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1.
Nanomaterials (Basel) ; 14(12)2024 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-38921900

RESUMO

A composite material of tungsten carbide and mesoporous carbon was synthesized by the sol-gel polycondensation of resorcinol and formaldehyde, using cetyltrimethylammonium bromide as a surfactant and Ludox HS-40 as a porogen, and served as a support for Pd-based electrodes. Phosphorus-modified Pd particles were deposited onto the support using an NH3-mediated polyol reduction method facilitated by sodium hypophosphite. Remarkably small Pd nanoparticles with a diameter of ca. 4 nm were formed by the phosphorus modification. Owing to the high dispersion of Pd and its strong interaction with tungsten carbide, the Pd nanoparticles embedded in the tungsten carbide/mesoporous carbon composite exhibited a hydrogen oxidation activity approximately twice as high as that of the commercial Pt/C catalyst under the anode reaction conditions of proton exchange membrane fuel cells.

2.
J Colloid Interface Sci ; 672: 107-116, 2024 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-38833730

RESUMO

Developing sustainable metal-free carbon-based electrocatalysts is essential for the deployment of metal-air batteries such as zinc-air batteries (ZABs), among which doping of heteroatoms has attracted tremendous interest over the past decade. However, the effect of the heteroatom covalent bonds in carbon matrix on catalysis was neglected in most studies. Here, an efficient metal-free oxygen reduction reaction (ORR) catalyst is demonstrated by the N-P bonds anchored carbon (termed N,P-C-1000). The N,P-C-1000 catalyst exhibits superior specific surface area of 1362 m2 g-1 and ORR activity with a half-wave potential of 0.83 V, close to that of 20 wt% Pt/C. Theoretical computations reveal that the p-band center for C-2p orbit in N,P-C-1000 has higher interaction strength with the intermediates, thus reducing the overall reaction energy barrier. The N,P-C-1000 assembled primary ZAB can attain a large peak power density of 121.9 mW cm-2 and a steady discharge platform of ∼1.20 V throughout 120 h. Besides, when served as the cathodic catalyst in a solid-state ZAB, the battery shows flexibility, conspicuous open circuit potential (1.423 V), and high peak power density (85.8 mW cm-2). Our findings offer a strategy to tune the intrinsic structure of carbon-based catalysts for improved electrocatalytic performance and shed light on future catalysts design for energy storage technologies beyond batteries.

3.
Mikrochim Acta ; 191(7): 428, 2024 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-38940957

RESUMO

A novel nitrogen-doped ordered mesoporous carbon (OMC) pore-embedded growth Pt-Ru-Fe nanoparticles (Pt1-Ru7.5-Fex@N-OMCs) composite was designed and synthesized for the first time. SBA-15 was used as a template, and dopamine was used as a carbon and nitrogen source and metal linking reagent. The oxidative self-polymerization reaction of dopamine was utilized to polymerize dopamine into two-dimensional ordered SBA-15 template pores. Iron porphyrin was introduced as an iron source at the same time as polymerization of dopamine, which was introduced inside and outside the pores using dopamine-metal linkage. Carbonization of polydopamine, nitrogen doping and iron nanoparticle formation were achieved by one-step calcination. Then the templates were etched to form Fex@N-OMCs, and finally the Pt1-Ru7.5-Fex@N-OMCs composites were stabilized by the successful introduction of platinum-ruthenium nanoparticles through the substitution reaction. The composite uniformly embeds the transition metal nanoparticles inside the OMC pores with high specific surface area, which limits the size of the metal nanoparticles inside the pores. At the same time, the metal nanoparticles are also loaded onto the surface of the OMCs, realizing the uniform loading of metal nanoparticles both inside and outside the pores. This enhances the active sites of the composite, promotes the mass transfer process inside and outside the pores, and greatly enhances the electrocatalytic performance of the catalyst. The material shows high electrocatalytic performance for adrenaline, which is characterized by a wide linear range, high sensitivity and low detection limit, and can realize the detection of actual samples.

