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1.
J Colloid Interface Sci ; 671: 134-144, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-38795534

RESUMO

The photocatalytic H2 production activity of polymer carbon nitride (g-C3N4) is limited by the rapid recombination of photoelectron-hole pairs and slow surface reduction dynamic process. Here, a supramolecular complex (named R-TAP-Pd(II)) was fabricated via self-assembly of (R)-N-(1-phenylethyl)-4-(4-(pyridin-2-yl)-1H-1,2,3-triazol-1-yl)benzamide (R-TAP) with Pd(II) and used to modify g-C3N4. In the R-TAP-Pd(II)@g-C3N4 composite photocatalyst, the spin polarization of R-TAP-Pd(II) can promote charge transfer and inhibit photogenerated carrier recombination, as confirmed by spectral tests and photoelectrochemical performance tests. Electrochemical tests and in situ X-ray photoelectron spectroscopy (XPS) tests proved that the Pd(II) ion in the R-TAP-Pd(II) molecule can serve as active sites to accelerate H2 production. The R-TAP-Pd(II)@g-C3N4 presented a photocatalytic H2 generation rate of 1085 µmol g-1 h-1 when exposed to visible light, which was a about 278-fold increase compared with g-C3N4. This work finds a new approach to boost the photocatalytic efficiency of g-C3N4 via supramolecular self-assembly.

2.
Adv Mater ; 36(24): e2313513, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38461147

RESUMO

The development of high-density and closely spaced frustrated Lewis pairs (FLPs) is crucial for enhancing catalyst activity and accelerating reaction rates. However, constructing efficient FLPs by breaking classical Lewis bonds poses a significant challenge. Here, this work has made a pivotal discovery regarding the Jahn-Teller effect during the formation of grain boundaries in carbon-encapsulated Ni/NiOx (Ni/NiOx@C). This effect facilitates the formation of high-density O (VO) and Ni (VNi) vacancy sites with different charge polarities, specifically FLP-VO-C basic sites and FLP-VNi-C acidic sites. The synergistic interaction between FLP-VO-C and FLP-VNi-C sites not only reduces energy barriers for water adsorption and splitting, but also induces a strong photothermal effect. This mutually reinforcing effect contributes to the exceptional performance of Ni/NiOx@C as a cocatalyst in photothermal-assisted photocatalytic hydrogen production. Notably, the Ni/NiOx@C/g-C3N4 (NOCC) composite photocatalyst exhibits remarkable hydrogen production activity with a rate of 10.7 mmol g-1 h-1, surpassing that of the Pt cocatalyst by 1.76 times. Moreover, the NOCC achieves an impressive apparent quantum yield of 40.78% at a wavelength of 380 nm. This work paves the way for designing novel defect-state multiphase cocatalysts with high-density and adjacent FLP sites, which hold promise for enhancing various catalytic reactions.

3.
Angew Chem Int Ed Engl ; 63(22): e202403022, 2024 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-38485698

RESUMO

Integrating solar energy into rechargeable battery systems represents a significant advancement towards sustainable energy storage solutions. Herein, we propose a win-win solution to reduce the shuttle effect of polysulfide and improve the photocorrosion stability of CdS, thereby enhancing the energy conversion efficiency of rGO/CdS-based photorechargeable integrated lithium-sulfur batteries (PRLSBs). Experimental results show that CdS can effectively anchor polysulfide under sunlight irradiation for 20 minutes. Under a high current density (1 C), the discharge-specific capacity of the PRLSBs increased to 971.30 mAh g-1, which is 113.3 % enhancement compared to that of under dark condition (857.49 mAh g-1). Remarkably, without an electrical power supply, the PRLSBs can maintain a 21 hours discharge process following merely 1.5 hours of light irradiation, achieving a breakthrough solar-to-electrical energy conversion efficiency of up to 5.04 %. Ex situ X-ray photoelectron spectroscopy (XPS) and in situ Raman analysis corroborate the effectiveness of this complementary weakness approach in bolstering redox kinetics and curtailing polysulfide dissolution in PRLSBs. This work showcases a feasible strategy to develop PRLSBs with potential dual-functional metal sulfide photoelectrodes, which will be of great interest in future-oriented off-grid photocell systems.

