Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 314
Filtrar
1.
Artículo en Inglés | MEDLINE | ID: mdl-39369341

RESUMEN

Poly(ethylene oxide) (PEO)-based solid polymer electrolytes (SPEs) are among the most promising materials for solid-state lithium metal batteries (LMBs) due to their inherent safety advantages; however, they suffer from insufficient room-temperature ionic conductivity (up to 10-6 S cm-1) and limited oxidation stability (<4 V). In this study, a novel "polymer-in-high-concentrated ionic liquid (IL)" (PiHCIL) electrolyte composed of PEO, N-propyl-N-methylpyrrolidinium bis(fluorosulfonyl) imide (C3mpyrFSI) IL, and LiFSI is designed. The EO/[Li/IL] ratio has been widely varied, and physical and electrochemical properties have been explored. The Li-coordination and solvation structure has been explored through Fourier-transform infrared spectroscopy and solid-state magic-angle spinning nuclear magnetic resonance. The newly designed electrolyte provides a promisingly high oxidative stability of 5.1 V and offers high ambient temperature ionic conductivity of 5.6 × 10-4 S cm-1 at 30 °C. Li|Li symmetric cell cycling shows very stable and reversible cycling of Li metal over 100 cycles and a smooth dendrite-free deposition morphology. All-solid-state cells using a composite lithium iron phosphate cathode exhibit promising cycling with 99.2% capacity retention at a C/5 rate over 100 cycles. Therefore, the novel approach of PiHCIL enables a new pathway to design high-performing SPEs for high-energy-density all-solid-state LMBs.

2.
J Colloid Interface Sci ; 678(Pt C): 1096-1111, 2024 Sep 12.
Artículo en Inglés | MEDLINE | ID: mdl-39341141

RESUMEN

HYPOTHESIS: Asphaltenes are primary stabilizers in water-in-oil (W/O) emulsions that cause corrosion and fouling issues. In oil sands industry, oil/water separation processes are generally conducted at high temperatures. A high temperature is expected to impact the interactions between asphaltenes and emulsion breakers (EBs), consequently influencing demulsification performance. EXPERIMENTS: The adsorption and interactions of asphaltenes and a PEO-PPO type EB (Pluronic F68) at the oil-water interface were investigated at various temperatures, using tensiometer, quartz crystal microbalance with energy dissipation (QCM-D), and atomic force microscopy (AFM). The effect of temperature on EB's demulsification performance was explored through bottle tests. Additionally, demulsification mechanisms were studied using direct force measurements with the droplet probe AFM technique. FINDINGS: Dynamic interfacial tension and QCM-D results demonstrate that the PEO-PPO type EB exhibits higher interfacial activity than asphaltenes and can disrupt rigid asphaltene films at the oil-water interfaces. Elevated temperatures accelerate the displacement of adsorbed asphaltenes by EB molecules, leading to sparse interfacial films, rapid droplet coalescence, and improved demulsification efficiency (supported by AFM and bottle test results). This work provides valuable insights into interfacial interactions between asphaltenes and EB at different temperatures, enhancing the understanding of demulsification mechanisms and offering useful implications for the development of efficient EBs to enhance oil/water separation performance.