4.
Pharmaceuticals (Basel) ; 17(6)2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38931400

RESUMO

This study assessed the effectiveness of a trastuzumab-targeted 177Lu-labeled mesoporous Carbon@Silica nanostructure (DOTA@TRA/MC@Si) for HER2-positive breast cancer treatment, focusing on its uptake, internalization, and efflux in breast cancer cells. The synthesized PEI-MC@Si nanocomposite was reacted with DOTA-NHS-ester, confirmed by the Arsenazo(III) assay. Following this, TRA was conjugated to the DOTA@PEI-MC@Si for targeting. DOTA@PEI-MC@Si and DOTA@TRA/MC@Si nanocomposites were labeled with 177Lu, and their efficacy was evaluated through in vitro radiolabeling experiments. According to the results, the DOTA@TRA/MC@Si nanocomposite was successfully labeled with 177Lu, yielding a radiochemical yield of 93.0 ± 2.4%. In vitro studies revealed a higher uptake of the [177Lu]Lu-DOTA@TRA/MC@Si nanocomposite in HER2-positive SK-BR-3 cells (44.0 ± 4.6% after 24 h) compared to MDA-MB-231 cells (21.0 ± 2.3%). The IC50 values for TRA-dependent uptake in the SK-BR-3 and BT-474 cells were 0.9 µM and 1.3 µM, respectively, indicating affinity toward HER-2 receptor-expressing cells. The lipophilic distribution coefficients of the radiolabeled nanocomposites were determined to be 1.7 ± 0.3 for [177Lu]Lu-DOTA@TRA/MC@Si and 1.5 ± 0.2 for [177Lu]Lu-DOTA@PEI-MC@Si, suggesting sufficient passive transport through the cell membrane and increased accumulation in target tissues. The [177Lu]Lu-DOTA@TRA/MC@Si nanocomposite showed an uptake into HER2-positive cell lines, marking a valuable step toward the development of a nanoparticle-based therapeutic agent for an improved treatment strategy for HER2-positive breast cancer.

5.
ChemSusChem ; : e202400596, 2024 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-38797710

RESUMO

Over the last years, solid-state electrolytes made of an ionic liquid (IL) confined in a solid (inorganic or polymer) matrix, also known as ionogels, have been proposed to solve the leakage problems occurring at high temperatures in classical electrical double-layer capacitors (EDLCs) with an organic electrolyte, and thereof improve the safety. However, making ionogel-based EDLCs perform with reasonable power at low temperature is still a major challenge due to the high melting point of the confined IL. To overcome these limitations, the present contribution discloses ionogel films prepared in a totally oxygen/moisture-free atmosphere by encapsulating 70 wt % of an equimolar mixture of 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide and 1-ethyl-3-methylimidazolium tetrafluoroborate - [EMIm][BF4]0.5[FSI]0.5 - into a poly(vinylidene fluoride-co-hexafluoropropylene) (PVdF-HFP) network. The further called "binary ionogel" films demonstrated a high flexibility and a good ionic conductivity of 5.8 mS cm-1 at 20 °C. Contrary to the ionogels prepared from either [EMIm][FSI] or [EMIm][BF4], displaying melting at Tm=-16 °C and -7 °C, respectively, the crystallization of confined [EMIm][BF4]0.5[FSI]0.5 is quenched in the binary ionogel, which shows only a glass transition at -101 °C. This quenching enables an increased ionicity and ionic diffusion at the interface with the PVdF host network, leading the binary ionogel membrane to display higher ionic conductivity below -20 °C than the parent binary [EMIm][BF4]0.5[FSI]0.5 liquid. Laminate EDLCs were built with a 100 µm thick binary ionogel separator and electrodes made from a hierarchical micro-/mesoporous MgO-templated carbon containing a reasonable proportion of mesopores to enhance the mass transport of ions, especially at low temperature where the ionic diffusion noticeably decreases. The EDLCs operated up to 3.0 V with ideal EDL characteristics from -40 °C to room temperature. Their output specific energy under a discharge power of 1 kW kg-1 is ca. 4 times larger than with a cell implementing the same carbon electrodes together with the binary [EMIm][BF4]0.5[FSI]0.5 liquid. Hence, this binary ionogel electrolyte concept paves the road for developing safe and flexible solid-state energy storage devices operating at subambient temperatures in extreme environments.

