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1.
Luminescence ; 39(4): e4746, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38644460

RESUMO

The use of photochromism to increase the credibility of consumer goods has shown great promise. To provide mechanically dependable anticounterfeiting nanofibres, it has also been critical to improve the engineering processes of authentication patterns. Mechanically robust and photoluminescent electrospun poly(ethylene oxide)/glass (PGLS) nanofibres (150-350 nm) immobilized with nanoparticles of lanthanide-doped aluminate (NLA; 8-15 nm) were developed using electrospinning technology for anticounterfeiting purposes. The provided nanofibrous membranes changed colour from transparent to green when irradiated with ultraviolet light. By delivering NLA with homogeneous distribution without aggregations, we were able to keep the nanofibrous membrane transparent. When excited at 365 nm, NLA@PGLS nanofibres showed an emission intensity at 517 nm. The hydrophobicity of NLA@PGLS nanofibres improved by raising the pigment concentration as the contact angle was increased from 146.4° to 160.3°. After being triggered by ultraviolet light, NLA@PGLS showed quick and reversible photochromism without fatigue. It was shown that the suggested method can be applied to reliably produce various anticounterfeiting materials.


Assuntos
Vidro , Nanofibras , Polietilenoglicóis , Raios Ultravioleta , Nanofibras/química , Polietilenoglicóis/química , Vidro/química , Tamanho da Partícula , Propriedades de Superfície
2.
Soft Robot ; 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38557240

RESUMO

A light-weight actuator developed in this work belongs to a class of soft robots, and in a sense, resembles an octopus. Its main function is in the attachment or detachment to a solid surface driven by an electro-thermopneumatic mechanism. In this study, a suction cup similar to that of an octopus is manufactured from an elastomer, which is actuated by an electro-thermopneumatic system, mimicking the movement of the octopus' acetabular muscle. Accordingly, the adhesion force generated by such an actuator is regulated by releasing the inner air or adjusting the cup's elasticity. This actuator is designed to be an assistive device that facilitates the individual's physical strength in case of conditions related to aging or cerebellar disease, or a person who lost limbs. In this study, the actuator capabilities are demonstrated in the form of a grip-assisting glove and prosthetic attacher. Moreover, the adhesion mechanism is quantified by numerical simulations and verified experimentally.

3.
Int J Biol Macromol ; 266(Pt 2): 131001, 2024 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-38547951

RESUMO

The main objective of this work is to develop biodegradable active films through the combination of the extracts with different solvents sourced from Eucalyptus citriodora leaves, with films made of chitosan (Cs) and polyvinylpyrrolidone (PVP). Chromatographic profiling investigations were carried out to examine the antibacterial characteristics of the E. citriodora extracts before their direct incorporation into the polymer films. At this point, the potent antimicrobial properties of the phenol compounds and bioactive components demonstrated an antibacterial activity that was particularly noticeable at a hexane resolution. Different morphological characteristics were seen on the films made from these solvent extracts, such as Cs/PVP-AE, Cs/PVP-EAE, and Cs/PVP-HE, when scanning electron microscopy was used. Numerous other outcomes of all the interactions between the extract particles and the film were shown by the pores defined by the Cs/PVP film's porous nature. The addition of the extracts, either alone or in combination, greatly enhanced the Cs/NC/PVP films' mechanical characteristics. It has also been shown that adding plant extracts greatly increased the antibacterial activity of these films. These findings reveal that the Cs/PVP films loaded with extract may be utilized as more environmentally acceptable substitutes for possible food packaging application by increasing shelf life of food products.

4.
Luminescence ; 39(3): e4688, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38444125

RESUMO

Nano-biocomposites of inorganic and organic components wereprepared to produce long-persistent phosphorescent artificial nacre-like materials. Biodegradable polylactic acid (PLA), graphene oxide (GO), and nanoparticles (13-20 nm) of lanthanide-doped aluminate pigment (NLAP) were used in a simple production procedure of an organic/inorganic hybrid nano-biocomposite. Both polylactic acid and GO nanosheets were chemically modified to form covalent and hydrogen bonding. The high toughness, good tensile strength, and great endurance of those bonds were achieved by their interactions at the interfaces. Long-persistent and reversible photoluminescence was shown by the prepared nacre substrates. Upon excitation at 365 nm, the nacre substrates generated an emission peak at 517 nm. When ultraviolet light was shone on luminescent nacres, they displayed a bright green colour. The high superhydrophobicity of the generated nacres was obtained without altering their mechanical characteristics.


Assuntos
Grafite , Nácar , Poliésteres
5.
Chem Asian J ; : e202301143, 2024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-38376002

RESUMO

The quest for sustainable and clean energy sources has intensified research on the Hydrogen Evolution Reaction (HER) in recent decades. In this study, we have presented a novel Ce-doped TiO2 catalyst synthesized through the sol-gel method, showcasing its potential as a superior electrocatalyst for HER in an acidic medium. Comprehensive characterization through X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Energy dispersive X-ray (EDX), and Raman spectroscopy confirms the successful formation of the catalyst. Electrocatalytic performance evaluation, including open circuit potential (OCP), electrochemical impedance spectroscopy (EIS), and Tafel analysis, demonstrates that GCE-5wt.%CeTiO2 outperforms bare GCE, as well as Ce and TiO2-based electrodes. Kinetic investigations reveal a Tafel slope of 105 mV dec-1, indicating the Volmer step as the rate-determining step. The onset potential for HER at GCE-5wt.%CeTiO2 is -0.16 V vs. RHE, close to the platinum electrode. Notably, the catalyst exhibits a low overpotential of 401 mV to achieve a current density of 10 mA cm-2 with an impressive 95 % Faradaic efficiency. Furthermore, the catalyst demonstrates outstanding durability, maintaining a negligible increase in overpotential during a 14-hour chronoamperometry test. These results have far-reaching implications for the development of cost-effective and efficient electrocatalysts for hydrogen production.

6.
Luminescence ; 39(1): e4626, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37986686

RESUMO

The use of photochromism to enhance the anti-counterfeiting of a wide range of economic goods is an intriguing prospect. Creating a translucent anti-counterfeiting nanocomposite is critical to improving the engineering procedures of the encoding materials. Herein, we use electrospinning to produce anti-counterfeiting nanofibrous films from nanoparticles of rare-earth aluminate (NREA) and recycled poly(ethylene terephthalate) (PET). Different nanofiber films with distinct emission properties were created using different ratios of NREA. The ultraviolet (UV)-induced photochromism of the NREA@PET nanofibers was proved. Immobilizing NREA at the nanoscale ensures better dispersion without agglomeration in the PET nanofibrous matrix, which is essential for the development of transparent NREA@PET films. Diameters of 4-13 nm for NREA were shown using transmission electron microscopy. X-ray fluorescence spectroscopy, energy-dispersive X-ray spectroscopy, Fourier-transform infrared spectroscopy, scanning electron microscopy, elemental mapping, and other techniques were used to investigate the photochromic nanofibers' morphology, elemental contents, optical transmittance, and mechanical performance. It was observed that the nanofiber diameter in NREA@PET was between 150 and 250 nm. Excitation and emission bands of electrospun NREA@PET nanofibrous films were monitored at 365 and 518 nm, respectively. The superhydrophobicity of NREA@PET increased with increasing NREA concentration. The transparent nanofibers exhibited fast and reversible dual-mode fluorescent photochromism to green emission without fatigue when stimulated beneath a UV source. Using the present anti-counterfeiting films can be regarded as a simple technique to develop flexible materials to launch an ideal marketplace with affordable societal and economic advantages.


Assuntos
Nanofibras , Ácidos Ftálicos , Nanofibras/química , Polietilenotereftalatos , Etilenos
7.
Int J Biol Macromol ; 258(Pt 1): 128874, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38128797

RESUMO

This study presents a novel approach in the synthesis and characterization of nanocomposites comprising cationic chitosan (CCS) blended with varying concentrations of silver nanoparticles/montmorillonite (AgNPs/MMT). AgNPs/MMT was synthesized using soluble starch as a reducing and stabilizing agent. Subsequently, nanocomposites, namely CCS/AgMMT-0, CCS/AgMMT-0.5, CCS/AgMMT-1.5, and CCS/AgMMT-2.5, were developed by blending 2.5 g of CCS with 0, 0.5, 1.5, and 2.5 g of AgNPs/MMT, respectively, and the corresponding nanocomposites were prepared using ball milling technique. Transmission electron microscopy (TEM) analysis revealed the formation of nanocomposites that exhibiting nearly spherical morphologies. Dynamic light scattering (DLS) measurements displayed average particle sizes of 1183 nm, 131 nm, 140 nm, and 188 nm for CCS/AgMMT-0, CCS/AgMMT-0.5, CCS/AgMMT-1.5, and CCS/AgMMT-2.5, respectively. The narrow polydispersity index (~0.5) indicated uniform particle size distributions across the nanocomposites, affirming monodispersity. Moreover, the zeta potential values exceeding 30 mV across all nanocomposites that confirmed their stability against agglomeration. Notably, CCS/AgMMT-2.5 nanocomposite exhibited potent antibacterial and antibiofilm properties against diverse pipeline materials. Findings showed that after 15 days of incubation, the highest populations of biofilm cells, Pseudomonas aeruginosa biofilm, developed over UPVC, MDPE, DCI, and SS, with corresponding HPCs of 4.79, 6.38, 8.81, and 7.24 CFU/cm2. The highest cell densities of Enterococcus faecalis biofilm in the identical situation were 4.19, 5.89, 8.12, and 6.9 CFU/cm2. The nanocomposite CCS/AgMMT-2.5 exhibited the largest measured zone of inhibition (ZOI) against both P. aeruginosa and E. faecalis, with measured ZOI values of 19 ± 0.65 and 17 ± 0.21 mm, respectively. Remarkably, the research indicates that the youngest biofilm exhibited the most notable rate of inactivation when exposed to a dose of 150 mg/L, in comparison to the mature biofilm. These such informative findings could offer valuable insights into the development of effective antibiofilm agents and materials applicable in diverse sectors such as water treatment facilities, medical devices, and industrial pipelines.


Assuntos
Quitosana , Nanopartículas Metálicas , Nanocompostos , Prata/farmacologia , Bentonita/farmacologia , Quitosana/farmacologia , Antibacterianos/farmacologia , Cátions/farmacologia , Biofilmes , Testes de Sensibilidade Microbiana
8.
ACS Biomater Sci Eng ; 9(5): 2170-2180, 2023 05 08.
Artigo em Inglês | MEDLINE | ID: mdl-36149264

RESUMO

Obesity is a complex disorder associated with immense health consequences including high risk of cardiovascular diseases, diabetes, and cancer. Abnormality in the thyroid gland, genetics, less physical activity, uptake of excessive diet, and leptin resistance are critical factors in the development of obesity. To determine the treatment strategy, understanding the pathophysiology of obesity is crucial. For instances, leptin resistance mediated obesity defined by the presence of excessive leptin hormone (Lep) in the systemic circulation is very common in diet induced obesity. Therefore, our hypothesis is that quantitative measurement of Lep from blood can help to identify individuals with Lep resistant mediated obesity and thereby guide toward a proper treatment strategy. In this work, we aim to utilize an electrochemical immunosensing platform for diagnosis of obesity by measuring the Lep content in systemic circulation. A porous carbon confined FeNi bimetallic system was synthesized with three different ratios of Fe and Ni ions using high temperature pyrolysis technique. The suitability of the sensor for detecting Lep was studied using both CV and EIS techniques. The limit of detection (LOD) for GCE was recorded as 157.4 fg/mL with a wide linear concentration range of 500 fg/mL to 80 ng/mL, while for SPCE the LOD was 184.9 fg/mL with a linear range of 500 fg/mL to 50 ng/mL. Finally, the feasibility and applicability of the sensor for Lep detection was tested with serum collected from high fat diet induced obese rats. The selectivity, sensitivity, storage, and experimental stability and reproducibility tests showed potential for this biosensor platform as a point-of-care Lep detection device.


Assuntos
Leptina , Obesidade , Ratos , Animais , Reprodutibilidade dos Testes , Obesidade/diagnóstico , Obesidade/terapia
9.
Front Chem ; 10: 1078163, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36505739

RESUMO

A series of pyrazolyl-s-triazine compounds with an indole motif was designed, synthesized, and evaluated for anticancer activity targeting dual EGFR and CDK-2 inhibitors. The compounds were tested for cytotoxicity using the MTT assay. Compounds 3h, 3i, and 3j showed promising cytotoxic activity against two cancer cell lines, namely A549, MCF-7, and HDFs (non-cancerous human dermal fibroblasts). Compound 3j was the most active candidate against A549, with an IC50 of 2.32 ± 0.21 µM. Compounds 3h and 3i were found to be the most active hybrids against MCF-7 and HDFs, with an IC50 of 2.66 ± 0.26 µM and 3.78 ± 0.55 µM, respectively. Interestingly, 3i showed potent EGFR inhibition, with an IC50 of 34.1 nM compared to Erlotinib (IC50 = 67.3 nM). At 10 µM, this candidate caused 93.6% and 91.4% of EGFR and CDK-2 inhibition, respectively. Furthermore, 3i enhanced total lung cancer cell apoptosis 71.6-fold (43.7% compared to 0.61% for the control). Given the potent cytotoxicity exerted by 3i through apoptosis-mediated activity, this compound emerges as a promising target-oriented anticancer agent.

10.
Pharmaceutics ; 14(8)2022 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-36015186

RESUMO

Here, we described the synthesis of novel pyrazole-s-triazine derivatives via an easy one-pot procedure for the reaction of ß-dicarbonyl compounds (ethylacetoacetate, 5,5-dimethyl-1,3-cyclohexadione or 1,3-cyclohexadionone) with N,N-dimethylformamide dimethylacetal, followed by addition of 2-hydrazinyl-4,6-disubstituted-s-triazine either in ethanol-acetic acid or neat acetic acid to afford a novel pyrazole and pyrazole-fused cycloalkanone systems. The synthetic protocol proved to be efficient, with a shorter reaction time and high chemical yield with broad substrates. The new pyrazolyl-s-triazine derivatives were tested against the following cell lines: MCF-7 (breast cancer); MDA-MB-231 (triple-negative breast cancer); U-87 MG (glioblastoma); A549 (non-small cell lung cancer); PANC-1 (pancreatic cancer); and human dermal fibroblasts (HDFs). The cell viability assay revealed that most of the s-triazine compounds induced cytotoxicity in all the cell lines tested. However, compounds 7d, 7f and 7c, which all have a piperidine or morpholine moiety with one aniline ring or two aniline rings in their structures, were the most effective. Compounds 7f and 7d showed potent EGFR inhibitory activity with IC50 values of 59.24 and 70.3 nM, respectively, compared to Tamoxifen (IC50 value of 69.1 nM). Compound 7c exhibited moderate activity, with IC50 values of 81.6 nM. Interestingly, hybrids 7d and 7f exerted remarkable PI3K/AKT/mTOR inhibitory activity with 0.66/0.82/0.80 and 0.35/0.56/0.66-fold, respectively, by inhibiting their concentrations to 4.39, 37.3, and 69.3 ng/mL in the 7d-treatment, and to 2.39, 25.34 and 57.6 ng/mL in the 7f-treatment compared to the untreated control.

11.
ACS Omega ; 7(28): 24858-24870, 2022 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-35874229

RESUMO

Here, we synthesized a newseries of mono- and bis(dimethylpyrazolyl)-s-triazine derivatives. The synthetic methodology involved the reaction of different mono- and dihydrazinyl-s-triazine derivatives with acetylacetone in the presence of triethylamine to produce the corresponding target products in high yield and purity. The antiproliferative activity of the novel mono- and bis(dimethylpyrazolyl)-s-triazine derivatives was studied against three cancer cell lines, namely, MCF-7, HCT-116, and HepG2. N-(4-Bromophenyl)-4-(3,5-dimethyl-1H-pyrazol-1-yl)-6-morpholino-1,3,5-triazin-2-amine 4f, N-(4-chlorophenyl)-4,6-bis(3,5-dimethyl-1H-pyrazol-1-yl)-1,3,5-triazin-2-amine 5c, and 4,6-bis(3,5-dimethyl-1H-pyrazol-1-yl)-N-(4-methoxyphenyl)-1,3,5-triazin-2-amine 5d showed promising activity against these cancer cells: 4f [(IC50 = 4.53 ± 0.30 µM (MCF-7); 0.50 ± 0.080 µM (HCT-116); and 3.01 ± 0.49 µM (HepG2)]; 5d [(IC50 = 3.66 ± 0.96 µM (HCT-116); and 5.42 ± 0.82 µM (HepG2)]; and 5c [(IC50 = 2.29 ± 0.92 µM (MCF-7)]. Molecular docking studies revealed good binding affinity with the receptor targeting EGFR/PI3K/AKT/mTOR signaling cascades. Compound 4f exhibited potent EGFR inhibitory activity with an IC50 value of 61 nM compared to that of Tamoxifen (IC50 value of 69 nM), with EGFR inhibition of 83 and 84%, respectively, at a concentration of 10 µM. Interestingly, 4f showed remarkable PI3K/AKT/mTOR inhibitory activity with 0.18-, 0.27-, and 0.39-fold decrease in their concentration (reduction in controls from 6.64, 45.39, and 86.39 ng/mL to 1.24, 12.35, and 34.36 ng/mL, respectively). Hence, the synthetic 1,3,5-triazine derivative 4f exhibited promising antiproliferative activity in HCT-116 cells through apoptosis induction by targeting the EGFR and its downstream pathway.

12.
Molecules ; 27(10)2022 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-35630715

RESUMO

This work aimed to use abietic acid (AA), as a widely available natural product, as a precursor for the synthesis of two new amphiphilic ionic liquids (AILs) and apply them as effective demulsifiers for water-in-crude oil (W/O) emulsions. AA was esterified using tetraethylene glycol (TEG) in the presence of p-toluene sulfonic acid (PTSA) as a catalyst obtaining the corresponding ester (AATG). AATG was reacted with 1-vinylimidazole (VIM) throughout the Diels-Alder reaction, forming the corresponding adduct (ATI). Following this, ATI was quaternized using alkyl iodides, ethyl iodide (EI), and hexyl iodide (HI) to obtain the corresponding AILs, ATEI-IL, and ATHI-IL, respectively. The chemical structure, surface activity, thermal stability, and relative solubility number (RSN) were investigated using different techniques. The efficiency of ATEI-IL and ATHI-IL to demulsify W/O emulsions in different crude oil: brine volumetric ratios were evaluated. ATEI-IL and ATHI-IL achieved promising results as demulsifiers. Their demulsification efficiency increased as the brine ratios decreased where their efficiency reached 100% at the crude oil: brine ratio (90:10), even at low concentrations.


Assuntos
Líquidos Iônicos , Petróleo , Emulsões/química , Iodetos , Líquidos Iônicos/química , Petróleo/análise , Água/química
13.
Polymers (Basel) ; 14(4)2022 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-35215696

RESUMO

In this study six new s-triazine bishydrazino and bishydrazido-based polymers were synthesized via condensation of bishydrazino s-triazine derivatives with terephthaldehyde or via nucleophilic substitution of dichloro-s-triazine derivatives with terephthalic acid hydrazide. The synthesized polymers were characterized by different techniques. The new polymers displayed good thermal behavior with great values in terms of limited oxygen indexed (LOI) 27.50%, 30.12% for polymers 5b,c (bishydrazino-s-triazine based polymers) and 27.23%, 29.86%, 30.85% for polymers 7a-c (bishydrazido-s-triazine based polymers) at 800 °C. Based on the LOI values, these polymers could be classified as flame retardant and self-extinguishing materials. The thermal results also revealed that the type of substituent groups on the triazine core has a considerable impact on their thermal behavior. Accordingly, the prepared polymers were mixed with ammonium polyphosphate (APP) in different proportions to form an intumescent flame-retardant (IFRs) system and were introduced into polypropylene (PP) to improve the flame-retardancy of the composites. The best results were obtained with a mass ratio of APP: 5a-c or 7a-c of 2:1, according to the vertical burning study (UL-94). In addition, the presence of 25% "weight ratio" of IFR in the composite showed great impact and passed UL-94 V-0 and V-1 tests.

14.
ACS Appl Mater Interfaces ; 14(3): 3919-3929, 2022 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-35014264

RESUMO

The design of alternative earth-abundant van der Waals (vdW) nanoheterostructures for bifunctional oxygen evolution/reduction (OER/ORR) electrocatalysis is of paramount importance to fabricate energy-related devices. Herein, we report a simple metal-organic framework (MOF)-derived synthetic strategy to fabricate low-dimensional (LD) nanohybrids formed by zero-dimensional (0D) ZrO2 nanoparticles (NPs) and heteroatom-doped two-dimensional (2D) carbon nanostructures. The 2D platforms controlled the electronic structures of interfacial Zr atoms, thus producing optimized electron polarization for boron and nitrogen-doped carbon (BCN)/ZrO2 nanohybrids. X-ray photoelectron spectroscopy (XPS) and theoretical studies revealed the key role of the synergistic couple effect of boron (B) and nitrogen (N) in interfacial electronic polarization. The BCN/ZrO2 nanohybrid showed excellent bifunctional electrocatalytic activity, delivering an overpotential (η10) of 301 mV to reach a current density of 10 mA-cm-2 for the OER process and a half-wave potential (E1/2) of 0.85 V vs reversible hydrogen electrode (RHE) for the ORR process, which are comparable to the state-of-the-art LD nanohybrids. Furthermore, BCN/ZrO2 also showed competitive performances for water-splitting and zinc-air battery devices. This work establishes a new route to fabricate highly efficient multifunctional electrocatalysts by tuning the electronic polarization properties of 0D-2D electrochemical interfaces.

16.
Soft Robot ; 9(5): 960-969, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-34918958

RESUMO

In this study, we fabricated a nanofiber-based electrothermo-pneumatic soft actuator (ETPSA) using electrospinning technique. The actuator uses liquid-vapor phase transition. The ETPSA developed in the present study goes beyond the limitations of the existing pneumatic soft actuators. The present ETPSA has a built-in source of heat (Joule heating from an embedded metal wire) and allows the smooth anthropomorphic movement of the actuator and, in particular, eliminates the use of external pumping systems that are indispensable in the existing pneumatic soft actuators and robots. In addition, since the present ETPSA can be operated effectively even using a portable miniature battery, it holds great promise as an adaptable soft actuator for various robotic applications with high energy efficiency and programmable motions.


Assuntos
Robótica , Robótica/métodos , Desenho de Equipamento , Movimento (Física)
17.
Luminescence ; 36(8): 2004-2013, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34453772

RESUMO

A smart photoluminescent nanocomposite surface coating was prepared for simple industrial production of long-persisting phosphorescence and superhydrophobic wood. The photoluminescent nanocomposite coatings were capable of continuing to emit light in the dark for prolonged time periods that could reach 1.5 h. Lanthanide-doped aluminium strontium oxide (LASO) nanoparticles at different ratios were immobilized in polystyrene (PS) and developed as a nanocomposite coating for wood substrates. To produce transparency in the prepared nanocomposite coating, LASO was efficiently dispersed in the form of nanoscaled particles to ensure homogeneous dispersion without agglomeration in the PS matrix. The coated wood showed an absorption band at 374 nm and two emission bands at 434 nm and 518 nm. The luminescence spectra showed both long-persisting phosphorescence as well as photochromic fluorescence relying on the LASO ratio. The improved superhydrophobicity and resistance to scratching of the coated wood could be attributed to the LASO NPs incorporated in the polystyrene matrix. Compared with the uncoated wood substrate, the coated LASO-PS nanocomposite film also displayed photostability and high durability. The current study demonstrated the potential high-scale manufacturing of smart wood for some applications such as safety directional signs in buildings, household products, and smart windows.


Assuntos
Nanocompostos , Madeira , Interações Hidrofóbicas e Hidrofílicas , Luminescência , Estrôncio
18.
Luminescence ; 36(8): 1922-1932, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34323352

RESUMO

Transparent wood with multifunctional properties has recently attracted more attention as an efficient building product. Here, we describe the development of transparent wood with long-persistent phosphorescence, tough surface, high durability, photostability, and reversibility without fatigue, and with ultraviolet shielding, superhydrophobicity, and flame-retardant activity. This long-persistent phosphorescent, or glow-in-the-dark, smart wood exhibited an ability to continue emitting light for prolonged periods of time. The photoluminescent translucent wooden substrate was prepared by immobilizing lignin-modulated wooden bulk with an admixture of methylmethacrylate (MMA), ammonium polyphosphate (APP), and lanthanide-doped strontium aluminate (LSA; SrAl2 O4 :Eu2+ ,Dy3+ ) phosphor nanoparticles. The photoluminescent transparent wood displayed a colour switch from colourless to bright white beneath ultraviolet (UV) light and greenish-yellow in the dark as reported by Commission Internationale de l'Éclairage laboratory colorimetric space coordinates. The generated phosphorescent wooden substrates demonstrated an absorbance band at 365 nm and an emission band at 516 nm. The phosphorescent transparent wood was improved flame-retardant properties, ultraviolet shielding, and superhydrophobic properties, as well as a reversible long-persistent phosphorescent responsiveness to UV light without fatigue. The current approach demonstrated a potential large-scale production strategy for multifunctional transparent wooden substrates for a range of applications such as smart windows, gentle indoor and outdoor lighting, and safety directional signs in buildings.


Assuntos
Retardadores de Chama , Madeira , Interações Hidrofóbicas e Hidrofílicas , Luminescência , Estrôncio
19.
Food Chem ; 359: 129859, 2021 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-33957323

RESUMO

This study aimed to investigate the release of silver ions from the packaging, their diffusion within a food hydrogel and the effect on the growth of Pseudomonas fluorescens. Biosorbed-silver nanoparticles (BSNPs) were synthesized using a plant extract and were incorporated into chitosan or poly (vinyl alcohol) polymer to prepare biocomposite films. The addition of BSNPs improved the physical and antimicrobial properties of the films as shown by tensile strength and inhibition of P. fluorescens in hydrogels, respectively. PVA based BSNPs film showed a stronger antimicrobial effect, compared to chitosan based BSNPs film and this correlated with a higher amount of silver ions release from the PVA film into the hydrogel. Results suggest that the strength of the interaction between BSNPs and the film polymer is the key factor leading to the difference in the release behaviour of the antimicrobials, which in turn determines the antimicrobial activity of the active packaging.


Assuntos
Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Nanopartículas Metálicas/química , Prata/química , Prata/farmacologia , Quitosana/química , Difusão , Embalagem de Alimentos , Hidrogéis/química , Álcool de Polivinil/química , Resistência à Tração
20.
ACS Appl Mater Interfaces ; 13(8): 10013-10025, 2021 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-33595267

RESUMO

Wearable electronic textiles are used in sensors, energy-harvesting devices, healthcare monitoring, human-machine interfaces, and soft robotics to acquire real-time big data for machine learning and artificial intelligence. Wearability is essential while collecting data from a human, who should be able to wear the device with sufficient comfort. In this study, reduced graphene oxide (rGO) and silver nanowires (AgNWs) were supersonically sprayed onto a fabric to ensure good adhesiveness, resulting in a washable, stretchable, and wearable fabric without affecting the performance of the designed features. This rGO/AgNW-decorated fabric can be used to monitor external stimuli such as strain and temperature. In addition, it is used as a heater and as a supercapacitor and features an antibacterial hydrophobic surface that minimizes potential infection from external airborne viruses or virus-containing droplets. Herein, the wearability, stretchability, washability, mechanical durability, temperature-sensing capability, heating ability, wettability, and antibacterial features of this metallized fabric are explored. This multifunctionality is achieved in a single fabric coated with rGO/AgNWs via supersonic spraying.


Assuntos
Antibacterianos/farmacologia , Grafite/química , Nanofios/química , Prata/farmacologia , Dispositivos Eletrônicos Vestíveis , Antibacterianos/química , Capacitância Elétrica , Escherichia coli/efeitos dos fármacos , Calefação , Humanos , Interações Hidrofóbicas e Hidrofílicas , Testes de Sensibilidade Microbiana , Monitorização Fisiológica/instrumentação , Monitorização Fisiológica/métodos , Maleabilidade , Prata/química , Staphylococcus aureus/efeitos dos fármacos , Termômetros , Ondas Ultrassônicas , Molhabilidade
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