3.
Colloids Surf B Biointerfaces ; 244: 114176, 2024 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-39217726

RESUMEN

Annonaceous acetogenins (ACGs) have great potential in the treatment of gliomas, but are extremely insoluble and difficult for delivery in vivo. Poly(ethylene oxide)-b-poly(butylene oxide) (PEO-PBO) is an amphiphilic polymer and can reduce the clearance of nanoparticles by mononuclear phagocyte system. To explore an efficient and safe nanomedicine for glioma, ACGs-loaded nanomicelles (ACGs/EB-NCs) was constructed using PEO-PBO as a carrier, and the effect of PEO-PBO content on the targeting and anti-glioma activity were also compared. ACGs/EB5-NCs, ACGs/EB10-NCs and ACGs/EB20-NCs, the three nanomicellels prepared with different ACGs/EB feeding ratios, had average particle sizes of 148.8±0.5 nm, 32.7±4.1 nm, and 27.1±0.3 nm, respectively. The three ACGs/EB-NCs were spherical in shape, with drug loading content close to the theoretical drug loading content, encapsulation efficiency greater than 97 %, and good stability in physiological media. The cumulative release rates of ACGs/EB5-NCs, ACGs/EB10-NCs and ACGs/EB20-NCs were 78.2 %, 63.4 %, and 56.3 % within 216 hours, respectively. The inhibitory effects of three ACGs/EB-NCs on U87 MG cells were similar and stronger than free ACGs (P<0.05), with half inhibitory concentration of 0.17, 0.18, and 0.16 ng/mL (P>0.05), respectively. In U87 MG tumor­bearing mice, ACGs/EB5-NC, ACGs/EB10-NCs and ACGs/EB20-NCs showed a similar tumor inhibition rate of 61.1±5.9 %, 56.2±8.6 % and 64.3±9.4 % (P>0.05), with good safety. Three ACGs/EB-NCs exhibited excellent liver escape ability and tumor targeting ability, with the tumor targeting index greater than 1.5. Three ACGs/EB-NCs were successfully prepared with strong anti-glioma activity and tumor targeting properties, which are expected to provide new options for the clinical treatment of gliomas. The content of PEO-PBO in micelles did not have a significant effect on the tumor targeting and anti-glioma activity of ACGs/EB-NCs.


Asunto(s)
Acetogeninas , Glioma , Micelas , Nanopartículas , Polietilenglicoles , Glioma/tratamiento farmacológico , Glioma/patología , Animales , Acetogeninas/química , Acetogeninas/farmacología , Polietilenglicoles/química , Humanos , Ratones , Nanopartículas/química , Tamaño de la Partícula , Línea Celular Tumoral , Antineoplásicos/farmacología , Antineoplásicos/química , Butileno Glicoles/química , Butileno Glicoles/farmacología , Proliferación Celular/efectos de los fármacos , Ratones Endogámicos BALB C , Supervivencia Celular/efectos de los fármacos , Ratones Desnudos , Neoplasias Encefálicas/tratamiento farmacológico , Neoplasias Encefálicas/patología , Portadores de Fármacos/química , Ensayos de Selección de Medicamentos Antitumorales
4.
Small ; : e2404297, 2024 Sep 16.
Artículo en Inglés | MEDLINE | ID: mdl-39282822

RESUMEN

Polymer solid-state electrolytes offer great promise for battery materials with high energy density, mechanical stability, and improved safety. However, their low ion conductivities have so far limited their potential applications. Here, it is shown for poly(ethylene oxide) block copolymers that the super-stoichiometric addition of lithium bis(trifluoromethanesulfonyl) imide (LiTFSI) as lithium salt leads to the formation of a crystalline PEO block copolymer phase with exceptionally high ion conductivities and low activation energies. The addition of LiTFSI further induces block copolymer phase transitions into bi-continuous Fddd and gyroid network morphologies, providing continuous 3D conduction pathways. Both effects lead to solid-state block copolymer electrolyte membranes with ion conductivities of up to 1·10-1 S cm-1 at 90 °C, decreasing only moderately to 4·10-2 S cm-1 at room temperature, and to >1·10-3 S cm-1 at -20 °C, corresponding to activation energies as low as 0.19 eV. The co-crystallization of PEO and LiTFSI with ether and carbonate solvents is observed to play a key role to realize a super-ionic conduction mechanism. The discovery of PEO super-ionic conductivity at high lithium concentrations opens a new pathway for fabrication of solid polymer electrolyte membranes with sufficiently high ion conductivities over a broad temperature range with widespread applications in electrical devices.

5.
Int J Mol Sci ; 25(15)2024 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-39125961

RESUMEN

Garlic is a vegetable with numerous pro-health properties, showing high antioxidant capacity, and cytotoxicity for various malignant cells. The inhibition of cell proliferation by garlic is mainly attributed to the organosulfur compounds (OSCs), but it is far from obvious which constituents of garlic indeed participate in the antioxidant and cytotoxic action of garlic extracts. This study aimed to obtain insight into this question by examining the antioxidant activity and cytotoxicity of six OSCs and five phenolics present in garlic. Three common assays of antioxidant activity were employed (ABTS● decolorization, DPPH● decolorization, and FRAP). Cytotoxicity of both classes of compounds to PEO1 and SKOV-3 ovarian cancer cells, and MRC-5 fibroblasts was compared. Negligible antioxidant activities of the studied OSCs (alliin, allicin, S-allyl-D-cysteine, allyl sulfide, diallyl disulfide, and diallyl trisulfide) were observed, excluding the possibility of any significant contribution of these compounds to the total antioxidant capacity (TAC) of garlic extracts estimated by the commonly used reductive assays. Comparable cytotoxic activities of OSCs and phenolics (caffeic, p-coumaric, ferulic, gallic acids, and quercetin) indicate that both classes of compounds may contribute to the cytotoxic action of garlic.


Asunto(s)
Compuestos Alílicos , Antioxidantes , Disulfuros , Ajo , Fenoles , Extractos Vegetales , Sulfuros , Ácidos Sulfínicos , Ajo/química , Humanos , Antioxidantes/farmacología , Antioxidantes/química , Fenoles/farmacología , Fenoles/química , Disulfuros/farmacología , Disulfuros/química , Línea Celular Tumoral , Extractos Vegetales/farmacología , Extractos Vegetales/química , Ácidos Sulfínicos/farmacología , Ácidos Sulfínicos/química , Sulfuros/farmacología , Sulfuros/química , Compuestos Alílicos/farmacología , Compuestos Alílicos/química , Compuestos de Azufre/farmacología , Compuestos de Azufre/química , Cisteína/análogos & derivados , Cisteína/química , Cisteína/farmacología , Supervivencia Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Fibroblastos/efectos de los fármacos , Fibroblastos/metabolismo
6.
ACS Appl Mater Interfaces ; 16(33): 44236-44248, 2024 Aug 21.
Artículo en Inglés | MEDLINE | ID: mdl-39121451

RESUMEN

Hybrid battery cells that combine a garnet-type Li7La3Zr2O12 (LLZO) solid electrolyte with other solid, polymer or liquid electrolytes are increasingly investigated. In such cells with layered electrolytes, ensuring a low-resistive heteroionic interface between neighboring electrolytes is crucial for preventing major additional overpotentials during operation. Electrochemical impedance spectroscopy is frequently used to extract such parameters, usually on multilayer symmetrical model cells that contain the different electrolytes stacked in series. Unfortunately, the impedance contributions of the heteroionic interfaces often overlap with those of the electrolyte|electrode interfaces, necessitating the use of sophisticated four-point cells that probe the electrochemical potential away from the polarization source. In this work, an alternative solution to this problem is demonstrated by taking advantage of the inherent fast charge transfer kinetics of LLZO with its parent metal electrode. The "resistance-free" nature of a reversible Li|LLZO interface enables a precise evaluation of the heteroionic interface impedance in symmetric two-point cells of the type Li|LLZO|electrolyte|LLZO|Li with negligible electrode contribution. This is exemplified for symmetric multilayer cells containing tantalum-doped LLZO and a poly(ethylene oxide) (PEO)-based dry polymer electrolyte. Validation and comparison of impedance data with results from symmetric four-point cells and two-point cells with ion-blocking electrodes demonstrate the advantage of the proposed method. Overall, this study presents a simple and reliable method for studying heteroionic interface impedances in LLZO-containing multilayer cells.

7.
ACS Appl Mater Interfaces ; 16(34): 45399-45410, 2024 Aug 28.
Artículo en Inglés | MEDLINE | ID: mdl-39146494

RESUMEN

Solid polymer electrolytes (SPEs) are regarded as a superior alternative to traditional liquid electrolytes of lithium-ion batteries (LIBs) due to their improved safety features. The practical implementation of SPEs faces challenges, such as low ionic conductivity at room temperature (RT) and inadequate interfacial contact, leading to high interfacial resistance across the electrode and electrolyte interfaces. In this study, we addressed these issues by designing a quasi-gel polymer electrolyte (QGPE), a blend of poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP), poly(ethylene oxide) (PEO), and succinonitrile (SN), with the desired mechanical strength, ionic conductivity, and interfacial stability through a simple solution casting technique. The QGPE features a thin solvated PEO layer on its surface, which wets the electrode, reducing the interfacial resistance and ensuring a homogeneous Li-ion flux across the interface. The optimized QGPE exhibits a good lithium-ion conductivity of 1.14 × 10-3 S cm-1 with a superior lithium-ion transference number of 0.7 at 25 °C. The Li/QGPE/Li symmetric cell exhibits a highly reversible lithium plating/stripping process for over 1300 h with minimal voltage polarization of ∼20 mV. The Li/QGPE/LiFePO4 full cell demonstrates good rate capability and excellent long-term cycling performance at a 0.1 C rate at 25 °C, maintaining a specific discharge capacity of 148 mAh g-1 over 200 cycles. The effectiveness of QGPE for LIBs is proven using a graphite/QGPE/LiFePO4 4 × 4 cm pouch cell, showcasing outstanding flexibility and tolerance against intentional abuse.

8.
Int J Biol Macromol ; 278(Pt 1): 134693, 2024 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-39142485

RESUMEN

It aims to prepare the chitosan (CS) and polyethylene oxide (PEO) hydrogel membranes with different CS/PEO blend ratios (100:0, 95:5, 90:10, 80:20 and 70:30) via solvent casting. The physicochemical properties of these membranes were investigated using various characterization techniques: Fourier Transform Infrared Spectroscopy (FTIR), X-ray diffraction (XRD), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), atomic force microscopy (AFM), energy dispersive X-ray (EDX), contact angle, and tensile testing. The interaction of PEO and chitosan was investigated by DSC in terms of freezing bound, freezing free, and non-freezing PEO fraction. The cross-sectional surface morphology of membranes displayed a smoother surface with increasing PEO content up to 20 %, beyond which nonhomogeneity on the surface was visible. The antifouling behavior of membranes was investigated by bacterial adherence study, which showed an enhanced antifouling nature of membranes with the increase in the PEO content. The peeling strength of the membranes was measured using a 90° angle peeling test, and it was found that 20 % and more PEO content promotes easy removal from the gelatin slab. In addition to this, live/ dead assay of the CS was performed to visualize the presence of live and dead bacteria on the surface. The CS/PEO blend with 20 % PEO content has properties makes it suitable for use as a protective layer on wound dressings to prevent bacterial growth. It's use in wound dressings has the potential to reduce the pain during the time of dressing removal and improve patient outcomes. The present investigation leads to the development of a CS hydrogel matrix which exhibits very interesting interaction with the PEO moiety along with its innovative feature of antifouling and antimicrobial nature.


Asunto(s)
Quitosano , Membranas Artificiales , Polietilenglicoles , Quitosano/química , Quitosano/farmacología , Polietilenglicoles/química , Incrustaciones Biológicas/prevención & control , Adhesión Bacteriana/efectos de los fármacos , Espectroscopía Infrarroja por Transformada de Fourier , Difracción de Rayos X , Hidrogeles/química , Hidrogeles/farmacología , Resistencia a la Tracción
9.
Sensors (Basel) ; 24(14)2024 Jul 20.
Artículo en Inglés | MEDLINE | ID: mdl-39066112

RESUMEN

This paper predicts the network security posture of an ICS, focusing on the reliability of Industrial Control Systems (ICSs). Evidence reasoning (ER) and belief rule base (BRB) techniques are employed to establish an ICS network security posture prediction model, ensuring the secure operation and prediction of the ICS. This model first integrates various information from the ICS to determine its network security posture value. Subsequently, through ER iteration, information fusion occurs and serves as an input for the BRB prediction model, which necessitates initial parameter setting by relevant experts. External factors may influence the experts' predictions; therefore, this paper proposes the Projection Equalization Optimization (P-EO) algorithm. This optimization algorithm updates the initial parameters to enhance the prediction of the ICS network security posture through the model. Finally, industrial datasets are used as experimental data to improve the credibility of the prediction experiments and validate the model's predictive performance in the ICS. Compared with other methods, this paper's prediction model demonstrates a superior prediction accuracy. By further comparing with other algorithms, this paper has a certain advantage when using less historical data to make predictions.

