Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 66
Filtrar
1.
Int J Biol Macromol ; : 133493, 2024 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-38960230

RESUMEN

Cotton has attracted considerable attention due to its functional characteristics. The focus of research on cotton has shifted in recent years towards designing multi-functional and modified media for cotton fibers, which can be firmly combined with textiles, giving them reusability and extending their service life. This study constructed a synergistic antibacterial layer of quaternary ammonium compounds (QACs) and N-halamine (Hals) using an in-situ free radical copolymerization method in water, named QACs/Hals@cotton-Cl. The route significantly increases the number of antibacterial active centers. FTIR, XPS, and SEM were used to systematically analyze the product's chemical structure, surface morphology, and other characteristics. The modified fabric's antibacterial efficiency, wound healing, renewability, and durability were also evaluated. The chlorinated modified cotton fabric could completely eradicate S. aureus and E. coli within 10 min. Compared with pure cotton, it notably promoted the healing rate of infected wounds in mice. The modification method imparted excellent hydrophobicity to the cotton fabric, with a contact angle exceeding 130°, making it easy to remove surface stains. After 30 days of regular storage and 24 h of UV irradiation, the active chlorine concentration (Cl+%) only decreased by 25 % and 39 %, respectively, and the reduced Cl+% was effectively recharged via simple re-chlorination. The hydrophobicity and antimicrobial properties of QACs/Hals@cotton-Cl remained stable even after 20 cycles of friction. This simple synthesis technique provides a convenient approach for the scalable fabrication of multifunctional and rechargeable antibacterial textiles, with potential applications in medical devices and personal hygiene protection.

2.
Clin Rheumatol ; 2024 Jul 04.
Artículo en Inglés | MEDLINE | ID: mdl-38963465

RESUMEN

Systemic lupus erythematosus (SLE) is a common autoimmune disease with a polymorphic clinical presentation involving multisystem damages with significant differences in prevalence and disease severity among different ethnic groups. Although genetic, hormonal, and environmental factors have been demonstrated to contribute a lot to SLE, the pathogenesis of SLE is still unknown. Numerous evidence revealed that gene variants within the type I interferons (IFN) signaling pathway performed the great genetic associations with autoimmune diseases including SLE. To date, through genome-wide association studies (GWAS), genetic association studies showed that more than 100 susceptibility genes have been linked to the pathogenesis of SLE, among which TYK2, STAT1, STAT4, and IRF5 are important molecules directly connected to the type I interferon signaling system. The review summarized the genetic associations and the detailed risk loci of STAT4 and IRF5 with Asian SLE patients, explored the genotype distributions associated with the main clinical manifestations of SLE, and sorted out the potential reasons for the differences in susceptibility in Asia and Europe. Moreover, the therapies targeting STAT4 and IRF5 were also evaluated in order to propose more personalized and targeted treatment plans in SLE.

3.
RSC Adv ; 14(26): 18519-18527, 2024 Jun 06.
Artículo en Inglés | MEDLINE | ID: mdl-38860246

RESUMEN

The traditional pyridine nitrogen oxide-based antimicrobial agents are often associated with health risks due to heavy metal enrichment. To mitigate this concern, we synthesized two novel complexes, Pr2(mpo)6(H2O)2 and Pr(hpo)(mpo)2(H2O)2, and integrated rare-earth salts, Hhpo (2-hydroxypyridine-N-oxide) and Nampo (2-mercapto-pyridine-N-oxide sodium salt). These complexes were characterized through infrared analysis, elemental analysis, thermogravimetric analysis, and X-ray crystallographic analysis. Our comparative analyses demonstrate that the synthesized rare-earth complexes exhibit stronger antimicrobial activity against Staphylococcus aureus (S. aureus ATCC6538) and Escherichia coli (E. coli ATCC25922) compared to the ligands and rare-earth salts alone. Quantitative results revealed the lowest inhibitory concentrations of the two complexes against S. aureus ATCC6538 and E. coli ATCC25922 at 3.125 µg mL-1, 6.25 µg mL-1, 3.125 µg mL-1 and 6.25 µg mL-1, respectively. Preliminary investigations indicated that the antibacterial mechanism of these complexes involved promoting intracellular substance exudation to achieve antibacterial effects. Incorporation of these complexes into polymeric antimicrobial films resulted in a potent antimicrobial effect, achieving a 100% inhibition rate against S. aureus ATCC6538 and E. coli ATCC25922 at a low addition level of 0.6 wt%. Our results suggest that nitrogen oxide-based praseodymium complexes have potential for various antimicrobial applications.

