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1.
Food Chem ; 447: 139046, 2024 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-38518620

RESUMO

The objective of this study was to systematically elucidate the effects of conventional (Cold Pressing, CP; Hot Pressing, HP; Soxhlet Extraction; SE) and novel methods (Microwave-Assisted Extraction, MAE) on the physicochemical properties, bio-active substances, flavor and lipidomics of Camellia oleifera oil (COO). The cold-pressed COO contained the highest contents of squalene (176.38 mg/kg), α-tocopherol (330.52 mg/kg), polyphenols (68.33 mg/kg) and phytosterols (2782.55 mg/kg). Oleic acid was observed as the predominant fatty acid with the content of approximately 80%. HS-GC-IMS identified 47 volatile compounds, including 11 aldehydes, 11 ketones, 11 alcohols, 2 acids, 8 esters, 2 pyrazines, 1 furan, and 1 thiophene. A total of 5 lipid classes and 30 lipid subclasses of 339 lipids were identifed, among which TGs and DGs were observed as the major lipids. In summary, both cold-pressed and microwave-assisted technologies provided high-quality COO with high content of bio-active substances and diglycerides/triglycerides.


Assuntos
Camellia , Lipidômica , Óleos de Plantas/química , Ácidos Graxos , Ácido Oleico , Camellia/química
2.
Int J Biol Macromol ; 238: 124022, 2023 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-36921822

RESUMO

GO/HEC/PGDE/Fe3O4 materials were successfully fabricated using environmentally-friendly hydroxyethyl cellulose (HEC), poly(ethylene glycol) diglycidyl ether (PGDE), graphene oxide (GO) and magnetic Fe3O4. Systematic investigations were completed to explore the influences of GO content in GO/HEC/PGDE/Fe3O4 and adsorption conditions on the adsorptions of cationic dyes (methylene blue (MB), crystal violet (CV)) and anionic dye acid blue 25 (AB-25). The increase of GO content can remarkably improve the adsorption capacity of GO/HEC/PGDE/Fe3O4 for the dyes. The three kinetic, four isothermic and three thermodynamic models were investigated to reveal the adsorption behaviors of the dyes. The formation of HEC/PGDE/Fe3O4 and adsorption mechanisms of the dyes by GO/HEC/PGDE/Fe3O4 were suggested. The GO/HEC/PGDE/Fe3O4 endowed with easy-fabrication, eco-friendly feature, efficient adsorption capacity of anionic/cationic dyes, convenient separation and reusability has potential applications in wastewater purification industry.


Assuntos
Grafite , Poluentes Químicos da Água , Corantes/química , Celulose , Adsorção , Grafite/química , Cátions/química , Poluentes Químicos da Água/química
3.
Bioresour Technol ; 369: 128391, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36435418

RESUMO

Ethylene glycol and ferric chloride pretreatment assisted by low-pressure carbon dioxide (1 MPa CO2) realized the targeted deconstruction of lignocelluloses at 170 °C for 5 min, achieving 98 % cellulose recovery with removal of 92 % lignin and 90 % hemicellulose. After the pretreatment, the formation of stable platform mono-phenol components would be with the destruction of the lignin-carbohydrate complexes structure, and the surface of rice straw became rough, with a less negative charge and higher specific surface area, while the enzyme adsorption rate increased by 8.1 times. Furthermore, the glucose yield of pretreated straw was remarkably increased by 5.6 times that of the untreated straw, reaching 91 % after hydrolyzed for 48 h. With Tween 80 added in concentrated solid (12 %) hydrolysis at low cellulase loading (3 FPU/g dry substrate), half of the hydrolysis time was shortened than that without Tween 80, with 45 % higher glucose yield.


Assuntos
Celulase , Oryza , Lignina/química , Dióxido de Carbono , Oryza/química , Etilenoglicol , Polissorbatos/farmacologia , Glucose , Hidrólise , Celulase/química
4.
Molecules ; 29(1)2023 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-38202799

RESUMO

Litsea cubeba is a characteristic woody oil resource in Hunan. As a solid waste of woody oil resources, Litsea cubeba kernels are rich in Litsea cubeba kernel oil with a carbon chain length of C10-12 fatty acid. In this work, aliphatic hydroxamic acids (AHAs) with carbon chain lengths of C10-12 were prepared from Litsea cubeba kernel oil via methylation and hydroximation reactions. The adsorption and hydrophobicity mechanism of AHA towards wolframite was explored by contact angle, zeta potential, Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The flotation results demonstrated that AHA was a superior collector than the traditional collector such as benzoyl hydroxamic acid (BHA). Zeta potential and contact angle results have shown that AHA was adsorbed on the surface of the Fe(III)-activated wolframite in its anionic form, which significantly improved the surface hydrophobicity of wolframite. FTIR and XPS revealed that AHA was chemically adsorbed on the surface of Fe(III)-activated wolframite in the form of a five-member ring, which made the hydrophobic chain reach into the solution, come in contact with bubbles, and achieve flotation separation.

5.
Molecules ; 27(24)2022 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-36558013

RESUMO

The aim of this study was to devise a method to protect Chinese cabbage (Brassica chinensis) and lettuce (Lactuca sativa) from bacterial-disease-induced damage during storage. Thus, the potential of rhapontigenin as a quorum sensing (QS) inhibitor against Pectobacterium carotovorum subsp. carotovorum (P. carotovorum) was evaluated. The QS inhibitory effects of rhapontigenin were confirmed by significant inhibition of the production of violacein in Chromobacterium violaceum CV026 (C. violaceum, CV026). The inhibitory effects of rhapontigenin on the motility, exopolysaccharide (EPS) production, biofilm formation and virulence−exoenzyme synthesis of P. carotovorum were investigated. Acyl-homoserine lactones (AHLs) were quantified using liquid chromatography−mass spectrometry (LC−MS). The inhibitory effects of rhapontigenin on the development of biofilms were observed using fluorescence microscopy and scanning electron microscopy (SEM). A direct-inoculation assay was performed to investigate the QS inhibitory effects of rhapontigenin on P. carotovorum in Chinese cabbage and lettuce. Our results demonstrated that rhapontigenin exhibited significant inhibition (p < 0.05) of the motility, EPS production, biofilm formation, virulence−exoenzyme synthesis and AHL production of P. carotovorum. Additionally, the result of the direct-inoculation assay revealed that rhapontigenin might provide vegetables with significant shelf-life extension and prevent quality loss by controlling the spread of soft-rot symptoms. Consequently, the study provided a significant insight into the potential of rhapontigenin as a QS inhibitor against P. carotovorum.


Assuntos
Brassica , Percepção de Quorum , Verduras , Pectobacterium carotovorum , Biofilmes , Chromobacterium , Antibacterianos/farmacologia
6.
Langmuir ; 38(50): 15858-15865, 2022 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-36473165

RESUMO

Lepidolite is an important mineral resource of lithium. With the increase in awareness of low-carbon and green travel, the demand for lithium has increased dramatically. Therefore, how to increase the output of lithium has to turn into high precedence. In this paper, amidoxime (DPA) was synthesized and used for the efficient collection of lepidolite. Dodecylamine (DA), a commonly used collector of lepidolite ore, was used for comparison. The collecting performances of DA and DPA for lepidolite were studied by the micro-flotation experiment, and the adsorption mechanism of DPA on lepidolite was verified by contact angle, zeta potential tests, FTIR spectra, and density functional theory (DFT) calculations. The results of flotation experiments showed that at the same collector dosage (3 × 10-4 mol/L), the recovery of lepidolite could reach 90%, while the recovery of lepidolite with DA was only 52.5%, and to achieve the maximum recovery of DA (77.5%), only half of the DPA was added. The contact angle test results showed that DPA could effectively improve the hydrophobicity of lepidolite than DA. FTIR spectra and zeta potential tests suggested that DPA molecules were adsorbed on the lepidolite surface by electrostatic attraction. DFT calculations revealed that DPA reacted with the nucleophilic reagent (lepidolite) by the reactive site of the -CH2NH(CH2)2C(NOH)N+H3 group and more easily absorbed on the surface of lepidolite than DA. Therefore, our new finding will provide an important prospect for the sustainable development and utilization of lithium resources.