10.
ACS Biomater Sci Eng ; 10(8): 4901-4915, 2024 Aug 12.
Artículo en Inglés | MEDLINE | ID: mdl-39072479

RESUMEN

Titanium plates are the current gold standard for fracture fixation of the mandible. Magnesium alloys such as WE43 are suitable biodegradable alternatives due to their high biocompatibility and elasticity modulus close to those of cortical bone. By surface modification, the reagibility of magnesium and thus hydrogen gas accumulation per time are further reduced, bringing plate fixation with magnesium closer to clinical application. This study aimed to compare bone healing in a monocortical mandibular fracture model in sheep with a human-standard size, magnesium-based, plasma electrolytic-oxidation (PEO) surface modified miniplate fixation system following 4 and 12 weeks. Bone healing was analyzed using micro-computed tomography and histological analysis with Movat's pentachrome and Giemsa staining. For evaluation of the tissue's osteogenic activity, polychrome fluorescent labeling was performed, and vascularization was analyzed using immunohistochemical staining for alpha-smooth muscle actin. Bone density and bone mineralization did not differ significantly between titanium and magnesium (BV/TV: T1: 8.74 ± 2.30%, M1: 6.83 ± 2.89%, p = 0.589 and T2: 71.99 ± 3.13%, M2: 68.58 ± 3.74%, p = 0.394; MinB: T1: 26.16 ± 9.21%, M1: 22.15 ± 7.99%, p = 0.818 and T2: 77.56 ± 3.61%, M2: 79.06 ± 4.46%, p = 0.699). After 12 weeks, minor differences were observed regarding bone microstructure, osteogenic activity, and vascularization. There was significance with regard to bone microstructure (TrTh: T2: 0.08 ± 0.01 mm, M2: 0.06 ± 0.01 mm; p = 0.041). Nevertheless, these differences did not interfere with bone healing. In this study, adequate bone healing was observed in both groups. Only after 12 weeks were some differences detected with larger trabecular spacing and more vessel density in magnesium vs titanium plates. However, a longer observational time with full resorption of the implants should be targeted in future investigations.


Asunto(s)
Placas Óseas , Magnesio , Mandíbula , Titanio , Animales , Magnesio/farmacología , Titanio/química , Titanio/farmacología , Ovinos , Mandíbula/cirugía , Mandíbula/diagnóstico por imagen , Curación de Fractura/efectos de los fármacos , Propiedades de Superficie , Osteogénesis/efectos de los fármacos , Fracturas Mandibulares/cirugía , Fracturas Mandibulares/diagnóstico por imagen , Microtomografía por Rayos X , Aleaciones/química
11.
Polymers (Basel) ; 16(13)2024 Jul 06.
Artículo en Inglés | MEDLINE | ID: mdl-39000789

RESUMEN

Electrospun drug-eluting fibers have demonstrated potentials in topical drug delivery applications, where drug releases can be modulated by polymer fiber compositions. In this study, blend fibers of polycaprolactone (PCL) and polyethylene oxide (PEO) at various compositions were electrospun from 10 wt% of polymer solutions to encapsulate a model drug of ibuprofen (IBP). The results showed that the average polymer solution viscosities determined the electrospinning parameters and the resulting average fiber diameters. Increasing PEO contents in the blend PCL/PEO fibers decreased the average elastic moduli, the average tensile strength, and the average fracture strains, where IBP exhibited a plasticizing effect in the blend PCL/PEO fibers. Increasing PEO contents in the blend PCL/PEO fibers promoted the surface wettability of the fibers. The in vitro release of IBP suggested a transition from a gradual release to a fast release when increasing PEO contents in the blend PCL/PEO fibers up to 120 min. The in vitro viability of blend PCL/PEO fibers using MTT assays showed that the fibers were compatible with MEF-3T3 fibroblasts. In conclusion, our results explained the scientific correlations between the solution properties and the physicomechanical properties of electrospun fibers. These blend PCL/PEO fibers, having the ability to modulate IBP release, are suitable for topical drug delivery applications.

12.
ACS Appl Mater Interfaces ; 16(25): 32209-32219, 2024 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-38863333

RESUMEN

Solid-state polymer electrolytes (SPEs), such as poly(ethylene oxide) (PEO), have good flexibility when compared to ceramic-type solid electrolytes. Therefore, it could be an ideal solid electrolyte for zero-excess all-solid-state Li metal battery (ZESSLB), also known as anode-free all-solid-state Li battery, development by offering better contact to the Cu current collector. However, the low Coulombic efficiencies observed from polymer type solid-state Li batteries (SSLBs) raise the concern that PEO may consume the limited amount of Li in ZESSLB to fail the system. Here, we designed ZESSLBs by using all-ceramic half-cells and an extra PEO electrolyte interlayer to study the reactivity between PEO and freshly deposited Li under a real battery operating conduction. By shuttling active Li back from the anode to the cathode, the PEO SPEs can be separated from the ZESSLBs for experimental studies without the influence from cathode materials or possible contamination from the usage of Li foil as the anode. Electrochemical cycling of ZESSLBs shows that the capacities of ZESSLBs with solvent-free and solvent-casted PEO SPEs significantly degraded compared to the ones with Li metal as the anode for the all-solid-state Li batteries. The fast capacity degradation of ZESSLBs using different types of PEO SPEs is evidenced to be associated with Li reacting with PEO, residual solvent, and water in PEO and dead Li formation upon the presence or absence of residual solvent. The results suggest that avoiding direct contact between the PEO electrolyte and deposited lithium is necessary when there is only a limited amount of Li available in ZESSLBs.