4.
J Mater Chem B ; 12(2): 508-524, 2024 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-38108579

RESUMO

Poly(lactide-co-glycolide) (PLGA) and calcium sulfate composites are promising biodegradable biomaterials but are still challenging to use in people with high levels of blood glucose or diabetes. To date, the influence of glucose on their degradation has not yet been elucidated and thus calls for more research attention. Herein, a novel calcium sulfate whisker with L-arginine was used to effectively tune its crystal morphology and was employed as a reinforced phase to construct the PLGA-based composite scaffolds (ArgCSH/PLGA) with a sleeve porous structure. ArgCSH/PLGA showed excellent elastic modulus and strength in the compression and bending models. Moreover, an in vitro immersion test showed that ArgCSH/PLGA possessed degradation and redeposition behaviors sensitive to glucose concentration, and the adsorbed Arg played a crucial role in the degradation process. The subsequent cell functional evaluation showed that ArgCSH could effectively protect cells from damage caused by AGEs and promote osteogenic differentiation. The corresponding degradation products of ArgCSH/PLGA displayed the ability to regulate osteoblast bone differentiation and accelerate matrix mineralization. These findings provide new insights into the interaction between biomaterials and the physiological environment, which may be useful in expanding the targeted choice of efficient bone graft biodegradable materials for diabetic osteoporosis.


Assuntos
Osteogênese , Poliglactina 910 , Humanos , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Poliglactina 910/química , Sulfato de Cálcio , Ácido Poliglicólico/química , Ácido Láctico/química , Arginina/farmacologia , Materiais Biocompatíveis/farmacologia , Materiais Biocompatíveis/química
5.
Small Methods ; 7(10): e2300390, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37452173

RESUMO

A multi-engine highly integrated microrobot, which is a Janus hemispherical shell structure composed of Pt and α-Fe2 O3 , is successfully developed. The microrobot can be efficiently driven and flexibly regulated by five stimuli, including an optical field, an acoustic field, magnetic field, an electric field, and chemical fuel. In addition, no matter which way it is driven by, the direction can be effectively controlled through the magnetic field regulation. Furthermore, this microrobot can also utilize magnetic or acoustic fields to achieve excellent aggregation control and swarm movement. Finally, this study demonstrates that the microrobots' propulsion can be effectively synergistically enhanced through the simultaneous action of two driving mechanisms, which can greatly improve the performance of the motor in applications, such as pollutant degradation. This multi-engine, highly integrated microrobot not only can adapt to more complex environments and has a wider application range, better application prospects, but also provides important ideas for designing future advanced micro/nanorobots.

6.
Nanotechnology ; 34(6)2022 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-36356304

RESUMO

Ni-Co binary hydroxide (NixCo1-x(OH)2) with nanostructure is prepared by one-step electrochemical deposition process with de-ionized water as electrolyte. The molar ratio of Ni/Co for NixCo1-x(OH)2can be accurately controlled via changing the composition of the alloy target. A series of typical hydroxides are synthesized with Ni/Co molar ratios of 1:2, 1:3, 1:4, 1:6, 6:1, 4:1, 3:1, 2:1 and 1:1. The electrochemical performances of NixCo1-x(OH)2exhibit remarkable improvement in rate capability and cycling stability compared to monometallic hydroxide. Electrochemical test results reveal that Ni4/5Co1/5(OH)2delivers the maximum specific capacitance of 2425 F g-1, while Ni0.5Co0.5(OH)2exhibits ultrahigh rate capability (a 14% capacity decrease after a 100-fold increase in scan rate and 7% capacity decrease after a 40-fold increase in current density) and super-long cycle life (no capacitance loss after 50 000 cycles). Especially, the Ni0.5Co0.5(OH)2//AC supercapacitor exhibits a super-long cycle life with a 2% capacitance loss after 100 000 cycles, which is quite better than that of crystalline devices.

