Accumulation characteristics and ecological risk evaluation of microplastics in sediment cores from the artificial reef area and surrounding seas of Haizhou Bay, north China.

One significant "sink" for microplastic (MP) pollution is the sediments. There's a considerable lack of reliable data regarding the historical status of MPs contamination in sediments within marine ranching. In this research, the study area encompassed Haizhou bay marine ranching and adjacent seas. The primary objective was to explore the potential relationships between the accumulation of MPs and both the sample depth and sediment characteristics within the cores. The results unveiled significant contamination of MPs within the sediment cores. The average MPs concentration of sediment was 1.01 ± 1.28 n/g. Fibrous polymers and particles smaller than 1000 µm were frequently found in the sediment. The abundance of MPs exhibited a tendency to decrease with an increase in sediment depth. Artificial reefs and currents affected on MPs distribution in sediment cores. The accumulation of MPs showed a significant correlation (P < 0.05) with the sediment content of different particle sizes, suggesting that the composition of sediment can serve as an indicator of the abundance of MPs. The risk of MP pollution in the sediments of the study area was assessed by establishing a risk assessment model using concentration data of MPs and polymer types. Due to the higher hazard score of polymers (PA and PET) in MPs, the Polymer hazard index (PHI) was elevated to grade II. However, it had a Pollution load index (PLIzone) value of 1.95 (level I). This suggested that contamination was minimal, yet the ecological risk remained relatively high. The ecological risk assessment of MPs served as the foundation for gaining a detailed understanding of the distribution characteristics of MPs. It also furnished essential data support for conducting a comprehensive assessment, developing feasible management strategies, and establishing water quality standards related to plastic waste.

Developing Air-Stable n-Type SWCNT-Based Composites with High Thermoelectric and Robust Mechanical Properties for Wearable Electronics.

Flexible organic thermoelectric generators are gaining prominence in wearable electronics, leveraging body heat as an energy source. Their advancement is hindered by the scarcity of air-stable n-type organic materials with robust mechanical properties. This study introduces two new polymers (HDCN4 and HDCN8), created through polycondensation of paraformaldehyde and diamine-terminated poly(ethylene glycol) (PEGDA) with molecular weights of 4000 and 8000 g/mol into single-walled carbon nanotubes (SWCNTs). The resulting HDCN4/SWCNT and HDCN8/SWCNT composites show impressive power factors of 225.9 and 108.2 µW m-1 K-2, respectively, and maintain over 90% in air for over four months without encapsulation. The HDCN4/SWCNT composite also demonstrates significant tensile strength (33.2 MPa) and flexibility (up to 10% strain), which is currently the best mechanically n-type thermoelectric material with such a high power factor reported in the literature. A thermoelectric device based on HDCN4/SWCNT generates 4.2 µW of power with a 50 K temperature difference. Additionally, when used in wearable temperature sensors, these devices exhibit high mechanical reliability and a temperature resolution of 0.1 K. This research presents a viable method to produce air-stable n-type thermoelectric materials with excellent performance and mechanical properties.

Distribution characteristics and ecological risk assessment of microplastics in intertidal sediments near coastal water.

Plastic products are widely distributed worldwide and continue to have a negative impact on the environment and organisms. Intertidal regions, which interface between upland and marine ecosystems, are regions of high ecological importance and serve as repositories for a variety of plastic wastes. However, ecological risk assessments of microplastics (MPs) in these transitional environments are still scarce. In this study, the morphological characteristics and spatial distribution of MPs in the intertidal surface sediments of Haizhou Bay were analyzed, and an ecological risk assessment framework for MPs was developed. Overall, the average abundance of MPs in the sediments was 2.31 ± 1.35 pieces/g dw. The size of the MPs was mainly less than 1 mm, and the main shape, color and polymer type of the MPs were mainly fibrous (58%), blue (30%), and PVC (22%), respectively. Cluster analyses showed that the sites could be well distinguished by size and polymer type but not by MP shape and color. According to the hazard scores, most of the sites in this area belonged to a risk level of IV, while the pollution loading index (PLI) showed that most of the sites belonged to a risk level of II. The ecological toxicity risk from the species-sensitive distribution (SSD) model showed that one-third of the sites had ecological MPs toxicity risks to marine organisms. We believe that normalized and standardized assessment methods should be implemented to monitor and manage the risk of MPs in the intertidal sediments. Particularly, the multiple dimensions, standard abundance of MPs, as well as MPs ingestion in the intertidal organisms, should be fully considered in the next step.

