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1.
Polymers (Basel) ; 16(7)2024 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-38611251

RESUMO

Polyureas have been widely applied in many fields, such as coatings, fibers, foams and dielectric materials. Traditionally, polyureas are prepared from isocyanates, which are highly toxic and harmful to humans and the environment. Synthesis of polyureas via non-isocyanate routes is green, environmentally friendly and sustainable. However, the application of non-isocyanate polyureas is quite restrained due to their brittleness as the result of the lack of a soft segment in their molecular blocks. To address this issue, we have prepared polyester polyureas via an isocyanate-free route and introduced polyester-based soft segments to improve their toughness and endow high impact resistance to the polyureas. In this paper, the soft segments of polyureas were synthesized by the esterification and polycondensation of dodecanedioic acid and 1,4-butanediol. Hard segments of polyureas were synthesized by melt polycondensation of urea and 1,10-diaminodecane without a catalyst or high pressure. A series of polyester polyureas were synthesized by the polycondensation of the soft and hard segments. These synthesized polyester-type polyureas exhibit excellent mechanical and thermal properties. Therefore, they have high potential to substitute traditional polyureas.

2.
Biomacromolecules ; 24(12): 5951-5963, 2023 12 11.
Artigo em Inglês | MEDLINE | ID: mdl-38033158

RESUMO

The excellent combined properties of poly(butylene succinate) (PBS) make it a promising biodegradable plastic. However, the lack of functionality and low impact strength limit its application. Poly(dimethylsiloxane) (PDMS) was introduced to prepare new high-performance and functional poly(butylene succinate)-b-poly(dimethylsiloxane) (PBS-b-PDMS) in this work. The resulting PBS-b-PDMS was found to possess high molecular weight, narrow molecular weight distribution, and excellent combined performance. PBS-b-PDMS had good thermal properties. The decomposition temperature of 5% weight loss (T5%) increased from 324 to 344 °C, and the temperatures at the maximum weight loss rate (Tmax) values increased from 385.1 to 396.7 °C. The impact strength increased significantly from 7.8 kJ/m2 of PBS to 53.9 kJ/m2 of PBS-b-PDMS. As the PDMS block endows copolymers with low surface energy and good liquid resistance, PBS-b-PDMS has excellent antismudge, self-cleaning, and solvent resistance. Finally, to minimize the surface energy, PDMS blocks preferentially enrich the surface, which imparts the polymers with self-cleaning properties.


Assuntos
Materiais Biocompatíveis , Polímeros , Humanos , Succinatos , Redução de Peso
3.
Polymers (Basel) ; 15(15)2023 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-37571061

RESUMO

The introduction of long-chain branched structures into biodegradable polyesters can effectively improve the melt strength and blow-molding properties of polyesters. In this study, pentaerythritol (PER) was used as a branching agent to synthesize branched poly(butylene dodecanedioate) (PBD), and the resulting polymers were characterized by Nuclear Magnetic Resonance Proton Spectra (1H NMR) and Fourier Transform Infrared spectroscopy (FT-IR). It was found that the introduction of a small amount of PER (0.25-0.5 mol%) can generate branching and even crosslinking structures. Both impact strength and tensile modulus can be greatly improved by the introduction of a branching agent. With the introduction of 1 mol% PER content in PBD, the notched impact strength of PBD has been increased by 85%, and the tensile modulus has been increased by 206%. Wide-angle X-ray diffraction and differential scanning calorimetry results showed that PER-branched PBDs exhibited improved crystallization ability compared with linear PBDs. Dynamic viscoelastics revealed that shear-thickening behaviors can be found for all branched PBD under low shear rates.

