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1.
Langmuir ; 39(40): 14451-14458, 2023 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-37773886

RESUMO

Polyamines have emerged as a promising class of CO2 absorbents due to their remarkable sequestration capacity. However, their potential industrial application as aqueous absorbents is significantly hindered by a low regeneration efficiency and high energy consumption. To address these issues, this study investigates the use of triethylenetetramine (TETA) and ethylene glycol (EG) to develop a nonaqueous absorbent. The incorporation of EG enhances absorption performance and reduces the regeneration energy needed for TETA, whereas the high viscosity of the absorbent impedes absorption rate, amine efficiency, and regeneration efficiency. In order to enhance CO2 capture, micron-sized reaction units (SiO2@TETA-EG) were developed by encapsulating TETA solution with nanosilica. The SiO2@TETA-EG composite exhibits a large specific surface area (99 m2/g), with a porous shell structure and improved fluidity, which effectively counteracts the negative effects caused by high viscosity. Notably, SiO2@TETA-EG indicates a noticeably higher apparent rate constant of 4.29 min-1 at 323.2 K compared to the TETA-EG solution. Furthermore, SiO2@TETA-EG displays a 28.4% boost in regeneration efficiency while maintaining favorable stability in pore size and shape after regeneration.

2.
Org Biomol Chem ; 21(31): 6410-6418, 2023 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-37505192

RESUMO

Expensive rhodium (Rh)-based catalysts have been widely used for the hydroformylation of propene. To find a cheaper and effective alternative to these Rh-based catalysts, herein, a series of phosphine ligands were used to coordinate with iridium, and their catalytic reactivities for the hydroformylation of propene were systematically investigated in this study. The effects of different phosphine ligands, pressures, temperatures, and catalyst dosages on the hydroformylation of propene were investigated. Tripyridyl phosphine iridium Ir2(cod)2Cl2-P(3-py)3 (Ir(I)-L5) and its derivatives exhibit the highest catalytic reactivity. Surprisingly, the catalytic reactivity of Ir(I)-L5 is higher than that of Rh2(cod)2Cl2-P(3-py)3 (Rh(I)-L5). When the Ir(I)-L5 complex is used as the catalyst, reactions performed in a polar solvent gave higher turnover number (TON) values than those in a non-polar solvent. Up to a TON of 503 can be obtained. Different n-butyraldehyde/iso-butyraldehyde (n/i) ratios can be obtained by adjusting the phosphine ligands or the proportion of gas pressure. The catalyst showed good reusability in five recycling experiments. Furthermore, based on DFT theoretical calculations, a probable reaction mechanism was proposed. It is reliable that an Ir-based catalyst can be considered as a highly effective catalyst for the hydroformylation of propylene with CO.

3.
Angew Chem Int Ed Engl ; 62(46): e202310741, 2023 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-37706280

RESUMO

Removal of trace impurities for natural gas purification coupled with waste gas conversion is highly desired in industry. We here report a type of porous ionic liquids (PILs) that can realize the continuous flow separation of CH4 /CO2 /H2 S and the conversion of the captured H2 S to useful products. The PILs are synthesized through a step-by-step surface modification of ionic liquids (ILs) onto UiO-66-OH nanocrystals. The introduction of free tertiary amine groups on the nanocrystal surface endows these PILs with an exceptional ability to enrich H2 S from CO2 and CH4 with impressive selectivity, while the permanent pores of UiO-66-OH act as containers to store an exceptionally higher amount of the selectively captured H2 S than the corresponding nonporous ILs. Simultaneously, the tertiary amines as dual functional moieties offer effective catalytic sites for the conversion of the H2 S stored in PILs into 3-mercaptoisobutyric acid, a key intermediate required for the synthesis of Captopril (an antihypertensive drug). Molecular dynamics, density functional theory calculations and Grand Canonical Monte Carlo simulations help understand both the mechanisms of separation and catalysis performance, confirming that the tertiary amines as well as the permanent pores in UiO-66-OH play vital roles in the whole procedure.

4.
BMC Infect Dis ; 22(1): 287, 2022 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-35351003

RESUMO

BACKGROUND: Biomarkers, such as leukocyte count, C-reactive protein (CRP), and procalcitonin (PCT), have been commonly used to predict the occurrence of life-threatening bacteremia and provide prognostic information, given the need for prompt intervention. However, such diagnosis methods require much time and money. Therefore, we propose a method with a high prediction capability using machine learning (ML) models based on complete blood count (CBC) and differential leukocyte count (DC) and compare its performance with traditional CRP or PCT biomarker methods and those of models incorporating CRP or PCT biomarkers. METHODS: We collected 366,586 daily blood culture (BC) results, of which 350,775 (93.2%), 308,803 (82.1%), and 23,912 (6.4%) cases were issued CBC/DC (CBC/DC group), CRP with CBC/DC (CRP&CBC/DC group), and PCT with CBC/DC (PCT&CBC/DC group), respectively. For the ML methods, conventional logistic regression and random forest models were selected, trained, applied, and validated for each group. Fivefold validation and prediction capability were also evaluated and reported. RESULTS: Overall, the ML methods, such as the random forest model, demonstrated promising performances. When trained with CBC/DC data, it achieved an area under the ROC curve (AUC) of 0.802, which is superior to the prediction conventionally made with CRP/PCT levels (0.699/0.731). Upon evaluating the performance enhanced by incorporating CRP or PCT biomarkers, it reported no substantial AUC increase with the addition of either CRP or PCT to CBC/DC data, which suggests the predicting power and applicability of using only CBC/DC data. Moreover, it showed competitive prognostic capability compared to the PCT test with similar all-cause in-hospital mortality (45.10% vs. 47.40%) and overall median survival time (27 vs. 25 days). CONCLUSIONS: The ML models using only CBC/DC data yielded more accurate bacteremia predictions compared to those by methods using CRP and PCT data and reached similar prognostic performance as by PCT data. Thus, such models are potentially complementary and competitive with traditional CRP and PCT biomarkers for conducting and guiding antibiotic usage.


Assuntos
Bacteriemia , Pró-Calcitonina , Bacteriemia/diagnóstico , Proteína C-Reativa/análise , Calcitonina , Humanos , Contagem de Leucócitos , Aprendizado de Máquina , Curva ROC
5.
J Cutan Pathol ; 49(4): 350-357, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34778979

RESUMO

BACKGROUND: Primary cutaneous gamma/delta T-cell lymphoma (PCDG-TCL) is aggressive, frequently presenting as multiple plaques, tumors, and/or subcutaneous nodules. METHODS: In this study, we conducted a retrospective study in a tertiary center in Taiwan to characterize this rare tumor. RESULTS: We identified six patients. Five presented with a solitary lesion, including two with clinical impression of epidermal inclusion cyst or lipoma. Two of four evaluable cases exhibited epidermotropism, with one mimicking Pautrier microabscess. The neoplastic cells were pleomorphic and mostly medium- to large-sized. In all cases, the neoplastic cells expressed T-cell receptor (TCR)-γ and/or TCR-δ, with four co-expressing ßF1. Two of these ßF1+ cases co-expressed TCR-γ but not TCR-δ (two different clones). All were negative for Epstein-Barr virus (EBV), low stage, and treated with radiotherapy alone or combined chemotherapy and radiotherapy. In two patients, lymphoma relapsed in 3 and 7 months, respectively, and one patient died of the disease in 7 months. Four other patients were free of disease for 6 to 126 months. CONCLUSION: PCGD-TCL cases in Taiwan are more commonly solitary, frequently with indolent courses. The two currently available TCR-δ clones alone might be insufficient to detect all tumors.


Assuntos
Linfoma Cutâneo de Células T/imunologia , Linfoma Cutâneo de Células T/patologia , Receptores de Antígenos de Linfócitos T gama-delta/metabolismo , Neoplasias Cutâneas/imunologia , Neoplasias Cutâneas/patologia , Adulto , Feminino , Humanos , Linfoma Cutâneo de Células T/terapia , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Neoplasias Cutâneas/terapia , Taiwan
6.
Int J Mol Sci ; 23(10)2022 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-35628209