Spatial distribution characteristics of microplastics in the seawater column and sediments of the artificial reef area and adjacent water in Haizhou Bay.

Recently, scholars have been increasing concerned about microplastics (MPs). Unfortunately, information is lacking on the spatial distribution patterns of MPs in coastal seas; therefore, our understanding of the extent of offshore MP contamination remains incomplete. MP distribution in the seawater and surface sediments of an aquaculture area (AA), artificial reef area (AR), and comprehensive effect area (CEA) in Haizhou Bay were investigated in this study. The results showed that the mean abundances of MPs in the surface, middle and bottom seawater were 6.98 ± 3.01 n/m3, 9.12 ± 3.07 n/m3 and 10.20 ± 2.41 n/m3, respectively, and that the abundance in the sediment was 3.09 ± 1.16 n/g. The MP abundance in the bottom seawater was significantly higher than that in the surface seawater (P < 0.05). The correlation among MPs at different depths was not significant, but MPs in most habitats showed a significant correlation. We discovered a significant correlation between the abundance of MPs in the CEA seawater and AR sediments, but not between that in the CEA sediments and AR sediments. MPs can be transported from surface seawater to deeper layers by natural deposition processes. The horizontal transport of MPs due to the coastal gulf current and regular semidiurnal tides lead to the correlations observed in of MP abundance among the AA, CEA, and AR. Migration of MPs from the CEA to the AR was primarily caused by the southern eddies in Haizhou Bay, while migration of MPs from the sediment to the seawater could be due to upwelling in the AR. This was also the main reason there was a lack of a correlation between the sediment from the AR and the seawater from the CEA. This work provides a theoretical and empirical foundation for MP transport and source tracking.

Salvianolic Acid B Protects Cardiomyocytes from Ischemia/Reperfusion Injury by Mediating circTRRAP/miR-214-3p/SOX6 Axis.

Circular RNAs (circRNAs) are a class of powerful regulators of gene expression. This study aimed to determine whether circTRRAP (hsa_circ_0081241) was implicated in the cardioprotective effects of salvianolic acid B (Sal B) against myocardial ischemia/reperfusion (I/R) injury and its associated mechanism.Cell viability was analyzed using Cell Counting Kit-8 (CCK-8), and flow cytometry was conducted to evaluate cell cycle progression and cell apoptosis. The leakage of lactic dehydrogenase (LDH), production of malondialdehyde (MDA), and activity of superoxide dismutase (SOD) were measured using their corresponding commercial kits to analyze cell death and oxidative stress.I/R treatment suppressed viability and cell cycle progression and induced the apoptosis and oxidative stress of AC16 cardiomyocytes, whereas Sal B protected AC16 cardiomyocytes against I/R injury. I/R upregulated circTRRAP expression, whereas Sal B dose-dependently reduced the circTRRAP level in AC16 cardiomyocytes. The protective effects of Sal B in I/R-induced AC16 cardiomyocytes were overturned by the overexpression of circTRRAP. CircTRRAP negatively regulated miR-214-3p expression by binding to it in AC16 cardiomyocytes. The circTRRAP overexpression-mediated effects were reversed by the addition of miR-214-3p mimics in AC16 cardiomyocytes. MiR-214-3p targeted the 3'-untranslated region (3'UTR) of SOX6, and SOX6 was regulated by the circTRRAP/miR-214-3p axis in AC16 cardiomyocytes. SOX6 knockdown overturned the circTRRAP overexpression-induced effects in AC16 cardiomyocytes.In conclusion, the silence of circTRRAP was implicated in Sal B-mediated cardioprotective effects against I/R injury by regulating the miR-214-3p/SOX6 axis.

Intrinsically Self-Healable and Wearable All-Organic Thermoelectric Composite with High Electrical Conductivity for Heat Harvesting.

