Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 45
Filtrar
1.
Angew Chem Int Ed Engl ; : e202409876, 2024 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-38923765

RESUMO

Lattice-oxygen activation has emerged as a popular strategy for optimizing the performance and selectivity of oxide-based thermocatalysis and electrolysis. However, the significance of lattice oxygen in oxide photocatalysts has been ignored, particularly in gas‒solid reactions. Here, using methane oxidation over a Ru1@ZnO single-atom photocatalyst as the prototypical reaction and via 18O isotope labelling techniques, we found that lattice oxygen can directly participate in gas‒solid reactions. Lattice oxygen played a dominant role in the photocatalytic reaction, as determined by estimating the kinetic constants in the initial stage. Furthermore, we discovered that dynamic diffusion between O2 and lattice oxygen proceeded even in the absence of targeted reactants. Finally, single-atom Ru can facilitate the activation of adsorbed O2 and the subsequent regeneration of consumed lattice oxygen, thus ensuring high catalyst activity and stability. The results provide guidance for next-generation oxide photocatalysts with improved activities and selectivities.

2.
Langmuir ; 2024 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-38315682

RESUMO

Polylactic acid (PLA) fiber is a degradable material with good environmental friendliness for textile applications. However, the main problems of difficult dyeing of PLA fibers were: high crystallinity to the adsorption of dyes, more ester and methyl groups producing non-hydrophilic problems, long chains making dyes difficult to penetrate, and producing a low dyeing rate. Here, we attempted to change the crystallinity of the PLA fiber to a lower degree from hydrophobic to hydrophilicity property variation, destroy the long chain structure to grant more staining sites, and improve the PLA fiber staining depth and the resilience dyeing effect with deep eutectic solvent (DES) treatment and natural dyes. We discovered that a controlled DES treatment process could make PLA fibers less crystallized, help amorphous areas form, and break up long chains, which lead to more dye sites. After DES treatment, the crystallinity decreased from 56.12 to 29.86%, and the instantaneous water contact angle decreased from 108.79 to 64.39°. The DES-treated PLA fabric exhibited a higher K/S value of 15.14 for natural dyes under specific conditions. The fabric, which had remarkable fastness characteristics and wash resistance, could endure frequent laundering and fulfill the demands of everyday use. Moreover, the fabric had good antimicrobial activity against Escherichia coli, Staphylococcus aureus, and Candida albicans and possessed a certain level of biocompatibility with fibroblasts. This DES treatment and natural dye combination method offered a new strategy for improving PLA fabric staining depth and color fastness, making it a promising option for low-carbon environmental protection in the textile industry.

3.
Chemphyschem ; 25(8): e202300897, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38323673

RESUMO

As a photocathode with a band gap of about 1.8 eV, copper bismuthate (CuBi2O4) is a promising material for photoelectrochemical (PEC) water splitting. However, weak charge transfer capability and severe carrier recombination suppress the PEC performance of CuBi2O4. In this paper, the conductivity and carriers transport of CuBi2O4 are improved via introducing Zn2+ into the synthesis precursor of CuBi2O4, driving a beneficial 110 mV positive shift of onset potential in photocurrent. Detailed investigations demonstrate that the introduction of an appropriate amount of zinc leads to in situ segregation of ZnO which serves as an electron transport channel on the surface of CuBi2O4, forming heterojunctions. The synergistic effect of heterojunctions and doping simultaneously promotes the charge transfer and the carrier concentration. OCP experiment proves that ZnO/Zn-CuBi2O4 possesses better charge separation; the Mott-Schottky curve shows that the doping of Zn significantly enhances the carrier concentration; carrier lifetime calculated from time-resolved photoluminescence confirms faster extraction of carriers.

4.
Nat Mater ; 23(3): 383-390, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38062169

RESUMO

Transparent conducting oxides are a critical component in modern (opto)electronic devices and solar energy conversion systems, and forming textured functional films on them is highly desirable for property manipulation and performance optimization. However, technologically important materials show varied crystal structures, making it difficult to establish coherent interfaces and consequently the oriented growth of these materials on transparent conducting oxides. Here, taking lattice-mismatched hexagonal α-Fe2O3 and tetragonal fluorine-doped tin oxide as the example, atomic-level investigations reveal that a coherent ordered structure forms at their interface, and via an oxygen-mediated dimensional and chemical-matching manner, that is, matched Voronoi cells of oxygen sublattices, [110]-oriented α-Fe2O3 films develop on fluorine-doped tin oxide. Further measurements of charge transport characteristics and photoelectronic effects highlight the importance and advantages of coherent interfaces and well-defined orientation in textured α-Fe2O3 films. Textured growth of lattice-mismatched oxides, including spinel Co3O4, fluorite CeO2, perovskite BiFeO3 and even halide perovskite Cs2AgBiBr6, on fluorine-doped tin oxide is also achieved, offering new opportunities to develop high-performance transparent-conducting-oxide-supported devices.