7.
Chem Commun (Camb) ; 58(62): 8678-8681, 2022 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-35822925

RESUMO

Herein we present the use of a Gemini surfactant and reverse froth flotation to efficiently separate magnetite from quartz and produce iron ore at 273 K. This surfactant achieved an obviously superior flotation performance (TFe recovery increased by 48.18%), and the dosage of the Gemini surfactant was three times less than that of a conventional monomeric surfactant. Our findings are expected to serve as a general guide to design a new and excellent collector for high-efficiency mineral flotation and to lead to an efficient and clean development of mineral resources.

8.
Langmuir ; 38(29): 9010-9020, 2022 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-35831986

RESUMO

The separation and enrichment of scheelite from calcite are hindered by the similar active Ca2+ sites of scheelite and the calcite with calciferous gangue. Herein, a novel trisiloxane surfactant, N-(2-aminoethyl)-3-aminopropyltrisiloxane (AATS), was first explored and synthesized and recommended as the collector for the flotation separation of scheelite from calcite. The micro-flotation and mixed binary mineral flotation tests showed that AATS had excellent collection performance for scheelite and high selectivity for calcite within a wide pH range. At the same time, contact angle and zeta-potential measurements, Fourier transform infrared (FTIR) analysis, and density functional theory (DFT) calculations revealed the relevant adsorption mechanism. The contact angle measurement showed that AATS can increase the contact angle of the scheelite surface from 41.7 to 95.8°, greatly enhancing the hydrophobicity of the mineral surface. The results of FTIR analysis and zeta-potential measurement explained that AATS was electrostatically adsorbed on the mineral surface, and DFT calculation further verified that the -N+H3-positive group in AATS was adsorbed on the negatively charged scheelite surface. Therefore, AATS can realize the expectation of high efficiency and selectivity of minerals and enhance the adhesion between the surface of scheelite minerals and bubbles, providing a fresh approach to industrial production.

9.
J Environ Manage ; 317: 115372, 2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-35617862

RESUMO

Tailings ponds for gangue mineral storage are widely recognized as a dangerous source of toxic minerals and heavy metal-bearing solution. Therefore, recovering valuable minerals and critical elements from tailings is an important means to protect the environment in an economic way. Wolframite tailings usually contain a considerable amount of tungsten resources, but the presence of high content of kaolinite sludge makes it very difficult to recycle wolframite. Herein, a novel sebacoyl hydroxamic acid (SHA) was synthesized and introduced as a novel wolframite collector to effectively utilize wolframite tailings, and its collection performance was compared with that of benzohydroxamic acid (BHA). Micro-flotation tests showed that SHA could still obtain 80% wolframite recovery in the presence of kaolinite slimes. Bench-scale flotation tests indicated that SHA can effectively recover wolframite concentrate with 55.64% WO3 grade and 75.28% WO3 recovery from wolframite tailings by the combined shaking table-flotation process. Polarized light microscope observations showed that SHA could promote the formation of hydrophobic agglomerates of wolframite particles. These results show that SHA can be used as an efficient collector for disposing of wolframite tailings, and provide an important reference for the development of efficient and comprehensive utilization of tailings.


Assuntos
Metais Pesados , Tungstênio , Ácidos Hidroxâmicos , Caulim , Minerais
10.
ACS Omega ; 5(38): 24256-24261, 2020 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-33015442

RESUMO

Poly(methyl methacrylate) (PMMA) is a thermoplastic polyester with excellent properties such as lightweight, low price, biocompatibility, and so on. However, its extensive utilization is restricted by the deficiencies of brittleness and poor mechanical properties. In this study, high-performance PMMA films enhanced by methylcellulose (MC) were fabricated by a simple procedure at ambient temperatures. The effects of PMMA/MC mass ratio and thermal compression treatment on mechanical properties (tensile strength and elongation) were systematically investigated. The PMMA/MC films showed remarkably enhanced mechanical properties compared with neat PMMA. The tensile strengths of the PMMA/MC (3:97) and PMMA/MC (1:1) films are higher than that of the PMMA/MC (9:1) film by about 471 and 83%, respectively. The mechanical properties were also improved after thermal compression treatment. Importantly, the PMMA/MC films could be recovered and reused. In addition, the morphologies, crystalline state, and chemical structures of the films were investigated by scanning electron microscopy, X-ray diffraction, and 13C NMR spectroscopy. The films are expected to be used as sustainable and potential alternatives to petroleum-based polymer film products because of their simple preparation procedure, high-performance mechanical properties, excellent recycling, eco-friendly features, and scale manufacture.

11.
J Agric Food Chem ; 68(40): 11114-11120, 2020 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-32936618

RESUMO

Phosphorite is generally used in the manufacture of phosphate fertilizer and plays a vital role in the development of agricultural and food production. Nonetheless, how to obtain phosphorite concentrates efficiently and sustainably has become an urgent problem. In this study, a newly designed trisiloxane surfactant, N-(2-Aminoethyl)-3-aminopropyltrisiloxane (AATS), has been prepared and utilized as an emerging collector for reverse flotation of phosphorite ore. Its collecting ability was compared with the conventional surfactant 1-dodecamine (DDA). In the collector concentration tests, AATS with lower concentrations showed stronger collecting ability for quartz. In the pH tests, AATS always performed better than DDA in the acidic or alkaline condition. In bench-scale flotation experiments, the P2O5 recovery of phosphorite concentrates with 150 g/t AATS was 10.77% higher than that with 300 g/t DDA, which proved that AATS can be applied to the sustainable production of phosphorite concentrates. For a 4000 t/d phosphorite ore processing plant, the profit could be increased 7,014,702.07 USD every year by using AATS as the collector. Therefore, this work provides a promising approach to enhance the production efficiency of phosphate fertilizer and to promote the sustainable development of agriculture.


Assuntos
Fertilizantes/análise , Minerais/química , Fosfatos/química , Siloxanas/química , Tensoativos/química , Quartzo/química , Tensoativos/síntese química
12.
Sci Rep ; 9(1): 11518, 2019 08 08.
Artigo em Inglês | MEDLINE | ID: mdl-31395927

RESUMO

The utilization of cellulose in industrial applicat is of great significance to sustainable development of human society and reducing dependence on dwindling fossil resources. Nevertheless, this utilization of cellulose has actually been limited due to its insolubilization. Here, novel solvents consisting of diallylimidazolium methoxy acetate ([A2im][CH3OCH2COO]) and N-methylpyrrolidinone (NMP) were developed. The solubility of cellulose in [A2im][CH3OCH2COO]/NMP was determined, and the influence of [A2im][CH3OCH2COO]/NMP molar ratio on cellulose dissolution was systematically investigated. Meanwhile, we also presented the affecting factors of the cellulose material fabrication including preparation approach, [A2im][CH3OCH2COO] and cellulose solution concentration. Attractively, the [A2im][CH3OCH2COO]/NMP solvents display much powerful dissolution capacity for cellulose even at 25 °C (25.4 g 100 g-1). This is mainly ascribed to the combined factors: The hydrogen bond interactions of the H2, H4 and H6 in [A2im]+ and carboxyl O atom in [CH3OCH2COO]- with the hydroxyl H atom and O atom in cellulose; the dissociation of NMP towards [A2im][CH3OCH2COO]; the stabilization of NMP towards the dissolved cellulose chains. In addition, the thermostability and chemical structure of the regenerated cellulose from the solvents was also estimated.

13.
Polymers (Basel) ; 11(5)2019 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-31083305

RESUMO

Cellulose is the most abundant natural biopolymer, with unique properties such as biodegradability, biocompability, nontoxicity, and so on. However, its extensive application has actually been hindered, because of its insolubility in water and most solvents. Herein, highly efficient cellulose solvents were developed by coupling diallylimidazolium methoxyacetate ([A2im][CH3OCH2COO]) with polar aprotic solvents dimethyl sulfoxide (DMSO), N,N-dimethylformamide (DMF), and N,N-dimethylacetamide (DMA). Attractively, these solvents showed extraordinarily powerful dissolution performance for cellulose (e.g., 26.1 g·100g-1) in [A2im][CH3OCH2COO]/DMSO(RDMSO = 1.01 solvent even at 25 °C), which is much more advantageous over previously reported solvents. To our knowledge, such powerful cellulose solvents have not been reported before. The cellulose dissolution mechanism is proposed to be of three combined factors: (1) The hydrogen bond interactions of the H2, H4 and H6 in [A2im]+ and the carboxyl O atom in [CH3OCH2COO]-, along with the hydroxyl H atom and O atom in cellulose, are main driving force for cellulose dissolution; (2) the dissociation of [A2im][CH3OCH2COO] by DMF increases the anion and cation concentrations and thus promotes cellulose dissolution; (3) at the same time, DMF also stabilizes the dissolved cellulose chains. Meanwhile, the porous cellulose material with a varying morphologic structure could be facially fabricated by modulating the cellulose solution concentration. Additionally, the dissolution of cellulose in the solvents is only a physical process, and the regenerated cellulose from the solvents retains sufficient thermostability and a chemical structure similar to the original cellulose. Thus, this work will provide great possibility for developing cellulose-based products at ambient temperatures or under no extra heating/freezing conditions.

14.
Appl Environ Microbiol ; 85(10)2019 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-30902851

RESUMO

Crude glycerol is largely generated as the main by-product of the biodiesel industry and is unprofitable for industrial application without costly purification. The direct bioconversion of crude glycerol into 1,3-propanediol (1,3-PDO) by microorganisms is a promising alternative for effective and economic utilization. In this study, Klebsiella pneumoniae 2e was newly isolated for the conversion of crude glycerol into 1,3-PDO. Batch fermentation analysis confirmed that crude glycerol and its main impurities had slight impacts on the growth, key enzyme activity, and 1,3-PDO production of K. pneumoniae 2e. The 1,3-PDO yield from crude glycerol by K. pneumoniae 2e reached 0.64 mol 1,3-PDO/mol glycerol, which was higher than that by most reported 1,3-PDO-producing Klebsiella strains. Genomic profiling revealed that K. pneumoniae 2e possesses 30 genes involved in glycerol anaerobic metabolism and 1,3-PDO biosynthesis. Quantitative real-time PCR analysis of these genes showed that the majority of the genes encoding the key enzymes for glycerol metabolism and 1,3-PDO biosynthesis were significantly upregulated during culture in crude glycerol relative to that in pure glycerol. Further comparative genomic analysis revealed a novel glycerol uptake facilitator protein in K. pneumoniae 2e and a higher number of stress response proteins than in other Klebsiella strains. This work confirms the adaptability of a newly isolated 1,3-PDO-producing strain, K. pneumoniae 2e, to crude glycerol and provides insights into the molecular mechanisms involved in its crude glycerol tolerance, which is valuable for industrial 1,3-PDO production from crude glycerol.IMPORTANCE The rapid development of the biodiesel industry has led to tremendous crude glycerol generation. Due to the presence of complex impurities, crude glycerol has low value for industry without costly purification. Obtaining novel microorganisms capable of direct and efficient bioconversion of crude glycerol to value-added products has great economic potential for industrial application. In this work, we characterized a newly isolated strain, Klebsiella pneumoniae 2e, with the capacity to efficiently produce 1,3-propanediol (1,3-PDO) from crude glycerol and demonstrated its adaptation to crude glycerol. Our work provides insights into the molecular mechanisms of K. pneumoniae 2e adaptation to crude glycerol and the expression patterns of its genes involved in 1,3-PDO biosynthesis, which will contribute to the development of industrial 1,3-PDO production from crude glycerol.


Assuntos
Glicerol/metabolismo , Klebsiella pneumoniae/metabolismo , Propilenoglicóis/metabolismo
15.
J Anal Methods Chem ; 2019: 8192439, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30719374

RESUMO

To improve essential oil quality, especially to reserve the thermal instability of compounds, supercritical CO2 extraction (SFE) was applied to recover essential oil from Cymbopogon citronella leaves. A response surface methodology was applied to optimize the extraction process. The highest essential oil yield was predicted at extraction time 120 min, extraction pressure 25 MPa, extraction temperature 35°C, and CO2 flow 18 L/h for the SFE processing. Under these experimental conditions, the mean essential oil yield is 4.40%. In addition, the chemical compositions of SFE were compared with those obtained by hydrodistillation extraction (HD). There were 41 compounds obtained of SFE, while 35 compounds of HD. Alcohols and aldehydes were the main compositions in the essential oils. Furthermore, the antioxidant activities and antimicrobial of essential oils obtained by HD and the evaluated condition of SFE were compared. Results showed that the antioxidant activities of SFE oil are better than those of HD. Minimum inhibitory concentrations (MICs) were determined by the microdilution method. Essential oil obtained from SFE and HD exhibited a significant antimicrobial activity against all tested microorganisms. It is confirmed that the SFE method can be an alternative processing method to extract essential oils from Cymbopogon citronella leaves.

16.
RSC Adv ; 9(36): 20976-20981, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-35515513

RESUMO

Cellulose solvents ([A2im][MOA]/MIM) were developed by combining diallylimidazolium methoxyacetate ([A2im][MOA]) with N-methylimidazole (MIM). The cellulose solubilities in the ([A2im][MOA]/MIM) solvents were determined at 25 °C, and the effect of the MIM/[A2im][MOA] molar ratio on cellulose solubility was systematically investigated. Attractively, the solvents show cellulose solubility as high as 25.2 g 100 g-1 even at 25 °C. It is proposed that the H2, H4 and H6 in [A2im]+ and the carboxyl O atom in [MOA]- primarily contribute to the dissolution of cellulose; MIM mainly acts to dissociate [A2im][MOA] into [A2im]+ and [MOA]-, and stabilize the dissolved cellulose chains. Moreover, the porous cellulose materials with varying morphological structures could be tailored by simply tuning the cellulose solution concentration, and the formation mechanism of the cellulose material was discussed.

17.
J Agric Food Chem ; 66(50): 13126-13132, 2018 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-30485094

RESUMO

Potassium fertilizer plays a critical role in increasing the food production. Carnallite is concentrated by reverse froth flotation and used as a raw material to produce potassium fertilizer (KCl) in agriculture. However, all the surfactants used in the carnallite reverse flotation process are conventional monomeric surfactants contain a single similar hydrophobic group in the molecule, which results in a low production efficiency. In this work, a new morpholine-based Gemini surfactant, 1,4-bis (morpholinododecylammonio) butane dibromide (BMBD), was prepared and originally recommended as a collector for reverse froth flotation separation of halite (NaCl) from carnallite ore. The flotation results indicated BMBD had higher flotation recovery and stronger affinity of halite against carnallite compared with conventional monomeric surfactant N-(n-Dodecyl) morpholine (DDM). Fourier transform infrared spectra suggested that BMBD molecules were adsorbed on halite surface rather than the carnallite surface. Additionally, BMBD molecules can strongly reduce the surface tension of NaCl saturated solution. Considering the BMBD's unique properties, such as double reactive centers to mineral surfaces, double hydrophobic groups, and stronger surface tension reducing ability, made it be a superior collector for reverse flotation desalination from carnallite ores than DDM.


Assuntos
Calcitriol/análogos & derivados , Fertilizantes/análise , Morfolinas/química , Potássio/química , Tensoativos/química , Calcitriol/química , Interações Hidrofóbicas e Hidrofílicas , Tensoativos/síntese química
18.
Int J Biol Macromol ; 115: 846-852, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29704601

RESUMO

Biodegradable porous materials based on natural lignocellulosic biomass have multiple advantages of low cost, lightweight, non-toxicity, and the potential in place of non-biodegradable petrochemical products. However, the fabrication process for the porous materials was complicated by the slow and costly prefreeze or supercritical drying methods. Herein, a facile and green/clean strategy was presented to fabricate corncob and willow wood porous materials in ambient conditions. The effect of biomass solution concentration and preparation condition on porous material morphology structure was investigated systematically by scanning electron microscope (SEM). Further, X-ray diffraction (XRD), Fourier transform infrared (FTIR), Brunauer-Emmet-Teller (BET) and thermogravimetric analysis (TGA) were used to estimate the structure and thermostability of the porous materials. Furthermore, the adsorptive properties of the biomass porous materials towards dye methylene blue and oil were evaluated. The biomass porous materials with a fluffy and porous structure were readily obtained via this procedure and showed effective adsorption capacity for dye methylene blue and oil.


Assuntos
Lignina/química , Purificação da Água/métodos , Adsorção , Biomassa , Lignina/metabolismo , Azul de Metileno/química , Azul de Metileno/isolamento & purificação , Óleos/química , Porosidade , Salix/química , Propriedades de Superfície , Temperatura , Poluentes Químicos da Água/química , Poluentes Químicos da Água/isolamento & purificação , Madeira/química , Zea mays/química
19.
Polymers (Basel) ; 10(8)2018 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-30960765

RESUMO

Four novel choline carboxylate aqueous solution systems were developed by mixing H2O with choline nicotinate [Ch][Na], choline ferulate [Ch][Fa], choline vanillate [Ch][Va] and choline syringate [Ch][Sa]. The solubility of lignin in the four solvents was determined at 25 °C. The influence of the molar ratio of H2O to [Ch][Na] ([Ch][Fa], [Ch][Va] and [Ch][Sa]) and the anionic structure on lignin solubility were systematically investigated. It was found that, the anionic structure and H2O content significantly affected lignin dissolution. Interestingly, H2O/[Ch][Na] and H2O/[Ch][Fa] solvents show efficient capacity for lignin dissolution even at room temperatures. The dissolution of lignin in H2O/[Ch][Na] and H2O/[Ch][Fa] solvents is mainly ascribed to the interaction of lignin with the alkyl chain in the anion and cation dissociated from [Ch][Na]([Ch][Fa]) by H2O. In addition, the recycling of the lignin solvent was examined, and the structure and thermostability of the lignin regenerated from the solvent were also estimated.

20.
Biotechnol Biofuels ; 10: 86, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28405217

RESUMO

BACKGROUND: As a natural renewable biomass, the tea oil fruit hull (TOFH) mainly consists of lignocellulose, together with some bioactive substances. Our earlier work constructed a two-stage solvent-based process, including one aqueous ethanol organosolv extraction and an atmospheric glycerol organosolv (AGO) pretreatment, for bioprocessing of the TOFH into diverse bioproducts. However, the AGO pretreatment is not as selective as expected in removing the lignin from TOFH, resulting in the limited delignification and simultaneously high cellulose loss. RESULTS: In this study, acetic acid organosolv (AAO) pretreatment was optimized with experimental design to fractionate the TOFH selectively. Alkaline hydrogen peroxide (AHP) pretreatment was used for further delignification. Results indicate that the AAO-AHP pretreatment had an extremely good selectivity at component fractionation, resulting in 92% delignification and 88% hemicellulose removal, with 87% cellulose retention. The pretreated substrate presented a remarkable enzymatic hydrolysis of 85% for 48 h at a low cellulase loading of 3 FPU/g dry mass. The hydrolyzability was correlated with the composition and structure of substrates by using scanning electron microscopy, confocal laser scanning microscopy, and X-ray diffraction. CONCLUSION: The mild AAO-AHP pretreatment is an environmentally benign and advantageous scheme for biorefinery of the agroforestry biomass into value-added bioproducts.

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