4.
Environ Sci Pollut Res Int ; 30(26): 68191-68205, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37119495

RESUMO

In response to Cd, Pb, and Cu pollution in acid mine drainage (AMD), a multigroup cellulose material (TCIS) containing thiol (-SH), carboxyl (-COOH), and imine (-C = N) groups was prepared through oxidation and grafting reactions. At pH 5, the maximum Cd(II), Pb(II), and Cu(II) adsorption performances of TCIS were 53.60, 120.6, and 36.01 mg/g, respectively. In the binary system, the interaction between metal ions was mainly inhibited by competitive adsorption. Cu(II) exhibited the most fierce inhibitory effect and had a relatively stable adsorption performance. In the ternary system, the adsorption order was Cu(II) > Cd(II) > Pb(II). In density functional theory (DFT) calculations, we combined the molecular electrostatic potentials, binding energies, differential charges, and total potentials to illustrate the competitive behavior of metal ions at different binding sites. Moreover, X-ray photoelectron spectroscopy (XPS) and DFT analysis revealed that the adsorption process of TCIS was dominated by the above functional groups, which caused competitive adsorption among Cd(II), Pb(II), and Cu(II).


Assuntos
Metais Pesados , Poluentes Químicos da Água , Cádmio/análise , Adsorção , Celulose , Comportamento Competitivo , Chumbo , Metais Pesados/química , Íons , Poluentes Químicos da Água/análise
5.
J Environ Sci (China) ; 124: 105-116, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36182120

RESUMO

Oil pollution is causing deleterious damage to aquatic ecosystems and human health. The utilization of agricultural waste such as corn stalk (CS) to produce biosorbents has been considered an ecofriendly and efficient approach for removing oil. However, most previous studies focused on the modification of the whole CS, which is inefficient due to the heterogeneity of CS. In this study, corn stalk pith (CP), which has excellent amphipathic characteristics, was selected to prepare a high-efficiency oil sorbent by grafting dodecyl gallate (DG, a long-chain alkyl) onto CP surface lignin via laccase mediation. The modified biomass (DGCP) shows high hydrophobicity (water contact angle = 140.2°) and superoleophilicity (oil contact angle = 0°) and exhibits a high oil sorption capacity (46.43 g/g). In addition, DGCP has good stability and reusability for adsorbing oil from the aqueous phase. Kinetic and isotherm models and two-dimensional correlation spectroscopy integrated with FTIR analyses revealed that the main sorption mechanism involves the H-bond effect, hydrophobic effect and van der Waals force. This work provides an ecofriendly method to prepare oil sorbents and new insights into the mechanisms underlying the removal of spilled oil from wastewater.


Assuntos
Poluição por Petróleo , Poluentes Químicos da Água , Adsorção , Biomassa , Ecossistema , Humanos , Interações Hidrofóbicas e Hidrofílicas , Lacase , Lignina , Águas Residuárias , Água , Zea mays
6.
Polymers (Basel) ; 14(22)2022 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-36433022

RESUMO

Novel poly(butylene succinate-butylene furandicarboxylate/polyethylene glycol succinate) (PBSF-PEG) was synthesized using two-step transesterification and polycondensation in the melt. There are characterized by intrinsic viscosity, GPC, 1H NMR, DSC, TGA, tensile, water absorption tests, and water degradation at different pH. GPC analysis showed that PBSF-PEG had high molecular weight with average molecular weight (Mw) up to 13.68 × 104 g/mol. Tensile tests showed that these polymers possessed good mechanical properties with a tensile strength as high as 30 MPa and elongation at break reaching 1500%. It should be noted that the increase of PEG units improved the toughness of the polyester material. In addition, the introduction of PEG promoted the water degradation properties of PBSF, and the copolymer showed a significantly faster water degradation rate when the PEG unit content was 20%. This suggests that the amount of PEG introduced could be applied to regulate the water degradation rate of the copolymers. Hence, these new polymers have great potential for application as environmentally friendly and sustainable plastic packaging materials.

7.
Soft Matter ; 18(19): 3762-3770, 2022 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-35506885

RESUMO

Three-dimensional (3D) self-assembled quantum dot (QD) aerogels have attracted attention due to the combined properties of both QDs and porous materials. However, the difficulty and complexity of structural composition control limit the practical application of 3D self-assembled QDs. Hence, convenient, available and multifunction QD aerogels need to be explored to promote broader practical applications. Herein, we propose a universal and facile self-assembly method of copper indium selenium (CISe) QD aerogels based on coordination interaction between Zn2+ and carboxyl. Both experiments and Monte Carlo simulations indicate that QDs are aggregated into oligomers by Zn2+, and then the oligomers are gradually interconnected to each other to form a 3D network as the concentration of Zn2+ increases. Moreover, Zn2+-induced 3D self-assembled aerogel could be depolymerized by EDTA reversibly. In combination with CISe QDs, Zn-CISe aerogel has been successfully applied in green pollution-free environment-friendly anti-counterfeiting and encryption systems.

8.
Polymers (Basel) ; 14(10)2022 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-35631921

RESUMO

A series of non-isocyanate poly(ether urethane) (PEU) were prepared by an environmentally friendly route based on dimethyl carbonate, diols and a polyether. The effect of the chemical structure of polyurethane hard segments on the properties of this kind of PEU was systematically investigated in this work. Polyurethane hard segments with different structures were first prepared from hexamethylene di-carbamate (BHC) and different diols (butanediol, hexanediol, octanediol and decanediol). Subsequently, a series of non-isocyanate PEU were obtained by polycondensation of the polyurethane hard segments with the polyether soft segments (PTMG2000). The PEU were characterized by GPC, FT-IR, 1H NMR, DSC, WAXD, SAXS, AFM and tensile testing. The results show that the urea groups generated by the side reaction affect the degree of crystallization of hard segments by influencing the hydrogen bonding of the hard segments molecular chains. The degree of hard segment crystallization, in turn, affects the thermal and mechanical properties of the polymer. The urea group content is related to the carbon chain length of the diol used for the synthesis of hard segments. When butanediol is applied to synthesize hard segment, the hard segment of the resulting PEU is unable to crystallize. Therefore, the tensile strength and modulus of elasticity of butanediol-based PEU is lowest among three, though it possesses the highest urea group content. When longer octanediol or decanediol is applied to synthesize the hard segment, the hard segments in the resulting polyether-based polyurethane are crystallizable and the resulting PEU possesses higher tensile strength.

9.
Environ Sci Pollut Res Int ; 29(24): 36575-36588, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35064503

RESUMO

TEMPO-NaDCC-oxidized cellulose (TNOCS) with a large surface area and an abundance of carboxyl groups was used to remove heavy metal ions (Cd, Cu, and Pb) and their organic acid complexes [HM-OAs] (OAs, i.e., citric acid (CA) and propionic acid (PA)), and then reveal their adsorption behaviors. Taking Cd and CA as examples, the results showed that some of Cd ions were first adsorbed onto TNOCS, and then, the existence of [Cd-CA-] complexes formed a coordinated structure with preloaded Cd ions to serve as a bridge for combining TNOCS and [Cd-CA]. The maximum adsorption capacities of TNOCS for Cd and Cd-CA were 16.50 and 22.15 mg/g, respectively. Moreover, adsorption energies and molecular orbital distributions indicated that the adsorption capacity of TNOCS for [Cd-CA] was better than that for Cd alone. TNOCS can maintain greater than 90% adsorption capacity in five times regeneration experiments using EDTA, indicating that it is very efficient and stable. In addition, the electron density, deformation charge, and Mulliken charge distribution were confirmed that the electron transfer direction was from carboxyl groups to cadmium, whether it was cadmium ions or complexed cadmium.


Assuntos
Celulose Oxidada , Poluentes Químicos da Água , Adsorção , Cádmio/análise , Óxidos N-Cíclicos , Concentração de Íons de Hidrogênio , Íons , Cinética , Água/química , Poluentes Químicos da Água/análise
10.
Small ; 17(45): e2101804, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34554644

RESUMO

A cationic monofunctional platinum anticancer drug, phenanthriplatin (PhenPt(II)), exhibits promising anticancer effect on various cancer cell lines. Unlike the conventional platinum(II) drugs, PhenPt(II) is more likely to bind the N7 adenosine base of DNA in situ, and consequently resulting in a unique cellular response profile and unusual potency. However, since this drug is positively charged, it can easily bind to plasma protein that leads to rapid systematic clearance and deleterious toxicities, which greatly limits its in vivo application. Herein, a lipophilic phenanthriplatin (PhenPt(IV)) prodrug is synthesized. To further reduce its toxicity, a negatively charged polymer P1 with reduction responsiveness is assembled with PhenPt(IV) to form PhenPt(IV) NPs. In comparison to cisplatin, PhenPt(IV) NPs exhibit up to 30 times greater in vitro potency against various cancer cell lines. Additionally, in vivo, no obvious side effect is found on PhenPt(IV) NPs. Significant enhancement in tumor accumulation and improvement of drug efficacy in 4T1 tumor model are demonstrated. Taken together, this study provides a promising strategy for the clinical translation of phenanthriplatin.


Assuntos
Antineoplásicos , Pró-Fármacos , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Cisplatino/farmacologia , Platina , Polímeros
11.
Biomater Sci ; 9(13): 4648-4661, 2021 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-34008632

RESUMO

Cancer resistance has been the huge challenge to clinical treatment. A photothermal therapy of second near-infrared (NIR-II) organic dye small molecule has been used to conquer the cancer resistance. However, the available NIR-II dye lacks selectivity and spreads throughout the body. It has toxicity and indiscriminate burn injuries normal cells and tissues during therapy. Hence, to improve the therapeutic outcomes, herein, for the first time, we report the mannose-modified zwitterionic nanoparticles loading IR1048 dye, aiming to overcome cancer cellular resistance. The targeting molecule mannose has been applied to modify zwitterionic polyester, and the obtained polyester is employed to load IR1048 to prolong the circulation time in the blood and improve the stability of loaded dye, due to the good cytocompatibility of polyester and the antifouling properties of zwitterions. In vitro experimental results show that the pH-responsive targeted nanoparticles display satisfactory photophysical properties, prominent photothermal conversion efficiency (44.07%), excellent photothermal stability, negligible cytotoxicity for normal cells and strong photothermal toxicity to drug-resistant cancer cells. Moreover, due to the mannose targeting effect, cancer cells can endocytose the nanoparticles effectively. All these results demonstrate potential application of this alternative hyperthermal delivery system with remote-controllable photothermal therapy of tumor for accurate diagnosis by NIR-II fluorescence imaging.


Assuntos
Hipertermia Induzida , Nanopartículas , Linhagem Celular Tumoral , Corantes Fluorescentes , Manose , Fototerapia , Terapia Fototérmica , Poliésteres
12.
J Hazard Mater ; 416: 125748, 2021 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-33823480

RESUMO

In view of the characteristics of heavy metal and antibiotic compound pollution in the Pearl River Basin in Guangzhou. More scientifically modified cellulose, named HVUC, is characterized by multiple hydrophilic groups, long chains and large space and displays highly efficient adsorption of both Cd and sulfamethoxazole (SMZ) and good adaptability in a wide pH range and at high ion strength. Furthermore, the coadsorption mechanism was elaborated from multiple angles. Multiple adsorption experiments explained the competition and synergy effect in the adsorption process. The electrostatic potential maps indicated that HVUC had advantageous adsorption sites for both Cd and SMZ and that electrostatic interactions had the greatest impact on the adsorption of Cd and SMZ. The electron density and differential charge density images proved that Cd more easily overlapped electron clouds and transferred electrons with HVUC and that SMZ- and could act as a bridge for SMZ-. The equilibrium configuration indicated that the formation of Cd-SMZ- complexes led to the bending and folding of SMZ-, which was not conducive to overall adsorption when SMZ- was close to HVUC and could lead to the release of SMZ- when Cd was close to HVUC, which confirmed the proposed mechanism of complexation-decomplexation-complexation.


Assuntos
Celulose , Poluentes Químicos da Água , Adsorção , Teoria da Densidade Funcional , Elétrons , Sulfametoxazol
13.
Environ Res ; 195: 110848, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33587945

RESUMO

2,2,6,6-Tetramethylpiperidine-1-oxyl (TEMPO) was oxidized to produce TEMPO-oxidized cellulose (TOCS) with a nanofunctionalized surface and abundant carboxyl groups. In a batch experiment, three pH values (2, 5 and 7), three modes (single, binary and multiple systems), and systems with inorganic and organic materials were applied to explore the adsorption of coexisting metals and antibiotics on TOCS. The adsorption capacity of TOCS was substantially influenced by these factors, and the adsorption behaviors were also different in these systems. In general, the coordination behaviors and electrostatic attraction between Cd(II) and carboxyl groups were identified as the mechanism employed by the single system, while hydrophobic interactions, π interactions, hydrogen bonding and pore filling contributed to the adsorption of sulfonamides (SAs) on TOCS in the binary system. The bridging effect was determined to be the key mechanism; i.e., most Cd(II) and SAs in the form of [SA-Cd] complexes interacted with carboxyl groups, especially in the presence of high concentrations of Cd(II) and SAs. These adsorption behaviors were determined quantitatively by performing density functional theory (DFT) calculations. In addition, TOCS showed excellent adsorption capacity in a more complex interference system, and the maximum adsorption capacity was 5.83 mg/g.


Assuntos
Celulose Oxidada , Poluentes Químicos da Água , Adsorção , Cádmio , Concentração de Íons de Hidrogênio , Oxirredução , Poluentes Químicos da Água/análise
14.
Ecotoxicol Environ Saf ; 209: 111803, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33360216

RESUMO

The development of efficient and sustainable sorbents for emergent oil cleanup has attracted tremendous attention. In this study, the feasibility of enzymatic grafting of octadecylamine (ODA) on corn stalk pith (CSP) by laccase-TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl) treatment for enhanced oil-water separation was investigated. The dynamic contact angle tests suggest that the modified CSP (LCSP) had higher hydrophobicity (WCA, 157.2˚) and lipophilicity (OCA, 0˚) than the CSP did. In addition, the introduction of ODA onto the surface of modified CSP was verified by a variety of characterization techniques including SEM, FT-IR, and XPS. Compared with the control, laccase-TEMPO treatment of CSP coupled with octadecylamine grafting greatly improved the oil sorption capacity from 13.24 g/g to 44.25 g/g, while substantially reduced the water sorption capacity from 15.52 g/g to 2.76 g/g. LCSP has fast kinetic (sorption equilibrium reached before 60 min) and high fits to the pseudo-second-order kinetic model. The results obtained in this study reveal the feasibility of using Laccase-TEMPO treatment to graft the ODA onto the surface of CSP, thereby enhancing the rate and capacity of oil separation from oily water. The method and sorbent developed in this study hold promise for green, simple and cost-effective oil cleanup during oil spillage emergency events.


Assuntos
Poluição por Petróleo , Poluentes Químicos da Água/química , Absorção Fisico-Química , Aminas , Interações Hidrofóbicas e Hidrofílicas , Cinética , Lacase , Espectroscopia de Infravermelho com Transformada de Fourier , Água , Poluentes Químicos da Água/análise
15.
J Hazard Mater ; 402: 124084, 2021 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-33254840

RESUMO

A new self-assembled cellulose (SACS) containing multi-functional amine, carboxyl and hydroxyl groups was successfully obtained through etherification, cross-linking and grafting processes. Then, the adsorption of sulfamethoxazole (SMZ) and Cd(II) onto SACS at pH values of 3, 5.7 and 7.5 was systematically investigated by batch experiments of single, sequential and binary systems, characterization and density functional theory (DFT) calculations. The presence of Cd(II) decreased the adsorption of SMZ because of hydrophilic site competition, while SMZ inversely increased the adsorption of Cd(II), which was attributed to bridging and especially to electrostatic shielding effects; moreover, both the inhibitory and synergistic effects were more obvious in the binary system and at a pH of 7.5. There was a dynamic balance between the inhibitory and synergistic effects that depended on the system, pH value and concentration ratio. DFT results further indicated that SMZ- more easily coordinated with Cd(II) at sulfonyl oxygen and nitrogen sites, and the cationic bridge of Cd(II) with SMZ- mainly occurred in the sequential system. Moreover, a complexation-decomplexation-complexation balance of SMZ- and Cd(II) probably occurred in the binary system.

16.
ACS Appl Mater Interfaces ; 12(40): 45383-45393, 2020 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-32964709

RESUMO

Low interfacial adhesion seriously limits the wide application of PBO fiber in composites. To solve this problem, a novel hierarchical reinforcement strategy was developed by introducing epoxy sizing, nanoreinforcement of amino-functionalized silicon dioxide (SiO2-NH2), and an interfacial compatibilizer of 2,6-bis(2-hydroxy-4-aminophenyl) benzobisoxazole (HABO) onto poly(p-phenylene benzobisoxazole) (PBO) fibers via a facile dip-coating approach. SiO2-NH2 and HABO were uniformly dispersed in epoxy sizing, forming an active interface layer. On this basis, wettability, surface roughness of the PBO fiber, and compatibility with the resin matrix were significantly improved, which gave 88.4 and 40.4% enhancement in the interfacial shear strength and interlaminar shear strength of the corresponding composites, respectively. Moreover, it should be noted that the outstanding mechanical and thermal properties of the PBO fiber were not impaired during the sizing treatment. In summary, our work provides an effective and damage-free approach to improve the interfacial adhesion of PBO/epoxy composites.

17.
Environ Sci Pollut Res Int ; 27(34): 43246-43261, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32734543

RESUMO

To improve the high-value application of corn stalk, phosphorus-containing stalk cellulose (PFC) was prepared, characterized, and utilized for the adsorption of sulfamethoxazole (SMZ) and sulfadiazine (SD), with maximum adsorption capacities of 1.385 and 2.527 mg/g at pH 7. As expected, the adsorption efficiency of PFC was strongly affected by pH, and the preferential adsorption order of SMZ- (SD0) > SMZ0 (SD-) > SMZ+ (SD+) was obtained from the experimental results and due to the charges of PFC and the SMZ and SD species. Furthermore, these results were qualitatively linked to the adsorption mechanism, e.g., π+-π electron donor-acceptor (EDA), anion-π bond electrostatic, and hydrophobic interactions. In particular, the adsorption mechanism was further characterized in terms of structure and analyzed systematically using density functional theory (DFT), frontier orbital theory (FOT), and molecular dynamics (MD) simulation, with the aim to explain the theoretical calculation and experimental results. As a result, the highest occupied molecular orbital (HOMO)-lowest unoccupied molecular orbital (LUMO) orbitals revealed the key role of the rings and functional groups of PFC and SMZ (or SD) and validated the optimized structures of PFC+ sulfonamides (SAs)+, PFC- SAs0, and PFC- SAs-, in which their binding energy values, energy gaps, and relevant molecular lengths determined their stability. Additionally, the van der Waals (vdW) energy confirmed the effect of various interactions on adsorption.


Assuntos
Sulfadiazina , Sulfametoxazol , Adsorção , Celulose , Concentração de Íons de Hidrogênio , Fósforo , Água
18.
Plant Dis ; 103(9): 2191-2198, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31293210

RESUMO

Tea-oil camellia (Camellia oleifera) is grown for tea seed oil production, with tea seed cake produced as a byproduct. Rather than disposing of the cake, agricultural uses increase the value of oil production. Constituents of C. oleifera are also utilized for traditional Chinese medicine, as are compounds produced by tree peony roots. Consequently, the unused C. oleifera cake, and stems from two tree peony species, Paeonia rockii and Paeonia suffruticosa, were studied for compounds antagonistic to soybean cyst nematode (Heterodera glycines) and root-knot nematode (Meloidogyne incognita). Extracts from C. oleifera cake and P. rockii stems suppressed hatch and were nematotoxic to second-stage juveniles (J2) of both nematode species. P. rockii extracts were more effective than P. suffruticosa extracts for decreasing M. incognita hatch and J2 viability. In greenhouse trials with soybean (Glycine max 'Essex'), powdered C. oleifera cake applied as a soil amendment suppressed H. glycines cysts/g root by up to 66% compared with nonamended controls. These results indicate that the extracts and cake contain compounds active against H. glycines and M. incognita, with activity varying between the two Paeonia species. C. oleifera tea seed cake, and constituents of the cake or of P. rockii, are candidates for further studies on management of these nematodes.


Assuntos
Camellia , Paeonia , Extratos Vegetais , Tylenchoidea , Animais , Antinematódeos/farmacologia , Camellia/química , Paeonia/química , Extratos Vegetais/farmacologia , Sementes/química , Tylenchoidea/efeitos dos fármacos
19.
Bioresour Technol ; 288: 121510, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31150967

RESUMO

Phosphonic chelating fiber (PCCSF) as a novel adsorbent was produced through alkalization, etherification, amination and phosphonation, and then it was applied to adsorb sulfonamides (SAs), such as sulfadiazine (SD), sulfamonomethoxine (SMM) and sulfamethoxazole (SMZ). Specially, their adsorption behavior at different pH values was studied. As a result, PCCSF was provided with amino (NH2 or NH) and PO(OH)2 (PO) groups, and its equilibrium data were generally represented by both Langmuir and Freundlich models. Combining adsorbent-to-solution distribution coefficients (Kd) values and the effect of pH, the primary mechanism suggested that adsorption capacity of PCCSF was lower in strong acid and alkali solution, due to the electrostatic repulsion and hydrophobic interactions. By contrast, its adsorption affinity became more excellent at 3 < pH < 9 owing to the π-π electron-donor-acceptor (EDA) charge-assisted H-bond, Lewis acid-base interaction and charge-assisted H-bond (CAHB).


Assuntos
Celulose , Sulfonamidas , Adsorção , Concentração de Íons de Hidrogênio , Sulfametoxazol
20.
Nano Lett ; 19(5): 2953-2959, 2019 05 08.
Artigo em Inglês | MEDLINE | ID: mdl-30969778

RESUMO

In order to lower the capital and operational cost of desalination and wastewater treatment processes, nanofiltration (NF) membranes need to have a high water permeation and ionic rejection, while also maintaining a stable performance through antifouling resistance. Recently, Turing-type reaction conditions [ Science 2018, 360, 518-521] and sacrificed metal organic frame (MOF) nanoparticles [ Nat. Commun. 2018, 9, 2004] have been reported to introduce nanovoids into thin-film composite (TFC) polyamide (PA) NF membranes for an improved performance. Herein, we report a one-step fabrication of thin-film nanocomposite membranes (TFNM) with controllable nanovoids in the polyamide layer by introducing hollow zwitterionic nanocapsules (HZNCs) during interfacial polymerization. It was found that embedding HZNCs increases the membrane internal free volume, external surface area, and hydrophilicity, thus enhancing the water permeation and antifouling resistance without trading off the rejection of multivalent ions. For example, water permeation of the NF membranes embedded with about 19.0 wt % of HZNCs (73 L m-2 h-1) increased by 70% relative to the value of the control TFC NF membrane without HZNCs (43 L m-2 h-1). This increase comes while also maintaining 95% rejection of Na2SO4. Further, we also determined the effect of the mass loading of HZNCs on the top surface of the TFC NF membranes on the membrane performance. This work provided a direct and simple route to fabricate advanced desalination membranes with a superior separation performance.

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