MICROPOROUS AND MESOPOROUS MATERIALS
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2021
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IF 5.455
Ying Shi,Qiuming Zhou,Zhangfeng Qin,Zhiwei Wu,Weiyong Jiao,Mei Dong,Weibin Fan,Jianguo Wang
The aromatization of alkanes is an important process for improving the quality of Fischer-Tropsch synthesis (FTS) gasoline and producing high-valued aromatics from naphtha ; however, currently available catalysts in this regard are often deficient due to the low aromatics yield and short lifetime. In this work, a series of hierarchically structured Beta (Beta-HS) zeolites with high crystallinity and meso-porosity were synthesized by steam treatment with various organosilanes as pore-forming reagent and ethanol as solvent. The nano-sized Beta-HS zeolites were further modified with K through ion-exchange and with Pt through incipient wetness impregnation; the resultant Pt/K-Beta-HS catalysts were then used in the aromatization of n -heptane. The results indicate that the abundant mesopores present in Beta-HS are conducive to the diffusion of reactants and products, whilst the modification with K is able to passivate the strong Brønsted acid sites and the loading of Pt metal can promote the dehydrogenation of alkanes and cycloalkanes, which can effectively suppress the cracking and carbonaceous deposition reactions and enhance the dehydrogenation aromatization activity. As a result, the Pt/K-Beta-HS catalysts exhibit excellent performance in the aromatization of n -heptane, with a much longer lifetime (205 h), higher selectivity to aromatics (80%) and larger turnover number of aromatic products (Pt-based TON, 240 × 10 3 ) than conventional Beta zeolites. These results prove that the steam treatment with organosilanes as pore-forming reagent is a facile and cost-effective strategy to synthesize the hierarchically structured Beta zeolites and after loading K and Pt, the Pt/K-Beta-HS zeolites can be an efficient catalyst for the conversion of n -heptane to aromatics.
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ACS Applied Materials & Interfaces
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2021
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IF 9.229
Zhenwei Miao,Dongpeng Yan,Teng Zhang,Fan Yang,Shuangkun Zhang,Wei Liu,Zhanpeng Wu
Modification by intumescent flame retardants is an effective way to impart antiflame properties to fabric materials. Polyphosphazene elastomers contain all three elements required by intumescent flame retardants: an acid source, a gas source, and a carbon source, making them all-in-one integrated intumescent flame retardants. In this work, halogen-free poly(dimethoxy)phosphazene (PDMP) loaded with 29.0 wt % phosphorus and 13.1 wt % nitrogen is shown to be an ideal flame retardant for fabric materials. For the first time, transparent and elastic PDMP was applied as an intumescent flame retardant for cotton fabric. The PDMP-coated cotton shows remarkable high-efficiency flame-retardant properties: (1) a self-extinguishing property during the vertical flame test is obtained when the add-on level reaches 5.3 wt %, with a lower smoke release character; (2) the limiting oxygen index (LOI) values of coated cotton are improved with increasing add-on level, and the thickness of the coating is measured to be at the nanolevel, 2540 nm when 10.9 wt % PDMP is coated. The coated cotton shows enhanced carbonization ability at lower temperatures, which is the key to imparting flame-retardant properties to cotton, and the PDMP-coated cotton shows remarkably lower peak heat release rate and total heat release compared to the control cotton during combustion. The durability of modified cotton was tested after 50 laundering cycles, which showed that the coating maintains 80% of its initial mass, and the after-laundering sample preserves the characteristics of self-extinguishing and a high LOI. Thus, the PDMP nanocoating-modified flame-retardant cotton fabric is sufficiently durable for practical application.
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ACS Applied Materials & Interfaces
·
2021
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IF 9.229
Chen Yang,Xijun Xu,Wajid Ali,Yaojin Wang,Yiping Wang,Ying Yang,Lang Chen,Guoliang Yuan
Ultrasonic sensors are widely applied in industries near room temperature; however, their application at high temperature is still a challenge mainly due to the lack of high-performance piezoelectric ceramics. Here, the 0.364BiScO3–0.636PbTiO3–0.005CaTiO3 ceramic exhibits excellent piezoelectric performances at 20–440 °C. Its piezoelectric coefficient d33 increases from 475 pC/N at 20 °C to 853 pC/N at 360 °C, and then it gradually decreases to 669 pC/N at 440 °C. Furthermore, the planar electromechanical coupling factor kp gradually increases from 0.59 at 20 °C to 0.67 at 200 °C, and then it remains at a stable value of 0.65–0.67 at 150–350 °C. These achievements are because the ceramic morphotropic phase boundaries have a flat Gibbs free energy versus polarization curve and a wide temperature range. Since the piezoelectric ceramic shows satisfactory piezoelectric properties at 20–440 °C, the corresponding ultrasonic sensors can in situ monitor many high-temperature devices, such as engines, wheels, drills, boilers, etc.
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ELECTROCHIMICA ACTA
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2021
·
IF 6.901
Xiaoqing Bin,Yapeng Tian,Yangyang Luo,Minhao Sheng,Yijia Luo,Maomao Ju,Wenxiu Que
In order to obtain high-performance flexible electrodes for supercapacitors, the nitrogen-doped delaminated-Ti 3 C 2 T x (N-d-Ti 3 C 2 T x ) decorated with MoO x nanoparticles (N-d-Ti 3 C 2 T x /MoO x ) films are prepared by a one-step solvothermal method. The N-d-Ti 3 C 2 T x nanosheets with high conductivity can facilitate electron transfer during the charge and discharge process, and the MoO x nanoparticles can contribute to high pseudocapacitance. Hence, their combination is expected to not only inhibit N-d-Ti 3 C 2 T x nanosheets from re-stacking, but also enhance the specific capacity of the whole electrode. Here, benefiting from the synergistic effect of the two components, the obtained optimal flexible and free-standing N-d-Ti 3 C 2 T x /MoO x film electrode delivers an ultrahigh capacity of 341.0 C g −1 (920.6 C cm −3 , 487.1 F g −1 , 1315.2 F cm −3 ) at the scan rate of 2 mV s −1 , and shows superior capacity retention of 99.2% after 11000 cycles at the current density of 5 A g −1 . Moreover, the flexible and free-standing N-d-Ti 3 C 2 T x /MoO x film electrode is also beneficial to promote the development of flexible supercapacitors.
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Materials Science & Engineering C-Materials for Biological Applications
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2021
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IF 7.328
Rongzhen Fang,Yan Liu,Lei Ma,Xiang Yu,Yiguang Jin
Drug solid dispersions improve the dissolution of drugs in aqueous media for enhancement of oral bioavailability. The current preparation methods of drug solid dispersions mainly involve the evaporation of solvents or the melting of drugs and matrix. Here, we create a new and simple method for the preparation of drug solid dispersions by dissolving drugs in N -vinyl-2-pyrrolidone (NVP) and then NVP photopolymerization. A variety of drugs were explored to find whether they were suitable for this method and only some of them were soluble in NVP and formed transparent and hard solid dispersions, including fluconazole, ketoconazole, bifonazole, miconazole nitrate, sulfamethoxazole, aspirin, ibuprofen and artesunate. The formation of photocuring solid dispersions was highly related to the free radical scavenging function of drugs. Those drugs with strong free radical scavenging capability, including curcumin, resveratrol, quercetin, genistein, puerarin, nicergoline, olanzapine, indomethacin, did not form solid dispersions. They scavenged 2,2-diphenyl-1-picrylhydrazyl free radicals, which was demonstrated by ultraviolet spectrometry and electron spin resonance. The scavenging of free radicals stopped the chain polymerization of NVP. The Fourier transform infrared spectra, X-ray diffraction and differential scanning calorimetry of ibuprofen solid dispersions and artesunate solid dispersions showed the molecularly miscible state of the drugs and the hydrogen bonding between the drugs and polyvinyl pyrrolidone. The NVP-based solid dispersions of the two drugs had faster and more complete dissolution than their traditional solid dispersions. The NVP photopolymerization-based solid dispersion method provides a new choice for the production of solid dispersions in the research and industrial fields.
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SEPARATION AND PURIFICATION TECHNOLOGY
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2021
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IF 7.312
Yi Wang,Qingjie Ji,Jixiang Xu,Jun Wan,Lei Wang
In this study, N-doped porous carbon materials embedded with NiN x species (Ni@NC) were fabricated via the pyrolysis of Ni-doped zeolitic imidazolate frameworks-8 (ZIF-8) at the temperature of 900 °C. The obtained Ni@NC-1 catalyst exhibited excellent activity in activating the peroxydisulfate (PDS) that was used for removing tetracycline (TC). The catalytic system exhibited good stability, wide pH adaptation, and high resistance to the operational environment. It was supposed that NiN x species could attach to PDS and act as electron acceptors to receive the electrons for activating the PDS, thus generating highly reactive superoxide radicals (⋅O 2 − ) and singlet oxygen ( 1 O 2 ) species for rapid degradation of TC. The electron transfer and dissolved oxygen-derived ⋅O 2 − were also responsible for the degradation of TC. In addition, the Ni@NC-1/PDS system exhibited high efficiency for removing oxytetracycline, ciprofloxacin, or levofloxacin. The results of this study would promote the design of other MOFs-derived carbon-encapsulated metal species for efficiently activating persulfate to remove antibiotics from the wastewater.
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Scientific Reports
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2021
·Vol. 11
·期 1
·1-9
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IF 4.38
Zhou Zhiyong,Qiu Nanqing,Ou Yuntao,Wei Qianqian,Tang Wenting,Zheng Mingcong,Xing Yaluan,Li Jie-Jia,Ling Yong,Li Junxu,Zhu Qing
Chronic pain is a significant public health problem that afflicts nearly 30% of the global population, but current pharmacotherapies are insufficient. Previous report indicated that N -demethylsinomenine, an active metabolite of sinomenine, is efficacious against postoperative pain. The present study investigated whether N -demethylsinomenine is effective for chronic painful conditions or whether repeated treatment alters its effect. Both chronic constriction injury (CCI) surgery and complete Freund’s adjuvant (CFA) intraplantar injection induced significant and reliable mechanical allodynia at least for 7 days. Acute treatment with N -demethylsinomenine (10–40 mg/kg, i.p.) dose-dependently attenuated the mechanical allodynia both in CCI-induced neuropathic pain and CFA-induced inflammatory pain in mice. The potency of N -demethylsinomenine for reducing CFA-induced mechanical allodynia was slightly higher than sinomenine. During the period of repeated treatment, N -demethylsinomenine maintained its anti-allodynic effect against both neuropathic and inflammatory pain without producing carry-over effect. Pretreatment with bicuculline, a selective γ-aminobutyric acid type A (GABA A ) receptor antagonist, almost completely blocked the anti-allodynia of N -demethylsinomenine (40 mg/kg) both in CCI and CFA-treated mice. Our findings indicated that N -demethylsinomenine exhibits GABA A receptor-mediated anti-allodynic effects in mouse models of neuropathic and inflammatory pain, suggesting it may be a useful novel pharmacotherapy for the control of chronic pain.
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CHINESE JOURNAL OF CHEMICAL ENGINEERING
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2021
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IF 3.171
Chen Chen,Qiong Tang,Hong Xu,Lei Liu,Mingxing Tang,Xuekuan Li,Jinxiang Dong
With the development of coal chemical industry, large amounts of naphthalene and n -butene are produced, and converting them into high value-added products through alkylation has gained particular importance and interest. In this work, liquid coordination complexes (LCCs) were used as acid catalysts for the first time in the naphthalene alkylation reaction under mild conditions to obtain multi-butylnaphthalenes with high yield. Various reaction conditions were thoroughly investigated. The LCC consisting of urea and AlCl 3 showed excellent catalytic performance under optimal reaction conditions, giving 100% conversion of naphthalene and 99.66% selectivity towards multi-butylnaphthalenes. Combining the catalyst properties and catalytic results, a plausible reaction mechanism was proposed. The lubricating properties of the synthesized products were investigated for their potential application as lubricating base oils. The synthesized multi-butylnaphthalenes showed comparable physicochemical properties and tribological performances as the commercial cycloalkyl base oil.
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IONICS
·
2021
·Vol. 27
·期 10
·4461-4471
·
IF 2.817
Zeng Depeng,Shu Dong,Yi Fenyun,Gao Aimei
A nest-like N-doped hierarchical porous active carbon (N-HAC) with higher specific surface area is achieved successfully by melamine cyanurate (MCA) sacrifice template molding and assistant chemical activation of NH 4 Cl and CaCl 2 . The results testify that the nest-like hierarchical porous character of N-HAC can form an interconnecting structure and introduce plenty of supercapacitor reactive sites, which can facilitate the ion diffusion/migration among the material, while nitrogen doping in N-HAC can change the charge distribution of N-HAC and then promote the electron transfer. Attributing to the synergistic effect of the hierarchical porous structure and nitrogen doping, N-HAC800 displays the highest specific capacitance (284.6 F g −1 at 1 A g −1 and 183.1 F g −1 even at 20 A g −1 ) and superior cycle stability (80.4% after 5000 cycles at 100 mV s −1 ). This study results prove that the N-doped hierarchical porous active carbon is a promising material for energy storage application in the future.
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ACS Applied Materials & Interfaces
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2021
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IF 9.229
Yuting Zeng,Yan Li,Xiaofeng Tan,Jindi Gong,Ziyu Wang,Yuhao An,Zhenqiang Wang,He Li
Among plentiful porous nanomaterials, noble metal aerogels taken as nanozymes attract broad attention in sensing applications with their distinct enzyme mimic functions. In the catalytic field, the heteroatom doping strategy is a kind of way with great promise in improving the enzyme mimic activity of noble metal aerogels. In this experiment, we find a type of creative materials that were prepared by the fast and simple method. Due to the unique porous structure and synergetic effect from doped atoms, PdRu aerogels co-doped with boron and nitrogen (B, N-PdRu aerogels) were prepared using NH3BH3 as a reductant, which present improved peroxidase mimicking activity. With the existence of H2O2, the oxidation of 3,3′,5,5′-tetramethylbenzidine was catalyzed by B, N-PdRu aerogels fairly efficiently, whose solution would be a blue appearance at optimum absorption wavelength 652 nm. Thus, by the tandem reaction bound to the enzyme glucose oxidase, the B, N-PdRu aerogels can be used for the sensitive determination of glucose. The new method has a good linear detection effect for glucose in the range of 10 μM to 2 mM. The minimum limit of detection can reach as low as 6 μM. This work will contribute to research on the rational design of metal aerogels based on the heteroatomic doping strategy and enhance the corresponding performance for a variety of applications.
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Progress in Natural Science-Materials International
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2021
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IF 3.607
Xinxin Jin,Yan Xie,Chaoyue Zhao,Yinghao Xu,Yang Lv,He Wang,Li Chen,Jiahui Huang
FeCo-based non-noble metal electrocatalysts (NNMEs) of FeCo/MCS-NPCS was fabricated by immobilization of hemin on mesoporous carbon shells modified N-doped porous carbon spheres (MCS-NPCS). The obtained FeCo/MCS-NPCS exhibits a half-wave potential (E 1/2 ) of 0.851 V versus the reversible hydrogen electrode (vs. RHE) and a limited-diffusion current density (J L ) of 5.45 mA cm −2 . In addition, FeCo/MCS-NPCS shows comparable oxygen reduction reaction (ORR) performances to 20 wt% Pt/C in terms of E 1/2 and J L and better electrochemical properties, including the methanol tolerance and durability in alkaline solution. Such outstanding electrochemical activities of FeCo/MCS-NPCS can be ascribed to Fe and/or Co-based nitrides and carbides as well as N-doped carbon matrixes modified with mesoporous carbon shells. This research introduces a promising path to design and synthesize highly efficient FeCo–N–C electrocatalysts towards ORR.
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JOURNAL OF HAZARDOUS MATERIALS
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2020
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IF 9.038
Kaihang Zhang,David Kujawski,Chris Spurrell,Dong Wang,Junchen Yan,John C. Crittenden
Polyfluoroalkyl Substances (PFAS) such as perfluorooctanoic acid (PFOA) are resistant to biodegradation leading to adverse health outcomes. Therefore, PFAS removal from drinking water is paramount. Liquid-liquid extraction processes can remove them from water; however, the hydrophobic and oleophobic properties of PFOA lead to the low extraction efficiency and severe emulsification , especially for the ppm-levels concentration of PFOA. Therefore, we introduced ionic liquid (IL) methyltrioctylammonium bis(trifluoromethylsulfonyl)imide ([A336][NTf 2 ]) as extractant into octanol. We found that using hexadecyl trimethyl ammonium bromide (CTAB) as an extractant caused severe and stable emulsion. In comparison, [A336][NTf 2 ] could suppress the emulsification with high extraction efficiency. The extraction performance of PFOA was examined as a function of various parameters. The results showed that the extraction efficiency was strongly dependent on the concentration of IL and aqueous pH. Further research revealed the extraction mechanisms at the molecular-level, and density functional theory (DFT) and molecular dynamic (MD) simulation agreed with the trends in the experiment. We determined that the extraction efficiency of PFOA from water could be up to 88.21 wt% for the optimized condition, indicating that the extraction system of [A336][NTf 2 ] + octanol was efficient for separating PFOA from the diluted aqueous solution.
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