13.
Small ; 20(35): e2310547, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38712578

RESUMEN

The interfacial instability between PEO-based solid electrolyte (SPE) and high-voltage cathode materials inhibits the longevity of high-energy-density all-solid-state polymer lithium metal batteries (ASSPLBs). Herein, for the first time it is demonstrated, that contact loss caused by gas generation from interfacial side reactions between the high-voltage cathode and solid polymer electrolyte (SPE) can also arise in ASSPLBs. To alleviate the interfacial side reactions, a LiNb0.6Ti0.5O3 (LNTO) layer is well coated on LiNi0.83Co0.07Mn0.1O2 (NCM83), denoted as (CNCM83). The LNTO layer with low electronic conductivity reduces the decomposition drive force of SPE. Furthermore, Ti and Nb in the LNTO layer spontaneously migrate inside the NCM83 surface to form a strong Ti/Nb─O bond, stalling oxygen evolution in high-voltage cathodes. The interfacial degradation phenomena, including SPE decomposition, detrimental phase transition and intragranular cracks of NCM83, and void formation between cathode and SPE, are effectively mitigated by the LNTO layer. Therefore, the growth rate of interfacial resistance (RCEI) decreases from 37.6 Ω h-0.5 for bare NCM83 to 2.4 Ω h-0.5 for CNCM83 at 4.2 V. Moreover, 4.2 V PEO-based ASSPLBs achieve impressive cyclability with high capacity retention of 135 mAh g-1 (75%) even after 300 cycles at 0.5 C.

14.
Biopolymers ; 115(4): e23584, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38695839

RESUMEN

In recent years, cationic polymer vectors have been viewed as a promising method for delivering nucleic acids. With the advancement of synthetic polymer chemistry, we can control chemical structures and properties to enhance the efficacy of gene delivery. Herein, a facile, cost-effective, and scalable method was developed to synthesize PEGylated PDMAEMA polymers (PEO-PDMAEMA-PEO), where PEGylation could enable prolonged polyplexes circulation time in the blood stream. Two polymers of different molecular weights were synthesized, and polymer/eGFP polyplexes were prepared and characterized. The correlation between polymers' molecular weight and physicochemical properties (size and zeta potential) of polyplexes was investigated. Lipofectamine 2000, a commercial non-viral transfection reagent, was used as a standard control. PEO-PDMAEMA-PEO with higher molecular weight exhibited slightly better transfection efficiency than Lipofectamine 2000, and the cytotoxicity study proved that it could function as a safe gene vector. We believe that PEO-PDMAEMA-PEO could serve as a model to investigate more potential in the gene delivery area.


Asunto(s)
Técnicas de Transferencia de Gen , Nylons , Polietilenglicoles , Transfección , Polietilenglicoles/química , Humanos , Nylons/química , Nylons/síntesis química , Transfección/métodos , Metacrilatos/química , Proteínas Fluorescentes Verdes/genética , Proteínas Fluorescentes Verdes/metabolismo , Lípidos/química , Supervivencia Celular/efectos de los fármacos
15.
Polymers (Basel) ; 16(10)2024 May 19.
Artículo en Inglés | MEDLINE | ID: mdl-38794629

RESUMEN

In a solid-state dye-sensitized solar cell, a fast-ion conducting (σ25°C > 10-4 S cm-1) solid redox mediator (SRM; electrolyte) helps in fast dye regeneration and back-electron transfer inhibition. In this work, we synthesized solid Co2+/3+ redox mediators using a [(1 - x)succinonitrile: x poly(ethylene oxide)] matrix, LiX, Co(tris-2,2'-bipyridine)3(bis(trifluoromethyl) sulfonylimide)2, and Co(tris-2,2'-bipyridine)3(bis(trifluoromethyl) sulfonylimide)3 via the solution-cast method, and the results were compared with those of their acetonitrile-based liquid counterparts. The notation x is a weight fraction (=0, 0.5, and 1), and X represents an anion. The anion was either bis(trifluoromethyl) sulfonylimide [TFSI-; ionic size, 0.79 nm] or trifluoromethanesulfonate [Triflate-; ionic size, 0.44 nm]. The delocalized electrons and a low value of lattice energy for the anions made the lithium salts highly dissociable in the matrix. The electrolytes exhibited σ25°C ≈ 2.1 × 10-3 (1.5 × 10-3), 7.2 × 10-4 (3.1 × 10-4), and 9.7 × 10-7 (6.3 × 10-7) S cm-1 for x = 0, 0.5, and 1, respectively, with X = TFSI- (Triflate-) ions. The log σ-T-1 plot portrayed a linear curve for x = 0 and 1, and a downward curve for x = 0.5. The electrical transport study showed σ(TFSI-) > σ(Triflate-), with lower activation energy for TFSI- ions. The anionic effect increased from x = 0 to 1. This effect was explained using conventional techniques, such as Fourier transform infrared spectroscopy (FT-IR), X-ray diffractometry (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), UV-visible spectroscopy (UV-vis), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA).

16.
J Biomed Mater Res B Appl Biomater ; 112(5): e35410, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38728112

RESUMEN

The dissipative particle dynamics (DPD) simulation was used to study the morphologies and structures of the paclitaxel-loaded PLA-b-PEO-b-PLA polymeric micelle. We focused on the influences of PLA block length, PLA-b-PEO-b-PLA copolymer concentration, paclitaxel drug content on morphologies and structures of the micelle. Our simulations show that: (i) with the PLA block length increase, the self-assemble structure of PLA-b-PEO-b-PLA copolymers with paclitaxel vary between onion-like structure (core-middle layer-shell) to spherical core-shell structure. The PEO shell thins and the size of the PLA core increases. The onionlike structures are comprised of the PEO hydrophilic core, the PLA hydrophobic middle layer, and the PEO hydrophilic shell, the distribution of the paclitaxel drug predominantly occurs within the hydrophobic intermediate layer; (ii) The system forms a spherical core-shell structure when a small amount of the drug is added, and within a certain range, the size of the spherical structure increases as the drug amount increases. When the drug contents (volume fraction) cdrug = 10%, it can be observed that the PLA4-b-PEO19-b-PLA4 spherical structures connect to form rod-shaped structures. With the length of PLA block NPLA = 8, as the paclitaxel drug concentrations cdrug = 4%, PEO has been insufficient to completely encapsulate the PLA and paclitaxel drug beads. To enhance drug loading capacity while maintaining stability of the system in aqueous solution, the optimal composition for loading paclitaxel is PLA4-b-PEO19-b-PLA4; the drug content is not higher than 4%; (iii) The paclitaxel-loaded PLA4-b-PEO19-b-PLA4 micelle undergo the transition from onionlike (core-middle layer-shell) to spherical (core-shell) to rod-shaped and lamellar structure as the PLA4-b-PEO19-b-PLA4 copolymer concentration increases from ccp = 10% to 40%.


Asunto(s)
Micelas , Paclitaxel , Poliésteres , Polietilenglicoles , Paclitaxel/química , Paclitaxel/farmacocinética , Polietilenglicoles/química , Poliésteres/química , Interacciones Hidrofóbicas e Hidrofílicas , Simulación de Dinámica Molecular , Portadores de Fármacos/química
17.
J Colloid Interface Sci ; 670: 385-394, 2024 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-38772255

RESUMEN

Solid-state lithium metal batteries (SSLMBs) are promising candidates for safe and high-energy-density next-generation applications. However, harmful interfacial decomposition and uneven Li deposition lead to poor ion transport, a short cycle life, and battery failure. Herein, we propose a novel poly(ethylene oxide) (PEO)-based composite solid electrolyte (CSE) containing succinonitrile (SN) and zinc oxide (ZnO) nanoparticles (NPs), which improves interface stability through a dual mechanism. (1) By anchoring bis(trifluoromethanesulfonyl)imide (TFSI) anions to ZnO, a reliable solid electrolyte interface (SEI) later with abundant LiF can be obtained to inhibit interface decomposition. (2) The immobilization of escaping SN molecules in the SEI layer by ZnO NPs promotes the self-polymerization of SN and facilitates charge transfer through the interface. As a result, the ion conductivity of the stainless steel-symmetrical battery reaches 1.1 × 10-4 S cm-1 at room temperature, and a LiFePO4 (LFP) full battery exhibits ultrahigh stability (800 cycles) at 0.5 C. Thus, the present study provides valuable insights for the development of advanced PEO-based SSLMBs.

18.
ACS Nano ; 18(19): 12311-12324, 2024 May 14.
Artículo en Inglés | MEDLINE | ID: mdl-38691642

RESUMEN

High-safety and high-energy-density solid-state lithium metal batteries (SSLMBs) attract tremendous interest in both academia and industry. Especially, composite polymer electrolytes (CPEs) can overcome the limitations of single-component solid-state electrolytes. In this work, a strategy of combining a rigid functional skeleton with a soft polymer electrolyte to prepare reinforced CPEs was adopted. The in situ grown zeolitic imidazolate frameworks (ZIFs) with three-dimensional cellulose fiber skeleton (ZIF-67@CF) and succinonitrile (SN) plasticizer into poly(ethylene oxide) (PEO) together form ZIF-67@CF/PEO-SN CPEs. The addition of ZIF-67@CF and SN to PEO synergistically enhanced the physical and electrochemical properties of CPEs. Furthermore, the conduction mechanism of lithium-ion (Li+) in CPEs was studied using density functional theory. It is impressive that the ZIF-67@CF/PEO-SN CPEs at 30 °C exhibit a high ionic conductivity of 1.17 × 10-4 S cm-1, a competitive Li+ transference number of 0.40, a wide electrochemical window of 5.0 V, a notable tensile strength of 18.7 MPa, and superior lithium plating/stripping stability (>550 h at 0.1 mA cm2). Such favorable features endowed LiFePO4/(ZIF-67@CF/PEO-SN)/Li cell at 30 °C with a high discharging capacity (152.5 mA h g-1 at 0.2 C), a long cycling lifespan (>150 cycles with 99% capacity retention), and superior operating safety. This work provides insights and promotes the application of functionalized CPEs for SSLMBs.

19.
Sensors (Basel) ; 24(8)2024 Apr 17.
Artículo en Inglés | MEDLINE | ID: mdl-38676181

RESUMEN

Active medical devices rely on a source of energy that is applied to the human body for specific purposes such as electrosurgery, ultrasounds for breaking up kidney stones (lithotripsy), laser irradiation, and other medical techniques and procedures that are extensively used. These systems must provide adequate working power with a commitment not to produce side effects on patients. Therefore, the materials used in these devices must effectively transmit energy, allow for security control, sense real-time variations in case of any issues, and ensure the implementation of closed-loop systems for control. This work extends to the experimental data adjustment of some different coating techniques based on plasma electro-oxidation (PEO) and thermal spray (TS) using fractional-order models. According to the physical structure of the coating in different coating techniques, Cole family models were selected. The experimental data were obtained by means of a vector network analyzer (VNA) in the frequency spectrum from 0.3 MHz to 5 MHz. The results show that some models from the Cole family (the single-dispersion model and inductive model) offered a goodness of fit to the experimental impedance in terms of RMSE error and a squared error R2 close to unity. The use of this type of fractional-order electrical model allows an adjustment with a very small number of elements compared to integer-order models, facilitating its use and a consequent reduction in instrumentation cost and the development of control devices that are more robust and easily miniaturized for embedded applications. Additionally, fractional-order models allow for more accurate assessment in industrial and medical applications.

20.
Polymers (Basel) ; 16(7)2024 Apr 03.
Artículo en Inglés | MEDLINE | ID: mdl-38611239

RESUMEN

The current work introduces the synthesis of inorganic salt nano/micro-crystals during the reduction of hydrogen tetrachloroaurate(III) by Pluronic triblock copolymers (P123, PEO20-PPO70-PEO20). The morphologies and component were confirmed using an electron microscope with an electronic differential system (EDS), and the crystal structures were determined with X-ray diffraction (XRD). The morphologies highly depend on the concentrations of Pluronic and pH values. The mean size of the nanocrystal and hollow micro-crystal were controlled typically in the range of 32-150 nm (side length) and 1.4 µm, respectively. Different from the electrospray-ionization (EI) method, a model in which KCl forms a supersaturated solution in the micellar core of Pluronic is used to explain the formation process. This work provides the new insight that inorganic salt nanocrystals could be synthesized with the template of micelles in pure aqueous solutions.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA