Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 108
Filtrar
1.
Proc Natl Acad Sci U S A ; 121(13): e2318475121, 2024 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-38466879

RESUMO

Deforestation poses a global threat to biodiversity and its capacity to deliver ecosystem services. Yet, the impacts of deforestation on soil biodiversity and its associated ecosystem services remain virtually unknown. We generated a global dataset including 696 paired-site observations to investigate how native forest conversion to other land uses affects soil properties, biodiversity, and functions associated with the delivery of multiple ecosystem services. The conversion of native forests to plantations, grasslands, and croplands resulted in higher bacterial diversity and more homogeneous fungal communities dominated by pathogens and with a lower abundance of symbionts. Such conversions also resulted in significant reductions in carbon storage, nutrient cycling, and soil functional rates related to organic matter decomposition. Responses of the microbial community to deforestation, including bacterial and fungal diversity and fungal guilds, were predominantly regulated by changes in soil pH and total phosphorus. Moreover, we found that soil fungal diversity and functioning in warmer and wetter native forests is especially vulnerable to deforestation. Our work highlights that the loss of native forests to managed ecosystems poses a major global threat to the biodiversity and functioning of soils and their capacity to deliver ecosystem services.


Assuntos
Ecossistema , Microbiota , Solo/química , Conservação dos Recursos Naturais , Biodiversidade , Florestas , Bactérias , Microbiologia do Solo
2.
Biomacromolecules ; 25(3): 1696-1708, 2024 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-38381837

RESUMO

Wood-derived hydrogels possess satisfactory longitudinal strength but lack excellent swelling resistance and dry shrinkage resistance when achieving high anisotropy. In this study, we displayed the preparation of highly dimensional stable wood/polyacrylamide hydrogels (wood/PAM-Al3+). The alkali-treated wood retains lignin as the skeleton of the hydrogel. Second, Al ions were added to the metal coordination with lignin. Finally, by employing free radical polymerization, we construct a conductive electronic network using polyaniline within the wood/PAM-Al3+ matrix to create the flexible sensor. This approach leverages lignin's integrated structure within the middle lamella to provide enhanced swelling resistance and stronger binding strength in the transverse direction. Furthermore, coordination between lignin and Al ions improves the mechanical strength of the wood hydrogel. Polyaniline provides stable linear pressure and temperature responses. The wood/PAM-Al3+ exhibits a transverse swelling ratio of 3.90% while achieving a longitudinal tensile strength of 20.5 MPa. This high-strength and high-stability sensor is capable of monitoring macroscale human behavior. Therefore, this study presents a simple yet innovative strategy for constructing tough hydrogels while also establishing an alternative pathway for exploring lignin networks in new functional materials development.


Assuntos
Compostos de Anilina , Hidrogéis , Lignina , Humanos , Lignina/química , Hidrogéis/química , Madeira , Íons/química , Condutividade Elétrica
3.
Environ Res ; 241: 117628, 2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-37956756

RESUMO

In this study, phycoremediation of textile wastewater (TWW) by freshwater cyanobacterial strains such as sp., Oscillatoria sp. F01 and Oscillatoria sp. F02 was evaluated, and lipids were simultaneously extracted from biomass for biodiesel production. Onset of the study, Phormidium sp. and Oscillatoria sp. F01 has better growth rates, increased biomass production, high chlorophyll content, and efficient nutrient utilization in TWW compared to Oscillatoria sp. F02. Phormidium sp. showed 1.41 g/L dry weight, followed by Oscillatoria sp. F01 with 1.39 g/L and Oscillatoria sp. F02 with 1.02 g/L biomass. Both strains demonstrated their capability to elevate the pH level while reducing TDS and eliminating/reducing several nutrients such as nitrates, nitrites, phosphates, sulphates, sulphides, chlorides, calcium, sodium, and magnesium. Further, the total lipids extracted from the TWW-grown Phormidium sp., Oscillatoria sp. F01 and Oscillatoria sp. F02 was estimated to be 8.20, 13.70 and 11.20 %, respectively, on day 21, which was higher than the lipid content obtained from control cultures. Further, biodiesel produced from the lipids of all strains showed higher levels of C12:0, C16:0, C16:1, C18:1, C18:2, and C18:3 among all the fatty acids. Therefore, they can potentially offer a valuable source of lipids and diverse fatty acids for high-quality biodiesel production. This integrated system not only offers a solution for TWW treatment but also provides a feedstock for renewable fuel production simultaneously.


