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1.
Anal Biochem ; 692: 115574, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38782251

RESUMO

Ascorbic acid (AA), a prominent antioxidant commonly found in human blood serum, serves as a biomarker for assessing oxidative stress levels. Therefore, precise detection of AA is crucial for swiftly diagnosing conditions arising from abnormal AA levels. Consequently, the primary aim of this research is to develop a sensitive and selective electrochemical sensor for accurate AA determination. To accomplish this aim, we used a novel nanocomposite comprised of CeO2-doped ZnO adorned on biomass-derived carbon (CeO2·ZnO@BC) as the active nanomaterial, effectively fabricating a glassy carbon electrode (GCE). Various analytical techniques were employed to scrutinize the structure and morphology features of the CeO2·ZnO@BC nanocomposite, ensuring its suitability as the sensing nanomaterial. This innovative sensor is capable of quantifying a wide range of AA concentrations, spanning from 0.5 to 1925 µM in a neutral phosphate buffer solution. It exhibits a remarkable sensitivity of 0.2267 µA µM-1cm-2 and a practical detection limit of 0.022 µM. Thanks to its exceptional sensitivity and selectivity, this sensor enables highly accurate determination of AA concentrations in real samples. Moreover, its superior reproducibility, repeatability, and stability underscore its reliability and robustness for AA quantification.


Assuntos
Ácido Ascórbico , Carbono , Cério , Técnicas Eletroquímicas , Nanocompostos , Óxido de Zinco , Ácido Ascórbico/análise , Ácido Ascórbico/química , Ácido Ascórbico/sangue , Nanocompostos/química , Óxido de Zinco/química , Técnicas Eletroquímicas/métodos , Cério/química , Carbono/química , Humanos , Biomassa , Eletrodos , Limite de Detecção
2.
Nano Lett ; 22(3): 1083-1090, 2022 02 09.
Artigo em Inglês | MEDLINE | ID: mdl-35049303

RESUMO

Bioinspired nanochannels have emerged as a powerful tool for bioengineering and biomedical research due to their robust mechanical and controllable chemical properties. Inspired by inward-rectifier potassium (K+) channels, herein, the charged peptide assembly has been introduced into a nano-confined space for the modulation of ion current rectification (ICR). Peptide-responsive reaction-triggered sequence changes can contribute to polarity conversion of the surface charge; therefore, ICR reversal (ICRR) is generated. Compared with other responsive elements, natural charged peptides show the merit of controllable charge polarity. By electrochemically monitoring the ICRR as an output signal, one can utilize the peptide assembly-mediated ICRR to construct an ionic sensory platform. In addition, a logic gate has been established to demonstrate the availability of an ionic sensory platform for inhibitor screening. As peptide nanoassemblies may also have various structures and functions due to their diverse properties, the ionic modulation system can provide alternatives for the assay of peptide-associated biotargets with biomedical applications.


Assuntos
Peptídeos , Transporte de Íons , Íons
3.
World J Microbiol Biotechnol ; 40(1): 12, 2023 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-37953333

RESUMO

The presence of harmful heavy metals (HMs) in the aquatic environment can damage the environment and threaten human health. Traditional remediation techniques can have secondary impacts. Thus, more sustainable approaches must be developed. Microalgae have biological properties (such as high photosynthetic efficiency and growth), which are of great advantage in the HMs removal. In this study, the effect of various concentrations (2×, 4×, and 6×) of copper (Cu), cobalt (Co), and zinc (Zn) on microalgae (C. sorokiniana GEEL-01, P. kessleri GEEL-02, D. asymmetricus GEEL-05) was investigated. The microalgal growth kinetics, HMs removal, total nitrogen (TN), total phosphor (TP), and fatty acids (FAs) compositions were analyzed. The highest growth of 1.474 OD680nm and 1.348 OD680nm was obtained at 2× and 4×, respectively, for P. kessleri GEEL-02. P. kessleri GEEL-02 showed high removal efficiency of Cu, Co, and Zn (38.92-55.44%), (36.27-68.38%), and (32.94-51.71%), respectively. Fatty acids (FAs) analysis showed that saturated FAs in C. sorokiniana GEEL-01 and P. kessleri GEEL-02 increased at 2× and 4× concentrations while decreasing at 6×. For P. kessleri GEEL-02, the properties of biodiesel including the degree of unsaturation (UD) and cetane value (CN) increased at 2×, 4×, and 6× as compared to the control. Thus, this study demonstrated that the three microalgae (particularly P. kessleri GEEL-02) are more suitable for nutrient and HMs removal coupled with biomass/biodiesel production.