The development of wearable electronics has led to the growing demand for the self-powered and maintenance-free power sources. Under these circumstances, thermoelectric generators are considered promising candidates, which can directly convert body heat into electricity to power wearable electronics. However, most of the thermoelectric materials are either brittle or unrecoverable under external physical damage. It is urgent to develop thermoelectric materials that possess both stretchability and intrinsic self-healing property, and the remaining challenge is to combine the high mechanical robustness and excellent electrical conductivity. Herein, a self-healing and wearable all-organic thermoelectric composite is reported. The composite film exhibits high electrical conductivity of 238 S cm-1, high flexibility of up to 119% strain, and a maximum tensile strength of 23 MPa. When the composite film is subjected to external physical damage, most functionalities can be maintained after self-healing, 78% recovery in electrical conductivity, and 80% recovery in tensile strength. Using the self-healing composite, we fabricated a thermoelectric generator with a power output of 85.5 nW at a temperature difference of 48 K, which is a significant advance over the recently reported thermoelectric generators based on intrinsic self-healing thermoelectric materials. This work represents a crucial step toward achieving intrinsic self-healing all-organic thermoelectric materials with high electrical conductivity.

Discussion on Repolarization Reserve between Patients with Coronary Heart Disease and Normal Controls.

Objective: To investigate the repolarization reserve of normal controls (NCs) and patients with coronary heart disease (CHD). Methods: From January 1st, 2010 to December 31st, 2018, 200 age- and gender-matched inpatients in the Second Hospital of Shanxi Medical University and Heji Hospital Affiliated to Changzhi Medical College were selected for treadmill exercise test (TET), including 67 patients in the myocardial ischemia group, 66 patients in the suspected myocardial ischemia group, and 67 patients in the normal control group. Coronary angiography (CAG) was performed on 49 of 133 patients in the myocardial ischemia group and the suspected myocardial ischemia group, and 9 positives and 40 negatives were identified. The heart rate (HR) and QT interval of TET examiners before exercise, during exercise (90 beats/min, 120 beats/min, maximum HR), and in the recovery period (1 minute and 3 minutes after exercise) were reviewed, and QTc values were calculated after being corrected by BaZett's. Results: The mean QTc values in NCs were all below 452 ms, before exercise, during exercise (90 beats/min, 120 beats/min and maximum HR), and during the recovery period (1 minute and 3 minutes after exercise). The comparison results of the RR interval between the two groups revealed P > 0.05, indicating no statistical significance. Significant differences were present when comparing the QT intervals when the HRs were 90 beats/minute and 120 beats/minute during exercise (P < 0.05). And comparing the QTc values, it was found that the QTc values during different exercise periods were statistically different between groups (P < 0.05). Conclusions: NCs have good repolarization reserve. CAG can confirm true myocardial ischemia patients (i.e., patients with CHD) among myocardial ischemia and suspected myocardial ischemia patients screened by TET. Patients with positive CAG have poor repolarization reserve as QT interval represents ventricular repolarization adaptability.

Application value of whole-course health management for patients with nonvalvular atrial fibrillation with oral warfarin treatment.

OBJECTIVE: To explore the effect of the whole-process health management model on the compliance of oral warfarin treatment in patients with non-valvular atrial fibrillation in primary hospitals. METHODS: We retrospectively analyzed the clinical data of 130 patients with non-valvular atrial fibrillation treated in the Department of Cardiovascular Medicine, Hai'an People's Hospital from January 2019 to December 2019. Among them, 63 patients who received routine continuing care were included in the control group, and 67 patients treated with whole-course health management model of primary hospitals were included in the observation group. The two groups were compared in terms of the following parameters: Warfarin anticoagulation knowledge, medication compliance, compliance rate (international normalized ratio, INR) monitoring, bleeding events (gingival bleeding, subcutaneous bleeding, gastrointestinal bleeding, etc.), embolic events (vascular thrombosis), negative emotions before and after management, and patient satisfaction. Logistic analysis was used to analyze independent risk factors affecting the effect of warfarin anticoagulation in patients with non-valvular atrial fibrillation. RESULTS: Compared with the control group, the warfarin anticoagulation knowledge, medication compliance, and INR compliance rate of the observation group were significantly higher, and the incidence of adverse events was significantly lower. Self-rating Anxiety Scale (SAS) and Self-rating Depression Scale (SDS) scores were not significantly different between the two groups before management. After management, SAS and SDS scores decreased significantly in both groups, and were lower in the observation group compared with the control group. The management satisfaction was also significantly higher in the observation group. CONCLUSION: Compared with the conventional continuation care model, the whole-process management in primary hospitals can improve patients' compliance with medical advice and treatment efficacy, with lower risk of bleeding and higher patient satisfaction, providing a better option for the out-of-hospital management of anticoagulation for non-valvular atrial fibrillation patients. Age, hypertension, diabetes, knowledge of warfarin anticoagulation and medication compliance were independent risk factors for the effect of warfarin anticoagulation in patients with non-valvular atrial fibrillation.

Superhydrophilic polyethersulfone (PES) membranes with high scale inhibition properties obtained through bionic mineralization and RTIPS.

Reverse thermally induced separation (RTIPS) was used to obtain a separation membrane with a better internal structure for a higher water flux and a surface that could easily form a hydration layer. In comparison to the traditional modification method, this work focused on the aspect that the internal structure obtained by changing the membrane-making method provided easier adhesion conditions for the dopamine/TiO2 hybrid nanoparticles (DA/TiO2 HNPs) obtained by biomimetic mineralization. It provided a basis for exploring the variation in adhesion with the water bath temperature and the amount of titanium added through the study of turbidity point, SEM images, water contact angle, thermogravimetric test, EDX, AFM, XPS, FTIR and other test results. The SEM images proved that the membrane obtained through the RTIPS method had a porous surface and spongy internal structure, furthermore, additional polymers were adsorbed. Use of EDX demonstrated that biomimetic mineralization prevented the production of agglomerated titanium dioxide. XPS and FTIR spectra confirmed the introduction and immobilization of HNP aggregation. Moreover, a decrease in the surface roughness and water contact angle further suggested an improvement in the hydrophilicity of the modified membrane. The introduction of HNP at a higher water bath temperature helped increase the water flux up to ten times, moreover, the oil-water separation efficiency could still reach over 99.50%. Lastly, a cycle test of the modified membrane under the optimal conditions helped confirm that the membrane forming conditions at this time could provide a better environment for the formation of the hydrophilic layer, which was conducive to the recycling of the separation membrane. In summary, more fixed more hydrophilic particles could be obtained through the RTIPS method based on biomimetic mineralization to prevent the accumulation of titanium dioxide, thus helping improve permeability and anti-fouling of the membrane.

Bimetallic polyphenol networks structure modified polyethersulfone membrane with hydrophilic and anti-fouling properties based on reverse thermally induced phase separation method.

In order to improve the hydrophobicity of traditional polyethersulfone (PES) membranes, this study combined the reverse thermally induced phase separation (RTIPS) method with the constructed bimetallic polyphenol networks (BMPNs) to prepare hydrophilic anti-fouling membranes. As for BMPNs, tannic acid (TA) was served as an intermediate to construct both the inner and surface hydrophilic layers of the PES membranes. On the one hand, etching Zeolitic imidazolate framework-8 (EZIF-8) with synergistic etching and surface functionalization via TA not only retained the high pore structure of MOFs, but also had good hydrophilicity. On the other hand, the MPN hydrophilic layer was formed on the membrane surface by the combination of TA from the surface of EZIF-8 and iron ions in the coagulation bath. Therefore, BMPNs structure penetrated the interior and surface of PES membrane, which greatly improved the hydrophilic properties. In addition, the membrane with porous surfaces and spongy cross sections by RTIPS method improved the permeability and mechanical properties of the membrane by several times compared with the membrane via NIPS method. The obtained membranes in this experiment showed excellent permeability, just like pure water flux reached 1662.16 L/m2 h, while BSA rejection rate remained at 92.78%. Compared with pure membrane, it showed a better flux recovery rate (FRR = 83.33%) after cleaning, and the reduction of irreversible (Rir = 16.67%) fouling indexes indicated that the adsorption of protein was inhibited. These results suggested that the hydrophilic anti-fouling PES membranes prepared by this method possessed great application potential in membrane separation technology.

Novel butterfly-shaped organic semiconductor and single-walled carbon nanotube composites for high performance thermoelectric generators.

Herein, a series of novel butterfly-shaped small-molecule organic semiconductors (OSCs) have been designed, synthesized and complexed with single-walled carbon nanotubes (SWCNTs) as p-type thermoelectric materials. The butterfly-shaped molecules exhibit curved molecular structures, which tune their frontier molecular orbitals and increase their interactions with SWCNTs. A systematic study shows that the composites based on butterfly-shaped OSCs exhibit significantly improved thermoelectric performances compared with that of the composite based on the analoguous planar OSC. The enhanced thermoelectric performances are attributable to the higher activation energy, improved doping level and charge transport process between the organic molecules and SWCNTs. The butterfly-shaped OSC and SWCNT composite opens up a new avenue for the design of thermoelectric materials and devices.

Crystalline Domain Formation to Enable High-Performance Polymer Thermoelectrics Inspired by Thermocleavable Materials.

Improving the electrical conductivity is an important role in realizing high thermoelectric performance of solution-processable polymers. Herein, a simple and robust approach to boost the mobility and doping efficiency of a diketopyrrolopyrrole-based copolymer with the introduction of thermocleavable side chains (PDPPS-X, where X is the molar ratio of the thermocleavable side chains and alkyl chains) is first provided. Notably, the incorporated thermocleavable groups can be effectively removed after thermal treatment and therefore contribute to the crystalline domain formation via hydrogen-bonded networks, which is critical for conductivity enhancements. Grazing incidence wide-angle X-ray scattering (GIWAXS) patterns give a clear indication that the thermal treatment of PDPPS-5 can greatly improve the structural arrangement, resulting in a significantly enhanced hole mobility (5.4 times that of PDPPS-0 without thermocleavable chains). Compared to PDPPS-0, a larger Fermi level shift is observed after doping PDPPS-5 with FeCl3, reflecting a better doping efficiency. Consequently, remarkably improved conductivity and power factor are achieved by PDPPS-5 after doping with 0.03 M FeCl3 at room temperature, which are about 2.2 and 3.5 times higher than that of PDPPS-0 at the same testing condition, respectively. Moreover, PDPPS-5 achieved a maximum power factor of 57.5 µW m-1 K-2 at 404 K.

The Application of Crisis Intervention in Middle-Aged and Young Patients with Acute Myocardial Infarction after PCI.

OBJECTIVE: To investigate the effect of crisis intervention in middle-aged and young patients with acute myocardial infarction after percutaneous coronary stent implantation (PCI). METHODS: A total of 108 middle-aged and young patients with acute myocardial infarction undergoing PCI were selected from July 2018 to July 2019 in the Department of Cardiology, Hai'an County People's Hospital. They were divided into two groups, according to a random number table, with 54 cases in each group. The control group implemented routine postoperative intervention, and the intervention group implemented postoperative crisis intervention. The changes in the two groups' sense of crisis, mental state, quality of life and hope level before and after the intervention were compared. RESULTS: The emotional, behavioral, and cognitive scores of the intervention group were lower than those of the control group after 4 weeks of intervention (P < .05). The mental state scores of the intervention group were lower than those of the control group (P < .05). Also, the various quality of life scores were higher than those of the control group (P < .05). The intervention group's hope level scores were higher than the control group (P < .05) after 4 weeks of intervention. CONCLUSION: The application of crisis intervention to middle-aged and young patients with acute myocardial infarction after PCI can reduce the sense of crisis, improve their mental state and quality of life, and raise the level of hope.

Oxygen-Rich Polymer Polyethylene Glycol-Functionalized Single-Walled Carbon Nanotubes Toward Air-Stable n-Type Thermoelectric Materials.

It is crucial for thermoelectric (TE) devices to obtain both p-type and n-type materials and control charge carrier density. However, n-type thermoelectric materials are quite deficient and have lower thermoelectric properties. We report one oxygen-rich polymer named polyethylene glycol (PEG) for converting p-type single-walled carbon nanotubes (SWCNTs) to air-stable n-type thermoelectric materials. When pristine SWCNTs were doped with 2 mg·mL-1 PEG in an ethanol solution, the optimal Seebeck coefficient of PEG/SWCNT composites reached -50.8 µV·K-1. The result of ultraviolet photoelectron spectroscopy demonstrated that the lone pair of oxygen atoms in the PEG chain has electron transferability to SWCNTs. According to the hard and soft acid and base theory, sodium hydroxide (NaOH) was further introduced to improve air stability and thermoelectric performance of doped SWCNTs. As a result, PEG/NaOH/SWCNT composites achieved the highest power factor of 173.8 µW·m-1·K-2 at 300 K. Meanwhile, their final changes in electrical conductivity and the Seebeck coefficient are less than 8% in the investigation of air stability over two months. Inspired by this finding, we fabricated the TE generator composed of the pristine p-type SWCNTs and n-type PEG/NaOH/SWCNT composites. The maximum output power of this robust TE device reached 5.3 µW at a temperature gradient of 76 K, which is superior to many reported TE devices. Moreover, the experimental procedure is attractive as a sustainable process for materials preparation. Our study has indicated that the oxygen-rich polymer-functionalized SWCNTs have huge potential for developing air-stable n-type carbon-based thermoelectric materials.

Development of hydrophilic PES membranes using F127 and HKUST-1 based on the RTIPS method: Mitigate the permeability-selectivity trade-off.

In this study, to mitigate the permeability-selectivity trade-off effect, Pluronic F127 (F127) and HKUST-1 were employed to construct high-performance membranes based on the reverse thermally induced phase separation (RTIPS) method. F127, as a hydrophilic modifier, was applied to increase permeability and resist polyethersulfone (PES) membrane fouling, while the collapse of HKSUT-1 caused by its instability in pure water improved the permeability and selectivity of the membrane. Characterizations demonstrated the successful synthesis of HKUST-1, together with the successful introduction of HKSUT-1 and F127 in PES membranes. It was observed that the membrane prepared by the RTIPS process possessed a uniformly porous surface and sponge-like cross-section with excellent mechanical properties, higher permeability, and selectivity compared to the dense skin and finger-like cross-section of the membrane prepared by the nonsolvent induced phase separation (NIPS) method. Moreover, the permeation and bovine serum albumin (BSA) rejection rate of the optimal membrane reached 2378 L/m2 h and 89.3%, respectively, which were far higher than those of the pure membrane. Hydrophilic F127 and many microvoids formed by the collapse of HKUST-1, played an important role in excellent antifouling properties, high permeability, and selectivity by pure water flux (PWF), flux recovery rate (FRR), BSA flux, and COD removal rate tests. Overall, the membrane with F127 and HKSUT-1 prepared via the RTIPS method not only obtained excellent antifouling properties but also mitigated the permeability-selectivity trade-off.

[Distribution Characteristics of Microplastics in Surface Water and Sediments of Haizhou Bay, Lianyungang].

In recent years, microplastics have emerged as a new marine pollutant and have attracted wide research attention. As the main activity areas of human beings in the coastal environment, gulfs have always been the hotspots of marine pollution. However, the distribution of microplastics in most small and medium-sized coastal environments has been rarely reported in China. To understand the characteristics of microplastic pollution in small and medium-sized inshore bays in China, the main types, abundance, and spatial distribution characteristics of microplastics in the surface water and sediments in Haizhou Bay of Jiangsu province were studied by qualitative and quantitative methods. The results showed that the abundances of microplastics in the surface water and sediments of Haizhou Bay were (2.60±1.40) n·m-3 and (0.33±0.26) n·g-1, respectively. In the domestic offshore environment, the abundance of microplastics was at a low level in the surface water, but at a high level in the sediments in Haizhou Bay (0.33-545.00 n·m-3 and 0.07-2.58 n·g-1, respectively). The range of size distribution of microplastics in water and sediments was 0.08-13.48 mm and 0.04-14.74 mm, respectively. More than 60% of the microplastics in water and sediments were small particles of sizes less than 2.00 mm. The shape of microplastics in Haizhou Bay was mainly fibrous, accounting for 92%. The main colors were blue and black, accounting for 70%. The materials were mainly man-made fibers and PET, accounting for 79.4%. There was a significant correlation between the distribution of microplastics in surface water and suspended matter concentration (P<0.05). The distribution of microplastics in sediments was affected by many factors, and its distribution pattern between the distribution of microplastics in surface water and the distribution of particle size in sediments was quite different. Through analysis of the morphological characteristics and composition of microplastics, the results showed that the microplastics in Haizhou Bay mainly come from mariculture and coastal land sources.

Significantly Reduced Thermal-Activation Energy for Hole Transport via Simple Donor Engineering: Understanding the Role of Molecular Parameters for Thermoelectric Behaviors.

Thermal activation energy for charge transfer (Eact,σ) plays a crucial role in determining the electrical properties of organic semiconductors, which are largely dominated by the Coulomb binding energy (Ecoul,ICTC) or static energy disorder (σICTC) of the formed integer charge transfer complexes at low or high doping concentration, respectively. Herein, we provide two typical donor-acceptor type polymers with distinct donors to disclose the role of molecular parameters in response for their corresponding thermoelectric (TE) behaviors. Noticeably, both the Ecoul,ICTC and σICTC of the polymers can be effectively restrained by varying the initial carbazole (CZ) donor to the dithieno[3,2-b:2',3'-d]pyrrole (DTP) moiety, which contributes to the remarkably decreased Eact,σ values of the PDTP-DPP than that of PCZ-DPP. Accordingly, the optimized power factors (PF) for PDTP-DPP (10.8 µW m-1 K-2) is almost 5 times higher than the primary PCZ-DPP (1.8 µW m-1 K-2) at ambient condition. In addition, a further improved PF over 85.5 µW m-1 K-2 can be achieved by PDTP-DPP at 488 K due to the synergy of thermal-induced dedoping and thermal-activated semiconducting behavior. Ultraviolet photoelectron and X-ray photoelectron spectroscopy measurements confirm the lower thermal activation energy for efficient p-doping of PDTP-DPP than that of PCZ-DPP.

Synthesis and Properties of Phosphoric-Acid-Doped Polybenzimidazole with Hyperbranched Cross-Linkers Decorated with Imidazolium Groups as High-Temperature Proton Exchange Membranes.

Highly phosphoric-acid (PA)-doped polybenzimidazole (PBI) membranes exhibit good proton conductivity at high temperatures; however, they suffer from reduced mechanical properties and loss of PA molecules due to the plasticity of PA and the weak interactions between PA and benzimidazoles, especially with the absorption of water. In this work, a series of PBIs with hyperbranched cross-linkers decorated with imidazolium groups (ImOPBI-x, where x is the weight ratio of the hyperbranched cross-linker) as high-temperature proton exchange membranes are designed and synthesized for the first time. We observe how the hyperbranched cross-linkers can endow the membranes with improved oxidative stability and acceptable mechanical performance, and imidazolium groups with strong basicity can stabilize the PA molecules by delocalization and hydrogen bond formation to endow the membranes with an enhanced proton conductivity and a decreased loss of PA molecules. We measured a high proton conductivity of the ImOPBI-x membranes, ranging from 0.058 to 0.089 S cm-1 at 160 °C. In addition, all the ImOPBI-x membranes displayed good mechanical and oxidative properties. At 160 °C, a fuel cell based on the ImOPBI-5 membrane showed a power density of 638 mW cm-2 and good durability under a hydrogen/oxygen atmosphere, indicating its promising use in anhydrous proton exchange membrane applications.

Effect of Chemical Structure and Degree of Branching on the Stability of Proton Exchange Membranes Based on Sulfonated Polynaphthylimides.

Hydrolytic stability and oxidative stability are the core properties of sulfonated polynaphthylimides (SPIs) as proton exchange membranes. The chemical structure of SPIs directly influences the performance. Herein, three different series of branched SPIs were designed and prepared using 1,3,5-tris (2-trifluoromethyl-4-aminophenoxy) benzene as a trifunctional monomer and three non-sulfonated diamine monomers, such as 4,4'-oxydianiline (ODA), 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane (6FODA), and 4,4'-(9-fluorenylidene)dianiline (BFDA). The effect of the chemical structure and degree of branching on SPIs properties is discussed. The results showed that by controlling the chemical structure and degree of branching, the chemical stability of SPIs changed significantly. SPI-6FODA with two ether linkages and a hydrophobic CF3 group has higher hydrolytic stability than SPI-ODA with only one ether linkage. In addition, with the increase of the introduced B3 monomer, the oxidation stability of SPI-6FODA has been greatly improved. We successfully synthesized SPIs with a high hydrolytic stability and oxidative stability.

Improving the quantum yields of fluorophores by inhibiting twisted intramolecular charge transfer using electron-withdrawing group-functionalized piperidine auxochromes.

Herein, we present that the negative inductive effect exerted by electron-withdrawing groups, such as sulfone groups, can obviously improve the ionization potential of amino auxochromes, thereby effectively inhibiting twisted intramolecular charge transfer (TICT) and markedly improving the quantum yields of several families of fluorophores in aqueous solution.