In printing applications, microparticles are commonly triboelectrically charged with larger carrier particles. Here, we develop an impaction-differential mobility analyzer-optical particle ...spectrometer (DMA-OPS) system to examine the size-dependent charge distributions of toner particles in the 0.3 – 10 μm range resulting from triboelectric charging via acrylic-coated ferrite carrier. The toner-carrier blend is aerosolized, and toner particles are released from the carrier via inertial impaction of toner-carrier complexes. The toner particles are then classified by electrical mobility and their optical diameters are determined. We can produce toner particle size-dependent charge distributions, which can be converted to surface potentials, and charge-to-mass ratios.
•A DMA and OPS are used to measure charge distributions of toner particles.•The toner particles are triboelectrically charged via a magnetic carrier.•Measurements yield size-resolved charge distributions for both polarities.
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•Carbon-coated ZnO NP can boost both triboelectric and piezoelectric effects of PVDF.•The β-phase of PVDF was greatly increased by adding ZnO@C.•ZnO@C negatively shifted the surface ...potential of PVDF to a high value of − 740 mV.•The ZnO@C/PVDF nanofiber-based flexible sensor shows high sensitivity of 0.98 V/kPa.
Piezoelectric and triboelectric effects are vital mechanisms in motion sensing. Improving both the piezoelectric performance and triboelectric effect for a single material is an important approach to further improve the sensitivity of the sensor. Herein, we achieve the enhancement of both effects in electrospun polyvinylidene fluoride (PVDF) nanofiber by simply adding carbon-coated zinc oxide (ZnO@C) nanoparticles as additive. We found that ZnO@C can not only increase the β-phase in PVDF, resulting in an enhanced piezoelectric coefficient. It also negatively shifted the surface potential of PVDF to a high value of −740 mV, thereby modifying the triboelectric effect. The fabricated ZnO@C/PVDF nanogenerator exhibits 4 times enhancement in the voltage output, thus resulting in high sensitivity of 0.98 V kPa−1 when used as wearable sensors. Due to the good mechanical properties of nanofibers, we also demonstrated the application of ZnO@C/PVDF nanogenerator as body motion sensor with excellent deformation stability. Therefore, adding carbon-coated piezoelectric nanoparticles provides an effective approach to simultaneously enhance the piezoelectric and triboelectric effects of ferroelectric polymer for highly sensitive wearable sensors.
In this work, we report on the structural and morphological modifications, and their subsequent influence on the optoelectronic properties of platinum modified ordered mesoporous platinum-doped ...Titania (Pt-OMT). We found that higher Pt contents (>1 %Pt) lead to the destruction of the ordered structure and thus exhibit complex electrical conductivity behavior, which is intrigued by the grain boundary approximation model. The comprehensive investigation of temperature dependent resistance measurements (R-T curves) indicates a robust response to various gas environments and strong relationship between resistance, temperature and intergranular potential barrier eVs. The samples showed low eVs values in without gas (eVs∼0.26–0.45 eV) and nitrogen environment (eVs∼0.30–0.45 eV), while higher (eVs∼0.33–0.57 eV) values in the oxygen environment. Interpreting the adsorption mechanism relies on the eVs values in the oxygen environment, as well as the optical band gap, resistance values, and structural changes. This exploration provides a basis that researchers can extend to other ordered mesoporous metal oxides, paving the way for enhanced gas sensors and beyond.
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The classification and utilization of coal macerals have become a vital focus for the advancement of the modern coal chemical industry and mineral processing. Flotation is a well-established ...technique for large-scale mineral separation, but as for maceral separation, it is often limited by a low recovery rate and poor selectivity. This study investigates the utilization of charged micro-nanobubble (CMNB) flotation to separate the vitrinite from a typical low-ash and inertinite-rich coal in Xinjiang. Results show that CMNB flotation demonstrated notable index advantages over conventional flotation. Optimal flotation was achieved by the CMNBs produced from a 0.75 mM sodium dodecyl sulfate (SDS) solution, with a yield, concentrate vitrinite content, and vitrinite recovery of 49.58 %, 74.31 %, and 77.28 %, respectively. It was revealed that the CMNBs not only promoted the aggregation of vitrinite particles but also increased the adhesion of vitrinite particles and their aggregates to conventional flotation bubbles, resulting in enhanced flotation performance.
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•Developed charged micro-nanobubble flotation-based separation of maceral.•Showed notable index advantages of CMNB flotation over conventional flotation.•Clarified mechanisms for charged micro-nanobubble enhancing maceral flotation.
The characterization of micro-surface mechanical and electrical properties of the natural rock materials remains inadequate, and their macroscopic performance can be better comprehended by ...investigating the surface properties. With this purpose, the present research focuses on characterizing the micro-surface morphology, Derjaguin-Muller-Toporov (DMT) modulus, adhesion, and potential of granite, shale, and limestone by employing the atomic force microscope (AFM) as a pioneer attempt. The results show that the micro-surface morphology of the rock fluctuates within hundreds of nanometers, among which the granite micro-surface is comparatively the smoothest, followed by limestone. The morphology of the shale is the roughest, indicating that the regional difference of shale micro-surface is dominant. The distribution of the adhesion on rock micro-surface is uneven; the average adhesion of eight measuring areas for shale is 23.93 nN, accounting for three times of granite and limestone, while the surface DMT modulus of shale is relatively lower than granite and limestone. It is inferred from the obtained results that higher surface adhesion is helpful to the gas adsorption of shale, and the lower surface DMT (elastic) modulus is useful to the formation of fractures and pores. Thus, these two are the micromechanical basis of shale gas adsorption. Additionally, introducing a method to reduce the surface adhesion will benefit the exploration of unconventional resources such as shale gas. The micro-surface of the three types of rocks all shows electricity, with average potential ranging from tens of millivolts to hundreds of millivolts. Besides, the micro-surface potential of the rocks are heterogeneous, and both positive and negative points can be found. The existence and uneven distribution of micro-surface potential provide a robust physical basis for the electromagnetic radiation generated by rock fracture under loading. This study offers a new method for revealing the adsorption characteristics of unconventional gas reservoir rocks and the electromagnetic radiation mechanism of the rock fracture.
Emotion is a complex physiological and psychological activity, accompanied by subjective physiological sensations and objective physiological changes. The body sensation map describes the changes in ...body sensation associated with emotion in a topographic manner, but it relies on subjective evaluations from participants. Physiological signals are a more reliable measure of emotion, but most research focuses on the central nervous system, neglecting the importance of the peripheral nervous system. In this study, a body surface potential mapping (BSPM) system was constructed, and an experiment was designed to induce emotions and obtain high-density body surface potential information under negative and non-negative emotions. Then, by constructing and analyzing the functional connectivity network of BSPs, the high-density electrophysiological characteristics are obtained and visualized as bodily emotion maps. The results showed that the functional connectivity network of BSPs under negative emotions had denser connections, and emotion maps based on local clustering coefficient (LCC) are consistent with BSMs under negative emotions. in addition, our features can classify negative and non-negative emotions with the highest classification accuracy of 80.77%. In conclusion, this study constructs an emotion map based on high-density BSPs, which offers a novel approach to psychophysiological computing.
A challenge of pulmonary vein isolation (PVI) in catheter ablation for paroxysmal atrial fibrillation (PAF) is electrical reconnection of the PV. EFFICAS I showed correlation between contact force ...(CF) parameters and PV durable isolation but no prospective evaluation was made. EFFICAS II was a multicentre study to prospectively assess the impact of CF guidance for an effective reduction of PVI gaps.
Pulmonary vein isolation using a radiofrequency (RF) ablation catheter with an integrated force sensor (TactiCath™) was performed in patients with PAF. Operators were provided EFFICAS I-based CF guidelines target 20 g, range 10-30 g, minimum 400 g s force-time integral (FTI). Conduction gaps were assessed by remapping of PVs after 3 months, and gap rate was compared with EFFICAS I outcome. At follow up, 24 patients had 85% of PVs remaining isolated, compared with 72% in EFFICAS I (P = 0.037) in which CF guidelines were not used. The remaining 15% of gaps correlated to the number of catheter moves at creating the PVI line, quantified as Continuity Index. For PV lines with contiguous lesions and low catheter moves, durable isolation was 81% in EFFICAS I and 98% in EFFICAS II (P = 0.005). At index procedure, the number of lesions was reduced by 15% in EFFICAS II vs. EFFICAS I.
The use of CF with the above guidelines and contiguous deployment of RF lesions in EFFICAS II study resulted in more durable PVI in catheter ablation of PAF.
Tricyclic medicine such as amitriptyline (AMT) hydrochloride, initially developed to treat depression, is also used to treat neuropathic pain, anxiety disorder, and migraines. The mechanism of ...functioning of this type of drugs is ambiguous. Understanding the mechanism is important for designing new drug molecules with higher pharmacological efficiency. Hence, in the present study, biophysical approaches have been taken to shed light on their interactions with a model cellular membrane of brain sphingomyelin in the form of monolayer and multi-lamellar vesicles. The surface pressure-area isotherm infers the partitioning of a drug molecule into the lipid monolayer at the air water interface, providing a higher surface area per molecule and reducing the in-plane elasticity. Further, the surface electrostatic potential of the lipid monolayer is found to increase due to the insertion of drug molecule. The interfacial rheology revealed a reduction of the in-plane viscoelasticity of the lipid film, which, depends on the adsorption of the drug molecule onto the film. Small-angle X-ray scattering (SAXS) measurements on multilamellar vesicles (MLVs) have revealed that the AMT molecules partition into the hydrophobic core of the lipid membrane, modifying the organization of lipids in the membrane. The modified physical state of less rigid membrane and the transformed electrostatics of the membrane could influence its interaction with synaptic vesicles and neurotransmitters making higher availability of the neurotransmitters in the synaptic cleft.
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•Understanding interaction of tricyclic drug with membrane helps developing new drug•Amitriptyline provides high area to lipid to reduce compressional modulus of membrane•Amitriptyline has positively charged surface, hence modifies membrane electrostatics•Amitriptyline helps fusion of synaptic vesicle by reducing bulk modulus of membrane•Amitriptyline helps repelling neurotransmitters to make available in synaptic cleft
Airborne particulate matter (PM) pollution has become a severe environmental concern calling for electret fibrous materials with high filtration efficiency and low pressure drop. However, restraining ...the dissipation of the electric charges in service to ensure the stabilized electrostatic force of the fibers for effectively adsorbing particles is extremely important and also challenging. Herein, we report novel electret nanofibrous membranes with numerous charges and desirable charge stability using polyvinylidene fluoride (PVDF) as the matrix polymer and polytetrafluoroethylene nanoparticles (PTFE NPs) as an inspiring charge enhancer through the in situ charging technology of electrospinning. Benefiting from the employment of PTFE NPs and optimized injection energy, the fibrous membranes are endowed with elevated surface potentials from 0.42 to 3.63 kV and reduced decrement of charges from 75.4 to 17.5%, which contribute to the ameliorative stability of filtration efficiency. Significantly, an electret mechanism is proposed, while deepened depth of the energy level and incremental polarized dipole charges with increasing PTFE NP concentrations and injection energy have been confirmed through the measurement of open-circuit thermally stimulated discharge and surface potential decay. Ultimately, the resultant fibrous membrane exhibited a high filtration efficiency of 99.972%, a low pressure drop of 57 Pa, a satisfactory quality factor of 0.14 Pa–1, and superior long-term service performance. The successful fabrication of such an intriguing material may provide a new approach for the design and development of electret materials for PM2.5 governance.
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