6.
Molecules ; 29(7)2024 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-38611716

RESUMO

Selective oxidation, which is crucial in diverse chemical industries, transforms harmful chemicals into valuable compounds. Heterogeneous sonocatalysis, an emerging sustainable approach, urges in-depth exploration. In this work, we investigated N-doped or non-doped carbonaceous materials as alternatives to scarce, economically sensitive metal-based catalysts. Having synthesized diverse carbons using a hard-template technique, we subjected them to sonication at frequencies of 22, 100, 500, and 800 kHz with a 50% amplitude. Sonochemical reaction catalytic tests considerably increased the catalytic activity of C-meso (non-doped mesoporous carbon material). The scavenger test showed a radical formation when this catalyst was used. N-doped carbons did not show adequate and consistent sonoactivity for the selective oxidation of 4-Hydroxy-3,5 dimethoxybenzyl alcohol in comparison with control conditions without sonication, which might be associated with an acid-base interaction between the catalysts and the substrate and sonoactivity prohibition by piridinic nitrogen in N-doped catalysts.

7.
Artigo em Inglês | MEDLINE | ID: mdl-38597319

RESUMO

A rechargeable aqueous hybrid ion alkaline battery, using a proton and a potassium ion as charge carriers for the anode and cathode, respectively, is proposed in this study by using well-developed potassium nickel hexacyanoferrate as the cathode material and mesoporous carbon sheets as the anode material, respectively. The constructed battery operates in a concentrated KOH solution, in which the energy storage mechanism for potassium nickel hexacyanoferrate involves the redox reaction of Fe2+/Fe3+ associated with potassium ion insertion/extraction and the redox reaction of Ni(OH)2/NiOOH. The mechanism for the carbon anode is electrochemical hydrogen storage. The cathode made of potassium nickel hexacyanoferrate exhibits both an ultrahigh capacity of 232.7 mAh g-1 under 100 mA g-1 and a consistent performance of 214 mAh g-1 at 2000 mA g-1 (with a capacity retention of 92.8% after 200 cycles). The mesoporous carbon sheet anode exhibits a capacity of 87.6 mAh·g-1 at 100 mA g-1 with a good rate and cyclic performance. The full cell provides an operational voltage of 1.55 V, a capacity of 93.6 mAh g-1 at 100 mA g-1, and 82.4% capacity retention after 1000 cycles at 2000 mA g-1 along with a low self-discharge rate. The investigation and discussion about the energy storage mechanisms for both electrode materials are also provided.

8.
Mikrochim Acta ; 191(4): 228, 2024 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-38558104

RESUMO

A cutting-edge electrochemical method is presented for precise quantification of amitraz (AMZ), a commonly used acaricide in veterinary medicine and agriculture. Leveraging a lab-made screen-printed carbon electrode modified with a synergistic blend of perylene tetracarboxylic acid (PTCA), mesoporous carbon (MC), and Nafion, the sensor's sensitivity was significantly improved. Fine-tuning of PTCA, MC, and Nafion ratios, alongside optimization of the pH of the supporting electrolyte and accumulation time, resulted in remarkable sensitivity enhancements. The sensor exhibited a linear response within the concentration range 0.01 to 0.70 µg mL-1, boasting an exceptionally low limit of detection of 0.002 µg mL-1 and a limit of quantification of 0.10 µg mL-1, surpassing maximum residue levels permitted in honey, tomato, and longan samples. Validation with real samples demonstrated high recoveries ranging from 80.8 to 104.8%, with a relative standard deviation below 10%, affirming the method's robustness and precision. The modified PTCA/MC/Nafion@SPCE-based electrochemical sensor not only offers superior sensitivity but also simplicity and cost-effectiveness, making it a pivotal tool for accurate AMZ detection in food samples. Furthermore, beyond the scope of this study, the sensor presents promising prospects for wider application across various electrochemical analytical fields, thereby significantly contributing to food safety and advancing agricultural practices.