6.
Adv Clin Exp Med ; 2023 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-38014931

RESUMO

BACKGROUND: Chronic nonbacterial prostatitis (CNP) is a chronic inflammatory disease. Patients often have trouble urinating, experience painful and frequent urination, and pelvic floor pain, which seriously affects their quality of life. Dihydroartemisinin (DHA) is the most important artemisinin derivative with good anti-inflammatory effects. However, the mechanism of DHA for CNP has not been fully elucidated. OBJECTIVES: To examine the protective effect of DHA on CNP in mice model and to explore the potential mechanisms from the perspective of microRNAs (miRNAs). MATERIAL AND METHODS: The CNP mouse model was induced using a prostate protein extract solution and complete Freund's adjuvant. The pain threshold was determined using von Frey filaments. Hematoxylin and eosin (H&E) staining, TUNEL staining, western blot, real-time polymerase chain reaction (PCR), and small RNA sequencing were used to evaluate the effect of DHA on CNP. RESULTS: Dihydroartemisinin significantly alleviated prostate tissue damage in CNP mice, reduced the pain threshold, improved the prostate index, and reduced cell apoptosis. It also reduced the expressions of interleukin-1ß (IL-1ß), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and macrophage chemoattractant protein-1 (MCP-1). Furthermore, after screening 48 differentially expressed genes, we found 4 miRNAs significantly downregulated and 2 miRNAs upregulated in the model group, which were later significantly reversed by DHA treatment. These results indicate that DHA treatment of CNP involves several signaling pathways. CONCLUSIONS: Dihydroartemisinin can improve the pathological state and inflammatory response in a CNP mouse model, which may be related to the regulation of miRNAs.

7.
Nat Commun ; 14(1): 4266, 2023 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-37460538

RESUMO

Durability is one prerequisite for material application. Photoelectrochemical decomposition of seawater is a promising approach to produce clean hydrogen by using solar energy, but it always faces the problem of serious Cl- corrosion. We find that the main deactivation mechanism of the photoanode is oxide surface reconstruction accompanied by the coordination of Cl- during seawater splitting, and the stability of the photoanode can be effectively improved by enhancing the metal-oxygen interaction. Taking the metastable ß-Fe2O3 photoanode as an example, Sn added to the lattice can enhance the M-O bonding energy and hinder the transfer of protons to lattice oxygen, thereby inhibiting excessive surface hydration and Cl- coordination. Therefore, the bare Sn/ß-Fe2O3 photoanode delivers a record durability for photoelectrochemical seawater splitting over 3000 h.

8.
Water Res ; 242: 120254, 2023 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-37354843

RESUMO

Biofouling is a major challenge limiting the practical application of biofiltration-facilitated gravity-driven membrane (GDM) systems in drinking water treatment. In this study, ultraviolet irradiation, including ultraviolet (UV) and vacuum ultraviolet (VUV) irradiation, was used for in-situ purification of membrane tanks to control membrane biofouling. After using UV and VUV, the permeate flux increased significantly by 26.1% and 78.3%, respectively, which was mainly due to the decreased cake layer resistance (Rc). The permeability of the biofouling layer improved after UV and VUV application, as evidenced by the increased surface porosity and decreased thickness. The contents of loosely bound extracellular proteins (LB-PN) and tightly bound extracellular proteins (TB-PN) in the biofouling layer were reduced after UV and VUV irradiation. The decreased LB-PN and TB-PN improved the interfacial free energy between the fouling itself and between the fouling and the membrane, which contributed to the reduction of interfacial cohesion and adhesion, resulting in a looser and thinner biofouling layer and a cleaner membrane. The concentration of protein-like material in the membrane tank decreased after UV and VUV irradiation, significantly altering the bacterial community structure on the membrane surface (Mantel's r > 0.7, p < 0.05). The changes in the metabolic state were responsible for the differences in the LB-PN and TB-PN contents. The inhibition of "Alanine, aspartate and glutamate metabolism" and "Glycine, serine and threonine metabolism" reduced amino acid biosynthesis, which restricted the secretion of LB-PN and TB-PN. Critical genera in the Proteobacteria phylum, such as Hirschia, Rhodobacter, Nordella, Candidatus_Berkiella, and Limnohabitans, were involved in metabolite transformation. Overall, the in-situ application of UV and VUV can be an effective alternative strategy to mitigate membrane biofouling, which would facilitate the practical application of biofiltration-facilitated GDM systems in drinking water treatment.


Assuntos
Água Potável , Purificação da Água , Vácuo , Multiômica , Filtração/métodos , Purificação da Água/métodos , Termodinâmica , Membranas Artificiais
9.
J Am Chem Soc ; 145(13): 7181-7189, 2023 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-36959719

RESUMO

Light-driven primary amine oxidation to imines integrated with H2 production presents a promising means to simultaneous production of high-value-added fine chemicals and clean fuels. Yet, the effectiveness of this strategy is generally limited by the poor charge separation of photocatalysts and uncontrolled hydrogenation of imines to secondary amines. Herein, a spatial decoupling strategy is proposed to isolate redox chemistry at distinct sites of photocatalysts, and CoP core-ZnIn2S4 shell (CoP@ZnIn2S4) coaxial nanorods are assembled as the proof-of-concept photocatalyst. Directional and ultrafast carrier separation occurs between the CoP core and the ZnIn2S4 shell, as confirmed by in situ X-ray photoelectron spectroscopy, surface photovoltage spectroscopy, and transient absorption spectroscopy analyses. Toward the photoconversion of model substrate benzylamine to N-benzylbenzaldimine, CoP@ZnIn2S4 exhibits a 48-time higher production rate and >99% selectivity when compared to ZnIn2S4 (ca. 20% selectivity), and the detailed reaction mechanism has been verified by in situ diffuse reflectance infrared Fourier transform spectroscopy.

10.
Nat Commun ; 14(1): 1013, 2023 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-36823177

RESUMO

The sustainable production of chemicals and fuels from abundant solar energy and renewable carbon sources provides a promising route to reduce climate-changing CO2 emissions and our dependence on fossil resources. Here, we demonstrate solar-powered formate production from readily available biomass wastes and CO2 feedstocks via photoelectrochemistry. Non-precious NiOOH/α-Fe2O3 and Bi/GaN/Si wafer were used as photoanode and photocathode, respectively. Concurrent photoanodic biomass oxidation and photocathodic CO2 reduction towards formate with high Faradaic efficiencies over 85% were achieved at both photoelectrodes. The integrated biomass-CO2 photoelectrolysis system reduces the cell voltage by 32% due to the thermodynamically favorable biomass oxidation over conventional water oxidation. Moreover, we show solar-driven formate production with a record-high yield of 23.3 µmol cm-2 h-1 as well as high robustness using the hybrid photoelectrode system. The present work opens opportunities for sustainable chemical and fuel production using abundant and renewable resources on earth-sunlight, biomass and CO2.

11.
J Cell Mol Med ; 27(1): 101-112, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36524848

RESUMO

Discordant abundances of different immune cell subtypes is regarded to be an essential feature of tumour tissue. Direct studies in Prostate cancer (PC) of intratumoral immune heterogeneity characterized by immune cell subtype, are still lacking. Using the single sample gene set enrichment analysis (ssGSEA) algorithm, the abundance of 28 immune cells infiltration (ICI) were determined for PC. A NMF was performed to determine tumour-sample clustering based on the abundance of ICI and PFS information. Hub genes of clusters were identified via weighted gene co-expression network analysis (WGCNA). The multivariate dimensionality reduction analysis of hub genes expression matrix was carried out via principal component analysis (PCA) to obtain immune score (IS). We analysed the correlation between clustering, IS and clinical phenotype. We divided the 495 patients into clusterA (n = 193) and clusterB (n = 302) on the basis of ICI and PFS via NMF. The progression-free survival (PFS) were better for clusterA than for clusterB (p < 0.001). Each immune cell subtypes was more abundant in clusterA than in clusterB (p < 0.001). The expression levels of CTAL-4 and PD-L1 were lower in clusterB than in clusterA (p < 0.001 and p = 0.006). We obtained 103 hub genes via WGCNA. In the training and validation cohorts, the prognosis of high IS group was worse than that of the low IS group (p < 0.05). IS had good predictive effect on 5-year PFS. The expression of immune checkpoint genes was higher in the low IS group than in the high IS group (p < 0.01). Patients with low IS and receiving hormone therapy had better prognosis than other groups. The combination of IS and clinical characteristics including lymph node metastasis and gleason score can better differentiate patient outcomes than using it alone. IS was a practical algorithm to predict the prognosis of patients. Advanced PC patients with low IS may be more sensitive to hormone therapy. CXCL10, CXCL5, MMP1, CXCL12, CXCL11, CXCL2, STAT1, IL-6 and TLR2 were hub genes, which may drive the homing of immune cells in tumours and promote immune cell differentiation.


Assuntos
Carcinoma , Neoplasias da Próstata , Humanos , Masculino , Algoritmos , Hormônios , Neoplasias da Próstata/genética
12.
Zhonghua Nan Ke Xue ; 29(8): 725-728, 2023 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-38619520

RESUMO

OBJECTIVE: To observe the effect of Nailifu Spray on the treatment of premature ejaculation. METHODS: A total of 90 patients were included in this study from January 1, 2022 to January 1, 2023. Nailifu spray was used to spray the surface of penile skin once a day, 2 sprays per session for 4 weeks.And the patients' premature ejaculation diagnostic tool (PEDT) scores, intravaginal ejaculation latency time (IELT), and international index of erectile function-5 (IIEF-5) scores were collected before and after treatment, respectively. RESUTS: The median (P25,P75) PEDT scores was 16.0(15.0,18.0) scores before treatment and 10.0(10.0,10.0) scores after treatment. The median (P25,P75) of IELT was 20.0 (10.0,30.0) s before treatment and 240.0 (180.0,300.0) s after treatment. The median (P25,P75) of IIEF-5 scores was 21.0 (21.0,22.0) scores before treatment and 21.0 (21.0,21.0) scores after treatment. Compared with baseline levels, IELT was significantly longer and PEDT scores were significantly lower, with statistically significant differences. No significant changes in IIEF-5 scores were seen. CONCLUSION: Nailifu spray treatment of premature ejaculation is accurate and effective, worthy of clinical promotion.


Assuntos
Ejaculação Precoce , Masculino , Humanos , Ejaculação Precoce/tratamento farmacológico , Ejaculação , Pelve , Pênis
14.
Proc Natl Acad Sci U S A ; 119(36): e2205562119, 2022 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-36037332

RESUMO

Hydrogen peroxide (H2O2) molecules play important roles in many green chemical reactions. However, the high activation energy limits their application efficiency, and there is still huge controversy about the activation path of H2O2 molecules over the presence of *OOH intermediates. Here, we confirmed the formation of the key species *OOH in the heterogeneous system, via in situ shell-isolated nanoparticle-enhanced Raman spectroscopy (SHINERS), isotope labeling, and theoretical calculation. In addition, we found that compared with *H2O2, *OOH was more conducive to the charge transfer behavior with the catalyst and the activation of an O-O bond. Furthermore, we proposed to improve the local coordination structure and electronic density of the YFeO3 catalyst by regulating the surface relaxation with Ti modification so as to reduce the activation barrier of H2O2 and to improve the production efficiency of •OH. As a result, the kinetics rates of the Fenton-like (photo-Fenton) reaction had been significantly increased several times. The •OH free radical activity mechanism and molecular transformation pathways of 4-chloro phenol (4-CP) were also revealed. This may provide a clearer vision for the further study of H2O2 activation and suggest a means of designing catalysts for efficient H2O2 activation.


Assuntos
Peróxido de Hidrogênio , Processos Fotoquímicos , Catálise , Peróxido de Hidrogênio/química , Ferro/química , Luz , Fenol
15.
Inflamm Res ; 71(4): 449-460, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35279736

RESUMO

OBJECTIVE: Chronic nonbacterial prostatitis (CNP) has remained one of the most prevalent urological diseases, particularly in older men. Dihydroartemisinin (DHA) has been identified as a semi-synthetic derivative of artemisinin that exhibits broad protective effects. However, the role of DHA in inhibiting CNP inflammation and prostatic epithelial cell proliferation remains largely unknown. MATERIALS AND METHODS: CNP animal model was induced by carrageenan in C57BL/6 mouse. Enzyme linked immunosorbent assay (ELISA), Real-time quantitative polymerase chain reaction (RT-qPCR) and Western blot were used to examine inflammatory cytokines and proliferation genes expression. Immunofluorescence and immunochemistry staining were used to detect and E2F7 expression. Human prostatic epithelial cells (HPECs) and RWPE-1 was induced by lipopolysaccharide (LPS) to mimic CNP model in vitro. Cell proliferation was determined using MTS assay. RESULTS: DHA significantly alleviated the rough epithelium and inhibited multilamellar cell formation in the prostatic gland cavity and prostatic index induced by carrageenan. In addition, DHA decreased the expression of TNF-α and IL-6 inflammatory factors in prostatitis tissues and in LPS-induced epithelial cells. Upregulation of transcription factor E2F7, which expression was inhibited by DHA, was found in CNP tissues, human BPH tissues and LPS-induced epithelial cells inflammatory response. Mechanically, we found that depletion of E2F7 by shRNA inhibited epithelial cell proliferation and LPS-induced inflammation while DHA further enhance these effects. Furthermore, HIF1α was transcriptional regulated by E2F7 and involved in E2F7-inhibited CNP and cellular inflammatory response. Interestingly, we found that inhibition of HIF1α blocks E2F7-induced cell inflammatory response but does not obstruct E2F7-promoted cell growth. CONCLUSION: The results revealed that DHA inhibits the CNP and inflammation by blocking the E2F7/HIF1α pathway. Our findings provide new evidence for the mechanism of DHA and its key role in CNP, which may provide an alternative solution for the prevention and treatment of CNP.


Assuntos
Prostatite , Idoso , Animais , Artemisininas , Carragenina/efeitos adversos , Fator de Transcrição E2F7 , Células Epiteliais/metabolismo , Humanos , Inflamação/metabolismo , Lipopolissacarídeos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Prostatite/induzido quimicamente , Prostatite/tratamento farmacológico , Prostatite/genética
16.
Am J Transl Res ; 14(12): 8991-9000, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36628202

RESUMO

OBJECTIVE: To investigate the efficacy of Bushen Huoxue Decoction (BSHXD) combined with moxibustion on inflammation and urinary symptoms in prostate cancer (PC) patients. METHODS: A total of 87 patients with PC admitted to the Hebei Provincial Hospital of Traditional Chinese Medicine from 08/2019 to 12/2021 were collected for this retrospective study. There were 42 patients treated with conventional treatment regimens who were regarded as the control group (CG). The remaining 45 patients treated with BSHXD and moxibustion were considered the experimental group (EG). The quality of survival of patients was assessed through the C30 and PR25 subscales of the European Organization for Research and Treatment of Cancer Core Quality of Life Questionnaire (EORTC QLQ). Patients' urinary symptom changes were evaluated using the International Prostate Symptom Score (IPSS). The levels of interleukin-6 (IL-6) and tumor necrosis factor α (TNF)-α were measured by Elisa assay before and after the treatment. The maximum urinary flow rate and residual urine volume of the patients were compared before and after the treatment. Logistic regression was used to analyze the risk factors affecting the progression to castration-resistant prostate cancer (CRPC). RESULTS: There was no statistical difference in the total response rate between the two groups of patients (P>0.05). Patients in the EG had a higher QLQ-C30 and maximum urinary flow rate scores than those in the CG after the treatment. The residual urine volume, IL-6, TNF-α, QLQ-PR25, and IPSS scores in the EG were lower (P<0.05). The multi-factorial regression analysis revealed that the Gleason score and the pre-treatment prostate-specific antigen (PSA) level were independent risk factors for the development of CRPC in patients (P<0.05). We plotted the receiver operating characteristic curves for predicting CRPC based on the indicators of patients. The area under the curve for Gleason score and the pre-treatment PSA level were 0.665 and 0.827, respectively, and 0.935 for the combination. CONCLUSION: BSHXD combined with moxibustion had no effect on patients' progressive values of CRPC and did not enhance their outcomes. It was effective in improving their lower urinary symptoms, inflammation, and quality of life.

17.
Small ; 17(45): e2103412, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34569148

RESUMO

High-entropy materials (HEMs) with unique configuration and physicochemical properties have attracted intensive research interest. However, 2D HEMs have not been reported yet. To find out unique properties of combining 2D materials and HEMs, a series of 2D high-entropy hydrotalcites (HEHs) is created by coprecipitation method, including quinary, septenary, and even novenary metallic elements. It is found that the fast synthetic kinetics of coprecipitation process conquers the thermodynamically solubility limitation of different elements, which is the prerequisite condition to form HEHs. As the oxygen evolution reaction (OER) electrocatalysts, HEHs show significantly decreased apparent activation energy compared with low-entropy hydrotalcites (LEHs) due to the lattice distortion induced by the multimetallic character of HEHs. This work opens up a new avenue for the development of 2D HEMs, which broadens the family of HEMs and presents a most promising platform for exploring the unknown properties of HEMs.

18.
ACS Appl Mater Interfaces ; 13(17): 19593-19602, 2021 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-33900060

RESUMO

Myocardial infarction (MI) constitutes the first cause of morbidity and mortality in our life, so using highly conductive and elastic materials to produce an engineered cardiac patch is an effective way to improve the myocardium infarction area function. Here, shape memory polymers of the polyurethane/polyaniline/silicon oxide (PU/PANI/SiO2) electrospinning sub-micron fiber patch were precisely produced in the case of the hydrogen bonding effect and interaction between the carboxyl groups to provide compatibility, phase mixing/miscibility, and stability. The sub-micron fiber patch prepared by our group has some remarkable characteristics, such as sub-micron fibers, 3D porous structure, special thickness to simulate the extracellular matrix (ECM), elastic deformation, good properties in conducting weak electrical signals, stability to maintain the whole structure, and self-adhesion. This sub-micron fiber material has been proven to be effective, easy, and reliable. Through precise design of the material system, structure regulation, and performance optimization, the aim is to produce a sub-micron fiber cardiac patch to simulate the myocardium ECM and improve conductive signal transduction for potential MI therapy.


Assuntos
Adesivos/química , Materiais Biocompatíveis/química , Miocárdio , Polímeros/química , Transdução de Sinais , Eletricidade , Matriz Extracelular , Humanos , Ligação de Hidrogênio , Microscopia Eletrônica de Varredura
19.
ACS Appl Mater Interfaces ; 12(10): 12317-12327, 2020 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-32115937

RESUMO

Peripheral nerve injury is a common serious disease, and the electrical conductivity of nerve scaffolds is of special significance for nerve regeneration. Here, a highly conductive silk knitted composite scaffold was prepared by utilizing hydrogen bonding and electrostatic adsorption between silk amino, graphene (RGO), and polyaniline (PANI). Compared to traditional in situ polymerization of aniline (ANI), the surface of the RGO/PANI/silk conductive knitted scaffold prepared by two-step electrostatic self-assembly had more uniform PANI particles and lower resistance; when GO was 1 g/L and ANI was 0.4, 0.6, or 0.8 mol/L, the RGO/PANI/silk scaffold had better electrical properties when the conductivity was between 0.62 × 10-3 and 1.72 × 10-3 S/cm. The scaffolds had good conductive stability under different physical stresses and good mechanical properties, wherein ultimately the strength, elongation at break, and Young's modulus ranges were 28.07-34.97 MPa, 105.91-109.85%, and 10.2-12.48 MPa, respectively, and so they provided good support. Conductive scaffolds had ordered loops, fiber structure, and large pore sizes between 40 and 70 µm. In summary, RGO/PANI/silk scaffold with good conductivity, pore size distribution, mechanical properties, thermal properties had potential applications in the field of peripheral nerve regeneration.


Assuntos
Nanoestruturas/química , Seda/química , Alicerces Teciduais/química , Compostos de Anilina/química , Condutividade Elétrica , Grafite/química , Teste de Materiais , Propriedades de Superfície , Engenharia Tecidual
20.
Sci Bull (Beijing) ; 65(9): 726-737, 2020 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-36659106

RESUMO

Inorganic lead halide perovskite CsPbBr3 offers attractive photophysical properties and phase stability for high-performance optoelectronic devices. However, CsPbBr3 films produced by the classic solution-based two-step method are always accompanied with impurity phases of CsPb2Br5 and Cs4PbBr6, which represents a major efficiency-limiting factor for future advances of CsPbBr3-based devices. The challenge lies in the complexity of the Cs-Pb-Br phase system, requiring both spatially and temporally precise control of the precursor stoichiometry during solution-phase growth of CsPbBr3 films. By adopting 2-methoxyethanol as the solution conversion medium instead of commonly applied methanol, the reaction between CsBr and PbBr2 can be finely controlled to yield single phase CsPbBr3 films within a few minutes; extending the solution-conversion step to 24 h does not alter the phase purity of resulting CsPbBr3 films. The present work paves the way to regulate the crystal growth behaviors of two-step solution-processed CsPbBr3 films by simple solvent engineering.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA