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1.
J Environ Manage ; 351: 119616, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38042071

RESUMO

Microplastic (MP) contamination poses a substantial threat to agroecosystems, disrupting soil properties, nutrient cycles, and microbial communities and ultimately affecting plant growth and ecosystem resilience. The effects of straw addition on the storage of soil organic carbon (SOC) and greenhouse gas emissions have been extensively explored, but these effects have not been examined in the context of MP contamination. To assess the impacts of legume straw and polyethylene microplastics on SOC fractions and carbon dioxide (CO2) and nitrous oxide (N2O) emissions, 7-month soil incubation experiments were performed. The results revealed that the inclusion of legume straw in soil considerably increased microbial SOC compared to the control. However, straw addition to MP-contaminated soil reduced microbial SOC compared to that in soil containing only straw. In contrast, the addition of straw to MP-contaminated soil elevated (+44%) the SOC mineral relative to the sole application of straw. Intriguingly, straw incorporation into MP-contaminated soil reduced microbial biomass carbon and nitrogen relative to soil containing only straw. Straw addition to MP-contaminated soil enhanced the nitrification activity and reduced the relative expression of AOBamoABC gene compared to sole straw-incorporated soil and the control. Greenhouse gas emissions were also modulated; for instance, straw incorporation into MP-contaminated soil reduced CO2 and N2O emissions by -11% and -46%, compared to straw incorporation alone. The urease and phosphatase activities were decreased (-58% and -12%) in the MP-polluted soil with straw incorporation compared with those in the soil in which only straw was applied. However, invertase and catalase activities were upregulated in the straw-incorporated soil contaminated with MPs. Straw addition in the MP-polluted soil considerably enhanced (+2%) the microbial community structure (indicated by PLFA) compared to the sole straw application. These results provide a comprehensive perspective on the role of legume straw incorporation in addressing MP pollution, showcasing its potential for sustainable agricultural practices in the face of evolving environmental challenges.


Assuntos
Gases de Efeito Estufa , Microbiota , Solo/química , Microplásticos , Plásticos , Dióxido de Carbono/análise , Carbono , Agricultura/métodos , Óxido Nitroso/análise , Verduras
2.
Environ Res ; 214(Pt 1): 113793, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-35780854

RESUMO

Biogas up-gradation is a useful method to control CO2 emission and enhance the green process. The demand for renewable sources is increasing due to the depletion of fossil fuels. Thin-film nanocomposites functionalized with tunable molecular-sieving nanomaterials have been employed to tailor membranes with enhanced permeability and selectivity. In this work, the cellulose nanocrystals as a filler in the polyvinyl alcohol matrix are prepared to achieve high-performance facilitated transport membranes for CO2 capture. Considering the mechanical stability, interfacial compatibility and high moisture uptake of the filler, the main objective of this work was to develop a novel aminated CNC (Am-CNC)/polyvinyl alcohol nanocomposite membrane for biogas upgrading. The hydroxyl groups (O-H) on the reducing end of the cellulose nanocrystals were replaced by amino groups (N-H2). It was discovered through Scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR) that adding Am-CNCs in PVA membranes shows an increment in the CO2 removal and effectively upgrades the biogas. The effect of change in concentration of Am-CNC and feed pressure was investigated. The results showed that with increasing Am-CNC concentration up to 1.5 wt%, the thickness of the selective membrane layer increased from 0.95 to 1.9 µm with a decrease in the moisture uptake from 85.04 to 58.84%. However, the best CO2 permeance and selectivity were achieved at 0.306 m3/m2.bar.h (STP) and 33.55, respectively. Furthermore, there was a more than two-fold decrease in CO2 permeance and a 27% decrease in the CO2/CH4 selectivity when the feed pressure increased from 5 to 15 bar. It was revealed that PVA/Am-CNC membrane is high performing for the biogas upgradation.


Assuntos
Nanocompostos , Nanopartículas , Biocombustíveis , Dióxido de Carbono , Celulose , Álcool de Polivinil
3.
Int J Biol Macromol ; 258(Pt 1): 128831, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38123034

RESUMO

Wound healing is an intricate and ever-evolving phenomenon that involves a series of biological processes and multiple stages. Despite the growing utilization of nanoparticles to enhance wound healing, these approaches often overlook properties like mechanical stability, toxicity, and efficacy. Hence, a multifunctional wound dressing is fabricated using Chitosan-PVA membrane crosslinked with vanillin and reinforced with nano-cellulose and CuO-Ag nanoparticles in this study. FTIR, SEM, and XRD were employed to study the morphology and structural properties of the membrane. Biomedical tests including biodegradability, antimicrobial study, cytotoxicity, and animal models were conducted to evaluate the membrane's performance as a wound healing material. The membrane displayed impressive mechanical strength, measuring as high as 49.985 ± 2.31 MPa, and had a hydrophilic nature, with moisture retention values up to 98.84 % and swelling percentages as high as 191.67 %. It also demonstrated biodegradable properties and high cell viability of up to 92.30 %. Additionally, the fabricated membranes exhibited excellent antimicrobial activity against both gram-positive and gram-negative bacteria, with maximum zone of inhibition measuring 16.8 ± 0.7 mm and 9.2 ± 0.1 mm, respectively. Moreover, the membranes also demonstrated superior wound healing properties. These results suggested great potential of fabricated membranes as an effective wound dressing material.


Assuntos
Benzaldeídos , Quitosana , Nanopartículas Metálicas , Animais , Quitosana/química , Antibacterianos/química , Hidrogéis/química , Prata , Bactérias Gram-Negativas , Bactérias Gram-Positivas , Bandagens/microbiologia , Álcool de Polivinil/química
4.
Chemosphere ; 336: 139213, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37331660

RESUMO

Electronic are usually constructed from non-renewable, non-biodegradable, and hazardous materials. Due to the frequent upgrading or discarding of electronic devices, which contributes significantly to environmental pollution, there is a high demand for electronics made from renewable and biodegradable materials with less harmful components. To this end, due to their flexibility, strong mechanical, and optical properties, wood-based electronics have become very appealing as substrates especially for flexible electronics and optoelectronics. However, incorporating numerous features including high conductivity and transparency, flexibility, and mechanical robustness into an environmentally friendly electronic device remains very challenging. Herein, authors have provided the techniques used to fabricate sustainable wood based flexible electronics coupled with their chemical, mechanical, optical, thermal, thermomechanical, and surface properties for various applications. Additionally, the synthesis of a conductive ink based on lignin and the development of translucent wood as a substrate are covered. Future developments and broader applications of wood-based flexible materials are discussed in the final section of the study, with an emphasis on their potential in fields including wearable electronics, renewable energy, and biomedical devices. This research improves upon prior efforts by demonstrating new ways to simultaneously attain better mechanical and optical qualities and environmental sustainability.


Assuntos
Dispositivos Eletrônicos Vestíveis , Madeira , Eletrônica , Lignina
5.
Chemosphere ; 287(Pt 1): 131956, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34523459

RESUMO

Hydrogel is the most emblematic soft material which possesses significantly tunable and programmable characteristics. Polymer hydrogels possess significant advantages including, biocompatible, simple, reliable and low cost. Therefore, research on the development of hydrogel for biomedical applications has been grown intensely. However, hydrogel development is challenging and required significant effort before the application at an industrial scale. Therefore, the current work focused on evaluating recent trends and issues with hydrogel development for biomedical applications. In addition, the hydrogel's development methodology, physicochemical properties, and biomedical applications are evaluated and benchmarked against the reported literature. Later, biomedical applications of the nano-cellulose-based hydrogel are considered and critically discussed. Based on a detailed review, it has been found that the surface energy, intermolecular interactions, and interactions of hydrogel adhesion forces are major challenges that contribute to the development of hydrogel. In addition, compared to other hydrogels, nanocellulose hydrogels demonstrated higher potential for drug delivery, 3D cell culture, diagnostics, tissue engineering, tissue therapies and gene therapies. Overall, nanocellulose hydrogel has the potential for commercialization for different biomedical applications.


Assuntos
Materiais Biocompatíveis , Hidrogéis , Celulose , Sistemas de Liberação de Medicamentos , Engenharia Tecidual
6.
Mater Sci Eng C Mater Biol Appl ; 126: 112127, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34082944

RESUMO

Hemodialysis considered as therapy of end-stage renal disease (ESRD) for the separation of protein and uremic toxins based on their molecular weights using semi-permeable membranes. Cellulose Acetate (CA) hemodialysis membrane has been widely used in the biomedical field particularly for hemodialysis applications. The main issue of CA membrane is less selectivity and hemocompatibility. In this study, to enhance the filtration capability and biocompatibility of CA hemodialysis membrane modified by using Polyvinyl Alcohol (PVA) and Polyethylene Glycol (PEG) as additives. CA-PVA flat sheet membranes were cast by phase inversion method, and separation was done by dead-end filtration cell. The synthesized membranes were described in terms of chemical structure using Fourier Transform Infrared Spectroscopy (FTIR) and morphology by Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), pure water flux, solute permeation, and protein retention. Biocompatibility of the membranes was tested by the platelet adherence, hemolysis ratio, thrombus formation, and plasma recalcification time. SEM images exposed that the CA-PVA membrane has a uniform porous structure. 42.484 L/m2 h is the maximum pure water flux obtained. The CA-PVA rejected up to 95% of bovine serum albumin (BSA). A similar membrane separated 93% of urea and 89% of creatinine. Platelet adhesion and hemolysis ratio of casted membranes were less than the pure CA membrane. Increased clotting time and less thrombus formation on the membrane's surface showed that the fabricated membrane is biocompatible. CA-PVA hemodialysis membranes are more efficient than conventional reported hemodialysis membranes. It revealed that CA-PVA is high performing biocompatible hemodialysis membrane.


Assuntos
Membranas Artificiais , Álcool de Polivinil , Celulose/análogos & derivados , Diálise Renal
7.
Carbohydr Polym ; 184: 453-464, 2018 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-29352941

RESUMO

Antimicrobial packaging is an area of emerging interest and is rapidly expanding with application of nanotechnology. The present work investigates the effect of nanocellulose (NC) and Ag NPs on the physical, mechanical and thermal properties of PVA nanocomposite films. The tensile strength of PVA was improved from 5.52 ±â€¯0.27 MPa to 12.32 ±â€¯0.61 MPa when filled with 8 wt% of NC. Nanocomposite films exhibited strong antibacterial activity against both Staphylococcus aureus (MRSA) and Escherichia coli (DH5-alpha). The maximum inhibition zone at 0.5 g Ag NPs with 12 wt% NC against DH5-alpha was 14 ±â€¯0.70 mm. While, the maximum inhibition zone at 0.3 g Ag NPs for 16 wt% NC was 13.6 ±â€¯0.68 mm against MRSA. Moreover, nanocomposites films have no cytotoxicity effect on HepG2 and cell viability was more than 90%. Based on mechanical properties and antibacterial potential of the developed nanocomposite films, it can be envisaged to use these films for packaging applications.


Assuntos
Nanopartículas Metálicas/química , Nanocompostos/química , Álcool de Polivinil/química , Prata/química , Antibacterianos/química , Anti-Infecciosos/química , Embalagem de Alimentos , Nanotecnologia/métodos
8.
Carbohydr Polym ; 177: 258-268, 2017 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-28962767

RESUMO

Cellulose nanofibrils (CNF) have strong reinforcing properties when incorporated in a compatible polymer matrix. This work reports the effect of the addition of phosphorylated nanocellulose (PCNF) on the mechanical, thermal and swelling properties of poly(vinyl alcohol) (PVA) nanocomposite membranes. The incorporation of nanocellulose in PVA reduced the crystallinity at 0%RH. However, when the films were exposed to higher humidities the crystallinity increased. No apparent trend is observed for mechanical properties for dry membranes (0% RH). However, at 93% RH the elastic modulus increased strongly from 0.12MPa to 0.82MPa when adding 6% PCNF. At higher humidities, the moisture uptake has large influence on storage modulus, tan δ and tensile properties. Membranes containing 1% PCNF absorbed most moisture. Swelling, thermal and mechanical properties indicate a good potential for applying of PVA/phosphorylated nanocellulose composite membranes for CO2 separation.


Assuntos
Celulose/química , Membranas Artificiais , Nanocompostos/química , Álcool de Polivinil/química , Módulo de Elasticidade , Fosforilação , Resistência à Tração
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