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1.
Sensors (Basel) ; 20(9)2020 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-32365594

RESUMO

Infrared thermography can be applied in different medical systems, for example it can be used to catch the images of living blood vessels. Far infrared rays can be used in a heating machine, which can be applied in the clinical hemodialysis patients. Infrared electronically sensitized images, which are generated by near-infrared Charge-coupled Device (CCD), are used to detect blood vessels, and used as a long-wavelength external stimulating therapeutic tissue repair system. When an infrared sensor detection and actuator treatment is applied during hemodialysis, a missing needle can be detected, and far infrared rays have a therapeutic effect on blood vessels. Because a far-infrared actuated light source can improve blood circulation, it is currently used to prevent fistula embolism in hemodialysis (HD) patients and reduce vascular occlusion after hemodialysis. Sensors used for sudden changes in heart rate variability (HRV) are used as predictive and evaluation indicators for our new method. Far-infrared actuated radiation can increase sympathetic nerve activity and regulation of parasympathetic and sympathetic nerves. We performed baseline measurements of the low-frequency/high-frequency ratio of autonomic nerve activity before hemodialysis (low frequency (LF), high frequency (HF), LF/HF, before HD) and after hemodialysis (LF/HF, after-HD). Based on data from the HRV continuity tracking report, 35 patients with autonomic nerve activation were treated and evaluated. We have demonstrated that the resulting near-infrared (NIR) sensor imaging and far-infrared actuator illumination can be used for the detection and treatment of hemodialysis patients.


Assuntos
Técnicas Biossensoriais , Raios Infravermelhos , Diálise Renal , Pressão Sanguínea , Frequência Cardíaca , Humanos , Sistema Nervoso Simpático
2.
Opt Express ; 25(3): 2687-2693, 2017 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-29519110

RESUMO

A light-driven tristable chiral-tilted homeotropic nematic (TCHN) cell is demonstrated. The liquid-crystal cell is photo-switchable among the three stable states: the tilted-homeotropic, fingerprint, and the tilted-twist states. The inclusion of a photosensitive chiral bis(azobenzene) compound into a typical nematic liquid crystal makes the resulting material possible to switch from one to another stable state directly and reversibly owing to the photoinduced trans-cis isomerization of the azo-chiral dopant and, hence, the configurational change of the liquid crystal via the guest-host effect. By further introducing dichroic dyes into the TCHN system, we devised a polarizer-free display and light modulators. The novel TCHN composite material opens up new possible applications in light-driven optical elements and devices.

3.
Opt Express ; 24(22): 25019-25025, 2016 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-27828442

RESUMO

We report on the spectral properties of an optically switchable tristable chiral-tilted homeotropic nematic liquid crystal (LC) incorporated as a tunable defect layer in one-dimensional photonic crystal. By varying the polarization angle of the incident light and modulating the light intensity ratio between UV and green light, various transmission characteristics of the composite were obtained. The hybrid structure realizes photo-tunability in transmission of defect-mode peaks within the photonic bandgap in addition to optical switchability among three distinct sets of defect modes via photoinduced tristable state transitions. Because the fabrication process is easier and less critical in terms of cell parameters or sample preparation conditions and the LC layer itself possesses an extra stable state compared with the previously reported bistable counterpart operating on the basis of biased-voltage dual-frequency switching, it has much superior potential for photonic applications such as a low-power-consumption multichannel filter and an optically controllable intensity modulator.