Assuntos
Carbono , Polímeros de Fluorcarboneto , Perileno , Toluidinas , Carbono/química , Perileno/química , Eletrodos
9.
Int J Biol Macromol ; 267(Pt 1): 131471, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38599419

RESUMO

The conversion of glucose into fructose can transform cellulose into high-value chemicals. This study introduces an innovative synthesis method for creating an MgO-based ordered mesoporous carbon (MgO@OMC) catalyst, aimed at the efficient isomerization of glucose into fructose. Throughout the synthesis process, lignin serves as the exclusive carbon precursor, while Mg2+ functions as both a crosslinking agent and a metallic active center. This enables a one-step synthesis of MgO@OMC via a solvent-induced evaporation self-assembly (EISA) method. The synthesized MgO@OMCs exhibit an impeccable 2D hexagonal ordered mesoporous structure, in addition to a substantial specific surface area (378.2 m2/g) and small MgO nanoparticles (1.52 nm). Furthermore, this catalyst was shown active, selective, and reusable in the isomerization of glucose to fructose. It yields 41 % fructose with a selectivity of up to 89.3 % at a significant glucose loading of 7 wt% in aqueous solution over MgO0.5@OMC-600. This performance closely rivals the current maximum glucose isomerization yield achieved with solid base catalysts. Additionally, the catalyst retains a fructose selectivity above 60 % even after 4 cycles, a feature attributable to its extended ordered mesoporous structure and the spatial confinement effect of the OMCs, bestowing it with high catalytic efficiency.


Assuntos
Carbono , Frutose , Glucose , Lignina , Óxido de Magnésio , Frutose/química , Lignina/química , Glucose/química , Carbono/química , Porosidade , Óxido de Magnésio/química , Catálise , Isomerismo
10.
Heliyon ; 10(5): e26690, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38455557

RESUMO

One of the most promising solutions to the current energy crisis is an efficient catalytic transformation of abundant low-cost renewable raw biomass into high-quality biofuel. Herein, a highly effective catalyst was constructed systematically for the selective synthesis of 2,5-dimethylfuran (DMF) biofuel from biomass-derived 5-hydroxymethylfurfural (HMF) via green catalytic transfer hydrogenolysis (CTH) using a nitrogen-doped ordered mesoporous carbon (N-CMK-1) decorated ruthenium (Ru)-based catalyst in i-propanol as hydrogen source. The structures and properties of different catalysts were characterized by different characterization techniques such as FTIR, XRD, N2-sorption, CO2-sorption, TGA, TEM, ICP-AES, CHNO analysis, and acid-base back titration. A complete HMF conversion with a high DMF yield of 88% was achieved under optimized reaction conditions. Regarding substrate conversion and product yield, the influence of reaction temperature, time, and hydrogen donors was thoroughly investigated. The nitrogen-promoted carbon support enhanced the dispersion of Ru due to the formation of appropriate basic site density which could efficiently promote the activation of alcohol hydroxyl in i-propanol and subsequent release of active hydrogen species. In the meantime, highly dispersed surface Ru nanoparticles (NPs) were beneficial for hydrogen transfer and activation of both carbonyl and hydroxyl groups in HMF. Moreover, Arrhenius kinetic analysis was studied by identifying 5-methyl furfural (5-MF) and 2,5-bishydroxymethylfuran (BHMF) as two key intermediates that dominate a distinct reaction pathway during hydrogenolysis of HMF to DMF via CTH. Furthermore, high stability without obvious loss of activity after three consecutive cycles was observed in a fabricated N-CMK-1 decorated Ru-based catalyst as a result of superior metal-support interaction and the mesoporous framework nature of the catalyst. These findings would not only offer a robust catalyst synthetic approach but also open a new avenue for the exploitation of biomass to specialty chemicals and advanced biofuels.

11.
Huan Jing Ke Xue ; 45(2): 885-897, 2024 Feb 08.
Artigo em Chinês | MEDLINE | ID: mdl-38471927

RESUMO

Using coconut shell and boric acid as raw materials, a new boron-doped coconut shell mesoporous carbon material (B-CSC) was prepared using a simple one-step pyrolysis method for efficient adsorption and removal of tetracycline pollutants in water. The effects of pyrolysis temperature and boron-carbon mass ratio on the adsorption performance under key preparation conditions were systematically studied, and their microstructure and physicochemical properties were characterized using a specific surface area and pore size analyzer (BET), field emission scanning electron microscopy (SEM), X-ray photon spectroscopy (XPS), Raman spectrometer (Raman), and Zeta potentiometer (Zeta). The effects of initial pH, different metal cations, and different background water quality conditions on the adsorption effect were systematically investigated. Combined with material characterization and correlation analysis, the enhanced adsorption mechanism was discussed and analyzed in depth. The results showed that one-step pyrolysis could incorporate boron into the surface and crystal lattice of coconut shell charcoal, resulting in a larger specific surface area and pore volume, and the main forms of boron introduced were H3BO3, B2O3, B, and B4C. The adsorption capacity of B-CSC to tetracycline reached 297.65 mg·g-1, which was 8.9 times that of the original coconut shell mesoporous carbon (CSC). At the same time, the adsorption capacity of B-CSC for rhodamine B (RhB), bisphenol A(BPA), and methylene blue (MB), common pollutants in aquatic environments, was as high as 372.65, 255.24, and 147.82 mg·g-1, respectively. The adsorption process of B-CSC to tetracycline was dominated by physicochemical interaction, mainly involving liquid film diffusion, surface adsorption, mesoporous and microporous diffusion, and active site adsorption, and H3BO3 was the main adsorption site. The adsorption strengthening mechanism mainly reduced the chemical inertness of the carbon network and enhanced its π-π interaction and hydrogen bonding with tetracycline molecules.

12.
Materials (Basel) ; 17(6)2024 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-38541529

RESUMO

This study presents the results of applying the methods of synthesizing mesoporous carbon and mesoporous polymer materials with an extended porous mesostructure as adsorbents for cationic dye molecules. Both types of adsorbents are synthetic materials. The aim of the presented research was the preparation, characterisation, and utilisation of obtained mesoporous adsorbents. The physicochemical properties, morphology, and porous structure characteristics of the obtained materials were determined using low-temperature nitrogen sorption isotherms, X-ray diffraction (XRD), small angle X-ray scattering (SAXS), and potentiometric titration measurements. The morphology and microstructure were imaged using scanning electron microscopy (SEM). The chemical characterisation of the surface chemistry of the adsorbents, which provides information about the surface-active groups, the elemental composition, and the electronic state of the elements, was carried out using X-ray photoelectron spectroscopy (XPS). The adsorption properties of the mesoporous materials were determined using equilibrium and kinetic adsorption experiments for three selected cationic dyes (derivatives of thiazine (methylene blue) and triarylmethane (malachite green and crystal violet)). The adsorption capacity was analysed to the nanostructural and surface properties of used materials. The Generalized Langmuir equation was applied for the analysis of adsorption isotherm data. The adsorption study showed that the carbon materials have a higher sorption capacity for both methylene blue and crystal violet, e.g., 0.88-1.01 mmol/g and 0.33-0.44 mmol/g, respectively, compared to the polymer materials (e.g., 0.038-0.044 mmol/g and 0.038-0.050 mmol/g, respectively). The kinetics of dyes adsorption was closely correlated with the structural properties of the adsorbents. The kinetic data were analysed using various equations: first-order (FOE), second-order (SOE), mixed 1,2-order (MOE), multi-exponential (m-exp), and fractal-like MOE (f-MOE).

13.
J Colloid Interface Sci ; 665: 286-298, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38531274

RESUMO

Tailoring porous host materials, as an effective strategy for storing sulfur and restraining the shuttling of soluble polysulfides in electrolyte, is crucial in the design of high-performance lithium-sulfur (Li-S) batteries. However, for the widely studied conductive hosts such as mesoporous carbon, how the aspect ratio affects the confining ability to polysulfides, ion diffusion as well as the performances of Li-S batteries has been rarely studied. Herein, ordered mesoporous carbon (OMC) is chosen as a proof-of-concept prototype of sulfur host, and its aspect ratio is tuned from over âˆ¼ 2 down to below âˆ¼ 1.2 by using ordered mesoporous silica hard templates with variable length/width scales. The correlation between the aspect ratio of OMCs and the electrochemical performances of the corresponding sulfur-carbon cathodes are systematically studied with combined electrochemical measurements and microscopic characterizations. Moreover, the evolution of sulfur species in OMCs at different discharge states is scrutinized by small-angle X-ray scattering. This study gives insight into the aspect ratio effects of mesoporous host on battery performances of sulfur cathodes, providing guidelines for designing porous host materials for high-energy sulfur cathodes.

14.
Molecules ; 29(3)2024 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-38338360

RESUMO

Currently, the obvious side effects of anti-tumor drugs, premature drug release, and low tumor penetration of nanoparticles have largely reduced the therapeutic effects of chemotherapy. A drug delivery vehicle (MCN-SS-GQDs) was designed innovatively. For this, the mesoporous carbon nanoparticles (MCN) with the capabilities of superior photothermal conversion efficiency and high loading efficiency were used as the skeleton structure, and graphene quantum dots (GQDs) were gated on the mesopores via disulfide bonds. The doxorubicin (DOX) was used to evaluate the pH-, GSH-, and NIR-responsive release performances of DOX/MCN-SS-GQDs. The disulfide bonds of MCN-SS-GQDs can be ruptured under high glutathione concentration in the tumor microenvironment, inducing the responsive release of DOX and the detachment of GQDs. The local temperature of a tumor increases significantly through the photothermal conversion of double carbon materials (MCN and GQDs) under near-infrared light irradiation. Local hyperthermia can promote tumor cell apoptosis, accelerate the release of drugs, and increase the sensitivity of tumor cells to chemotherapy, thus increasing treatment effect. At the same time, the detached GQDs can take advantage of their extremely small size (5-10 nm) to penetrate deeply into tumor tissues, solving the problem of low permeability of traditional nanoparticles. By utilizing the photothermal properties of GQDs, synergistic photothermal conversion between GQDs and MCN was realized for the purpose of synergistic photothermal treatment of superficial and deep tumor tissues.


Assuntos
Antineoplásicos , Grafite , Hipertermia Induzida , Nanopartículas , Neoplasias , Pontos Quânticos , Humanos , Pontos Quânticos/química , Grafite/química , Antineoplásicos/farmacologia , Antineoplásicos/química , Doxorrubicina , Nanopartículas/química , Fototerapia , Carbono/química , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Dissulfetos , Microambiente Tumoral
15.
J Colloid Interface Sci ; 663: 1-8, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38387182

RESUMO

We developed a new method to synthesize polyethylene glycol modified ultra small iron embedded in mesoporous carbon nanoparticle (C/Fe-PEG NP) for hydrogen (H2) assisted photothermal synergistic therapy. Herein, we use a simple in-situ reduction method to obtain the C/Fe NP in one-step carbonizing process, which is further modified by the biocompatible polyethylene glycol (PEG) on the surface of C/Fe NP to acquire high stability in physiological solutions. Utilizing the excellent photothermal property from the mesoporous carbon and the controllable H2 release property in the weakly acidic tumor microenvironment by the ultra-small Fe, the obtained C/Fe-PEG NPs can effective kill the cancer cells, meanwhile, protect normal cells without drugs. This selective anti-cancer mechanism of C/Fe-PEG NPs may because the produced H2 selective change the mitochondrial energy metabolism. In vivo results prove that the C/Fe-PEG NPs achieve excellent tumor ablation therapeutic effect and normal tissue protecting ability benefit from the H2-assisted photothermal therapy, promising the use of novel nanomaterials with more safety method for future cancer therapy.


Assuntos
Nanopartículas , Terapia Fototérmica , Ferro/farmacologia , Fototerapia , Polietilenoglicóis , Carbono/farmacologia , Linhagem Celular Tumoral , Doxorrubicina/uso terapêutico
16.
J Food Sci Technol ; 61(3): 573-584, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38327853

RESUMO

In this study, determination of aromatic compounds in cheese samples was performed by headspace solid-phase microextraction (HS-SPME) using a new adsorbent as a novel coated fiber in combination with a gas chromatography/mass spectrometry or flame ionization detector to evaluate the changes during ripening. Brine and ultrafiltrated (UF) cheese were sampled via HS-SPME and analyzed by gas chromatography/mass spectrometry. Polysulfone and mesoporous carbon nitride were used as two types of fibers for coating. The results showed that the pH had significant decreased during the 120 days for brine cheese (p < 0.001), and during the 90 days (p < 0.001) for UF cheese. Acidity was relatively stable during the ripening period for both cheeses (p > 0.05). Protein content decreased during the ripening period for both cheeses (p < 0.001). Moisture content also significantly decreased during the ripening period for both cheeses (p < 0.001). 74 compounds were identified in brine cheese and 27 major components in UF cheese. Fatty acids were the predominant components, followed by aldehydes (n: 17, 22.9%), alcohol (n; 12, 16.2%), ester (n: 11, 14.8%), alkane (n: 7, 9.4%), and ketone (n: 6, 8.1%) for white brine cheese, while for UF cheese fatty acid (n: 12, 44.4%) and aldehyde (n: 5, 18.5%), alcohol (n: 3, 11.1%), ketone (n: 3, 11.1%), ester (n: 2, 7.4%) and alkane (n: 1, 3.7%).

17.
Polymers (Basel) ; 16(3)2024 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-38337244

RESUMO

Monodisperse mesoporous carbon spheres (MCS) were synthesized and their potential applications in ethylene propylene diene monomer (EPDM) foam were evaluated. The obtained MCS exhibited a high specific surface area ranging from 621-to 735 m2/g along with large pore sizes. It was observed that the incorporation of MCS into EPDM foam rubber significantly enhances its mechanical properties. The prepared MCS-40 rubber composites exhibit the highest tear strength of 210 N/m and tensile strength of 132.72 kPa, surpassing those of other samples. The enhancement mechanism was further investigated by employing computer simulation technology. The pores within the MCS allowed for the infiltration of EPDM molecular chains, thereby strengthening the interaction forces between the filler and matrix. Moreover, a higher specific surface area resulted in greater adsorption of molecular chains onto the surface of these carbon spheres. This research offers novel insights for understanding the enhancement mechanism of monodisperse mesoporous particles/polymer composites (MCS/EPDM) and highlights their potential application in high-performance rubber composites.

18.
Int J Biol Macromol ; 259(Pt 1): 129093, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38185306

RESUMO

MOF-derived heteroatom-doped mesoporous carbons have gained the significant consideration in heterogenous catalytic reactions because of their multipurpose features. Especially, the high Specific Surface Area (SSA) of these materials provides abundant activated sites for the catalytic reactions, while the mesoporous structure allows for the effective mass transfer, enhancing the overall capability of the catalytic process. Herein, the efficient NiO/CN-T (T referred to the pyrolysis temperature) was prepared by facile pyrolysis of MOF/CS composite (Ni-MOF (74), Chitosan) in the presence of excess amount of starch as the carbon precursor. The NiO/CN-T as heterogenous catalyst has desired SSA varied from 1094 to 491 m2.g-1. The optimized catalyst (NiO/CN-600) possesses the superior catalytic activity toward the oxidation of the BnOHs due to its high SSA (1094 m2.g-1), which can notably rectify the mass transfer proficiency. Additionally, the NiO/CN-600 heterogenous catalyst also represents the acceptable chemical stability. So, it was demonstrated that such an innovative strategy can provide several versatile tunability insights for the preparation of MOF/biopolymer-derived heterogenous catalysts.


Assuntos
Quitosana , Álcool Benzílico , Carbono , Catálise , Oxirredução
19.
Small ; 20(1): e2304558, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37649197

RESUMO

Near-neutral zinc-air batteries (ZABs) have garnered significant research interest due to their high energy density, exceptional electrochemical reversibility, and adaptability to ambient air. However, these batteries suffer from substantial electrochemical polarization, low energy efficiency, and poor rate performance. In this study, a mesoporous carbon (meso-C) with a high specific surface area (1081 m2 g-1 ) and abundant porous structure for the cathode of near-neutral ZABs using a scalable synthesis method is prepared. The meso-C-based cathode is endowed with stable hydrophobicity and abundant electrochemical active sites, which considerably improve the energy efficiency, rate performance, and cycle life of the battery compare to commercial carbon black-based cathode when applied to near-neutral ZABs with 1 mol kg-1 (1 m) zinc acetate and 1 m zinc trifluoromethanesulfonate electrolytes. Additionally, the mesopores of meso-C facilitate the construction of better three-phase reaction interfaces and contribute to better electrochemical reversibility. The work presents a general and scalable approach for carbon materials in the cathode of near-neutral ZABs.

20.
Bioelectrochemistry ; 156: 108613, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37995504

RESUMO

Cancer antigen 125 (CA125)1 is the most important biological screening indicator used to monitor epithelial ovarian cancers, and it plays a vital role in distinguishing ovarian cancers from benign diseases. Biosensors show great potential in the analysis and detection of disease markers. In this study, we designed electrochemical sensors based on three-dimensional amino-functionalized reduced graphene oxide (3D-rGOF-NH2),2 MgAl layered double hydroxide nanocomposites containing ordered mesoporous carbon (CMK-3),3 and ferrocene carboxylic acids(Fc-COOH)4for the detection of CA125. 3D-rGOF-NH2 possesses good conductivity, a large surface area, and high porosity, enabling more immobilized nanoparticles to be deposited on its surface with excellent stability. CMK-3@Fc@MgAl-LDH nanocomposite was used as a carrier to enhance the immobilization of antibodies and the loading of Fc, conductors to enhance conductivity, and enhancers to gradually amplify the signal of Fc. The surface morphology, elemental composition, and surface groups of the materials were characterized using scanning electron microscopy (SEM),5 transmission electron microscopy (TEM),6 and X-ray diffraction (XRD)7 techniques. The response signal of the electrochemical sensor was measured by DPV. Under the optimal conditions, the electrochemical sensor obtained a linear detection range of 0.01 U/mL-100 U/mL with a detection limit of 0.00417 U/mL.


Assuntos
Técnicas Biossensoriais , Grafite , Nanopartículas Metálicas , Nanocompostos , Humanos , Antígeno Ca-125 , Técnicas Biossensoriais/métodos , Anticorpos Imobilizados/química , Imunoensaio/métodos , Nanocompostos/química , Grafite/química , Técnicas Eletroquímicas/métodos , Limite de Detecção , Nanopartículas Metálicas/química , Ouro/química
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