7.
Front Bioeng Biotechnol ; 10: 988300, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36110316

RESUMO

The endogenous electrical potential generated by native bone and periosteum plays a key role in maintaining bone mass and quality. Inspired by the electrical properties of bone, different negative surface potentials are built on microspheres to restore electric microenvironment for powerful bone regeneration, which was prepared by the combination of strontium-doped barium titanate (Sr-BTO) nanoparticles and poly (lactic-co-glycolic acid) (PLGA) with high electrostatic voltage field (HEV). The surface potential was modulated through regulating the phase composition of nanoparticles in microspheres by the doping amount of strontium ion (Sr2+). As a result, the 0.1Sr-BTO/PLGA group shows the lowest surface potential and its relative permittivity is closer to natural bone. As expected, the 0.1Sr-BTO/PLGA microspheres performed cytocompatibility, osteogenic activity in vitro and enhance bone regeneration in vivo. Furthermore, the potential mechanism of Sr-BTO/PLGA microspheres to promote osteogenic differentiation was further explored. The lower surface potential generated on Sr-BTO/PLGA microspheres regulates cell membrane potential and leads to an increase in the intracellular calcium ion (Ca2+) concentration, which could activate the Calcineurin (CaN)/Nuclear factor of activated T-cells (NFAT) signaling pathway to promote osteogenic differentiation. This study established an effective method to modulate the surface potential, which provides a prospective exploration for electrical stimulation therapy. The 0.1Sr-BTO/PLGA microsphere with lower surface potential and bone-matched dielectric constant is expected to have great potential in the field of bone regeneration.

8.
J Mater Chem B ; 10(38): 7808-7826, 2022 10 05.
Artigo em Inglês | MEDLINE | ID: mdl-36069314

RESUMO

Wound healing is a complex process. Wound-repair materials require multiple functionalities, such as anti-inflammatory, antibacterial, angiogenesis, pro-proliferation, and remodeling. To achieve rapid tissue regeneration, magnetic field-assisted therapy has become a promising means. In this study, a homogeneous magnetic responsive nanocomposite hydrogel with enhanced mechanical properties was obtained through a tannin (TA)-assisted bridge between magneto-deformable cobalt ferrite nanoparticles (CFO NPs) and polyvinyl alcohol (PVA) matrix. In the presence of an external static magnetic field (SMF), the TA bridge could efficiently transmit magnetically actuated deformation to the PVA, which originated from the CFO NPs, generating a larger topographic change on the surface. The change of topography provided a mechanical cue to increase cell adhesion and proliferation. Moreover, due to the synergistic effects of TA modification and CFO NPs, the obtained magnetic responsive hydrogel exhibited considerable antibacterial activity. Furthermore, the results of in vivo study confirmed the anti-inflammatory properties of the TA-CFO/PVA hydrogel. More importantly, the TA-CFO/PVA hydrogel accelerated wound healing under a SMF, which contributed to the early vascularization induced by mechanical stimuli generated from the TA-CFO/PVA nanocomposite hydrogel. As a proof-of-concept, we provided an optimizing strategy for magneto-controlled skin tissue regeneration, which may have important guiding significance for the clinical application of magnetic field-assisted therapy.


Assuntos
Hidrogéis , Álcool de Polivinil , Antibacterianos/farmacologia , Anti-Inflamatórios/farmacologia , Hidrogéis/farmacologia , Fenômenos Magnéticos , Nanogéis , Álcool de Polivinil/farmacologia , Taninos/farmacologia , Cicatrização
9.
Materials (Basel) ; 15(6)2022 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-35329437

RESUMO

The microstructure and mechanical properties of pure W, sintered and swaged W-1.5ZrO2 composites after 1.5 × 1015 Au+/cm2 radiation at room temperature were characterized to investigate the impact of the ZrO2 phase on the irradiation resistance mechanism of tungsten materials. It can be concluded that the ZrO2 phase near the surface consists of two irradiation damage layers, including an amorphous layer and polycrystallization regions after radiation. With the addition of the ZrO2 phase, the total density and average size of dislocation loops, obviously, decrease, attributed to the reason that many more glissile 1/2<111> loops migrate to annihilate preferentially at precipitate interfaces with a higher sink strength of 7.8 × 1014 m−2. The swaged W-1.5ZrO2 alloys have a high enough density of precipitate interfaces and grain boundaries to absorb large numbers of irradiated dislocations. This leads to the smallest irradiation hardening change in hardness of 4.52 Gpa, which is far superior to pure W materials. This work has a collection of experiments and conclusions that are of crucial importance to the materials and nuclear communities.

10.
Chemosphere ; 298: 134297, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35283143

RESUMO

Photocatalytic elimination of antibiotic pollutant is an appealing avenue in response to the water contamination, but it still suffers from sluggish charge detachment, limited redox capacity as well as poor visible light utilization. Herein, a particular S-scheme FeOOH/MgIn2S4 heterojunction with wide visible light absorption was triumphantly constructed by in-situ growth of MgIn2S4 nanoparticles onto the surface of FeOOH nanorods, and employed as a high-efficiency visible light driven photocatalyst for removing tetracycline (TC). Conspicuously, the as-obtained FeOOH(15 wt%)/MgIn2S4 elucidated the optimal TC removal rate of 0.01258 min-1 after 100 min of visible light illumination, which was almost 33.1 and 6.6 times larger than those of neat FeOOH and MgIn2S4, separately. The exceptional degradation performance was principally put down to the establishment of S-scheme heterojunction between FeOOH and MgIn2S4, which could not merely accelerate the detachment of photogenerated carriers, but also retain the powerful reducing ability of photoinduced electrons for MgIn2S4 and high oxidizing capacity of photoexcited holes for FeOOH, strongly driving the generation of plentiful active species including holes, superoxide and hydroxyl radicals. Additionally, the possible degradation mechanism and pathways of TC were also speculated. This work offers a valuable perspective for constructing high-efficiency S-scheme heterojunction photocatalysts for eradicating antibiotics.


Assuntos
Antibacterianos , Poluentes Ambientais , Catálise , Oxirredução , Tetraciclina
11.
Appl Intell (Dordr) ; 52(9): 10369-10383, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35039715

RESUMO

Deep convolutional networks have been widely used for various medical image processing tasks. However, the performance of existing learning-based networks is still limited due to the lack of large training datasets. When a general deep model is directly deployed to a new dataset with heterogeneous features, the effect of domain shifts is usually ignored, and performance degradation problems occur. In this work, by designing the semantic consistency generative adversarial network (SCGAN), we propose a new multimodal domain adaptation method for medical image diagnosis. SCGAN performs cross-domain collaborative alignment of ultrasound images and domain knowledge. Specifically, we utilize a self-attention mechanism for adversarial learning between dual domains to overcome visual differences across modal data and preserve the domain invariance of the extracted semantic features. In particular, we embed nested metric learning in the semantic information space, thus enhancing the semantic consistency of cross-modal features. Furthermore, the adversarial learning of our network is guided by a discrepancy loss for encouraging the learning of semantic-level content and a regularization term for enhancing network generalization. We evaluate our method on a thyroid ultrasound image dataset for benign and malignant diagnosis of nodules. The experimental results of a comprehensive study show that the accuracy of the SCGAN method for the classification of thyroid nodules reaches 94.30%, and the AUC reaches 97.02%. These results are significantly better than the state-of-the-art methods.

12.
Nanomaterials (Basel) ; 11(10)2021 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-34684972

RESUMO

The photophysical properties of Cu-doped CdSe quantum dots (QDs) can be affected by the oxidation state of Cu impurity, but disagreement still exists on the Cu oxidation state (+1 or +2) in these QDs, which is debated and poorly understood for many years. In this work, by using density functional theory (DFT)-based calculations with the Heyd-Scuseria-Ernzerhof (HSE) screened hybrid functional, we clearly demonstrate that the incorporation of Cu dopants into the surface of the magic sized Cd33Se33 QD leads to non-magnetic Cu 3d orbitals distribution and Cu+1 oxidation state, while doping Cu atoms in the core region of QDs can lead to both Cu+1 and Cu+2 oxidation states, depending on the local environment of Cu atoms in the QDs. In addition, it is found that the optical absorption of the Cu-doped Cd33Se33 QD in the visible region is mainly affected by Cu concentration, while the absorption in the infrared regime is closely related to the oxidation state of Cu. The present results enable us to use the doping of Cu impurity in CdSe QDs to achieve special photophysical properties for their applications in high-efficiency photovoltaic devices. The methods used here to resolve the electronic and optical properties of Cu-doped CdSe QDs can be extended to other II-VI semiconductor QDs incorporating transition-metal ions with variable valence.

13.
J Colloid Interface Sci ; 587: 831-844, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33248700

RESUMO

Construction of Z-scheme heterojunction has been deemed to be an effective and promising approach to boost the photocatalytic activity on account of accelerating the separation efficiency of the photogenerated carriers and maintaining the strong redox ability. Herein, an attractive CeO2/Zn3V2O8 Z-scheme heterojunction photocatalyst was rationally constructed by zero-dimensional (0D) CeO2 nanoparticles immobilized on the surface of three-dimensional (3D) Zn3V2O8 nanoflowers using a simple mixing method, and applied to the photocatalytic degradation of tetracycline (TC) under visible light irradiation. As expected, it was observed that the prepared CeO2/Zn3V2O8 hybrid illustrated significantly boosted the photocatalytic activity for the elimination of TC compared to pure Zn3V2O8. More importantly, the optimized CeO2(40 wt%)/Zn3V2O8 hybrid owned the largest elimination rate of TC with 1.13 × 10-2 min-1, which was around 8.1 and 3.8 times as high as single CeO2 (0.14 × 10-2 min-1) and Zn3V2O8 (0.30 × 10-2 min-1), respectively. The appreciable performance improvement was mainly ascribed to the formation of Z-scheme heterojunction between CeO2 and Zn3V2O8, facilitating the transfer rate of photogenerated carriers and remaining the high reducibility of photoexcited electrons in CeO2 and strong oxidizability of photoinduced holes in Zn3V2O8. Active species capture experiments and electron spin resonance spectra showed that superoxide radicals and holes were the main active species for TC degradation. Besides, the possible degradation pathways of TC were speculated by identifying degradation intermediates, and the reasonable degradation mechanism including migration and transport behaviors of charge carriers and generation processes of reactive species were revealed in depth. This investigation enriches Zn3V2O8-based Z-scheme heterojunction photocatalytic system and offers a new inspiration for the construction and fabrication of high-efficiency Z-scheme heterojunction photocatalysts to remove the antibiotics from wastewater.


Assuntos
Nanopartículas , Vanadatos , Antibacterianos , Catálise , Cério , Luz , Tetraciclina , Zinco
14.
J Phys Chem Lett ; 11(8): 3025-3031, 2020 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-32182078

RESUMO

The proton transport behaviors through graphane in the electrochemical environment are not only determined by the film but also correlated with the properties of the electrolytes. Here, the effect of electrolytes is studied for this transport process. The step of proton transfer from electrolyte to graphane is the rate-determining step of the whole transport process in most of the studied cases and is indeed influenced much by the electrolytes, while the following steps are affected little. Its energy barrier increases significantly with the number of water molecules but only fluctuates with the number of mimicked Nafion molecules until the bulk case. This barrier could be further affected by the hydration number of Nafion and be reduced by increasing local proton concentrations. The dynamical effect of the environment and the nuclear quantum effect are found to further reduce the energy barrier of the transport process but by a relatively small amount.

15.
J Mater Chem B ; 8(13): 2673-2688, 2020 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-32147674

RESUMO

An effective treatment for spinal cord injury (SCI) remains a severe clinical challenge due to the intrinsically limited regenerative capacity and complex anatomical structure of the spinal cord. The combination of biomaterials, which serve as scaffolds for axonal growth, cells and neurotrophic factors, is an excellent candidate for spinal cord regeneration. Herein, a new micropatterned conductive electrospun nanofiber mesh was constructed with poly{[aniline tetramer methacrylamide]-co-[dopamine methacrylamide]-co-[poly(ethylene glycol) methyl ether methacrylate]}/PCL (PCAT) using a rotation electrospinning technology. The aim was to study the synergistic effects of electrical stimulation (ES) and a micropatterned conductive electrospun nanofiber mesh incorporated with nerve growth factor (NGF) on the differentiation of rat nerve stem cells (NSCs). The hydrophilicity of the conductive nanofiber mesh could be tailored by changing the dopamine (DA) and aniline tetramer (AT) content from 19° to 79°. A favorable electroactivity and conductivity was achieved by the AT segment of PCAT. The as-fabricated micropatterned electrospun nanofiber mesh possessed a regularly aligned valley and ridge structure, and the diameter of the nanofiber was 312 ± 58 nm, while the width of the valley and ridge was measured to be 210 ± 17 µm and 200 ± 16 µm, respectively. The growth and neurite outgrowth of differentiated NSCs were observed along the valley of the micropatterned nanofiber mesh. In addition, the NGF loaded micropatterned conductive electrospun nanofiber mesh combined with ES exhibited the highest cell viability, and effectively facilitated the differentiation of NSCs into neurons and suppressed the formation of astrocytes, thus exhibiting a great application potential for nerve tissue engineering.


Assuntos
Nanofibras/química , Regeneração Nervosa , Células-Tronco Neurais/citologia , Engenharia Tecidual , Alicerces Teciduais/química , Animais , Adesão Celular , Diferenciação Celular , Células Cultivadas , Condutividade Elétrica , Estimulação Elétrica , Camundongos , Estrutura Molecular , Células NIH 3T3 , Fator de Crescimento Neural/química , Células PC12 , Tamanho da Partícula , Polímeros/química , Ratos , Propriedades de Superfície
16.
Int J Biol Macromol ; 150: 823-830, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-32068058

RESUMO

The interaction behavior between food bio-macromolecules is the key point to develop the novel functional food ingredients. Effects of high pressure (HP) or microwave treatment (MW) on the physicochemical properties and microstructures of soy protein hydrolysates (SH)/ß-glucan/ferulic acid complexes (S-G-F) were investigated. The results showed that both HP and MW treatment significantly reduced the S-G-F complex particle size and fluorescence intensity along with the improved thermal stability and antioxidant activity but did not affect the zeta potential and the crystal structure. HP treatment changed the conformation of SH by increasing the ß-sheet content and decreasing the unordered structure, while MW treatment induce the increase in random coils content and the decreased in the α-helix content of SH. Accordingly, compared with MW treatment, HP treatment could result in the formation of a more compact structure with the uniform distribution through the stronger hydrogen bonding and hydrophobic interaction between components. This work revealed the interaction behaviors of food multi-component self-assembled nanoscale aggregation under high-technology in the food processing, which could provide a new direction for the development of antioxidant food ingredients by effectively utilizing the interaction between food components.


Assuntos
Ácidos Cumáricos/química , Manipulação de Alimentos/métodos , Tecnologia de Alimentos/métodos , Micro-Ondas , Hidrolisados de Proteína/química , Proteínas de Soja/química , beta-Glucanas/química , Antioxidantes , Interações Hidrofóbicas e Hidrofílicas , Tamanho da Partícula , Pressão , Conformação Proteica em alfa-Hélice , Conformação Proteica em Folha beta , Difração de Raios X
17.
Nanotechnology ; 31(9): 095404, 2020 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-31726430

RESUMO

Although secondary batteries are common in many fields, new electrode materials with a reasonable structure are desired for high battery performance. Herein, Sb/N-doped graphene nanosheets (NGNS-Q) were constructed with the help of 7,7,8,8-tetracyanoquinodimethane anions (TCNQ·-). TCNQ·- were used to anchor Sb3+ into the graphene layer by electrostatic interaction, which improves the distribution of Sb nanoparticles. Meanwhile, TCNQ·- act as a N source to form N-doped graphene, enhancing the electron conductivity of the composite. Benefiting from the stable structure and good conductivity, the Sb/NGNS-Q composite achieved good electrochemical battery performance for Li/Na ion batteries (LIBs/SIBs). At a current density of 0.1 A g-1, Sb/NGNS-Q exhibited a capacity of 615 mAh g-1 after cycling 200 times and 240 mAh g-1 after 100 cycles for LIBs and SIBs, respectively.

18.
Nanotechnology ; 31(9): 095401, 2020 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-31711047

RESUMO

Despite many recent attempts to restrict it, the dissolution and diffusion of polysulfides, leading to inferior cycling performance, is still the main bottleneck hindering commercialization of the Li-S battery. Herein, a new strategy of using lithium polyacrylate (LiPAA) to clad multiwalled carbon nanotube/sulfur (MWNT/S) composites as the interface layer for an MWNT/S/LiPAA cathode was proposed, not only to suppress polysulfide migration through physical encapsulation and chemical adsorption, but also to facilitate Li+ diffusion during the charge/discharge process. Attributed to these functions of LiPAA, MWNT/S/LiPAA exhibited a rate capability and cycling performance superior to those of MWNT/S and MWNT/S/PAA. Moreover, thanks to the introduction of LiPAA, the MWNT/S/LiPAA was endowed with robust mechanical properties, making it suitable for a flexible cathode in a flexible Li-S battery with stable output under deformation. This work could open up a promising way to suppress polysulfide migration for high-performance flexible Li-S batteries.

19.
Nanomaterials (Basel) ; 9(11)2019 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-31689988

RESUMO

A series of helium (He) charged nanograin-sized erbium (Er) films were deposited by direct current (DC)-magnetron sputtering with different He/Ar mixture gases. The microstructure and mechanical properties of He-charged Er films were investigated by X-ray diffraction (XRD), transmission electron microscopy (TEM), and nanoindentation. The helium concentrations in Er films, determined by elastic recoil detection analysis (ERDA), ranged from 0 to 49.6%, with the increase in He:Ar flow ratio up to 18:1. The XRD results show that the grain sizes of Er films decreased with and increase in He content. The embedded He atoms induced the formation of spherical nanometer He bubbles, and the diameter of the He bubbles increased with the He content. The hardness and Young's modulus increased and decreased with the decreasing grain sizes of polycrystalline Er-He films. The mechanisms of mechanical properties with respect to the grain size and He content were discussed based on the Hall-Petch formula and composite spheres model.

20.
J Microencapsul ; 36(7): 622-634, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31478411

RESUMO

Aim: To design novel emulsifiers with the ability to improve the storage and digestion stability of curcumin emulsions, besides to investigate the influence of phenolic acids types on the emulsify ability of soy protein-pectin-phenolic acids complexes obtained by ultrasonication. Methods: The ternary complexes were characterised by particle size, morphology, zeta potential, X-ray diffraction, Fourier transform infra-red and fluorescence spectroscopy. Additionally, changes in droplet size, charge, and microstructure were monitored as quantitative stability index of curcumin emulsions. Results: Phenolic acid types significantly affected the formation of ternary complexes. Soy protein-pectin-ferulic acid complex (S-P-F) stabilised curcumin emulsion had the best emulsifying property, followed by soy protein-pectin- ellagic acid (S-P-E), and soy protein-pectin-tannic acid complexes (S-P-T). Moreover, S-P-F emulsion was found to retain efficiently cucumin within 30 days storage (77.35%) and simulated gastrointestinal tract (64.09%). Conclusion: Protein-polysaccharide-phenolic acids emulsions are effective oral delivery systems for hydrophobic bioactives.


Assuntos
Antineoplásicos/administração & dosagem , Curcumina/administração & dosagem , Emulsões/química , Hidroxibenzoatos/química , Pectinas/química , Proteínas de Soja/química , Antineoplásicos/química , Curcumina/química , Digestão , Portadores de Fármacos/química , Estabilidade de Medicamentos , Emulsificantes/química , Humanos
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