4.
Int J Biol Macromol ; 271(Pt 2): 132529, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38777010

RESUMEN

The poor UV shielding property of PLA limit it further applications on food packaging. The rare-earth complex Eu(DBM)3phen converts absorbed ultraviolet (UV) light to red light, which inspires the development of new UV shielding materials. However, this complex has low photostability and decomposes easily under UV irradiation. Thus, we prepared a long-lasting rare-earth complex transluminant Eu(DBM)2(BP-2)phen by introducing BP-2 into Eu(DBM)3phen, and blended it with PLA to obtain PLA/Eu(DBM)2(BP-2)phen composite films. The test results showed that the complex could reduce the UV transmittance of PLA films by emitting luminescence and heat. The UV transmittance of the composite film with 0.5 % mass fraction decreased from 87.4 % to 7.7 %, compared to pure PLA films, and remained at 11.6 % after 12 days of UV aging. The film had long-lasting UV shielding performance, good transparency and mechanical properties. Finally, In the storage experiments of flaxseed oil, the P/E25 film effectively retarded the oxidation process of the oil.


Asunto(s)
Europio , Embalaje de Alimentos , Poliésteres , Rayos Ultravioleta , Poliésteres/química , Europio/química , Embalaje de Alimentos/métodos , Aceite de Linaza/química
5.
Int J Biol Macromol ; 271(Pt 1): 132636, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38795567

RESUMEN

The synthesis and characterization of [Ce2(PPPA)4(OH)2]·4H2O, wherein PPPA denotes 3-(hydroxy(phenyl)phosphoryl)propanoate, were conducted. Its potential as a flame-retardant additive for poly(L-lactic acid) (PLA) in conjunction with ammonium polyphosphate (APP) was investigated. Remarkably, with just incorporation of the 1 % Ce-complex and 4 % APP, the resulting PLA composite (PLA-8) meets the V-0 standard, exhibiting an impressive limiting oxygen index (LOI) of 29.4 %. Moreover, the introduction of the Ce-complex leads to a significant extension of ignition time (TTI), a significant 24.1 % decrease in total heat release (THR) compared to pure PLA, and a notable increase in residual carbon rate from 0.3 % to 3.51 %. Although PLA-8 exhibits a minor decline of 8.7 % in tensile strength and 3.4 % in elongation at break, respectively, compared to pure PLA, there is a substantial improvement of 32.2 % in Young's modulus and 29.9 % in impact resistance. These results emphasise the potential of cerium-based phosphorus-containing flame retardants, with cerium playing a key role in enhancing the flammability characteristics of PLA. This study contributes to the development of sustainable and fire-resistant materials in polymer chemistry.


Asunto(s)
Cerio , Retardadores de Llama , Fósforo , Poliésteres , Retardadores de Llama/síntesis química , Poliésteres/química , Poliésteres/síntesis química , Cerio/química , Fósforo/química , Resistencia a la Tracción , Polifosfatos/química
6.
Adv Mater ; 36(26): e2313612, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38574762

RESUMEN

Continuous monitoring of blood pressure (BP) and multiparametric analysis of cardiac functions are crucial for the early diagnosis and therapy of cardiovascular diseases. However, existing monitoring approaches often suffer from bulky and intrusive apparatus, cumbersome testing procedures, and challenging data processing, hampering their applications in continuous monitoring. Here, a heterogeneously hierarchical piezoelectric composite is introduced for wearable continuous BP and cardiac function monitoring, overcoming the rigidity of ceramic and the insensitivity of polymer. By optimizing the hierarchical structure and components of the composite, the developed piezoelectric sensor delivers impressive performances, ensuring continuous and accurate monitoring of BP at Grade A level. Furthermore, the hemodynamic parameters are extracted from the detected signals, such as local pulse wave velocity, cardiac output, and stroke volume, all of which are in alignment with clinical results. Finally, the all-day tracking of cardiac function parameters validates the reliability and stability of the developed sensor, highlighting its potential for personalized healthcare systems, particularly in early diagnosis and timely intervention of cardiovascular disease.


Asunto(s)
Dispositivos Electrónicos Vestibles , Humanos , Monitoreo Fisiológico/instrumentación , Monitoreo Fisiológico/métodos , Presión Sanguínea , Análisis de la Onda del Pulso/instrumentación , Enfermedades Cardiovasculares/diagnóstico , Hemodinámica
7.
ACS Nano ; 18(17): 11183-11192, 2024 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-38630641

RESUMEN

E-skins, capable of responding to mechanical stimuli, hold significant potential in the field of robot haptics. However, it is a challenge to obtain e-skins with both high sensitivity and mechanical stability. Here, we present a bioinspired piezoresistive sensor with hierarchical structures based on polyaniline/polystyrene core-shell nanoparticles polymerized on air-laid paper. The combination of laser-etched reusable templates and sensitive materials that can be rapidly synthesized enables large-scale production. Benefiting from the substantially enlarged deformation of the hierarchical structure, the developed piezoresistive electronics exhibit a decent sensitivity of 21.67 kPa-1 and a subtle detection limit of 3.4 Pa. Moreover, an isolation layer is introduced to enhance the interface stability of the e-skin, with a fracture limit of 66.34 N/m. Furthermore, the e-skin can be seamlessly integrated onto gloves without any detachment issues. With the assistance of deep learning, it achieves a 98% accuracy rate in object recognition. We anticipate that this strategy will render e-skin with more robust interfaces and heightened sensing capabilities, offering a favorable pathway for large-scale production.

8.
Molecules ; 29(6)2024 Mar 12.
Artículo en Inglés | MEDLINE | ID: mdl-38542890

RESUMEN

An unparalleled copper(I)-catalyzed synthesis of 1,3,4-oxadiazoles from tertiary amines in one step has been described. The one-pot reactions involving (N-isocyanimine)triphenylphosphorane, tertiary amines, and carboxylic acids resulted in the formation of 1,3,4-oxadiazoles in moderate to good yields through a consecutive oxidative Ugi/aza-Wittig reaction, enabling the direct functionalization of sp3 C-H bonds adjacent to the nitrogen atom. This method offered several notable advantages, including ligands-free, exceptional productivity and a high functional group tolerance. The preliminary biological evaluation demonstrated that compound 4f inhibited hepatoma cells efficiently, suggesting potentially broad applications of the approach for synthesis and medicinal chemistry.


Asunto(s)
Cobre , Compuestos Organofosforados , Oxadiazoles , Cobre/química , Oxadiazoles/química , Aminas/química , Catálisis , Estrés Oxidativo
9.
J Ginseng Res ; 48(2): 190-201, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38465215