RESUMO

The Sugars Will Eventually be Exported Transporters (SWEET) family is a class of sugar transporters that play key roles in phloem loading, seed filling, pollen development and the stress response in plants. Here, a total of 18 JcSWEET genes were identified in physic nut (Jatropha curcas L.) and classified into four clades by phylogenetic analysis. These JcSWEET genes share similar gene structures, and alternative splicing of messenger RNAs was observed for five of the JcSWEET genes. Three (JcSWEET1/4/5) of the JcSWEETs were found to possess transport activity for hexose molecules in yeast. Real-time quantitative PCR analysis of JcSWEETs in different tissues under normal growth conditions and abiotic stresses revealed that most are tissue-specifically expressed, and 12 JcSWEETs responded to either drought or salinity. The JcSWEET16 gene responded to drought and salinity stress in leaves, and the protein it encodes is localized in both the plasma membrane and the vacuolar membrane. The overexpression of JcSWEET16 in Arabidopsis thaliana modified the flowering time and saline tolerance levels but not the drought tolerance of the transgenic plants. Together, these results provide insights into the characteristics of SWEET genes in physic nut and could serve as a basis for cloning and further functional analysis of these genes.


Assuntos
Arabidopsis , Jatropha , Arabidopsis/genética , Arabidopsis/metabolismo , Regulação da Expressão Gênica de Plantas , Jatropha/genética , Proteínas de Membrana Transportadoras/genética , Proteínas de Membrana Transportadoras/metabolismo , Filogenia , Proteínas de Plantas/metabolismo , Açúcares/metabolismo
7.
Org Biomol Chem ; 18(22): 4272-4275, 2020 06 14.
Artigo em Inglês | MEDLINE | ID: mdl-32441731

RESUMO

The Friedel-Crafts reaction of alkalinous substrates is challenging because of the coordination between amines and traditional acid catalysts. Based on theoretical research, we designed a catalytic process for the Friedel-Crafts reactions of N,N-dialkylanilines in the presence of CAAC-CuCl [CAAC = cyclic(alkyl)(amino)carbene] and KB(C6F5)4. Experimental results show that the catalytic system is suitable for a series of N,N-dialkylanilines and styrenes with good to excellent yields of para-selectivity products. The results are comparable to those obtained in carbene-gold catalyzed processes.

8.
Environ Res ; 182: 109082, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31891828

RESUMO

Restrictions of legacy brominated flame retardants, such as polybrominated diphenyl ether (PBDE) and polybrominated biphenyl (PBB), have resulted in increased usage of alternative halogenated flame retardants (AHFRs). Consequently, AHFRs contamination has caused a major concern in the scientific community. However, there is limited information on their presence in marine mussels. In this study, we investigated the occurrence and distribution of polybrominated biphenyls (PBBs), AHFRs and dehalogenated products in green mussels collected from 22 locations in the northern South China Sea (SCS). Our results revealed that ∑AHFRs were ubiquitous in green mussels with concentrations in the range of 1.08-7.71 ng/g lipid weight (lw). Among target AHFRs, hexabromobenzene (HBB), decabromodiphenyl (DBDPE) and dechlorane plus (DP) were predominant with their mean values of 1.19, 1.00 and 0.82 ng/g lw, respectively. There were negligible stereoisomer enrichments of DP in green mussels based on fanti values, indicating a limited bioaccumulation and metabolism of DP in green mussels. In comparison with other locations, concentrations of the AHFRs in green mussels determined here were at moderate levels. Additionally, there were significant linear relationships between some AHFRs (e.g., HBB and PBEB), suggesting their similar commercial applications and sources in the environment. The estimated daily intakes of AHFRs through consumption of green mussels by the local population in South China were 0.05-0.14 ng/kg body weight/day and 0.17-0.44 ng/kg body weight/day based on the mean and 95th concentrations, respectively. To the best of our knowledge, the present study is the first to report AHFRs and dehalogenated products in green mussels.


Assuntos
Bivalves , Retardadores de Chama , Animais , China , Monitoramento Ambiental , Éteres Difenil Halogenados
9.
Angew Chem Int Ed Engl ; 58(3): 722-726, 2019 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-30403435

RESUMO

Hydrogenation of CO2 to formate with H2 in the absence of transition metal is a long-standing challenge in catalysis. The reactions between tris(pentafluorophenyl)borane (BCF) and K2 CO3 (or KHCO3 ) are found to form a Lewis pair (K2 [(BCF)2 -CO3 ]) which can react with both H2 and CO2 to produce formate. Based on these stoichiometric reactions, the first catalytic hydrogenation process of CO2 to formate using transition metal free catalyst (BCF/M2 CO3 , M=Na, K, and Cs) is reported. The highest TON value of this catalytic process is up to 3941. Further research revealed the reaction mechanism in which the Lewis pair enables the splitting of H2 and the insertion of CO2 into the B-H bond.

11.
Chem Asian J ; 19(11): e202400234, 2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38567977

RESUMO

Carbon capture, utilization, and storage (CCUS) are among the key technologies to achieve large-scale carbon emission reduction globally. Deep eutectic solvents (DESs) are considered as designable solvents, which has attracted intensive attention for CO2 capture. Here, a series of binary DESs are synthesized through one-step mixing with the starting materials of protic ionic liquid (PIL) and amine. The eutectic behavior was investigated by measuring the melting point of PILs and amine. The saturated vapor of these DESs and industrial MDEA solution were measured and compared. These DESs are investigated to have high absorption capacity (0.1 g ⋅ g-1 at 1.0 bar and 25 °C), superior apparent absorption rate constant (0.381 min-1 vs 0.012 min-1 of 70 wt.% MDEA), moderate interaction with CO2 (the enthalpy change is as low as -34.8 kJ ⋅ mol-1). The absorption mechanism is also investigated by NMR analysis. Eight absorption/desorption regeneration experiments are carried out to show their reversibility. Considering the advantages, including convenience of synthesis, large absorption capacity, fast absorption rate, and moderate interaction energy as well as good regeneration, these DESs are believed to be as potential CO2 absorbent in practical applications.

12.
Chem Commun (Camb) ; 60(50): 6443-6446, 2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38832406

RESUMO

A series of novel protic amino acid ionic liquids (PAAILs) are designed and synthesized for the first time through acid-base neutralization and an ion exchange reaction. Among the synthesised PAAILs, the [DBNH][Maba] PAAIL has the largest CO2 absorption capacity of 0.78 mol mol-1 (0.142 g g-1) at 313.2 K. The PAAILs are found to be efficient, reversible, and selective CO2 absorbents.

13.
Adv Sci (Weinh) ; : e2401423, 2024 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-38884169

RESUMO

Effectively neutralizing inflammatory cytokines is crucial for managing a variety of inflammatory disorders. Current techniques that target only a subset of cytokines often fall short due to the intricate nature of redundant and compensatory cytokine networks. A promising solution to this challenge is using cell membrane-coated nanoparticles (CNPs). These nanoparticles replicate the complex interactions between cells and cytokines observed in disease pathology, providing a potential avenue for multiplex cytokine scavenging. While the development of CNPs using experimental animal models has shown great promise, their effectiveness in scavenging multiple cytokines in human diseases has yet to be demonstrated. To bridge this gap, this study selected macrophage membrane-coated CNPs (MФ-CNPs) and assessed their ability to scavenge inflammatory cytokines in serum samples from patients with COVID-19, sepsis, acute pancreatitis, or type-1 diabetes, along with synovial fluid samples from patients with rheumatoid arthritis. The results show that MФ-CNPs effectively scavenge critical inflammatory cytokines, including interleukin (IL)-6, IL-8, interferon (IFN)-γ, and tumor necrosis factor (TNF)-α, in a dose-dependent manner. Overall, this study demonstrates MФ-CNPs as a multiplex cytokine scavenging formulation with promising applications in clinical settings to treat a range of inflammatory disorders.

14.
J Hazard Mater ; 460: 132515, 2023 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-37703738

RESUMO

SO2 is a major atmospheric pollutant leading to acid rain and smog. As a new generation of green solvents, deep eutectic solvents (DESs) have been widely investigated for gas capture. Nevertheless, studies on DES-based membranes for SO2 separation are yet minimal. Herein, we devised polymer/DES blended membranes comprising 1-butyl-3-methyl-imidazolium bromide ([Bmim]Br)/diethylene glycol (DEG) DES and poly (vinylidene fluoride) (PVDF), and these membranes were firstly used for selective separation of SO2 from N2 and CO2. The permeability of SO2 reaches up to 17480 Barrer (0.20 bar, 40 ºC) in PVDF/DES blended membrane containing 50 wt% of [Bmim]Br/DEG (2:1), with ultrahigh SO2/N2 and SO2/CO2 selectivity of 3690 and 211 obtained, respectively, far exceeding those in the state-of-the-art membranes reported in literature. The highly-reversible multi-site interaction between SO2 and [Bmim]Br/DEG DES was revealed by spectroscopic analysis. Furthermore, the PVDF/DES blended membrane was also able to efficiently and stably separate SO2/CO2/N2 (2.5/15/82.5%) mixed gas for at least 100 h. This work demonstrates for the first time that [Bmim]Br-based DESs are very efficient media for membrane separation of SO2. The easy preparation, low cost and high performance enable polymer/DES blended membranes to be promising candidates for flue gas desulfurization.

15.
iScience ; 26(5): 106672, 2023 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-37216122

RESUMO

Hydrogenation of carbon dioxide (CO2) to produce formic acid (HCOOH) in base-free condition can avoid waste producing and simplify product separation process. However, it remains a big challenge because of the unfavorable energy in both thermodynamics and dynamics. Herein, we report the selective and efficient hydrogenation of CO2 to HCOOH under neutral conditions with imidazolium chloride ionic liquid as the solvent, catalyzed by a heterogeneous Ir/PPh3 compound. The heterogeneous catalyst is more effective than the homogeneous one because it is inert in catalyzing the decomposition of product. A turnover number (TON) of 12700 can be achieved, and HCOOH with a purity of 99.5% can be isolated by distillation because of the non-volatility of the solvent. Both the catalyst and imidazolium chloride can be recycled at least 5 times with stable reactivity.

16.
Chem Commun (Camb) ; 58(13): 2132-2135, 2022 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-34704994

RESUMO

In this work, cyclic (alkyl)(amino)carbene copper ((CAAC)Cu) catalyzed aerobic oxidation of aldehydes in water at room temperature has been reported. Good to excellent yields were obtained using different substrates. A possible reaction mechanism was proposed, in which (CAAC)Cu dioxygen activates the C-H bond of aldehyde with a low barrier of 10.6 kcal mol-1.

17.
ACS Omega ; 7(30): 26368-26374, 2022 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-35936454

RESUMO

The synthesis of a novel class of ionic liquids (ILs) with sulfimide-type anions is presented herein. [Py14][PTSNTF] (N-butyl-N-methylpyrrolidinium p-tosyl(trifluoromethyl)sulfonimide) shows that the maximal electrochemical window is as high as 5.3 V, higher than that of most reported ILs. In addition, thermogravimetry analysis, differential scanning calorimetry, and the flammability test were also carried out for its thermal stability and practical safety. Impressively, these ILs exhibited good flame resistance and demonstrated an admirable intrinsic safety, in sharp contrast to ordinary electrolytes. Furthermore, the electrostatic potential of ILs was calculated theoretically, and the distribution of surrounding charge is intuitively understood. Cyclic voltammetry, galvanostatic charge-discharge tests, and cycling stability measurement were performed to evaluate the potential as the electrolyte for supercapacitors. The insights obtained from the study of novel anions provide new ideas for the design of novel IL electrolytes for energy applications.

18.
J Neurooncol ; 105(3): 563-72, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21667225

RESUMO

Meningeal hemangiopericytoma (HPC) is a clinicopathologically well-characterized malignancy with a high tendency to recur locally and to metastasize outside the central nervous system (CNS). We render clinicopathologic features of 12 cases of this uncommon tumor to further elucidate the relationship between the status of the DNA-repair enzyme O(6)-methylguanine-DNA methyltransferase (MGMT) and the prognosis. Twenty-five specimens of meningeal HPC belonging to 12 patients were obtained at a single institution from 1992 to 2001. Correlations of histologic parameters, immunohistochemical study and clinical features were assessed. This series included five men and seven women with a median age of 37.5 years at the first surgery. The median post-operative follow-up period was 7.6 years. Six patients (55%) had single or multiple local tumor recurrences. The mean time to recurrence was 6.7 years. Distant metastasis occurred in three patients (27%) at a mean time of 6.5 years after first operation. The most frequent metastatic sites were liver and lung. Histopathologically, eight primary tumors (67%) belonged to WHO grade II, while four primary tumors (33%) belonged to WHO grade III. Immunohistochemically, 18% primary tumors exhibited 3+ to 4+ nuclear staining for MGMT protein, 18% exhibited 2+ staining, and 64% exhibited 0 to 1+ staining. The overall survival rate was 67 and 33% for primary tumors with 0 to 1+ and 2+ to 4+ MGMT staining, respectively (P = 0.018). The study illustrates aggressive behavior of meningeal HPC and the prognostic value of the status of MGMT protein expression.


Assuntos
Metilases de Modificação do DNA/biossíntese , Enzimas Reparadoras do DNA/biossíntese , Meningioma/metabolismo , Meningioma/mortalidade , Proteínas Supressoras de Tumor/biossíntese , Adulto , Biomarcadores Tumorais/análise , Metilases de Modificação do DNA/análise , Enzimas Reparadoras do DNA/análise , Intervalo Livre de Doença , Feminino , Humanos , Imuno-Histoquímica , Estimativa de Kaplan-Meier , Masculino , Meningioma/patologia , Pessoa de Meia-Idade , Gradação de Tumores , Recidiva Local de Neoplasia/epidemiologia , Prognóstico , Proteínas Supressoras de Tumor/análise , Adulto Jovem
19.
J Neurooncol ; 103(3): 551-9, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20872042

RESUMO

Clear cell meningioma is an uncommon variant of meningiomas that often occurs in young patients, shows a proclivity for spinal intradural extramedullary and cerebellopontine angle, and follows an aggressive clinical course. We render clinicopathologic features of ten cases of this rare tumor to further elucidate its behavior. Fifteen specimens of clear cell meningioma belonging to ten patients were obtained at a single institution from 2001 to 2009. Correlations of histologic parameters, immunohistochemical study, and clinical features were assessed. This series included eight men and two women with a mean age of 62.1 years at the first surgery. The mean post-operative follow-up period was 3.9 years. Four patients (40%) had single or multiple local tumor recurrences. The mean time to recurrence was 2.3 years. Seven tumors (46.7%) were combined with chordoid features. There was a wide range of MIB-1 labeling indices (4.4-33.5%, mean 15.8%), which were higher in recurrent tumors, tumors with chordoid features, and tumors with necrosis. There was no correlation between MIB-1 labeling indices and brain invasion. The study illustrates aggressive behavior of clear cell meningioma and frequently combined chordoid features in our cases.


Assuntos
Agressão , Neoplasias Meníngeas/patologia , Neoplasias Meníngeas/psicologia , Meningioma/patologia , Meningioma/psicologia , Notocorda/patologia , Idoso , Idoso de 80 Anos ou mais , Agressão/psicologia , Feminino , Glicogênio/metabolismo , Humanos , Antígeno Ki-67/metabolismo , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Mucina-1/metabolismo , Estudos Retrospectivos , Proteínas S100/metabolismo , Vimentina/metabolismo , Adulto Jovem
20.
Environ Sci Technol ; 45(24): 10627-33, 2011 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-22066493

RESUMO

By grafting butyl or ethyl onto tetramethylethylenediamine, quaternary ammonium salts with two positive charge centers were formed at the first step. Metathesis with Ag(2)O followed. Through neutralization with glycine, l-alanine, or valine, a series of new ditetraalkylammonium amino acid ionic liquids (DILs) for CO(2) capture were generated. The structures of DILs, as shown in Figure 1, were verified by using (1)H NMR and EA. These DILs were found to be of quite high viscosity which militated against their industrial application in CO(2) removal. Drawing on the experience of mixed amines' aqueous solutions, these DILs were blended with water or N-methyldiethanolamine (MDEA) aqueous solutions to act as special absorbents of CO(2). Using a Double-Tank Absorption System, the absorption performance of these DIL solutions was investigated in detail. The experimental results indicated that among the three aqueous solutions of DILs (20%, 40%, and 80 wt %), the solution of 40% DIL had a higher absorption rate of CO(2) than the other two, demonstrating the different effects of concentration and viscosity on the absorption. The solution of 40% DIL or the 15% DIL + 15% MDEA had much higher capacity for CO(2) than the corresponding monocation tetraalkylammonium AAILs, due to the special structure of the dication which could influence the solubility of CO(2) in the aqueous solution.


Assuntos
Dióxido de Carbono/química , Líquidos Iônicos/química , Compostos de Amônio Quaternário/química , Poluentes Químicos da Água/química , Adsorção , Poluição do Ar/prevenção & controle , Dióxido de Carbono/análise , Recuperação e Remediação Ambiental , Modelos Químicos , Estrutura Molecular , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/análise
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