4.
Phys Chem Chem Phys ; 18(46): 31836-31844, 2016 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-27841415

RESUMO

Engineering the interface between the active layer and the electrodes has proven to be a promising strategy to enhance the power conversion efficiency (PCE) of hybrid perovskite solar cells (PeSCs). Here, we present an effective approach to achieve highly efficient PeSCs by inserting an easy-accessible hexamethonium bromide (HMB)-doped [6,6]-phenyl-C61-butyric acid methyl ester (PC61BM) film between the active perovskite layer and the Ag cathode. This doped interfacial layer delivers several remarkable features for use in PeSCs, including solution processability, good electrical conductivity, fine work-function tunability of the Ag electrode, and general applicability to different fullerene materials. As a consequence, planar-heterojunction PeSCs deliver a PCE up to ∼18%, showing an approximately 5.6-fold enhancement compared with the control device using an undoped PC61BM layer. In particular, benefitting from the high conductivity of this doped film, a prominent PCE as high as 15.58% can be achieved even when a large thickness of the PC61BM layer (120 nm) is used. To the best of our knowledge, this is the highest performance ever reported for PeSCs with a PC61BM thickness more than 100 nm. More encouragingly, large-area PeSCs (active area = 1.2 cm2) via the doctor-blade coating technique also exhibit a remarkable PCE (15.23%) and good long-term stability under an inert atmosphere. Our results indicate that the HMB-doped PC61BM film is a promising interfacial layer for PeSCs and can be compatible with high throughput roll-to-roll manufacturing processes.

5.
Opt Express ; 23(17): 22636-42, 2015 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-26368231

RESUMO

A non-iridescent cholesterol liquid crystal (CLC) thin film is demonstrated by using the polymer-stabilized electrohydrodymanic (PSEHD) method. The photopolymerized cell made from a CLC/monomer mixture exhibits an optically stable gridlike pattern. The helical axis of thus-formed CLC is aligned with the hydrodynamic flow induced by a space charge motion, and the arrayed CLC grid configuration renders a wide viewing angle thanks to the limited color shift at various lines of sight. The formation of the PSEHD structure was verified with polarized optical microscopy, ascertaining that the electrohydrodymanic pattern can be photo-cured or stabilized. The PSEHD CLC is simple to fabricate and potentially suitable for applications in wide-viewing-angle or non-iridescent devices.

6.
Opt Lett ; 40(7): 1201-3, 2015 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-25831292

RESUMO

Cholesteric liquid-crystalline materials are abundant in nature such as condensed phases of DNA, plant cell walls, and chiral biopolymers. These self-organized helical structures produce unique optical properties, giving rise to the selective Bragg reflection of colorful light. In this Letter, we focus on the focal conic state of cholesteric liquid crystals and report on stable, tunable, and reversible color switching among red, green, and blue in polymer-stabilized cholesteric films. The experimental results indicate that, with appropriate voltage pulses, the electrically induced color switching of all six routes can be realized in a single cell reflecting green light. The scattered transmissive color persists at zero voltage due to the polymer stabilization.

7.
Opt Express ; 22(3): 3593-9, 2014 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-24663650

RESUMO

Photonic defect modes induced by in situ formation of an ill-defined defect layer is demonstrated in a cholesteric liquid crystal (CLC). The local deformation of the one-dimensionally periodic helical structure is achieved by means of the thermodielectric effect, which alters the pitch in the middle of the cholesteric structure. The defect-mode peak in the photonic band gap appears in the transmission spectrum only when the incident circularly polarized light has the same handedness as that of the CLC structure. The wavelength of the deformation-induced defect mode can be tuned upon varying the dielectric heating power by simply applying a frequency-modulated voltage.

8.
Opt Express ; 22(25): 31347-55, 2014 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-25607083

RESUMO

The ionic effect in nematic liquid-crystal (LC) cells containing the azo dye methyl red was investigated by means of dielectric spectroscopy, measurements of voltage holding ratio (VHR) and ultraviolet/visible absorption spectroscopy. The experimental results indicated that incorporating a minute amount of the methyl red (< 0.03 wt%) in the LC host leads to the suppression of the ionic effect caused by impurity ions. Practically, the doped LC cells with a dye content of 0.02 wt% showed improved VHR and promoted lifetime by 15% and 180%, respectively, in virtually no expense of the optical transmittance.

9.
ACS Omega ; 9(15): 17028-17035, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38645333

RESUMO

Gluten is a well-known food allergen globally, and it can induce immune responses in celiac- and nonceliac gluten-sensitive patients. The gliadin proteins from gluten have a special amino acid sequence that make it hydrophobic. One way to deal with gluten allergies is to provide a gluten-free diet. The hydrophobic characteristic of gliadin makes gliadin detection more difficult. An analyst needs to use an organic solvent or multiple processes to denature gluten for extraction. Although organic solvents can rapidly extract gluten in a sample, organic solvent also denatures the antibody and induces false biotest results without buffer dilute, and the accuracy will reduce with buffer dilute. An ionic liquid (IL) is a highly modifiable green chemical organic salt. The imidazolium has a cationic structure and is modified with different lengths (C = 0, 1, 3, 5, 7, 9, and 12) of carbon side chains with organic and inorganic anions [methanesulfonate (MSO), Cl-, F-, NO3-, HSO4-, and H2PO4-] to make different kinds of ILs for testing the solubility of gliadin. Different IL/water ratios were used to test the solubility of gluten. We measured the solubility of gliadin in different imidazolium ILs, and the kinetic curve of gliadin dissolved in 1% [C5DMIM][MSO]aq was conducted. We also used circular dichroism spectroscopy and an enzyme-linked immunosorbent assay to measure the gliadin structure and the effect of binding with an antibody after 1% [C5DMIM][MSO]aq treatment. An 2,3-bis-(2-methoxy-4- nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) assay was used to test the toxicity of [C5DMIM][MSO]aq in N2a cells. In our research, 1% [C5DMIM][MSO]aq produced a good solubility of gluten, and it could dissolve more than 3000 ppm of gluten in 5 min. [C5DMIM][MSO]aq did not break down the gluten structure and did not restrict antibody binding to gluten, and more importantly, [C5DMIM][MSO] did not exhibit cell toxicity. In this report, we showed that [C5DMIM][MSO] could be a good extraction solution applied for gluten detection.

10.
J Chin Med Assoc ; 2024 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-39017650

RESUMO

BACKGROUND: Acute kidney injury (AKI) is a severe complication of coronavirus disease 2019 (COVID-19) and is associated with a higher risk of mortality. Understanding the risk factors contributing to COVID-19-related AKI and mortality before vaccination is important for the initiation of preventative measures and early treatment strategies. METHODS: This study included patients aged ≥18 years diagnosed with COVID-19 through polymerase chain reaction from May 2020 to July 2021, admitted in three local hospitals in Taiwan, with an extended follow-up until June 30, 2022. A median follow-up period of 250 days was used to assess AKI development and mortality. AKI was defined according to the Kidney Disease Improving Global Outcomes criteria. Multivariate Cox regression analysis of AKI and mortality-related risk factors was performed. RESULTS: Of the 720 hospitalized patients with COVID-19, 90 (22%) developed AKI. Moreover, 80%, 10.1%, and 8.9% of the patients had stage 1, 2, and 3 AKI, respectively. Patients with stage 1-3 AKI had significantly lower survival rates than those without AKI (p = 0.0012). The mean duration of post-admission AKI occurrence was 9.50 ± 11.32 days. Older age, hypoalbuminemia, and higher D-dimer and ferritin levels were associated with COVID-19 mortality. In COVID-19 AKI, in addition to older age and high D-dimer and ferritin levels, chronic kidney disease emerged as an independent risk factor. CONCLUSION: COVID-19-related AKI develops early, exhibits a temporal association with respiratory failure, and is linked to an unfavorable prognosis. The mortality rate increased according to the AKI stage (p = 0.0012). Age; albumin, D-dimer, and ferritin levels; and the underlying chronic kidney disease status upon admission are crucial factors for predicting AKI development, which increases the mortality risk. Monitoring the renal function not only within 10 days of COVID-19 onset, but also within one month after the disease onset.

11.
Opt Express ; 21(20): 23927-33, 2013 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-24104303

RESUMO

Dual-frequency cholesteric liquid crystal (DFCLC) devices characteristically require high operation voltage, which hinders their further development in thin-film-transistor driving. Here we report on a lower-voltage switching method based on the thermodielectric effect. This technique entails applying a high-frequency voltage to occasion dielectric oscillation heating so to induce the increase in crossover frequency. The subsequent change in dielectric anisotropy of the DFCLC allows the switching, with a lower operation voltage, from the planar state to the focal conic or homeotropic state. The temperature rise incurred by the dielectric heating is described.

12.
Bioorg Med Chem Lett ; 23(20): 5744-7, 2013 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-23993331

RESUMO

In nature, antimicrobial peptides (AMPs) represent the first line of defense against infection by pathogens; thus, they are generally good candidates for the development of antimicrobial agents. Recently, we reported two potent antimicrobial peptides, KWLRRVWRWWR-amide (MAP-04-03) and KRLRRVWRRWR-amide (MAP-04-04), which were derived from a fragment of Ixosin-B-amide (KSDVRRWRSRY). Since some cationic AMPs exhibited cytotoxic activity against cancer cells, in the current study, we further investigated the anticancer activity of these potent antimicrobial peptides by antiproliferative assays and wound-healing assays, and the effect of peptide on the cytoskeleton alteration and cell morphology were analyzed by confocal microscopy. Results indicated that MAP-04-03 not only exhibited inhibitory effects on the proliferation (IC50=61.5 µM) and on the cell migration of MCF-7 breast cancer cells (at a concentration of 5 µM), but also affected the cytoskeleton at the concentration of 25 µM. These results demonstrated that MAP-04-03 can serve as a lead peptide analog for developing potent anticancer agents.


Assuntos
Peptídeos Catiônicos Antimicrobianos/química , Antineoplásicos/química , Proteínas de Artrópodes/química , Amidas/química , Sequência de Aminoácidos , Peptídeos Catiônicos Antimicrobianos/toxicidade , Antineoplásicos/toxicidade , Proteínas de Artrópodes/toxicidade , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Citoesqueleto/efeitos dos fármacos , Humanos , Células MCF-7 , Estrutura Secundária de Proteína
13.
J Pept Sci ; 19(11): 676-83, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24123584

RESUMO

Id proteins, inhibitors of DNA binding proteins, have highly conserved dimerization motif known as the helix-loop-helix (HLH) domain that acts as a negative regulator of basic HLH (bHLH) transcription factors. In signaling pathways, Id proteins play an important role in cellular development, proliferation, and differentiation. The mechanism of Id proteins is to antagonize bHLH proteins, thereby preventing them from binding to DNA and inhibiting transcription of cellular differentiation-associated genes in cancer. Recently, we reported an inhibitor of Id1, peptide 3C, which showed good affinity to Id1 protein and exhibited inhibitory effects in cancer cells. In this study, Ala (A)-substituted analogs of peptide 3C were synthesized by SPPS, purified by RP-HPLC, and characterized by MALDI-TOF MS. Binding of each peptide to Id1 or Id1-HLH (the HLH domain of Id1) was monitored by surface plasmon resonance (SPR)-based biosensor. Biological effect of each peptide in MCF-7 breast cancer cells was analyzed by MTT cell viability assay. The secondary structure of substituted analogs of peptide 3C was investigated by circular dichroism (CD) spectroscopy. SPR results revealed that A-substituted analogs of peptide 3C showed weaker binding to Id1 than that of peptide 3C, indicating that the six amino acid residues in the N-terminal of peptide 3C were all essential for binding to Id1 and the importance of amino acid residue was I(2) > Q(6) > Y(1) > G(4) > L(5) > E(3). In addition, substitution of E(3) in peptide 3C with D, Q, and R did not improve the binding potency of peptide 3C. MTT assay demonstrated that neither A-substituted nor position 3-substituted analogs of peptide 3C showed increased antiproliferative effect in MCF-7 cancer cells. CD results indicated that peptide 3C exhibited the highest content of α-helical structure (39.37%), suggesting that the α-helical structure may contribute to its binding potency for Id1 and Id1-HLH. SAR results provided important information for the development of peptidic inhibitors of Id1 as anticancer agents and demonstrated peptide 3C as a promising lead for further modifications.


Assuntos
Antineoplásicos/farmacologia , Proteína 1 Inibidora de Diferenciação/antagonistas & inibidores , Proteína MyoD/química , Fragmentos de Peptídeos/farmacologia , Sequência de Aminoácidos , Antineoplásicos/síntese química , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Células MCF-7 , Fragmentos de Peptídeos/síntese química , Ligação Proteica , Estrutura Secundária de Proteína , Técnicas de Síntese em Fase Sólida , Relação Estrutura-Atividade
14.
Front Bioeng Biotechnol ; 11: 1148446, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36926691

RESUMO

Rapid and low-cost diagnosis of coronavirus disease 2019 (COVID-19) is essential to identify infected subjects, particularly asymptomatic cases, primarily to arrest the spread of the disease through local transmission. Antibody-based chromatographic serological tests, as an alternative to the RT-PCR technique, offer only limited help due to high false positives. We propose to exploit our cholesteric liquid crystal biosensor platform for one-step, wash-free, rapid detection of the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) virus directly with minimal sample pre-processing. As mentioned above, cholesteric liquid crystals are an effective and innovative approach to healthcare as a rapid test for the diagnosis of COVID-19 and other diseases.

15.
Adv Healthc Mater ; 12(28): e2301504, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37421244

RESUMO

Traditional thrombolytic therapeutics for vascular blockage are affected by their limited penetration into thrombi, associated off-target side effects, and low bioavailability, leading to insufficient thrombolytic efficacy. It is hypothesized that these limitations can be overcome by the precisely controlled and targeted delivery of thrombolytic therapeutics. A theranostic platform is developed that is biocompatible, fluorescent, magnetic, and well-characterized, with multiple targeting modes. This multimodal theranostic system can be remotely visualized and magnetically guided toward thrombi, noninvasively irradiated by near-infrared (NIR) phototherapies, and remotely activated by actuated magnets for additional mechanical therapy. Magnetic guidance can also improve the penetration of nanomedicines into thrombi. In a mouse model of thrombosis, the thrombosis residues are reduced by ≈80% and with no risk of side effects or of secondary embolization. This strategy not only enables the progression of thrombolysis but also accelerates the lysis rate, thereby facilitating its prospective use in time-critical thrombolytic treatment.


Assuntos
Terapia Trombolítica , Trombose , Camundongos , Animais , Medicina de Precisão , Fibrinolíticos/química , Fibrinolíticos/uso terapêutico , Trombose/diagnóstico por imagem , Trombose/tratamento farmacológico , Fenômenos Magnéticos
16.
Biosensors (Basel) ; 12(4)2022 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-35448264

RESUMO

A novel device for cholesteric liquid crystal (LC; CLC)-based biosensing chips for detecting heme oxygenase (HO)-1 within the cerebrospinal fluid (CSF) was invented. In the CLC device, the reorientation of the LCs was strongly influenced by the alignment layer surface and adjacent LCs. When the substrate was coated with the alignment layer, the CLCs oriented homeotropically in a focal conic state. Once HO-1 was immobilized onto the orientation sheet-coated substrate, the CLC changed from a focal conic state to a bright planar state by disrupting the CLCs. The concentration of HO-1 within CSF was shown to be an effective outcome indicator for patients with a spontaneous subarachnoid hemorrhage. We showed that the CLC immunoassaying can be used to measure HO-1 with a lower detection limit of about 10 ng/mL. The linear range was 10 ng/mL to 1 mg/mL. An easy-to-use, rapid-detection, and label-free CLC immunoassay device is proposed.


Assuntos
Cristais Líquidos , Hemorragia Subaracnóidea , Heme Oxigenase-1 , Humanos , Imunoensaio , Cristais Líquidos/química , Hemorragia Subaracnóidea/líquido cefalorraquidiano , Hemorragia Subaracnóidea/diagnóstico
17.
Biosensors (Basel) ; 13(1)2022 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-36671895

RESUMO

The early diagnosis of acute myocardial infarction is difficult in patients with nondiagnostic characteristics. Acute myocardial infarction with chest pain is associated with increased mortality. This study developed a portable test kit based on cholesteric liquid crystals (CLCs) for the rapid detection of AMI through eye observation at home. The test kit was established on dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride-coated substrates covered by a CLC-binding antibody. Cardiac troponin I (cTnI) is a major biomarker of myocardial cellular injury in human blood. The data showed that the concentration of cTnI was related to light transmittance in a positive way. The proposed CLC test kit can be operated with a smartphone; therefore, it has high potential for use as a point-of-care device for home testing. Moreover, the CLC test kit is an effective and innovative device for the rapid testing of acute myocardial infarction-related diseases through eye observation, spectrometer, or even smartphone applications.


Assuntos
Cristais Líquidos , Infarto do Miocárdio , Humanos , Infarto do Miocárdio/diagnóstico , Troponina I , Biomarcadores , Diagnóstico Precoce
18.
Talanta ; 250: 123698, 2022 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-35763951

RESUMO

An early diagnosis of acute myocardial infarction (AMI) or thrombosis is complicated in patients with non-diagnostic features. AMI or thrombosis patients with chest pain are unintentionally discharged and have increased mortality. The study aimed to develop a smartphone biomedical sensor as a rapid test for AMI or thrombosis by naked-eye observation. The system was built on dimethyloctadecyl [3-(trimethoxysilyl)propyl]ammonium chloride (DMOAP)-coated glass substrates, which refers to a nematic liquid crystal (LC)-binding antibody. One of the main biomolecules, cardiac troponin I (cTnI), is a substance in blood in people whose bodies are vulnerable to suffering a myocardial infarction or thrombosis. The other medium, LC, is a sensing biomaterial as an earlier detection method of ameliorating the disadvantages of older methods. Results revealed that the density of cTnI was positively correlated with the coefficient of light transmittance, and it has a high chance of being developed as a point-of-care device for a home inspection as it can be operated with a smartphone. As discussed above, the nematic LC is an effective and innovative healthcare method as a rapid test for diagnosis of AMI or thrombosis related diseases by naked-eye observation.


Assuntos
Cristais Líquidos , Infarto do Miocárdio , Cloreto de Amônio , Materiais Biocompatíveis , Biomarcadores , Humanos , Infarto do Miocárdio/diagnóstico , Smartphone , Troponina I
19.
Int J Nanomedicine ; 17: 6821-6842, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36605560

RESUMO

Across the planet, outbreaks of bacterial illnesses pose major health risks and raise concerns. Photodynamic, photothermal, and metal ion release effects of transition metal-based nanocomposites (TMNs) were recently shown to be highly effective in reducing bacterial resistance and upsurges in outbreaks. Surface plasmonic resonance, photonics, crystal structures, and optical properties of TMNs have been used to regulate metal ion release, produce oxidative stress, and generate heat for bactericidal applications. The superior properties of TMNs provide a chance to investigate and improve their antimicrobial actions, perhaps leading to therapeutic interventions. In this review, we discuss three alternative antibacterial strategies based on TMNs of photodynamic therapy, photothermal therapy, and metal ion release and their mechanistic actions. The scientific community has made significant efforts to address the safety, effectiveness, toxicity, and biocompatibility of these metallic nanostructures; significant achievements and trends have been highlighted in this review. The combination of therapies together has borne significant results to counter antimicrobial resistance (4-log reduction). These three antimicrobial pathways are separated into subcategories based on recent successes, highlighting potential needs and challenges in medical, environmental, and allied industries.


Assuntos
Anti-Infecciosos , Nanocompostos , Elementos de Transição , Nanocompostos/uso terapêutico , Nanocompostos/química , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Antibacterianos/química , Metais/química
20.
J Colloid Interface Sci ; 628(Pt A): 540-552, 2022 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-35940141

RESUMO

Nickel and cobalt layered double hydroxide (NiCo-LDH) has large specific surface area and interlayer spacing, multiple redox states and high ion-exchange capability, but poor electrical conductivity, severe agglomerations and structural defect restrict energy storage ability of NiCo-LDH as active materiel of battery supercapacitor hybrids (BSH). In this study, it is the first time to design sulfur-doped NiCo-LDH and polypyrrole nanotubes composites (NiCo-LDH-S/PNTs) from zeolitic imidazolate framework-67 (ZIF-67) as the efficient active material of BSH using electrospinning and hydrothermal processes. Effects of sulfur doping amounts are investigated. The one-dimensional hollow polypyrrole decorated with NiCo-LDH-S sheets with high aspect ratio provides straight charge-transfer routes and abundant contacts with electrolyte. The highest specific capacitance (CF) of 1936.3 F/g (specific capacity of 322.8 mAh/g) is achieved for the NiCo-LDH-S/PNTs with sulfur doping amount of 7% at 10 mV/s. The BSH comprising graphene LDH negative electrode and NiCo-LDH-S/PNTs positive electrode shows the maximum energy density of 16.28 Wh/kg at 650 W/kg. The CF retention of 74% and Coulombic efficiency of 90% are also achieved after 8000 charge/discharge cycles.

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