RESUMEN

Background: Deposition of immune complexes drives podocyte injury acting in the initial phase of lupus nephritis (LN), a process mediated by B cell involvement. Accordingly, targeting B cell subsets represents a potential therapeutic approach for LN. Ginsenoside compound K (CK), a bioavailable component of ginseng, possesses nephritis benefits in lupus-prone mice; however, the underlying mechanisms involving B cell subpopulations remain elusive. Methods: Female MRL/lpr mice were administered CK (40 mg/kg) intragastrically for 10 weeks, followed by measurements of anti-dsDNA antibodies, inflammatory chemokines, and metabolite profiles on renal samples. Podocyte function and ultrastructure were detected. Publicly available single-cell RNA sequencing data and flow cytometry analysis were employed to investigate B cell subpopulations. Metabolomics analysis was adopted. SIRT1 and AMPK expression were analyzed by immunoblotting and immunofluorescence assays. Results: CK reduced proteinuria and protected podocyte ultrastructure in MRL/lpr mice by suppressing circulating anti-dsDNA antibodies and mitigating systemic inflammation. It activated B cell-specific SIRT1 and AMPK with Rhamnose accumulation, hindering the conversion of renal B cells into plasma cells. This cascade facilitated the resolution of local renal inflammation. CK facilitated the clearance of deposited immune complexes, thus reinstating podocyte morphology and mobility by normalizing the expression of nephrin and SYNPO. Conclusions: Our study reveals the synergistic interplay between SIRT1 and AMPK, orchestrating the restoration of renal B cell subsets. This process effectively mitigates immune complex deposition and preserves podocyte function. Accordingly, CK emerges as a promising therapeutic agent, potentially alleviating the hyperactivity of renal B cell subsets during LN.

10.
ACS Appl Bio Mater ; 7(1): 104-113, 2024 01 15.
Artículo en Inglés | MEDLINE | ID: mdl-38149377

RESUMEN

The pursuit of environmentally friendly and highly effective antifouling materials for marine applications is of paramount importance. In this study, we successfully synthesized novel rare earth-based complexes by coordinating cerium (Ce III), samarium (Sm III), and europium (Eu III) with pyrithione (1-hydroxy-2-pyridinethione; PT). Extensive characterizations were performed, including single-crystal X-ray analysis, which revealed the intriguing binuclear structure of these complexes. This structural motif comprises two rare-earth ions intricately double-bridged by two oxygen atoms from the PT ligand, resulting in a distinctive and intriguing geometry. Furthermore, the central rare earth ion is surrounded by three sulfur atoms and two additional oxygen atoms, forming a unique distorted bicapped trigonal prismatic configuration. Compared with conventional antifouling biocides such as sodium pyrithione (NaPT), copper pyrithione (CuPT), and zinc pyrithione (ZnPT), these newly synthesized rare-earth complexes exhibited a remarkable boost in their in vitro antibacterial efficacy against both Gram-positive and Gram-negative bacteria. Additionally, these complexes demonstrated significant potential as antialgal agents, displaying impressive activity against marine planktonic organisms. These findings underscore the promising application prospects of these rare-earth complexes in the field of marine antifouling.


Asunto(s)
Antibacterianos , Bacterias Gramnegativas , Piridinas , Tionas , Antibacterianos/farmacología , Bacterias Grampositivas , Oxígeno
11.
Heliyon ; 9(12): e23093, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-38144284

RESUMEN

The volume fraction and rafting degree of the γ'-Ni3Al phase under stress and high temperature are the key characteristics of mechanical properties in Ni-based superalloys, the rafting and redissolution of γ' phase caused by the creep at high temperature damage the morphology and properties of Ni-based superalloys. The phase-field simulation is performed to study the rafting accompany with the redissolution of γ' phase under high temperature and loading stress in Ni-Al alloy, the driving force and kinetics evolution of the γ' rafting were revealed. During the rafting under continuous heating, the elastic energy in the vertical γ channel is different to that of the horizontal γ channel, this difference in elastic energy drives the elements diffusion directionally to form the γ' rafts morphology. With the increased tensile stress, the decrease of specific surface of the γ' phase slows down the redissolution, a higher volume fraction is reserved for the rafted γ' phase. With temperature increases, the interface of γ/γ' phase becomes more diffusional and wider under stress. The results give an insight on the rafting mechanism of γ' phase and the kinetics evolution in Ni-based superalloys under excess temperature.

12.
Int J Biol Macromol ; 253(Pt 7): 127291, 2023 Dec 31.
Artículo en Inglés | MEDLINE | ID: mdl-37806420

RESUMEN

Resolving the flammability of poly(L-lactic acid) (PLA) while ensuring its environmental friendliness and preserving key flame retardancy and mechanical properties represents a critical challenge. We have successfully developed a highly efficient and environmentally friendly flame retardant called Hexamethylenediamine tetramethylene phosphonic acid amine (HDME). The flame retardancy of PLA/HDME composites was significantly improved, as indicated by the LOI value of 29.1 % and UL-94 V-0 rating for PLA/3.5 HDME with only 3.5 % HDME addition. The results show a 23.4 % reduction in the total heat release (THR), a 40.0 % increase in the time to ignition (TTI), and a 21.2 % increase in the flame propagation index (FPI) compared to original PLA. Flame retardant mechanism of HDME involves the gas phase, condensed phase, and interrupted heat exchange effects. The HDME also preserved the original mechanical properties of PLA, with the elongation at break and tensile strength retention of PLA/3.5 HDME reaching 93.05 % and 89.65 %. This work provides a simple and efficient method for flame retardant modification of PLA, which can expand its application scope.


Asunto(s)
Ciclobutanos , Retardadores de Llama , Poliésteres , Aminas
13.
Mater Horiz ; 10(11): 5045-5052, 2023 Oct 30.
Artículo en Inglés | MEDLINE | ID: mdl-37655796

RESUMEN

Advanced flexible electronic devices make urgent demand for wearing comfort and data accuracy. Piezoelectric composites exhibit great potential, but mutually constrained mechanical strength and electrical output limit their further applications. Here, we design a gradient PMN-PT/PVDF nanocomposite via a non-equilibrium process integrated with a modified electrospinning and hot-pressing process to modulate the piezoelectric output and mechanical strength. The enhanced piezoelectric output together with the mechanical strength of the gradient structure are verified from both the experimental and simulation results. Ascribed to a unique three-dimensional gradient distribution, the prepared PMN-PT/PVDF nanocomposite exhibits an excellent mechanical strength (830 MPa) and piezoelectric performance (1.08 V), which are substantially higher than those of a randomly dispersed nanocomposite. The enhancement mechanism is revealed in terms of polarization, stress and crystallinity. These results of the gradient structure offer new opportunities to understand the structure-related mechanical and electrical behaviors of a nanocomposite, and support the design of a nanocomposite with overall performance.

14.
Environ Pollut ; 336: 122507, 2023 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-37673318

RESUMEN

Lake microbiomes are essential indicators of lake health and are strongly influenced by allochthonous microbial communities from various sources within the watershed. However, quantifying the contributions of multiple inputs to lake microbiomes is challenging because of the complex nature of river‒lake systems and the presence of many untraceable sources. Here, Jianhu Lake‒‒a geographically simple and closed plateau lake in southwestern China, was surveyed to disentangle the contributions of five distinct sources (three input rivers that receive town sewage, stormwater runoff, and creek spring water, as well as two nonpoint sources, duck ponds and dry farmland) to the overall lake microbiomes. We found that feces-loading sources, namely town sewage and duck aquaculture, accounted for 48.7% of the total variations in lake microbiomes. In contrast, the combined contribution of the remaining three sources amounted to 13.21%, despite these less-influential sources (e.g., stormwater runoff) may introduce an even larger volume of allochthonous materials into the lake. In addition, approximately 38.1% of the variations in the lake microbiomes were attributed to unknown sources. Sewage effluents also caused a significant loss of lake microbial diversity, and there was a tendency for large-scale microbial homogeneity in lake sediments that resembled those from duck ponds. We then used a targeted approach to track host-specific fecal pollution, and found that human feces were the primary source, followed by ruminant and chicken/duck feces, all of which can be successfully traced back to the feces-loading sources. In our further modelling of sediment transport from three rivers into the whole lake, we observed a significant relationship between sediment accumulation and adsorbed microorganisms only for the sewage-receiving river. Together, lines of evidence indicate that both point and nonpoint fecal-related anthropogenic sources possess discriminatory power for shaping microbial geographic patterns of the lake, posing threats to the survival of local indigenous lake microbiomes.

15.
PeerJ Comput Sci ; 9: e1386, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37346543

RESUMEN

The goal of local community detection algorithms is to explore the optimal community with a reference to a given node. Such algorithms typically include two primary processes: seed selection and community expansion. This study develops and tests a novel local community detection algorithm called OIRLCD that is based on the optimization of interaction relationships between nodes and the community. First, we introduce an improved seed selection method to solve the seed deviation problem. Second, this study uses a series of similarity indices to measure the interaction relationship between nodes and community. Third, this study uses a series of algorithms based on different similarity indices, and designs experiments to reveal the role of the similarity index in algorithms based on relationship optimization. The proposed algorithm was compared with five existing local community algorithms in both real-world networks and artificial networks. Experimental results show that the optimization of interaction relationship algorithms based on node similarity can detect communities accurately and efficiently. In addition, a good similarity index can highlight the advantages of the proposed algorithm based on interaction optimization.

16.
Front Aging Neurosci ; 15: 1109914, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37009459

RESUMEN

Background: Previous studies reported inconsistent results regarding association between diabetes mellitus (DM), prediabetes and risk, disease progression of Parkinson's disease (PD). The meta-analysis was made to investigate association between DM, prediabetes and risk, disease progression of PD. Methods: Literatures investigating association between DM, prediabetes and risk, disease progression of PD were searched in these databases: PubMed and Web of Science. Included literatures were published before October 2022. STATA 12.0 software was used to compute odds ratios (ORs)/relative risks (RRs) or standard mean differences (SMDs). Results: DM was associated with a higher risk of PD, compared to non-diabetic participants with a random effects model (OR/RR = 1.23, 95% CI 1.12-1.35, I 2 = 90.4%, p < 0.001). PD with DM (PD-DM) was associated with a faster motor progression compared to PD without DM (PD-noDM) with a fixed effects model (RR = 1.85, 95% CI 1.47-2.34, I 2 = 47.3%, p = 0.091). However, meta-analysis for comparison in change rate of United Rating Scale (UPDRS) III scores from baseline to follow-up time between PD-DM and PD-noDM reported no difference in motor progression between PD-DM and PD-noDM with a random effects model (SMD = 2.58, 95% CI = -3.11 to 8.27, I 2 = 99.9%, p < 0.001). PD-DM was associated with a faster cognitive decline compared to PD-noDM with a fixed effects model (OR/RR = 1.92, 95% CI 1.45-2.55, I 2 = 50.3%, p = 0.110). Conclusions: In conclusion, DM was associated with a higher risk and faster disease decline of PD. More large-scale cohort studies should be adopted to evaluate the association between DM, prediabetes and PD.

17.
ACS Appl Mater Interfaces ; 15(9): 12146-12153, 2023 Mar 08.
Artículo en Inglés | MEDLINE | ID: mdl-36811621

RESUMEN

As an important part of human-machine interfaces, piezoelectric voice recognition has received extensive attention due to its unique self-powered nature. However, conventional voice recognition devices exhibit a limited response frequency band due to the intrinsic hardness and brittleness of piezoelectric ceramics or the flexibility of piezoelectric fibers. Here, we propose a cochlear-inspired multichannel piezoelectric acoustic sensor (MAS) based on gradient PVDF piezoelectric nanofibers for broadband voice recognition by a programmable electrospinning technique. Compared with the common electrospun PVDF membrane-based acoustic sensor, the developed MAS demonstrates the greatly 300%-broadened frequency band and the substantially 334.6%-enhanced piezoelectric output. More importantly, this MAS can serve as a high-fidelity auditory platform for music recording and human voice recognition, in which the classification accuracy rate can reach up to 100% in coordination with deep learning. The programmable bionic gradient piezoelectric nanofiber may provide a universal strategy for the development of intelligent bioelectronics.

18.
J Funct Biomater ; 14(1)2023 Jan 08.
Artículo en Inglés | MEDLINE | ID: mdl-36662084

RESUMEN

Piezoelectric wearable electronics, which can sense external pressure, have attracted widespread attention. However, the enhancement of electromechanical coupling performance remains a great challenge. Here, a new solid solution of Ba1-xSrxSn0.09Ti0.91O3 (x = 0.00~0.08) is prepared to explore potential high-performance, lead-free piezoelectric ceramics. The coexistence of the rhombohedral phase, orthorhombic phase and tetragonal phase is determined in a ceramic with x = 0.06, showing enhanced electrical performance with a piezoelectric coefficient of d33~650 pC/N. Furthermore, Ba0.94Sr0.06Sn0.09Ti0.91O3 (BSST) is co-blended with PDMS to prepare flexible piezoelectric nanogenerators (PENGs) and their performance is explored. The effects of inorganic particle concentration and distribution on the piezoelectric output of the composite are systematically analyzed by experimental tests and computational simulations. As a result, the optimal VOC and ISC of the PENG (40 wt%) can reach 3.05 V and 44.5 nA, respectively, at 138.89 kPa, and the optimal sensitivity of the device is up to 21.09 mV/kPa. Due to the flexibility of the device, the prepared PENG can be attached to the surface of human skin as a sensor to monitor vital movements of the neck, fingers, elbows, spine, knees and feet of people, thus warning of dangerous behavior or incorrect posture and providing support for sports rehabilitation.

19.
Small ; 19(16): e2207947, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-36651008

RESUMEN

The interfacial effect is widely used to optimize the properties of ferroelectric nanocomposites, however, there is still a lack of direct evidence to understand its underlying mechanisms limited by the nano size and complex structures. Here, taking piezoelectricity, for example, the mechanism of interfacial polarization in barium titanate/poly(vinylidene fluoride-ran-trifluoroethylene) (BTO/P(VDF-TrFE)) nanocomposite is revealed at multiple scales by combining Kelvin probe force microscope (KPFM) with theoretical stimulation. The results prove that the mismatch of permittivity between matrix and filler leads to the accumulation of charges, which in turn induces local polarization in the interfacial region, and thus can promote piezoelectricity independently. Furthermore, the strategy of interfacial polarization to enhance piezoelectricity is extended and validated in other two similar nanocomposites. This work uncovers the mechanism of interfacial polarization and paves newfangled insights to boost performances in ferroelectric nanocomposites.

20.
J Colloid Interface Sci ; 629(Pt A): 534-540, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-36088698

RESUMEN

Piezoelectric semiconductor zinc oxide (ZnO) shows promising applications in many fields, however, its excellent piezoelectric performance is limited by the intrinsic screening effect. Forming p-n junction through interface engineering is an effective strategy to enhance its piezoelectric output, but the unclear regulation mechanism is a bottleneck in developing high-performance devices. In this work, the enhancement mechanism of interface engineering on the piezoelectric performance of ZnO nanorods (NRs) based devices is revealed from the perspective of carrier concentration. Both the theoretical and experimental results show that the piezoelectric output is significantly correlated with the carrier concentration, which is mainly attributed to the suppression of screening effect and the modulation of the device capacitance. After a reasonable matching design of carrier concentration, the piezoelectric potential of the ZnO NRs-based device is greatly enhanced by about 12 times. Apparently, these findings provide a fresh insight to further understand the enhancement mechanism of interface engineering on the electrical output of piezoelectric semiconductor devices, and provide effective support for the design of p-n junction piezoelectric devices.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA