Characterization and metabolic pathway of Pseudomonas fluorescens 2P24 for highly efficient ammonium and nitrate removal.

The ammonium and nitrate removal performance and metabolic pathways of a biocontrol strain, Pseudomonas fluorescens 2P24, were investigated. Strain 2P24 could completely remove 100 mg/L ammonium and nitrate, with removal rates of 8.27 mg/L/h and 4.29 mg/L/h, respectively. During these processes, most of the ammonium and nitrate were converted to biological nitrogen via assimilation, and only small amounts of nitrous oxide escaped. The inhibitor allylthiourea had no impact on ammonium transformation, and diethyl dithiocarbamate and sodium tungstate did not inhibit nitrate removal. Intracellular nitrate and ammonium were detectable during the nitrate and ammonium transformation process, respectively. Moreover, the nitrogen metabolism functional genes (glnK, nasA, narG, nirBD, nxrAB, nirS, nirK, and norB) were identified in the strain. All results highlighted that P. fluorescens 2P24 is capable of assimilatory and dissimilatory nitrate reduction, ammonium assimilation and oxidation, and denitrification.

Efficient Mn(II) removal mechanism by Serratia marcescens QZB-1 at high manganese concentration.

Manganese (Mn(II)) pollution has recently increased and requires efficient remediation. In this study, Serratia marcescens QZB-1, isolated from acidic red soil, exhibited high tolerance against Mn(II) (up to 364 mM). Strain QZB-1 removed a total of 98.4% of 18 mM Mn(II), with an adsorption rate of 71.4% and oxidation rate of 28.6% after incubation for 48 h. The strain synthesized more protein (PN) to absorb Mn(II) when stimulated with Mn(II). The pH value of the cultural medium continuously increased during the Mn(II) removal process. The product crystal composition (mainly MnO2 and MnCO3), Mn-O functional group, and element-level fluctuations confirmed Mn oxidation. Overall, strain QZB-1 efficiently removed high concentration of Mn(II) mainly via adsorption and showed great potential for manganese wastewater removal.

Effects of microorganisms on soil selenium and its uptake by pak choi in selenium-enriched lateritic red soil.

Data on selenium (Se) transformation, specifically the mineralization or activation of Se bound by microorganisms in natural Se-enriched soil, is limited. Therefore, this study investigates the effects of microorganisms on Se availability of Se-enriched lateritic red soil and Se uptake by pak choi. Following the incubation of Stenotrophomonas maltophilia S1 and arbuscular mycorrhizal (AM) fungi agent, the available Se content of soils increased from 35 to 66.69-117.04 µg/kg, corresponding to an increase of 90.50-234.40%. The Se bioconcentration and translocation factors in pak choi increased after adding the AM fungi agent and strain S1. The soil acid phosphatase activity, and pak choi root length, surface area, and diameter also increased. Moreover, the soil acid phosphatase activity showed a significant positive correlation with soil available Se and phosphorus content (p < 0.01). Overall, the AM fungi agent and strain S1 increased Se bioavailability by enhancing soil acid phosphatase and promoting root activity, ultimately increasing pak choi's ability to absorb available Se.

Selenium nanoparticle rapidly synthesized by a novel highly selenite-tolerant strain Proteus penneri LAB-1.

Microorganisms with high selenite-tolerant and efficient reduction ability of selenite have seldom been reported. In this study, a highly selenite-resistant strain (up to 500 mM), isolated from lateritic red soil, was identified as Proteus penneri LAB-1. Remarkably, isolate LAB-1 reduced nearly 2 mM of selenite within 18 h with the production of selenium nanoparticles (SeNPs) at the beginning of the exponential phase. Moreover, in vitro selenite reduction activities of strain LAB-1 were detected in the membrane protein fraction with or without NADPH/NADH as electron donors. Strain LAB-1 transported selenite to the membrane via nitrate transport protein. The selenite was reduced to SeNPs through the glutathione pathway and the catalysis of nitrate reductase, and the glutathione pathway played the decisive role. P. penneri LAB-1 could be a potential candidate for the selenite bioremediation and SeNPs synthesis.

Highly Selenite-Tolerant Strain Proteus mirabilis QZB-2 Rapidly Reduces Selenite to Selenium Nanoparticles in the Cell Membrane.

The application of biosynthesized nano-selenium fertilizers to crops can improve their nutrient levels by increasing their selenium content. However, microorganisms with a high selenite tolerance and rapid reduction rate accompanied with the production of selenium nanoparticles (SeNPs) at the same time have seldom been reported. In this study, a bacterial strain showing high selenite resistance (up to 300 mM) was isolated from a lateritic red soil and identified as Proteus mirabilis QZB-2. This strain reduced nearly 100% of 1.0 and 2.0 mM selenite within 12 and 18 h, respectively, to produce SeNPs. QZB-2 isolate reduced SeO3 2 - to Se0 in the cell membrane with NADPH or NADH as electron donors. Se0 was then released outside of the cell, where it formed spherical SeNPs with an average hydrodynamic diameter of 152.0 ± 10.2 nm. P. mirabilis QZB-2 could be used for SeNPs synthesis owing to its simultaneously high SeO3 2 - tolerance and rapid reduction rate.

Soil aggregate stability and its response to overland flow in successive Eucalyptus plantations in subtropical China.

Soil aggregates constitute the basic units of the soil structure, and soil aggregate stability is an important indicator of soil erodibility. Successive planting of fast-growing plantations can change the erosion resistance of the soil under rainfall conditions. Pure Eucalyptus plantations in this study (first- to fourth-generations, i.e., I, II, III, and IV, respectively) were investigated. The stability and abrasion characteristics of soil aggregates were analyzed by the wet sieving method, the Le Bissonnais (LB) method and a slope flow scouring experiment. With an increase in successive generations of Eucalyptus, the soil bulk density increased, and the saturated water content, porosity, organic matter and Iron, Aluminum and Manganese (Fe-Al-Mn) oxide contents decreased. Additionally, the wet sieving results showed that the first- and second-generations had higher macroaggregate content than the fourth generation. The mean weight diameter (MWD) values decreased with the number of planting significantly. Based on fast wetting (FW), slow wetting (SW) and mechanical breakdown by shaking after pre-wetting (WS), the aggregate stability was ranked in a decreasing order as MWDSW > MWDWS > MWDFW. The relative dissipation index (RSI) and mechanical crushing index (RMI) increased with increasing number of planting generations. Aggregate stability was significantly negatively correlated with the soil bulk density and was significantly positively correlated with the organic matter and Fe-Mn oxide contents. The extent of aggregate abrasion (Wr/Wi) values and MWD values decreased with increasing scouring distance and slope gradient during the transport process. The α and Wr/Wi values of the scoured aggregates were significantly correlated with aggregate stability. Hence, with successive planting of Eucalyptus, the soil aggregate stability decreased, and the soil was prone to erosion when subjected to slope flow.

Acute toxicity of eucalyptus leachate tannins to zebrafish and the mitigation effect of Fe3+ on tannin toxicity.

Fish ponds polluted by the black water of eucalyptus forests (formed by the complexation of eucalyptus tannins with Fe3+) have experienced fish deaths. However, the toxicity of the components of black water is still unclear. To study the acute toxicities of eucalyptus leachate tannins to fish, their changes in the presence of Fe3+, and the underlying mechanisms, the static bioassay test method was adopted for acute exposure testing of zebrafish. Zebrafish were exposed to three kinds of tannins, namely, tannic acid (TA), epigallocatechin gallate (EGCG) and tannins from fresh eucalyptus leaf leacheate (TFL), and to solutions of these tannins with different molar ratios of Fe3+, under both no-aeration and aeration conditions. The results showed that the 48 h LC50 values of TA, EGCG and TFL were respectively 92, 47, and 186 mg·L-1, under no aeration, and 171, 86, and 452 mg·L-1 under aeration. When Fe3+ at 2, 1, and 6 times the molar amount of tannin was added to LC100 solutions of TA, EGCG and TFL, zebrafish mortality in 24 h was reduced to 0-33%. Acute fish death in eucalyptus plantation areas is related to high concentrations of eucalyptus tannins in the water. However, with increasing dissolved oxygen and Fe3+ levels, the acute toxicity of tannins to fish can be reduced. Thus, the black water in eucalyptus plantation areas reflects a water quality phenomenon that reduces the acute toxicity of eucalyptus tannins to fish. The mechanism of tannin toxicity to fish may be related to the impairment of oxygen delivery by fish blood, but the mechanism needs further study. These results provide a scientific basis for the prevention and control of fish suffering from acute eucalyptus tannin poisoning in eucalyptus plantation areas and for the protection of water resources.

Certain Environmental Conditions Maximize Ammonium Accumulation and Minimize Nitrogen Loss During Nitrate Reduction Process by Pseudomonas putida Y-9.

Realizing the smallest nitrogen loss is a challenge in the nitrate reduction process. Dissimilatory nitrate reduction to ammonium (DNRA) and nitrate assimilation play crucial roles in nitrogen retention. In this study, the effects of the carbon source, C/N ratio, pH, and dissolved oxygen on the multiple nitrate reduction pathways conducted by Pseudomonas putida Y-9 are explored. Strain Y-9 efficiently removed nitrate (up to 89.79%) with glucose as the sole carbon source, and the nitrogen loss in this system was 15.43%. The total nitrogen decrease and ammonium accumulation at a C/N ratio of 9 were lower than that at 12 and higher than that at 15, respectively (P < 0.05). Besides, neutral and alkaline conditions (pH 7-9) favored nitrate reduction. Largest nitrate removal (81.78%) and minimum nitrogen loss (10.63%) were observed at pH 7. The nitrate removal and ammonium production efficiencies of strain Y-9 increased due to an increased shaking speed. The expression patterns of nirBD (the gene that controls nitrate assimilation and DNRA) in strain Y-9 were similar to ammonium patterns of the tested incubation conditions. In summary, the following conditions facilitated nitrate assimilation and DNRA by strain Y-9, while reducing the denitrification: glucose as the carbon source, a C/N ratio of 9, a pH of 7, and a shaking speed of 150 rpm. Under these conditions, nitrate removal was substantial, and nitrogen loss from the system was minimal.

Stretchable OFET Memories: Tuning the Morphology and the Charge-Trapping Ability of Conjugated Block Copolymers through Soft Segment Branching.

The mechanical properties and structural design flexibility of charge-trapping polymer electrets have led to their widespread use in organic field-effect transistor (OFET) memories. For example, in the electrets of polyfluorene-based conjugated/insulating block copolymers (BCPs), the confined fiberlike polyfluorene nanostructures in the insulating polymer matrix act as effective hole-trapping sites, leading to controllable memory performance through the design of BCPs. However, few studies have reported intrinsically stretchable charge-trapping materials and their memory device applications, and a practical method to correlate the thin-film morphology of BCP electrets with their charge-trapping ability has not yet been developed. In this study, a series of new conjugated/insulating BCPs, poly(9,9-di-n-hexyl-2,7-fluorene)-block-poly(δ-decanolactone)s (PF-b-PDLx, x = 1-3), as stretchable hole-trapping materials are reported. The linear and branched PDL blocks with comparable molecular weights were used to investigate the effect of polymer architecture on morphology and device performance. Moreover, the coverage area of the polyfluorene nanofibers on the BCP films was extracted from atomic force microscopy images, which can be correlated with the trapping density of the polymer electrets. The branched PDL segments not only improve stretchability but also tailor crystallinity and phase separation of the BCPs, thus increasing their charge-trapping ability. The OFET memory device with PF-b-PDL3 as the electret layer exhibited the largest memory window (102 V) and could retain its performance at up to 100% strain. This research highlights the importance of the BCP design for developing stretchable charge-trapping materials.

[Effects of plantation on aggregate distribution and stability of lateritic red soil in south subtropical China]. / 南亚热带人工林种植对赤红壤团聚体分布及稳定性的影响.

We examined the stability of soil aggregates in five typical plantations, i.e., Eucalyptus urophylla × E. grandis plantation, Cunninghamia lanceolata plantation, Pinus massoniana plantation, Mytilaria laosensis plantation and Castanopsis hystrix plantation, in the south subtropical China by the Elliott wet sieving and Le Bissonnais (LB) methods. The results showed that the content of water stability aggregate (WR>0.25) was more than 62.2% after wet sieving. The mean weight diameter (MWD) and geometric mean diameter (GMD) of aggregates were 1.58-3.71 mm and 0.57-2.02 mm, respectively, which were the largest in C. lanceolata plantation and the smallest in E. urophylla × E. grandis plantation. Percentage of aggregate destruction (PAD) of five kinds of plantations ranged from 4.6% to 31.5%. The transfer matrix method was used to evaluate the soil aggregates, with the aggregate stability index (ASI) following the order of C. lanceolata plantation > C. hystrix plantation > M. laosensis plantation > P. massoniana plantation > E. urophylla × E. grandis plantation. Under the three treatments of LB method, the FW treatment was the most destructive to the stability of soil aggregates, indicating that dissipation played a major role in the disintegration of soil aggregates. The WS treatment had the least damage to the aggregates. The effect of slow wetting (SW) treatment was between the fast wetting (FW) and wet stirring (WS). Both the MWD and GMD values followed the order of WS>SW>FW, which gradually decreased with the increases of soil depth. The GMD value of aggregates under FW treatment by LB method of five plantations was significantly positively correlated with ASI, MWD and GMD of wet sieving method, indicating that the traditional wet sieving method had a good correlation with FW treatment and was feasible to determine the stability of soil aggregates in the subtropical red soil. Based on the aggregate stability indices of MWD, GMD, PAD and ASI, C. lanceolata plantation was more conducive to the improvement of soil aggregation level, with more stable soil structure than the other four plantations.

[Characteristics of soil saturated hydraulic conductivity on different positions and their controlling factors of granite collapsing gullies]. / èŠ±å²—å²©å´©å²—ä¸åŒéƒ¨ä½åœŸå£¤é¥±å’Œå¯¼æ°´çŽ‡ç‰¹å¾åŠå ¶å½±å“å› ç´ .

Collapsing gully is a common phenomenon of hydraulic-gravity combined soil erosion in granite hilly area of south China. The study aimed to explore the relationship between soil hydraulics pro-perties and erosion mechanism and the intrinsic controlling factors. The active, semi-stable, and stable types of granite collapsing gullies in southeastern Guangxi were selected to examine the spatial variation of soil saturated hydraulic conductivity and identify the influencing factors. Main results were as follows: 1) Soil saturated hydraulic conductivity of collapsing gullies fluctuated on different positions, with the bottom of collapsing wall showing the minimum value, the top of colluvial deposit showing the maximum, and followed by the top of alluvial fan. 2) All the models being selected to model the soil saturated hydraulic conductivity, including Cosby, Compbell, Julià, and Hypre, performed poor. 3) Results of correlation analysis showed that soil saturated hydraulic conductivity was negatively correlated with capillary porosity and clay content, and positively correlated with non-capillary porosity and sand content. 4) Results of path analysis showed that sand content was the most influencing factor in controlling soil saturated hydraulic conductivity of collapsing gullies, followed by non-capillary porosity and soil bulk density, where sand content and non-capillary porosity exerted a positive effect and bulk density exerted a negative one. Our findings will provide theoretical basis for the mechanistic understanding and prevention of collapsing gullies erosion.

Facile Fabrication of Stretchable Touch-Responsive Perovskite Light-Emitting Diodes Using Robust Stretchable Composite Electrodes.

Perovskite light-emitting diode (PeLED) has been vigorously developed in recent years. As it has demonstrated good performance on the rigid substrates, the next important direction of PeLED is its integration with stretchable components to realize stretchable, responsive device. Here, we describe a facile fabrication of stretchable perovskite light-emissive touch-responsive devices (PeLETDs) by utilizing highly transparent and conductive polyurethane/silver nanowires (PU/AgNWs) as the electrode. Meanwhile, a stretchable tricomposite perovskite emissive layer was developed by blending a small amount of poly(ethylene oxide) (PEO) and poly(vinylpyrrolidone) (PVP) with CsPbBr3. Additionally, a thin PVP layer was introduced at the bottom of the emissive layer. On one hand, it can further improve the morphology of the emissive layer; on the other hand, it can serve as an electron-injection barrier to reduce the high nonradiative recombination at the corresponding interface. Further, to fulfill the responsive function of the fabricated PeLEDs, a poly(ethylene terephthalate) (PET) spacer with a 100 µm thickness was inserted between the top electrode and the emissive layer. A stretchable PeLETD is finally demonstrated to possess a low turn-on voltage of 2 V with a brightness of 380.5 cd m-2 at 7.5 V and can sustain 30% uniaxial strain with a small luminance variation of 24%. More interestingly, our stretchable PeLETD exhibited high stability, which could be well touch responsivity, where the luminance is on/off switched for 300 cycles by repeatedly applying pressure.

Light Down-Converter Based on Luminescent Nanofibers from the Blending of Conjugated Rod-Coil Block Copolymers and Perovskite through Electrospinning.

We demonstrated a novel strategy for the preparation of light down-converter by combining rod-coil block copolymers with perovskite quantum dots (QDs) through electrospinning. Reports have shown that polymer deformability can be enhanced by incorporating a soft segment and controlled by varying the rod/coil ratio. Therefore, we first synthesized the rod-coil block copolymer through the click reaction of polyfluorene (PF) and poly(n-butyl acrylate) (PBA). Next, the CsPbBr3@PF8k-b-PBA12k composite fibers were fabricated by blending perovskite through electrospinning. Optical spectral evidence demonstrated the success of the strategy, as light down-converters were prepared through the controlled variance of QD/polymer ratios to achieve tunable color and stretchability. This result reveals the potential of using rod-coil block copolymers to fabricate color-tunable perovskite light down-converters.

Multiple Scattering from Electrospun Nanofibers with Embedded Silver Nanoparticles of Tunable Shape for Random Lasers and White-Light-Emitting Diodes.

Random lasers (RLs) are convenient, tunable, and widely applicable. However, the influence of fluorescence lifetime on the scattering and nanofiber distribution of nanofibers with various shapes of silver nanoparticles (Ag NPs) embedded within is unclear. We prepared poly(vinyl alcohol) (PVA) nanofibers with Ag NPs through electrospinning (ES) and pyrromethene 597 dye doping. We determined the influences of the particles on scattering enhancement and localized surface plasmon resonance (LSPR) in RLs. The distinct scattering rates and LSPR can be used to control optical properties for sensing devices and other applications. Compared with traditional films, the threshold of the nanofibers with Ag NPs is 35% lower. In addition to improved matching between the LSPR and emission spectra, enhanced coupling of the electric field with nonradiative energy amplifies the radiative emission. Furthermore, the luminescence lifetime shortened by increasing the scattering rate. An excessive scattering rate may accelerate radiative recombination and convert some recombination into nonradiative recombination to produce a more sensitive device. Finally, we applied the prepared nanofibers to a backlight display and fabricated a white-light-emitting diode (LED) with a distinct thickness of nanofibers. The fabricated device is suitable for application in other LEDs and RL devices.

Facile 3D Boron Nitride Integrated Electrospun Nanofibrous Membranes for Purging Organic Pollutants.

Elegant integration of three-dimensional (3D) boron nitride (BN) into the porous structure of a polymer nanofiber (NF) membrane system results in a surface with enhanced absorption capacity for removal. Various BN-based applications were designed and developed successfully, but BN-based absorption systems remain relatively unexplored. To develop a reusable absorption strategy with high removal efficiency, we used a composite of 3D BN and polyacrylonitrile (PAN) to prepare a NF membrane with a porous structure by using electrospinning and spray techniques (BN-PAN ES NFs). The removal efficiency of the 3D BN NF membrane was higher than that of a pure carbon NF membrane. Water pollutants, such as the dyes Congo red (CR), basic yellow 1 (BY), and rhodamine B (Rh B), were tested, and the absorption ratios were 46%, 53%, and 45%, respectively. Furthermore, the aforementioned dyes and pollutants can be completely eliminated and removed from water by heating because of the high heat resistance of 3D BN. The membrane can be recycled and reused at least 10 times. These results indicate that BN-PAN ES NFs have can be used in water purification and treatment for absorption applications, and that they can be reused after heat treatment.

Occurrence patterns of black water and its impact on fish in cutover areas of Eucalyptus plantations.

Black runoff occasionally flows from cutover areas of Eucalyptus plantations, polluting rivers and ponds, and resulting in fish death in severe cases. However, the occurrence patterns and environmental impacts of this black water remain unclear. Herein, we analyzed the major characteristics of black water at the occurrence sites, tested the complexation reaction of ground eucalyptus leaves with a solution of Fe3+, and determined the color and absorbance of the complex solution. The results showed that the water was dark blue, with weak acidity and strong light absorbance. The water contained a high level of dissolved organic matter content, while its chemical oxygen demand, total N, total P, NO3--N, and NH4+-N concentrations were significantly higher than those in the stream water from Eucalyptus, Pinus massoniana Lamb., and Cunninghamia lanceolata stands during the growth period. Additionally, the tannic acid concentration in the black water was 1.0 mg L-1 higher than that in the stream water from the Eucalyptus stand. The input of black water increases the concentration of tannic acid and NH4+-N, and the degradation of organic matter consumes dissolved oxygen in downstream ponds, leading to fish deaths. The presence of fresh logging residues and hot, humid weather also enable black water formation. Field investigations and simulation experiments revealed fresh Eucalyptus residues decompose rapidly under high-temperature and rainfall conditions, releasing large amounts of tannic acid, which reacts with Fe3+ to form a dark blue tannic acid­iron complex and results in black water. These results indicate that the rich Fe3+ in runoff may be a key factor in the occurrence of black water. The logging of Eucalyptus plantations during the dry season or on non-rainy days and a reduction in the logging area could prevent the occurrence of black water or mitigate the extent of its environmental hazards.

Facile Preparation of Cu/Ag Core/Shell Electrospun Nanofibers as Highly Stable and Flexible Transparent Conductive Electrodes for Optoelectronic Devices.

Novel transparent conductive electrodes (TCEs) with copper (Cu)/silver (Ag) core/shell nanofibers (NFs) containing random, aligned, and crossed structures were prepared using a combination of electrospinning (ES) and chemical reduction. The ES process was used to prepare continuous copper nanofibers (Cu-NFs), which were used as core materials and were then immersed in silver ink (Ag ink) to form a protective layer of Ag to protect the Cu-NFs from oxidation. The Ag shell layer protected the Cu-NFs against oxidation and enhanced their conductivity. Such Cu/Ag core/shell webs can be easily transferred on the flexible matrix and can be applied in TCEs. The metal NF webs of different structures exhibited various degrees of conductivity and followed the order random type > crossed type > aligned type; however, the order with respect to transmittance ( T) was inverse. The aligned nanowire networks exhibited a high T of over 80%, and the random ones exhibited a low sheet resistance of less than 102 Ω/sq (the best value is 7.85 Ω/sq). The present study demonstrated that TCEs based on Cu/Ag core/shell NF webs have considerable flexibility, transparency, and conductivity and can be applied in novel flexible light-emitting diode devices and solar cells in the future.

A mechanically robust silver nanowire-polydimethylsiloxane electrode based on facile transfer printing techniques for wearable displays.

Silver nanowire (AgNW) networks have attracted considerable attention as transparent electrodes for emerging flexible optoelectronics. However, the transference of such networks onto diverse arbitrary substrates with high conductivity remains a challenge because of the possibility of detaching and sliding occurring at the interface. Therefore, we developed a water-assisted transfer printing method for the fabrication and transfer of an AgNW-polydimethylsiloxane (PDMS) electrode. This innovative approach exhibits a robust ability for thin film transfer onto arbitrary substrates and has highly controlled and nondestructive characteristics. The obtained electrodes exhibited a high ratio of DC conductivity to optical conductivity of 200, a low sheet resistance of 9 Ω sq-1 at 82%, tensile strain (0% to 50%), and flexibility (bending radius of less than 2 mm) without significant loss of conductivity compared with devices fabricated through conventional methods. Furthermore, we demonstrated a novel textile-based flexible light-emitting electrochemical cell (PLEC) based on the stretchable AgNW-PDMS electrode and buckling concept, thereby realizing highly stretchable PLECs with excellent performance and mechanical robustness. The luminance intensity of the strained device was optimized to 58 cd m-2 at 7 V under 10% linear strain without damaging the electroluminescence properties. Notably, this effective and practical transfer method provides a way to develop electronic nanowire devices with unique configurations and high performances.

Novel stretchable thermochromic transparent heaters designed for smart window defroster applications by spray coating silver nanowire.

A productive and novel method for fabricating stretchable transparent heaters with recognised thermochromic properties using commercially available thermochromic ink (TM-55-blue) and silver nanowire (AgNW)-coated polydimethylsiloxane (PDMS) is proposed. Lower resistance, elevated heat generation, and higher transparencies were the expected essential prerequisites for the fabrication of items such as smart windows and window defrosters. AgNW-coated PDMS (hereafter PH devices) satisfied the essential prerequisites but did not produce sufficient color change. In addition to the appreciable electrical and optical characteristics and mechanical robustness, observable color changes represent a critical factor in effortless temperature monitoring by the heating device. Blending TM-55-blue thermochromic ink with PDMS (PBH device) improves the heating rate and color transformation and promotes the ultralow response time appreciably. More notably, it produces a visible transformation from blue to colorless. Color changes visible to the naked eye, ultralow response time, and heating rate represent valuable features for deploying the PBH devices as window defrosters and in smart window applications.

Water-Resistant Efficient Stretchable Perovskite-Embedded Fiber Membranes for Light-Emitting Diodes.

Cesium lead halide perovskite nanocrystals (NCs) with excellent intrinsic properties have been employed universally in optoelectronic applications but undergo hydrolysis even when exposed to atmospheric moisture. In the present study, composite CsPbX3 (X = Cl, Br, and I) perovskite NCs were encapsulated with stretchable (poly(styrene-butadiene-styrene); SBS) fibers by electrospinning to prepare water-resistant hybrid membranes as multicolor optical active layers. Brightly luminescent and color-tunable hydrophobic fiber membranes (FMs) with perovskite NCs were maintained for longer than 1 h in water. A unique remote FMs packaging approach was used in high-brightness perovskite light-emitting diodes (PeLEDs) for the first time.