Assuntos
Metais Pesados , Microalgas , Humanos , Ácidos Graxos/análise , Biomassa , Biocombustíveis , Nutrientes/análise , Suplementos Nutricionais/análise
4.
Sensors (Basel) ; 22(9)2022 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-35590835

RESUMO

Cyber-threats are becoming a big concern due to the potential severe consequences of such threats is false data injection (FDI) attacks where the measures data is manipulated such that the detection is unfeasible using traditional approaches. This work focuses on detecting FDIs for phasor measurement units where compromising one unit is sufficient for launching such attacks. In the proposed approach, moving averages and correlation are used along with machine learning algorithms to detect such attacks. The proposed approach is tested and validated using the IEEE 14-bus and the IEEE 30-bus test systems. The proposed performance was sufficient for detecting the location and attack instances under different scenarios and circumstances.

5.
Sensors (Basel) ; 22(10)2022 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-35632272

RESUMO

Faults frequently occur in the sensors and actuators of process machines to cause shutdown and process interruption, thereby creating costly production loss. centrifugal compressors (CCs) are the most used equipment in process industries such as oil and gas, petrochemicals, and fertilizers. A compressor control system called an anti-surge control (ASC) system based on many critical sensors and actuators is used for the safe operation of CCs. In this paper, an advanced active fault-tolerant control system (AFTCS) has been proposed for sensor and actuator faults of the anti-surge control system of a centrifugal compressor. The AFTCS has been built with a dedicated fault detection and isolation (FDI) unit to detect and isolate the faulty part as well as replace the faulty value with the virtual redundant value from the observer model running in parallel with the other healthy sensors. The analytical redundancy is developed from the mathematical modeling of the sensors to provide estimated values to the controller in case the actual sensor fails. Dual hardware redundancy has been proposed for the anti-surge valve (ASV). The simulation results of the proposed Fault-tolerant control (FTC) for the ASC system in the experimentally validated CC HYSYS model reveal that the system continued to operate in the event of faults in the sensors and actuators maintaining system stability. The proposed FTC for the ASC system is novel in the literature and significant for the process industries to design a highly reliable compressor control system that would continue operation despite faults in the sensors and actuators, hence preventing costly production loss.

6.
Anal Chem ; 93(25): 8994-9001, 2021 06 29.
Artigo em Inglês | MEDLINE | ID: mdl-34151551

RESUMO

Metal-organic framework (MOF) thin films with flexible nature and prominent qualities have opened doors to new technological applications in different fields. Herein, we propose an electrochemical biosensor for the dual detection of Staphylococcus aureus based on the electrodeposition of Cu metal-organic framework (Cu-MOF) thin films. The promising sensing layer with features of good electronic conductivity and enhanced electron-transfer property can not only identify S. aureus through specific micrococcal nucleases in the supernatant but also detect the pathogen directly via aptamer recognition. The dual analysis design ensures the accuracy of this method for S. aureus detection in the range of 7-7 × 106 cfu/mL with the limits of detection of 1.9 and 5.2 cfu/mL. Moreover, the analytical method validation confirmed that the biosensor could efficiently work in complex biological samples, showing good selectivity and specificity and great potential for clinical diagnosis. More importantly, the current proposed strategy is simple and easy to implement without the need for extra signaling elements, which is convenient for timely clinical detection.


Assuntos
Técnicas Biossensoriais , Estruturas Metalorgânicas , Infecções Estafilocócicas , Humanos , Limite de Detecção , Staphylococcus aureus
7.
Small ; 17(46): e2103255, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34605143

RESUMO

CsPbX3 perovskite nanocrystals (NCs), with excellent optical properties, have drawn considerable attention in recent years. However, they also suffer from inherent vulnerability and hydrolysis, causing the new understanding or new applications to be difficultly explored. Herein, for the first time, it is discovered that the phospholipid membrane (PM)-coated CsPbX3 NCs have intrinsic biocatalytic activity. Different from other peroxidase-like nanozymes relying on extra chromogenic reagents, the PM-CsPbX3 NCs can be used as a self-reporting nanoprobe, allowing an "add-to-answer" detection model. Notably, the fluorescence of PM-CsPbX3 NCs can be rapidly quenched by adding H2 O2 and then be restored by removing excess H2 O2 . Initiated from this unexpected observation, the PM-CsPbX3 NCs can be explored to prepare multi-color bioinks and metabolite-responsive paper analytical devices, demonstrating the great potential of CsPbX3 NCs in bioanalysis. This is the first report on the discovery of nanozyme-like property of all-inorganic CsPbX3 perovskite NCs, which adds another piece to the nanozyme puzzle and opens new avenues for in vitro disease diagnostics.


Assuntos
Compostos de Cálcio , Nanopartículas , Óxidos , Titânio
8.
Sensors (Basel) ; 21(17)2021 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-34502682

RESUMO

The power industry is in the process of grid modernization with the introduction of phasor measurement units (PMUs), advanced metering infrastructure (AMI), and other technologies. Although these technologies enable more reliable and efficient operation, the risk of cyber threats has increased, as evidenced by the recent blackouts in Ukraine and New York. One of these threats is false data injection attacks (FDIAs). Most of the FDIA literature focuses on the vulnerability of DC estimators and AC estimators to such attacks. This paper investigates FDIAs for PMU-based state estimation, where the PMUs are comparable. Several states can be manipulated by compromising one PMU through the channels of that PMU. A Phase Locking Value (PLV) technique was developed to detect FDIAs. The proposed approach is tested on the IEEE 14-bus and the IEEE 30-bus test systems under different scenarios using a Monte Carlo simulation where the PLV demonstrated an efficient performance.


Assuntos
Indústrias , Tecnologia , Simulação por Computador
9.
Anal Chem ; 92(19): 13478-13484, 2020 10 06.
Artigo em Inglês | MEDLINE | ID: mdl-32844648

RESUMO

The development of a simple, sensitive, and effective method for the analysis of circulating tumor cells (CTCs) is essential for cancer diagnosis and metastasis prediction. In this work, we have proposed an enzyme-free electrochemical method for specific capture, sensitive quantification, and efficient release of CTCs. To achieve this, the specific interaction between CTCs and the corresponding aptamer designed to be located in the identification probe (IP) will unfold the hairpin structure of IP. Consequently, IP will initiate a hybridization reaction to produce a duplex, which will further trigger the hybridization chain reaction (HCR) process to form a composite product of CTCs and double-stranded DNA polymers. Therefore, a significantly amplified signal readout can be obtained. Moreover, the composite product can be brought to the electrode surface by tetrahedral DNA nanostructures to achieve the purpose of capturing and quantifying CTCs. More significantly, these captured CTCs can be controlled released without compromising cell viability via a simple strand displacement reaction. Taking the breast cancer cell MCF-7 as a representative, the newly developed approach led to an ultralow detection limit of 3 cells mL-1, which is superior to several studies previously reported. The current method has also been demonstrated to analyze CTCs in human whole blood and hence revealed a great potential in the future.