Assuntos
Cianobactérias , Microalgas , Oscillatoria , Águas Residuárias , Phormidium , Biocombustíveis/microbiologia , Biomassa , Ácidos Graxos , Nutrientes
4.
Small ; 19(2): e2205168, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36399644

RESUMO

Excessive anthropogenic CO2 emission has caused a series of ecological and environmental issues, which threatens mankind's sustainable development. Mimicking the natural photosynthesis process (i.e., artificial photosynthesis) by electrochemically converting CO2 into value-added products is a promising way to alleviate CO2 emission and relieve the dependence on fossil fuels. Recently, Sn-based catalysts have attracted increasing research attentions due to the merits of low price, abundance, non-toxicity, and environmental benignancy. In this review, the paradigm of nanostructure engineering for efficient electrochemical CO2 reduction (ECO2 R) on Sn-based catalysts is systematically summarized. First, the nanostructure engineering of size, composition, atomic structure, morphology, defect, surficial modification, catalyst/substrate interface, and single-atom structure, are systematically discussed. The influence of nanostructure engineering on the electronic structure and adsorption property of intermediates, as well as the performance of Sn-based catalysts for ECO2 R are highlighted. Second, the potential chemical state changes and the role of surface hydroxides on Sn-based catalysts during ECO2 R are introduced. Third, the challenges and opportunities of Sn-based catalysts for ECO2 R are proposed. It is expected that this review inspires the further development of highly efficient Sn-based catalysts, meanwhile offer protocols for the investigation of Sn-based catalysts.


Assuntos
Dióxido de Carbono , Nanoestruturas , Adsorção , Eletrônica , Engenharia
5.
Environ Res ; 221: 115250, 2023 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-36646201

RESUMO

Diabetes mellitus is a growing disease that affects people of different ages due to deficiencies in insulin action and secretion. Diabetes causing long-term hyperglycemia damages, destroys, and fails essential organs, including kidneys, eyes, hearts, nerves, and blood vessels. The involvement of pathogenic factors makes diabetes mellitus a severe disease. The autoimmune process results in insulin deficiency by destroying the beta-cells in the pancreas. This leads to insulin resistance. As a result of defects and abnormalities in fat, carbohydrate, and protein synthesis, insulin does not work as it should on the target tissues. As diabetes mellitus becomes, more severe, long-term and effective treatment becomes necessary. A wide range of nanomaterials can be used to treat diabetes mellitus in patients. In addition to being potential imaging, diagnostic, and treatment agents for diabetes mellitus, carbon nanomaterials (CNMs) are another group of nanoparticles that exhibit potential interest. The CNMs acts as implantable nanosensor to track and detect blood glucose level in patients with diabetes. CNMS are possible drug carriers that can treat diabetes mellitus selectively, precisely, and effectively. Diabetes mellitus can be diagnosed and treated with CNMs due to their structural specificity and high drug-loading efficiency. The present review explores CNMs for their types, synthesis, and anti-diabetic properties. This review aims to provide a detailed view of the new technology that can be used to decipher the mechanism of CNMs in diabetes mellitus.


Assuntos
Diabetes Mellitus , Nanopartículas , Nanoestruturas , Humanos , Carbono/química , Diabetes Mellitus/diagnóstico , Insulina , Nanoestruturas/uso terapêutico , Nanoestruturas/química
6.
Environ Res ; 222: 115318, 2023 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-36693465

RESUMO

Clean freshwater has been required for drinking, sanitation, agricultural activities, and industry, as well as for the development and maintenance of the eco - systems on which all livelihoods rely. Water contamination is currently a significant concern for researchers all over the world; hence it is essential that somehow this issue is resolved as soon as possible. It is now recognised as one of the most important research areas in the world. Current wastewater treatment techniques degrade a wide range of wastewaters efficiently; however, such methods have some limitations. Recently, nanotechnology has emerged as a wonderful solution, and researchers are conducting research in this water remediation field with a variety of potential applications. The pollutants remediation capability of nanocomposites as adsorbents, photocatalysts, magnetic separation, and so on for contaminant removal from contaminated water has been examined in this study. This study has spotlighted the most significant nanocomposites invention reported to date for contaminated and effluent remediation, as well as a research gap as well as possible future perspectives.


Assuntos
Poluentes Ambientais , Nanocompostos , Poluentes Químicos da Água , Purificação da Água , Poluição da Água , Nanotecnologia , Águas Residuárias , Água
7.
Environ Res ; 231(Pt 1): 115958, 2023 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-37086880

RESUMO

The shift in focus towards biofuels has led to the attention towards fourth-generation fuels, particularly microalgae, due to its high oil productivity and simple cultivation processes. The current study aimed to examine the effects of spirulina microalgae blends in a naturally aspirated diesel engine by testing two blend percentages (15% and 30%) and incorporating Fe2O3 nanoparticles (75 ppm). A series of test conducted in a single-cylinder engine with an optimum compression ratio of 17.5. The fuels tested include 100% diesel (D0), diesel with Fe2O3 nanoparticles (DF), diesel with 15% microalgae blends (B15), diesel with 15% microalgae blends and Fe2O3 nanoparticles (B15F), diesel with 30% microalgae blends (B30), and diesel with 30% microalgae blends and Fe2O3 nanoparticles (B30F). The results showed that the addition of microalgae blends led to a marginal increase in engine performance, while the addition of Fe2O3 nanoparticles led to a significant increase in brake thermal efficiency and decreased fuel consumption. The emissions rate was also lower compared to diesel, but the addition of Fe2O3 nanoparticles increased the oxygen content in the fuel, thereby improving the combustion rates. By ensuring the complete combustion the formation of CO2, HC and smoke intensity was also found to be significantly lower compared to diesel fuel. On the contrary, NOx increased due to the cylinder temperatures. This research highlights the potential of using microalgae as a sustainable source of biofuel, and the positive effects of adding Fe2O3 nanoparticles to enhance the fuel's efficiency.


Assuntos
Gases de Efeito Estufa , Microalgas , Spirulina , Emissões de Veículos/análise , Gasolina/análise , Biocombustíveis/análise , Monóxido de Carbono/análise
8.
Environ Res ; 218: 114921, 2023 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-36504007

RESUMO

Nanomaterials have many advantages over bulk materials, including enhanced surface-to-volume proportion as well as magnetic traits. It has been a steady rise in research with using nanomaterials in various biomedical fields in the past few decades. Constructing nanomaterials has emerged as a leading research primary concern in order to discover specialized biomedical applications. Since, their advantageous properties including chemical stability, non-toxicity, bio - compatibility, relatively high magnetization, and strong magnetic vulnerability, nanoparticles of iron oxide had already influenced implementations in different biomedical fields. Nanomaterials can be divided up into four nanomaterials such as metallic nanomaterials, bimetallic or alloy nanomaterials, metal oxide nanomaterials, as well as magnetic nanomaterials. Hence, the purpose of this review is to conduct such in discussion on emerging advancements in nanomaterials for biomedical, with such a special emphasis upon those options of nanomaterials including metallic nanomaterials: Au and Ag, bimetallic nanomaterials: Fe-Co and Fe-Pt, and metal oxides: TiO2 and CeO2. Securing this information gap will result in a better comprehension of the contribution of nanomaterial type and subsequent huge-scale applications in aspects of both their potential and challenges.


Assuntos
Nanopartículas Metálicas , Nanoestruturas , Nanopartículas Metálicas/toxicidade , Nanoestruturas/toxicidade , Óxidos
9.
Environ Res ; 218: 114947, 2023 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-36462692

RESUMO

Advanced biochar blended nanoparticles substances, such as nano biochar or nanocomposites, have provided long-term solutions to a wide range of modern-day problems. Biochar blended nano-composites can be created to create better composite materials that combine the benefits of biochar and nanoparticles. Such materials have been typically improved with active functional groups, porous structure, active surface area, catalytic deterioration ability, as well as easy recovery or separation of pollutants. Such biochar-basednanocomposites have good adsorption properties for a variety of pollutants in various form of polluted medium (soil and water contamination). Catalytic nanoparticle encapsulated biochar, can perform concurrently the adsorption (by biochar) as well as catalytic degradation (nanoparticles) functions for pollutants removal from polluted sites. In this review, the advanced and practically feasible techniques involved in the biochar blended nanoparticles-based nanocomposites have been discussed with environmental applications. Furthermore, the mechanisms involved in this composite material in remediation, as well as the advantages and disadvantages of biochar blended nanoparticles-based nanocomposites, were discussed, and future directions for study in this field were suggested.


Assuntos
Poluentes Ambientais , Recuperação e Remediação Ambiental , Nanocompostos , Nanopartículas , Poluentes do Solo , Poluentes Químicos da Água , Carvão Vegetal/química , Solo , Adsorção , Poluentes Químicos da Água/análise
10.
Environ Res ; 232: 116363, 2023 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-37295587

RESUMO

Due to their widespread occurrence and detrimental effects on human health and the environment, endocrine-disrupting hazardous chemicals (EDHCs) have become a significant concern. Therefore, numerous physicochemical and biological remediation techniques have been developed to eliminate EDHCs from various environmental matrices. This review paper aims to provide a comprehensive overview of the state-of-the-art remediation techniques for eliminating EDHCs. The physicochemical methods include adsorption, membrane filtration, photocatalysis, and advanced oxidation processes. The biological methods include biodegradation, phytoremediation, and microbial fuel cells. Each technique's effectiveness, advantages, limitations, and factors affecting their performance are discussed. The review also highlights recent developments and future perspectives in EDHCs remediation. This review provides valuable insights into selecting and optimizing remediation techniques for EDHCs in different environmental matrices.


Assuntos
Disruptores Endócrinos , Recuperação e Remediação Ambiental , Humanos , Biodegradação Ambiental , Substâncias Perigosas/toxicidade
11.
Environ Res ; 231(Pt 1): 116059, 2023 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-37149019

RESUMO

Petroleum-based polymers have raised significant environmental concerns. It is critical to create compostable, good biocompatibility, and nontoxic polymers to replace petroleum-based polymers. Thus, this research was performed to extract the gelatin from fish waste cartilage and coated it over the surface of spherical shaped pre-synthesized ZnNPs along with a suitable plasticizer to produce the biodegradable film. The presence of gelatin on the surface of ZnNPs was first confirmed using UV-visible spectrophotometers, as well as the characteristic functional groups involved in the coating were investigated using Fourier-Transform Infrared Spectroscopy (FTIR). The morphological appearance of gelatin coated ZnNPs was ranged from 41.43 to 52.31 nm, the shape was found as platonic to pentagonal shape, and the fabricated film was observed through Scanning Electron Microscope (SEM). The thickness, density, and tensile strength of fabricated film were found to be 0.04-0.10 mm, 0.10-0.27 g/cm3, and 31.7 kPa. These results imply that the fish waste cartilage gelatin coated ZnNPs-based nanocomposite can be used for film preparation as well as a wrapper for food and pharmaceutical packaging.


Assuntos
Gelatina , Embalagem de Produtos , Animais , Gelatina/química , Resistência à Tração , Biopolímeros , Alimentos , Embalagem de Alimentos/métodos
12.
Environ Res ; 231(Pt 1): 116074, 2023 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-37150391

RESUMO

The starch is one of the most essential food stuff and serves as a raw material for number of food products for the welfare of human. During the production process enormous volume of effluents are being released into the environment. In this regard, this study was performed to evaluate the physicochemical traits of Manihot esculenta processing effluent and possible sustainable approach to treat this issue using Eichhornia crassipes based biochar. The standard physicochemical properties analysis revealed that the most the parameters (EC was recorded as 4143.17 ± 67.12 mhom-1, TDS: 5825.62 ± 72.14 mg L-1, TS: 7489.21 ± 165.24 mg L-1, DO: 2.12 ± 0.21 mg L-1, BOD 2673.74 ± 153.53 mg L-1, COD: 6672.66 ± 131.21 mg L-1, and so on) were beyond the permissible limits and which can facilitate eutrophication. Notably, the DO level was considerably poor and thus can support the eutrophication. The trouble causing E. crassipes biomass was used as raw material for biochar preparation through pyrolysis process. The temperature ranging from 250 to 350 °C with residence time of 20-60 min were found as suitable temperature to provide high yield (56-33%). Furthermore, 10 g L-1 concentration of biochar showed maximum pollutant adsorption than other concentrations (5 g L-1 and 15 g L-1) from 1 L of effluent. The suitable temperature required to remediate the pollutants from the effluent by biochar was found as 45 °C and 35 °C at 10 g L-1 concentration. These results conclude that at such optimized condition, the E. crassipes effectively adsorbed most of the pollutants from the M. esculenta processing effluent. Furthermore, such pollutants adsorption pattern on biochar was confirmed by SEM analysis.


Assuntos
Eichhornia , Poluentes Ambientais , Manihot , Poluentes Químicos da Água , Humanos , Eichhornia/química , Adsorção , Poluentes Químicos da Água/análise
13.
Environ Res ; 229: 115964, 2023 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-37100363

RESUMO

Wood is an insulator material, using its porous structure to endow it with efficient microwave absorption and broaden its application range is still a major challenge. Here, wood-based Fe3O4 composites with excellent microwave absorption properties and high mechanical strength were prepared by alkaline sulfite method, in-situ co-precipitation method and compression densification method. The results showed that the magnetic Fe3O4 was densely deposited in the wood cells, and the prepared wood-based microwave absorption composites had both high electrical conductivity, magnetic loss, excellent impedance matching performance and attenuation performance, as well as effective microwave absorption properties. In the frequency range of 2-18 GHz, the minimum reflection loss value was -25.32 dB. At the same time, it had high mechanical properties. Compared with the untreated wood, its modulus of elasticity (MOE) in bending increased by 98.77%, and modulus of rapture (MOR) in bending improved by 67.9%. The developed wood-based microwave absorption composite is expected to be used in electromagnetic shielding fields such as anti-radiation and anti-interference.


Assuntos
Óxido Ferroso-Férrico , Madeira , Campos Eletromagnéticos , Micro-Ondas , Porosidade
14.
Environ Res ; 231(Pt 2): 116078, 2023 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-37182832

RESUMO

Nannochloropsis microalgae biochar has become increasingly attractive due to its potential as a component of microalgae-based biodiesel blends. This biochar is a by-product of the pyrolysis process, but its use in the energy sector has been limited. In this study, pellets were formed using microalgae residues and their physiochemical properties were analyzed to assess the feasibility of using microalgae biochar as a fuel source. Three types of biomasses, namely date seed dust, coconut shell waste, and microalgae biochar, were utilized to produce fuel pellets. These pellets were categorized into three types, B1, B2, and B3, based on the composition of the biomass. The inclusion of microalgae biochar in the pellets resulted in enhanced calorific value, as well as improved heating value and bulk density. Moreover, the mechanical strength of microalgae-based pellets was higher due to their high lignin content compared to another biomass. The moisture absorption test results showed that the use of mixed biomass reduced the moisture content over an extended period. Microalgae pellets exhibited higher young's modulus and greater impact resistance, indicating greater mechanical strength. Furthermore, due to their higher calorific value, the combustion time of microalgae pellets was greater than that of other biomass. In conclusion, the results of this study suggest that microalgae biochar can be a promising alternative fuel source for the energy sector.


Assuntos
Microalgas , Biomassa , Pirólise , Micro-Ondas
15.
Environ Res ; 232: 116300, 2023 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-37268207

RESUMO

Microalgae is one the promising source of energy for the production of biofuel and other value-added products to replace the existing conventional fossil fuels. However, low lipid content and poor cell harvesting are the key challenges. Based on the growth conditions the lipid productivity will be affected. The current study examines the mixtures of both wastewater and NaCl on the microalgae growth was studied. The microalgae used for conducting the tests were Chlorella vulgaris microalgae. Mixtures of the wastewater was prepared under the different concentrations of the seawater, classified as S0%, S20%, and S40%. The growth of microalgae was studied in the presence of these mixtures, and the addition of Fe2O3 nanoparticles was included to stimulate the growth. The results showed that increasing the salinity in the wastewater resulted in decreased biomass production, but significantly increased lipid content compared to S0%. The highest lipid content was recorded at S40%N with 21.2%. The Highest lipid productivity was also witnessed for S40% with 45.6 mg/Ld. The cell diameter was also found to increase with increasing salinity content in the wastewater. The addition of Fe2O3 nanoparticles in the seawater was found to enhance the productivity of the microalgae extensively, resulting in 9.2% and 6.15% increased lipid content and lipid productivity respectively compared to conventional cases. However, the inclusion of the nanoparticles slightly increased the zeta potential of microalgal colloids, with no noticeable effects on the cell diameter or bio-oil yields. Based on these findings, Chlorella vulgaris was identified as a suitable candidate for treating wastewater with high salinity exposure.


Assuntos
Chlorella vulgaris , Microalgas , Nanopartículas , Lipídeos , Águas Residuárias , Água do Mar , Biocombustíveis , Biomassa
16.
J Environ Manage ; 345: 118837, 2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37634401

RESUMO

Process Intensification (PI) is the modification or integration of conventional or novel processes within a single unit operation in order to improve product quality and reduce waste. PI offers numerous advantages, including a reduction in the initial and operational costs, an improvement in product quality/quantity, the generation of less waste, and an increase in process safety. The synergistic effect of PI in comparison to the conventional procedure ensures maximizing resource efficiency. PI can be accomplished in two ways: either by integrating various processes or by modifying the design of equipment to improve operational efficiency. In this regard, the present review provides a comprehensive insight into the application of PI in wastewater and sludge treatment methods and discusses the operational advantages. This review provides a comprehensive list of different PI approaches applied in wastewater and sludge treatment to remove pollutants and the various equipment, techniques and reactors used in PI. The second section addresses the challenges of PI in wastewater treatment that removes dyes, pesticides, organic and inorganic pollutants, micro- and nano-plastics, persistent organic pollutants, pharmaceutical and personal care pollutants.


Assuntos
Poluentes Ambientais , Poluentes Químicos da Água , Águas Residuárias , Esgotos , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/análise
17.
J Environ Manage ; 345: 118911, 2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37657294

RESUMO

Photocatalytic technology is regarded as a promising approach for fast degradation of refractory organic pollutant in water. However, the performance of the photocatalyst can be restricted by the variation of water matrix conditions. Herein, coconut shell fiber was pyrolyzed to biochar (CSB800) and incorporated with α-MnO2 to degrade bisphenol A (BPA) in water under visible light irradiation. The prepared α-MnO2/CSB800 composites demonstrated high efficacy in degrading BPA. Specifically, 0.01 mM of BPA could be completely degraded by 0.1 g/L of MnO2/CSB800 within 45 min. It was found that the incident light could effectively trigger the separation of electron and hole in α-MnO2. The electron and hole were afterwards converted to hydroxyl radical (●OH), superoxide radical (●O2-) and non-radical singlet oxygen (1O2), which subsequently initiated the photocatalytic degradation of BPA. Additionally, α-MnO2/CSB800 could simultaneously participate the oxidative degradation pathway of BPA with its high oxidation-reduction potential. The introduction of CSB800 led to higher BPA degradation efficiency since CSB800 could accelerate the charge carrier transferring rate during BPA degradation process via either pathway. The co-existence of both photocatalytic and oxidative degradation synergy enables α-MnO2/CSB800/visible light system with high catalytic performance stability towards various water matrices. This study proposes an effective strategy to prepare easy-available photocatalysts with high and stable performance towards for addressing organic pollution issues in water.


Assuntos
Cocos , Compostos de Manganês , Óxidos , Oxirredução , Luz
18.
Molecules ; 28(7)2023 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-37049854

RESUMO

As an important forestry biomass resource, rosin has a wide range of applications in medicine, adhesives, surfactants and other fields. Using natural dehydroabietic acid as a raw material, dehydroabietic acid-based phosphorus monoester (DPM) and diester (DPD) surfactants were designed and synthesized. The chemical structures and self-assembly properties were characterized by FT-IR, NMR and TEM, and the effects of pH on critical micelle concentration, γCMC, emulsifying properties, foam properties and micelle morphology were studied. The results showed that the CMC, γCMC value and aggregate morphology had certain pH responsiveness. The γCMC value under acidic conditions was smaller than γCMC under alkaline conditions, and the foaming performance and foam stability under acidic conditions were better than those under alkaline conditions. TEM micelle morphology studies have shown that DPM and DPD surfactants can self-assemble into rod-shaped and spherical micelle morphologies with a pH change in an aqueous solution. At the same pH, the foaming and emulsification properties of DPD were better than those of DPM. The best foaming and emulsification ability of DPD were 11.8 mL and 175 s, respectively. At the same time, the foaming ability of DPD is also affected by pH. DPD has excellent foaming properties in acidic conditions, but these disappeared in neutral conditions.

19.
Molecules ; 28(3)2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36771056

RESUMO

Soy protein isolate (SPI) is an attractive natural material for preparing wood adhesives that has found broad application. However, poor mechanical properties and unfavorable water resistance of wood composites with SPI adhesive bonds limit its more extensive utilization. The combination of lysine (Lys) with a small molecular structure as a curing agent for modified soy-based wood adhesive allows Lys to penetrate wood pores easily and can result in better mechanical strength of soy protein-based composites, leading to the formation of strong chemical bonds between the amino acid and wood interface. Scanning electron microscopy (SEM) results showed that the degree of penetration of the S/G/L-9% adhesive into the wood was significantly increased, the voids, such as ducts of wood at the bonding interface, were filled, and the interfacial bonding ability of the plywood was enhanced. Compared with the pure SPI adhesive, the corresponding wood breakage rate was boosted to 84%. The wet shear strength of the modified SPI adhesive was 0.64 MPa. When Lys and glycerol epoxy resin (GER) were added, the wet shear strength of plywood prepared by the S/G/L-9% adhesive reached 1.22 MPa, which increased by 29.8% compared with only GER (0.94 MPa). Furthermore, the resultant SPI adhesive displayed excellent thermostability. Water resistance of S/G/L-9% adhesive was further enhanced with respect to pure SPI and S/GER adhesives through curing with 9% Lys. In addition, this work provides a new and feasible strategy for the development and application of manufacturing low-cost, and renewable biobased adhesives with excellent mechanical properties, a promising alternative to traditional formaldehyde-free adhesives in the wood industry.


Assuntos
Lisina , Proteínas de Soja , Proteínas de Soja/química , Lisina/análise , Resinas Epóxi/análise , Adesivos/química , Madeira/química , Água/análise
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA