firstly investigated with an expectation of acid alleviation, performance enhancement and microbial mechanism. Results indicated that the methane production rate in the 20 g/L bentonite-added digester was 2.87 fold higher than that of the control digester. Chemical oxygen demand (COD) removal rate was elevated by 140.1% via bentonite supplementation. Besides, the rapid decrease of VFAs and ammonia indicated that bentonite supplementation could offer buffering capacity and alleviate acid inhibition. Microbial community analysis revealed that acetoclastic methanogenesis (Methanosaeta and Methanosarcina) was the predominant methanogenesis pathway in this AD system. Syntrophic acetate oxidation (SAO) bacteria were discovered in the bentonite-added digester, and they converted acetate into H2/CO2 to support hydrogenotrophic methanogenesis. This study could offer guidance for acidulated swine manure AD in the practical biogas project.

Enhanced anaerobic digestion of kitchen waste at different solids content by alkali pretreatment and bentonite addition: Methane production enhancement and microbial mechanism.

High solid anaerobic digestion (AD) has been considered as a promising and sustainable technology for treating kitchen waste. To enhance AD of kitchen waste, alkali pretreatment and bentonite addition treatment (AP/Be) was performed on kitchen waste, and microbial community was investigated at different total solids (TS) content (10%, 13%, 19%, 22% and 25%). The results indicated that after AP/Be treatment, methane yield was as high as 198 mL CH4/g volatile solid (VS), which increased by 236% as the control. Moreover, microbial community analysis revealed that AP/Be treatment enriched bacterial microbial diversity. At TS of 10%, AP/Be treatment enhanced the hydrogenotrophic methanogens (Methanobacterium) significantly. In addition, the dominant methanogenic pathways changed at different TS content. These results demonstrated AP/Be treatment had a positive effect on methanogenesis during kitchen waste anaerobic digestion process. This study threw new insights towards enhancing kitchen waste anaerobic digestion, as well as the microbial mechanism.

A Multifunctional Flexible Electronic Skin for Dynamic Thermal Radiation Regulation and Electromagnetic Interference Shielding.

A multifunctional electronic skin with thermal radiation regulation and electromagnetic interference (EMI) shielding is urgent for electronic systems because of the thermal radiation emission and electromagnetic wave pollution. Herein, a flexible electronic skin was designed and fabricated, where the polyaniline (PANI) served as the functional layer and Ti3C2Tx MXene was employed as the conductive electrode. The transformation of emeraldine salt (ES) and leucoemeraldine base (LB) of PANI makes the skin achieve an infrared emissivity modulation, and the electromagnetic loss of PANI and ultrahigh electrical conductivity of Ti3C2Tx MXene make it exhibit EMI shielding ability. Benefiting from the special structural design, the multifunctional skin with a small thickness (0.3 mm) and low surface density (0.06 g/cm2) exhibits an excellent infrared emissivity modulation ability (Δε) of 0.32 with emissive power of 119.1 W/m2 at the wavelength range of 2.5-25 µm and total shielding effectiveness (SET) of 36.3 dB over the X-band (8.2-12.4 GHz). Meanwhile, the multifunctional skin remains black in the visible spectrum but a changeable color in the infrared spectrum. Even after repeated bending and twisting, the multifunctional skin still maintains a good emissivity adjustment. The simultaneous realization of dynamic thermal radiation regulation and EMI shielding endows the skin promising potential for various fields, such as adaptive infrared camouflage, thermal regulation, anticounterfeiting, and EMI shielding-related crossing field.

Activation of peroxymonosulfate by ZIFs derived Fe/Cu encapsulated N-doped carbon for bisphenol A degradation: The role of N doping.

Bisphenol A (BPA) is a typical kind of endocrine disruption chemical, which has a negative effect on human health, and thus it is necessary to remove BPA from water. Herein, activation of peroxymonosulfate (PMS) by Fe, Cu-Coordinated ZIF-Derived Carbon Framework bifunctional catalyst (Fe/Cu@NC-x) fabricated via hydrothermal-calcination method for BPA removal. The physicochemical properties of Fe/Cu@NC-x were studied by X-ray diffraction, Transmission electron microscopy, Scanning electron microscopy, Raman Spectroscopy, Brunauer-Emmett Teller, and X-ray photoelectron spectroscopy. The effects of the Fe/Cu@NC-900 dosage and PMS concentration, initial pH, and co-existing anions on BPA degradation were evaluated. Under optimized factors (pH unadjusted, Fe/Cu@NC-900 = 0.2 g/L, and PMS = 0.75 g/L), the degradation efficiency of BPA can reach 98% after 30 min. In addition, the BPA degradation efficiency was different extents restrain by inorganic anions (SO42- > Cl- > HCO3- > NO3-). Furthermore, the free radicals (SO4-·, ·OH, and O2-·) and non-radical (1O2) contribute to rapid BPA degradation in Fe/Cu@NC-900/PMS system. This study presents a novel material with significant performance for the removal of organic pollutants.

Quantitative hydrodynamic characterization of high solid anaerobic digestion: Correlation of "mixing-fluidity-energy" and scale-up effect.

High solid anaerobic digestion (HSAD)'s complex rheological behavior exhibits short-circuiting and dead zone. Mixing optimization is potential to enhance HSAD hydrodynamics. Besides, scale-up effect is quite essential for HSAD's applications, but remains rarely studied yet. Effect of impeller with different width on the correlation of "mixing-fluidity-energy" at different rotating speeds was first investigated at pilot-scale in present work. Then, scale-up effect based on rotating speed and a generalized Reynolds number was revealed from the aspects of fluidity and energy consumption. Results show that impeller width of 100 mm (10 rpm), 200 mm and 300 mm (5 and 10 rpm) are preferred for hydrodynamics and energy economics. Furthermore, Re similarity has better referential significance for the scale-up. In this study, new insight is gained into the correlation of "mixing-fluidity-energy" within a pilot-scale digester. Scale-up effect based Re similarity could potentially offer guidance for HSAD's application in the practical engineering.

High efficiency degradation of tetracycline by peroxymonosulfate activated with Fe/NC catalysts: Performance, intermediates, stability and mechanism.

Carbon-based catalysts have the advantages of biological cleaning, eco-friendly and cost-effective in water treatment. While, nitrogen doped biochar promotes the development of non-radical peroxymonosulfate (PMS) activation in environmental remediation. Thus, three-dimensional sponge-like porous Fe and N co-doped biochar (Fe/CN-30) with high catalytic activity for PMS activation was synthesized. In a wide pH range (1-11), the Fe/CN-30 catalyst can efficiently degrade tetracycline (TC) with a small amount of PMS. The non-radical pathways are prominent in the TC decomposition process according to the quenching experiments, electron paramagnetic resonance (EPR) and gas chromatograph-mass spectrometer (GC-MS) analysis, in which the contribution of high-valent iron-oxo species (Fe(IV) = O) was dominant. X-ray photoelectron spectroscopy and reaction kinetic experiments confirmed that the coordination sites of Fe and N in the Fe/CN-30 are the reactive centers for TC degradation. Moreover, the successive addition of low concentration PMS into the system was confirmed to favor the PMS utilization, and the high selectivity of the Fe/CN-30 was confirmed by the analysis of pollutant structure. Furthermore, by-products of TC degradation in the Fe/CN-30/PMS system and the possible TC degradation pathways were proposed via liquid chromatography-mass spectrometry (LC-MS). Therefore, this study dedicates to providing new insights into the non-radical pathway-catalyzed AOPs.

Smart Materials for Dynamic Thermal Radiation Regulation.

Thermal radiation in the mid-infrared region profoundly affects human lives in various fields, including thermal management, imaging, sensing, camouflage, and thermography. Due to their fixed emissivities, radiance features of conventional materials are usually proportional to the quadruplicate of surface temperature, which set the limit, that one type of material can only present a single thermal function. Therefore, it is necessary and urgent to design materials for dynamic thermal radiation regulations to fulfill the demands of the age of intelligent machines. Recently, the ability of some smart materials to dynamically regulate thermal radiation has been evaluated. These materials are found to be competent enough for various commands, thereby, providing better alternatives and tremendously promoting the commercial potentials. In this review, the dynamic regulatory mechanisms and recent progress in the evaluation of these smart materials are summarized, including thermochromic materials, electrochromic materials, mechanically and humidity responsive materials, with the potential applications, insufficient problems, and possible strategies highlighted.

Effect of Unit Cell Shape on Switchable Infrared Metamaterial VO2 Absorbers/Emitters.

Metamaterial absorber/emitter is an important aspect of infrared radiation manipulation. In this paper, we proposed four simple switchable infrared metamaterial absorbers/emitters with Ag/VO2 disks on the Ag plane employing triangle, square, hexagon, and circle unit cells. The spectral absorption peaks whose intensities are above 0.99 occur at ~4 µm after structure optimization when VO2 is in insulating state and disappear when VO2 becomes metallic state. The simulated electromagnetic field reveals that the spectral absorption peaks are attributed to the excitation of magnetic polariton within the insulating VO2 spacer layer, whose values exceed 1.59 orders of magnitude higher than the incident magnetic field. Longer resonant wavelength would be excited in square arrays because its configuration is a better carrier of charges at the same spans. For absorption stability, the absorbers/emitters with square and circular structures do not have any change with the polarization angles changing from 0° to 90°, due to the high rotational symmetric structure. And four absorbers/emitters reveal similar shifts and attenuations under different incident angles. We believed that the switchable absorber/emitter demonstrates promising applications in the sensing technology and adaptive infrared system.

Fabrication of graphitic carbon nitride functionalized P-CoFe2O4 for the removal of tetracycline under visible light: Optimization, degradation pathways and mechanism evaluation.

In this study, nano-sized CoFe2O4 composites were prepared through co-precipitation process. Then the phosphorus-doped strong magnetic graphitic carbon nitride hybrids composites (P-CoFe2O4@GCN) was stemmed from the CoFe2O4 composites via the thermal polymerization method. The TEM results show that the CoFe2O4 nanoparticles have been successfully embedded into the graphitic carbon nitride (GCN). The BET specific surface area of P-CoFe2O4@GCN-1 could reach 36.91 m2/g, which was 5.38 times higher than that of GCN. Thus, it provided sufficient reaction active sites to enhance the photocatalytic activity for tetracycline (TC) decomposition. The results from the photocatalytic experiments showed that the degradation efficiency of TC by P-CoFe2O4@GCN-1 could reach 96.2% within 60 min, which is 3.19 times higher than that of GCN. The h+, O2•- and •OH radicals detected by the electron spin resonance (ESR) were responsible for the TC decomposition in the photocatalytic reaction system. Persulfate (PS) can further activate the hybrid mixture system, and the fitting model predicted by the response surface methodology (RSM) indicated that the maximum tetracycline removal could reach 99.6% within 30 min. In addition, the degradation intermediates of TC were detected by HPLC-MS and the photodegradation mechanism was discussed.

Prediction and optimization of adsorption properties for Cs+on NiSiO@NiAlFe LDHs hollow spheres from aqueous solution: Kinetics, isotherms, and BBD model.

In this work, novel NiSiO@NiAlFe layered double hydroxides (LDHs) hollow spheres were prepared by hydrothermal method. It was worth noting that LDHs' grafting towards NiSiO hollow spheres could avoid the LDHs' aggregation, and thus enhanced the material's adsorption capacity. Furthermore, adsorption kinetics, adsorption isotherms, and Box-Behnken Design (BBD) model were conducted. Results indicated that NiSiO@NiAlFe LDHs hollow spheres had sufficient adsorption capability towards Cs+. The adsorption kinetics satisfied the pseudo-second-order adsorption model, Temkin model and Langmuir isotherm model. The adsorption process was efficient at the alkaline condition (pH = 10). The adsorption kinetics indicated that the adsorption process could reach the equilibrium in only 20 min. The maximum adsorption capacity of Cs+ towards NiSiO@NiAlFe LDHs hollow spheres was estimated to be 61.5 mg g-1. Moreover, the adsorption thermodynamics indicated that the adsorption process was exothermal, feasible and spontaneous. Thus, NiSiO@NiAlFe LDHs hollow spheres presented a broad potential for treating cesium containing wastewater.

Carbon quantum dots decorated heteroatom co-doped core-shell Fe0@POCN for degradation of tetracycline via multiply synergistic mechanisms.

In this study, novel core-shell catalyst with a new ternary heterostructure was synthesized (Fe0@POCN/CQDs) for the degradation of tetracycline (TC). The TEM results showed that the Fe0 particles were wrapped in POCN material and many nano CQDs were uniformly dispersed in the material. The new ternary nanocomposite exhibits excellent photocatalytic activity for the removal of TC, which was approximately 4.76 times higher than that of GCN. The enhancement of photocatalytic activity was attributed to the effective heterojunction as well as the multiply synergistic effects of POCN combined with Fe0 and CQDs, which was beneficial for retardation of recombination rate of photogenerated electron-hole pairs and generation of more free radicals for the oxidation of TC. Besides, the reactive oxygen species (ROS) of h+, •O2- and •OH played pivotal roles in the degradation of TC by Fe0@POCN/CQDs during the photocatalytic reaction. At the same times, sulfate radical (SO4•-) and hydroxyl radical (•OH) highlighted the dominant role in the degradation process compared with other free radicals under persulfate hybrid mixture system (PS system), which was further confirmed by radical scavenger experiments and electron spin resonance (ESR) analysis. The response surface methodology (RSM) study indicated that the optimal removal parameters of tetracycline could reach 97.57% within 30 min under PS system. In addition, the possible degradation pathway intermediates of TC were studied by HPLC-MS and the reaction catalytic activity mechanism of Fe0@POCN/CQDs/persulfate system was discussed.

A new aggregation-induced emission fluorescent probe for rapid detection of nitroreductase and its application in living cells.

The biological activity of nitroreductase (NTR) is closely related to biological hypoxia status in organisms. The development of effective methods for monitoring the activity of NTR is of great significance for medical diagnosis and tumor research. Toward this goal, we have developed a new aggregation-induced emission (AIE) fluorescence NTR probe TPE-HY used the tetraphenylethene as the fluorophore, and used the nitro group as the NTR recognition site. The probe TPE-HY has many excellent properties, including rapid response, AIE characteristics, high sensitivity and selectivity, and low cytotoxicity. Importantly, the probe TPE-HY is successfully applied to monitor endogenous NTR in living HeLa cells.

A turn-on endoplasmic reticulum-targeted two-photon fluorescent probe for hydrogen sulfide and bio-imaging applications in living cells, tissues, and zebrafish.

As one of the important gas signal molecules, hydrogen sulfide (H2S) is associated with many important physiological processes in living organisms. Organelles, especially endoplasmic reticulum (ER), play a crucial role in the cell metabolism. Accordingly, the detection of H2S in the ER is of high interest. Toward this goal, we have described the development of the first ER-targeted fluorescent H2S probe (Na-H 2 S-ER). The new probe exhibited favorable features, such as a large turn-on fluorescence signal (45-fold fluorescence enhancement), high sensitivity and selectivity. The probe was successfully employed for imaging exogenous and endogenous H2S in the living HeLa cells. Significantly, the new probe Na-H 2 S-ER was employed to visualize H2S in the ER of living cells for the first time. In addition, the probe was also successfully used for imaging H2S in the living tissues up to a depth of 100 µm and in the living zebrafish.

A turn-on fluorescent probe for endogenous formaldehyde in the endoplasmic reticulum of living cells.

As the simplest aldehyde compounds, formaldehyde (FA) is implicated in nervous system diseases and cancer. Endoplasmic reticulum is an organelle that plays important functions in living cells. Accordingly, the development of efficient methods for FA detection in the endoplasmic reticulum (ER) is of great biomedical importance. In this work, we developed the first ER-targeted fluorescent FA probe Na-FA-ER. The detection is based on the condensation reaction of the hydrazine group and FA to suppress the photo-induced electron transfer (PET) pathway, resulting in a fluorescence increase. The novel Na-FA-ER showed high sensitivity to FA. In addition, the Na-FA-ER enabled the bio-imaging of exogenous and endogenous FA in living HeLa cells. Most significantly, the new Na-FA-ER was employed to visualize the endogenous FA in the ER in living cells for the first time.

A TICT-based fluorescent probe for rapid and specific detection of hydrogen sulfide and its bio-imaging applications.

By blocking the intramolecular twisted internal charge transfer (TICT) process, we designed and sythesized the first TICT-based fluorescent probe for hydrogen sulfide. The new probe exhibits high selectivity, good membrane-permeability and is suitable for visualization of exogenous and endogenous hydrogen sulfide in living cells.

A lysosome-targeted and ratiometric fluorescent probe for imaging exogenous and endogenous hypochlorous acid in living cells.

Hypochorous acid plays important roles in numerous physiological and pathological processes. At the cell organelle level, an abnormal concentration of hypochorous acid in the lysosomes causes redox imbalance and the loss of function of the lysosomes. Herein, the first small molecule based, lysosomal-targeted ratiometric fluorescent HOCl probe (Lyso-HA) was synthesized through a rational design. The new probe was highly selective toward HOCl over other reactive oxygen species and exhibits a large variation (up to 97-fold) in its fluorescence ratio (I585/I450), with good signal resolution. The probe Lyso-HA is membrane-permeable and is suitable for ratiometric visualization of exogenous and endogenous HOCl at lysosomes in living cells.

Characteristics of electrical field and ion motion in surface-electrode ion traps.

In this article, we calculated the potential function of the surface-electrode ion trap (SEIT) by using Green's function method, optimized trap size, obtained the coefficients of the multipoles and analyzed ion trajectories in the RF potential. The optimized SEIT not only increases its trapping well depth by a factor of about 15, but also has relatively good linearity of the field (or large quadrupole component). The current design of SEIT can work well either as the ion guide for ion transmission or as the ion trap for ion confinement. Our research can be used to calculate the potential function in the SEIT with different device parameters, understand ion motions in the traps and optimize instrument performance. The method for calculating potential function can be expanded to planar and halo ion traps.

The development of charge detection-quadrupole ion trap mass spectrometry driven by rectangular and triangular waves.

In this article, the charge detection quadrupole mass spectrometry (CD-ITMS) driven by rectangular and triangular waveforms (rect-CD-ITMS and tri-CD-ITMS) was developed for the characterization of microparticles. Since the frequency scan of rectangular and triangular waveform could be realized easier than that of sinusoidal waveform, this research intends to provide simpler operation modes for CD-ITMS. In order to demonstrate the feasibility of rect-CD-ITMS and tri-CD-ITMS, the discharge onset voltage, ejection point of analyzed particles, and the achieved mass resolution were analyzed and compared with the case in conventional sinusoidal CD-ITMS (sin-CD-ITMS). The results indicated that the rect-CD-ITMS and tri-CD-ITMS can work well for the mass measurement of microparticles by using frequency scan. Identical mass resolutions were achieved under the same root mean square (RMS) voltage of different waveforms. The mass resolution was further improved by increasing the applied voltage and signal-to-noise ratio (S/N) of charge detector. Moreover, the rect-CD-ITMS and tri-CD-ITMS were applied to characterize red blood cells (RBCs). According to the obtained mean masses and mass distributions, normal and anemic RBCs were distinguished successfully.