Assuntos
Células Neoplásicas Circulantes/patologia , Células Cultivadas , DNA/química , Eletrodos , Células HEK293 , Humanos , Células MCF-7 , Microscopia de Fluorescência , Nanoestruturas/química , Propriedades de Superfície
10.
Environ Pollut ; 344: 123370, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38244902

RESUMO

Wastewater treatment plants (WWTPs) usually contain microplastics (MPs) due to daily influents of domestic and municipal wastewater. Thus, the WWTPs act as a point source of MPs distribution in the environment due to their incapability to remove MPs completely. In this study, MPs occurrence and distribution in anaerobic sludge from WWTPs in different regions (Kaifeng "KHP", Jinan "JSP", and Lanzhou "LGP") were studied. Followed by MPs identification by microscopy and Fourier transform infrared (FTIR) spectrum. The microbial communities associated with anaerobic sludge and MPs were also explored. The results showed that MPs concentrations were 16.5, 38.5, and 17.2 particles/g of total solids (TS) and transparent MPs accounted for 49.1%, 58.5%, and 48.3% in KHP, JSP, and LGP samples, respectively. Fibers represented the most common shape of MPs in KHP (49.1%), JSP (56.0%), and LGP (69.0%). The FTIR spectroscopy indicated the predominance of polyethylene polymer in 1-5 mm MPs. The Proteobacteria, Chloroflexi, Actinobacteria, Bacteroidetes, and Planctomycetes were the abundant phyla in all anaerobic sludge. The bacterial genera in KHP and LGP were similar, in which Caldilinea (>23%), Terrimonas (>10%), and Ferruginibacter (>7%) formed the core bacterial genera. While Rhodococcus (15.3%) and Rhodoplanes (10.9%) were dominating in JSP. The archaeal genera Methanosaeta (>69%) and Methanobrevibacter (>10%) were abundant in KHP and LGP sludge. While Methanomethylovorans accounted for 90% of JSP. Acetyltransferase and hydratase were the major bacterial enzymes, while reductase was the key archaeal enzyme in all anaerobic sludge. This study provided the baseline for MPs distribution, characterization, and MPs associated microbes in WWTPs.


Assuntos
Chloroflexi , Microbiota , Esgotos , Anaerobiose , Microplásticos , Plásticos , Archaea , Bacteroidetes
11.
RSC Adv ; 14(9): 5959-5974, 2024 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-38362070

RESUMO

Heavy metal contamination in water is a serious environmental issue due to the toxicity of metals like lead. This study developed zeolite and multi-walled carbon nanotube (MWCNT) incorporated polyacrylonitrile (PAN) nanofibers via needleless electrospinning and examined their potential for lead ion adsorption from aqueous solutions. The adsorption process was optimized using response surface methodology (RSM) and artificial neural network (ANN) modeling approaches. The adsorbent displayed efficient lead removal of 84.75% under optimum conditions (adsorbent dose (2.21 g), adsorption time (207 min), temperature (48 °C), and initial concentration (62 ppm)). Kinetic studies revealed that the adsorption followed pseudo-first-order kinetics governed by interparticle diffusion. Isotherm analysis indicated Langmuir monolayer adsorption with improved 5.90 mg g-1 capacity compared to pristine PAN nanofibers. Thermodynamic parameters suggested the adsorption was spontaneous and endothermic. This work demonstrates the promise of electrospun zeolite/MWCNT nanofibers as adsorbents for removing lead from wastewater.

12.
Nanoscale Adv ; 6(6): 1750-1764, 2024 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-38482029

RESUMO

Nano-carbon-reinforced polymer composites have gained much consideration in functional applications due to their attractive mechanical strength and cost-effectiveness. The surface chemistry and associated mechanical strength of carbon nanotubes (CNTs), graphene, and other carbon derivative-based nanocomposites are well understood. While CQDs are considered emerging carbon derivatives, their surface chemistry, unique physio-chemical properties, and dispersion behavior in polymers are yet to be explored. Therefore, in this work, CQDs with different structures were synthesized from lemon pulp and urea, and their rheology and mechanical strength were studied in the PVA matrix. The surface chemistry and structure of CQDs were controlled using different solvents and reaction temperatures, respectively. CQDs possessed a circular shape, with a size of <10 nm, having a suitable carbon core and functional groups, as confirmed by TEM and FTIR spectroscopy. The dynamic viscosity and particle size of PVA/CQDs films peaked at 4% inclusion due to the maximum crosslinking of U-CQDs with reinforcement at 180 °C. Compared with pure PVA, the optimized composite showed an 80% larger particle size with 67% better tensile strength at 4% U-CQDs concentration. In addition to enhanced mechanical strength, CQDs exhibited antibacterial activity in composites. These CQDs-reinforced PVA composites may be suitable for different functional textile applications (shape memory composites and photo-active textiles).

13.
ACS Omega ; 9(5): 5265-5272, 2024 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-38343923

RESUMO

Polycyclic aromatic hydrocarbons (PAHs) are persistent organic pollutants that may contaminate various water sources and pose serious dangers to human health and the environment. Due to their capacity for size-based separation, nanofiltration membranes have become efficient instruments for PAH removal. However, issues such as membrane fouling and ineffective rejection still exist. To improve PAH rejection while reducing fouling problems, this work created a new gradient cross-linking poly(vinylpyrrolidone) (PVP) nanofiltration membrane. The gradient cross-linking technique enhanced the rejection performance and antifouling characteristics of the membrane. The results demonstrated that the highest membrane flow was achieved at a 0.15% SDS-PVP membrane. There is a trade-off between membrane flux and salt rejection since salt rejection increases with SDS owing to the growth of big pores. The membrane flux was reduced for the 0.25% SDS-PVP membrane owing to poor SDS dispersion. The prepared membrane showed enhanced removal efficiencies for the removal of the PAH compounds. The PVP membrane has the potential to be used in several water treatment applications, improving water quality, and preserving the environment.

14.
Environ Sci Pollut Res Int ; 30(22): 61710-61725, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36933133

RESUMO

Appropriate material selection and proper understanding of bandgap modification are key factors for the development of efficient photocatalysts. Herein, we developed an efficient, well-organized visible light oriented photocatalyst based on g-C3N4 in association with polymeric network of chitosan (CTSN) and platinum (Pt) nanoparticles utilizing a straightforward chemical approach. Modern techniques like XRD, XPS, TEM, FESEM, UV-Vis, and FTIR spectroscopy were exploited for characterization of synthesized materials. XRD results confirmed the involvement of α-polymorphic form of CTSN in graphitic carbon nitride. XPS investigation confirmed the establishment of trio photocatalytic structure among Pt, CTSN, and g-C3N4. TEM examination showed that the synthesized g-C3N4 possesses fine fluffy sheets like structure (100 to 500 nm in size) intermingled with a dense layered framework of CTSN with good dispersion of Pt nanoparticles on g-C3N4 and CTSN composite structure. The bandgap energies for g-C3N4, CTSN/g-C3N4, and Pt@ CTSN/g-C3N4 photocatalysts were found to be 2.94, 2.73, and 2.72 eV, respectively. The photodegradation skills of each created structure have been examined on antibiotic gemifloxacin mesylate and methylene blue (MB) dye. The newly developed Pt@CTSN/g-C3N4 ternary photocatalyst was found to be efficacious for the elimination of gemifloxacin mesylate (93.3%) in 25 min and MB (95.2%) just in 18 min under visible light. Designed Pt@CTSN/g-C3N4 ternary photocatalytic framework exhibited ⁓ 2.20 times more effective than bare g-C3N4 for the destruction of antibiotic drug. This study provides a simple route towards the designing of rapid, effective visible light oriented photocatalyts for the existing environmental issues.


Assuntos
Quitosana , Nanopartículas , Antibacterianos/química , Gemifloxacina , Azul de Metileno/química , Platina , Catálise , Luz
15.
ACS Omega ; 8(50): 47623-47634, 2023 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-38144129

RESUMO

Even low concentrations of pollutants in water, particularly heavy metals, can significantly affect the ecosystem and human health. Adsorption has been determined to be one of the most effective techniques of removing pollution from wastewater among the various strategies. To remove heavy metals such as Zn2+ and Pb2+, we prepared a silica-coated CuMgFe2O4 magnetic adsorbent using sol-gel method and tested it for wastewater treatment. X-ray diffraction investigation validated the creation of cubic spinel structure, while morphological analysis showed that silica coating reduces the particle size but boosts the surface roughness of the nanoparticles and also reduces the agglomeration between particles. UV-visible spectroscopy indicates a rise in bandgap and magnetic characteristics analysis indicates low values of magnetization due to silica coating. The kinetic and isotherm parameters for heavy metal ions adsorption onto silica-coated Cu0.50Mg0.50Fe2O4 nanoparticles are calculated by applying pseudo-first-order, pseudo-second-order, Langmuir and Freundlich models. Adsorption kinetics revealed that the pseudo-second-order and Langmuir models are the best fit to explain adsorption kinetics. Synthesized adsorbent revealed 92% and 97% removal efficiencies for Zn2+ and Pb2+ ions, respectively.

16.
Membranes (Basel) ; 13(2)2023 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-36837659

RESUMO

Nanofiber-based facial masks have attracted the attention of modern cosmetic applications due to their controlled drug release, biocompatibility, and better efficiency. In this work, Azadirachta indica extract (AI) incorporated electrospun polyvinyl alcohol (PVA) nanofiber membrane was prepared to obtain a sustainable and hydrophilic facial mask. The electrospun AI incorporated PVA nanofiber membranes were characterized by scanning electron microscope, Ultraviolet-visible spectroscopy (UV-Vis) drug release, water absorption analysis, 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging, and antibacterial activity (qualitative and quantitative) at different PVA and AI concentrations. The optimized nanofiber of 376 ± 75 nm diameter was obtained at 8 wt/wt% PVA concentration and 100% AI extract. The AI nanoparticles of size range 50~250 nm in the extract were examined through a zeta sizer. The water absorption rate of ~660% and 17.24° water contact angle shows good hydrophilic nature and water absorbency of the nanofiber membrane. The UV-Vis also analyzed fast drug release of >70% in 5 min. The prepared membrane also exhibits 99.9% antibacterial activity against Staphylococcus aureus and has 79% antioxidant activity. Moreover, the membrane also had good mechanical properties (tensile strength 1.67 N, elongation 48%) and breathability (air permeability 15.24 mm/s). AI-incorporated nanofiber membrane can effectively be used for facial mask application.

17.
Polymers (Basel) ; 15(6)2023 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-36987136

RESUMO

Nowadays, synthetic polymers are used in medical applications due to their special biodegradable, biocompatible, hydrophilic, and non-toxic properties. The materials, which can be used for wound dressing fabrication with controlled drug release profile, are the need of the time. The main aim of this study was to develop and characterize polyvinyl alcohol/polycaprolactone (PVA/PCL) fibres containing a model drug. A dope solution comprising PVA/PCL with the drug was extruded into a coagulation bath and became solidified. The developed PVA/PCL fibres were then rinsed and dried. These fibres were tested for Fourier transform infrared spectroscopy, linear density, topographic analysis, tensile properties, liquid absorption, swelling behaviour, degradation, antimicrobial activity, and drug release profile for improved and better healing of the wound. From the results, it was concluded that PVA/PCL fibres containing a model drug can be produced by using the wet spinning technique and have respectable tensile properties; adequate liquid absorption, swelling %, and degradation %; and good antimicrobial activity with the controlled drug release profile of the model drug for wound dressing applications.

18.
Nanomaterials (Basel) ; 13(7)2023 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-37049240

RESUMO

Nanoscale surface roughness has conventionally been induced by using complicated approaches; however, the homogeneity of superhydrophobic surface and hazardous pollutants continue to have existing challenges that require a solution. As a prospective solution, a novel bubbled-structured silica nanoparticle (SiO2) decorated electrospun polyurethane (PU) nanofibrous membrane (SiO2@PU-NFs) was prepared through a synchronized electrospinning and electrospraying process. The SiO2@PU-NFs nanofibrous membrane exhibited a nanoscale hierarchical surface roughness, attributed to excellent superhydrophobicity. The SiO2@PU-NFs membrane had an optimized fiber diameter of 394 ± 105 nm and was fabricated with a 25 kV applied voltage, 18% PU concentration, 20 cm spinning distance, and 6% SiO2 nanoparticles. The resulting membrane exhibited a water contact angle of 155.23°. Moreover, the developed membrane attributed excellent mechanical properties (14.22 MPa tensile modulus, 134.5% elongation, and 57.12 kPa hydrostatic pressure). The composite nanofibrous membrane also offered good breathability characteristics (with an air permeability of 70.63 mm/s and a water vapor permeability of 4167 g/m2/day). In addition, the proposed composite nanofibrous membrane showed a significant water/oil separation efficiency of 99.98, 99.97, and 99.98% against the water/xylene, water/n-hexane, and water/toluene mixers. When exposed to severe mechanical stresses and chemicals, the composite nanofibrous membrane sustained its superhydrophobic quality (WCA greater than 155.23°) up to 50 abrasion, bending, and stretching cycles. Consequently, this composite structure could be a good alternative for various functional applications.

19.
ACS Omega ; 8(20): 17976-17982, 2023 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-37251157

RESUMO

Recently, polyvinyl chloride (PVC) gel materials appeared promising for developing actuators, artificial muscles, and sensors. However, their energized response time and recovery limitations restrict their broader applications. Herein, a novel soft composite gel was prepared by mixing functionalized carboxylated cellulose nanocrystals (CCNs) and plasticized PVC. The surface morphology of the plasticized PVC/CCNs composite gel was characterized by scanning electronic microscopy (SEM). The prepared PVC/CCNs gel composites have increased polarity and electrical actuation with a fast response time. Experimental results demonstrated good response characteristics within the actuator model with a multilayer electrode structure when stimulated with a specified DC voltage (1000 V), with deformation of approximately 36.7%. Moreover, this PVC/CCNs gel has excellent tensile elongation, and the elongation at break of the PVC/CCNs gel is greater than the elongation at break of the pure PVC gel under the same thickness conditions. However, these PVC/CCNs composite gels showed excellent properties and development potential and are directed for broad applications in actuators, soft-robotics, and biomedical applications.

20.
ACS Omega ; 7(6): 4859-4867, 2022 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-35187306

RESUMO

Nanostructured polymeric membranes are of great importance in enhancing the antifouling properties during water filtration. Nanomaterials with tunable size, morphology and composition, surface modification, and increased functionality provide considerable opportunities for effective wastewater treatment. Thus, in this work, an attempt has been made to use spinel-structured MnCo2O4 as a nanofiller in the fabrication of nanostructured polysulfone (PSF) mixed matrix membranes and is investigated in terms of morphology, hydrophilicity, permeability, protein and natural organic matter separation, dye removal, and, finally, antifouling properties. The MnCo2O4 nanomaterials are synthesized and characterized via X-ray diffraction and field emission scanning electron microscopy and are loaded into a membrane matrix with varied concentrations (0 to 1.5 wt %). PSF nanocomposite membranes are prepared via a nonsolvent-induced phase-separation process. The results show an enhancement in hydrophilicity, porosity, and permeability with respect to the modified nanocomposite membranes because of oxygen-rich species in the membrane matrix, which increases affinity toward water. It was also found that the modified membranes display remarkably greater pure water flux (PWF) (220 L/m2 h), higher Congo red rejection coefficient (99.86%), higher humic acid removal (99.81%), higher fouling resistance, and a significant flux recovery ratio (FRR) (88%) when tested with bovine serum albumin protein when compared to a bare PSF membrane (30 L/m2 h PWF and 35% FRR). This is because the addition of MnCo2O4 nanoparticles into the polymeric casting solution yielded tighter PSF membranes with a denser skin layer and greater selectivity. Thus, the enhanced permeability, greater rejection coefficient, and antifouling properties show the promising potential of the fabricated PSF-spinel nanostructured membrane to be utilized in membrane technology for wastewater treatment.

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