CATALYSIS LETTERS
·
2022
·Vol. 152
·期 12
·3795-3806
·
IF 2.936
Tao Wanyi,Bo Longli,Li Mingxin,Liu Jiadong
The modification of cordierite honeycomb (CH) carrier is conducive to improve the catalytic activity of catalyst that applying in the treatment of real VOCs waste gas. A honeycombed calcium aluminum silicate hydrate (C–A–S–H) thin layer was self-assembled successfully by alkaline corrosion with supersaturated Ca(OH) 2 and contacted robustly onto the CH surface (named as CHC) by chemical bond. CuMnCeO x /CHC catalyst was prepared and applied in microwave catalytic combustion of toluene to check the catalytic activity in this work. Compared with CuMnCeO x /CH catalyst, CuMnCeO x /CHC catalyst exhibited a higher catalytic capacity and the removal rate of toluene reached 99%, which was higher than 75% of CuMnCeO x /CH catalyst under same reaction conditions of toluene initial concentration 1000 mg m −3 , air flow 0.12 m 3 h −1 and bed temperature 200 °C. Based on SEM, BET, XRD, XPS, UV-Raman, H 2 -TPR and NH 3 -TPD characterizations, it showed clearly that honeycombed C–A–S–H thin layer made CuMnCeO x active particles with smaller size more uniformly embedded into the pores of itself to hinder effectively the agglomeration of active particles in reaction. The valence reversible conversion of Cu + /Cu 2+ , Mn 2+ /Mn 3+ /Mn 4+ and Ce 3+ /Ce 4+ and total valence increase of CuMnCeO x produced abundant oxygen vacancies on the catalyst surface and simultaneously improved the transformation of surface adsorbed oxygen (O ads ) to lattice oxygen (O latt ). Toluene was oxidized completely by O ads and O latt species onto the active sites and “hot spots” under microwave irradiation that following both L–H mechanism and MvK mechanism. The research work lays down a theoretical basis for the preparation of highly effective catalyst and further application in the treatment of industrial VOCs waste gas. Graphical Abstract
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APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
·
2022
·Vol. 128
·期 3
·1-16
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IF 2.983
Zhang Dandan,Yang Fanghong,Wang Rumin
Magnetic nanoparticle-coated graphene oxide (GO) can be oriented in polymers under magnetic field due to the anisotropy of GO and excellent magnetism of magnetic nanoparticles. In this study, ferroferric oxide nanoparticles coated GO (Fe 3 O 4 -GO) was synthesized successfully using oxidation-coprecipitation method. The synthesized Fe 3 O 4 -GO was then added to epoxy and oriented by applying magnetic field using (1) the electromagnetic coil and (2) permanent magnets to toughen the epoxy matrix. Non-isothermal differential scanning calorimetry (DSC) tests were performed to determine the curing process of Fe 3 O 4 -GO/E-51/3a-methyl-5,6-dihydro-4 H -isobenzofuran-1,3-dione (MeTHPA)/2,4,6 Tris(dimethyl aminomethyl)phenol (DMP-30) system (Fe 3 O 4 -GO/E-51/MeTHPA/DMP-30). Transmission electron microscope images show that Fe 3 O 4 nanoparticles were coated on the GO surface homogenously and Fe 3 O 4 -GO were highly oriented in E-51/MeTHPA/DMP-30 epoxy system under different magnetic field conditions. The maximum impact strength of Fe 3 O 4 -GO/E-51/MeTHPA/DMP-30 composite was observed at 0.2 wt% Fe 3 O 4 -GO loading, with values of 28.64 and 30.54 kJ/m 2 in case of the magnetic field applied through permanent magnets and electromagnetic coil respectively, which is an increase by 39.6 and 48.8% respectively when compared with the pure E-51/MeTHPA/DMP-30 system (20.52 kJ/m 2 ). In addition, at 0.4 wt% Fe 3 O 4 -GO loading and application of magnetic field through electromagnetic coil, the maximum increase in flexural modulus was observed, which was increased by 41.8% and 17.23% compared with the pure epoxy system and the one without application of magnetic field at same Fe 3 O 4 -GO loading respectively. The fracture morphologies from the scanning electron microscope also indicated that the oriented Fe 3 O 4 -GO under magnetic field improved the toughness of the E-51/MeTHPA/DMP-30 resin system.
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JOURNAL OF NANOPARTICLE RESEARCH
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2022
·Vol. 24
·期 3
·1-18
·
IF 2.533
Zhou Jinglu,Wen Zhen,Yan Shilun,Guo Hui,Zhou Chuyue
To improve the properties of mesoporous silica nanoparticles (MSNs), the surface of MSNs was functionally modified with a pH-sensitive polymer. Using polyethylene glycol 2000-distearoyl phosphatidylethanolamine (PEG2000-DSPE) as a modifier and doxorubicin (DOX) as a model drug, the pH-sensitive mesoporous silica composite nanocarriers were formed. When the MSNs were modified with PEG2000-DSPE at (m(PEG2000-DSPE):m(MSNs) = 1:5), DOX loaded in PEG2000-DSPE-MSNs (DOX-PEG-DSPE-MSNs) possessed good physicochemical properties including the highest drug loading (loading efficiency of (76.58 ± 0.75)% and loading capacity of (9.34 ± 0.03)%), the lowest average particle size ((298 ± 2) nm) and uniform size distribution (PDI of (0.14 ± 0.01)), colloid stability (zeta potential of (− 16.5 ± 0.3) mV), large specific surface area ((512 ± 4) m 2 g −1 ) and high pore capacity ((0.29 ± 0.02) cm 3 g −1 ). A lipid bilayer formed by PEG-DSPE2000 and phospholipid coated the MSN surface, acting as the “gatekeeper” for blocking the nanopores of MSNs, preventing the leakage and burst release of DOX absorbed in the mesoporous channel. Due to the hydrolysis of the amino group of PEG-DSPE in an acidic media, the “gatekeeper” broken, leading to destabilization and destruction of the lipid bilayer, exhibiting the pH-responsive release of DOX, which was fitted with a bi-phase exponential kinetic release model. PEG-DSPE-MSNs exhibited low cytotoxicity to LO2 cells and improved the biocompatibility of MSNs. PEG-DSPE-MSNs delivered DOX to tumor cells effectively due to pH-sensitive and sustained release, contributing to the significant inhibition of Hepg-2 cells. The results confirm the benefits of surface functionalization of MSNs with PEG-DSPE, and the potential application of tumor-targeted drugs.
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Journal of the Korean Ceramic Society
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2022
·Vol. 59
·期 5
·604-613
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IF 2.506
Zhang Feng,Wang Yaqin,Miao Wenfei,Liu Zhaoming,Oh Won-Chun
Modified tourmaline (TM) minerals were prepared using hydrothermal method, followed by surface coating with sorbitan monostearate (SPAN-60), as well as characterization of FTIR, XRD, zeta potential, and antibacterial property analysis. The as-synthesized TM particles were incorporated with polyethersulfone (PES) substrate of thin-film composite forward osmosis (TFC-FO) membrane for alleviated structural resistance and biofouling tendency based on two different approaches, polymer blending into and polymer coating onto the inorganic deposited layer, respectively. To investigate the micromorphology of the prepared membranes, SEM was used to obtain the surface and cross-section images, and elemental mapping with EDS was applied to analyze the dispersion state of TM particles in PES matrix. In comparison to the control membrane, the water flux in FO mode of the nanocomposite membranes significantly increased with TM loading content, which is attributed to the optimization of microstructure and enhancement of inner osmotic pressure resulted from the ions released by TM. More importantly, the results showed TM endowed antibacterial activity in the membrane when TM deposited layer combined with the bottom surface of substrate. It is confirmed by our work that TM is a versatile additive for FO membrane with high performance.
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Microbial Cell Factories
·
2022
·Vol. 21
·期 1
·1-12
·
IF 6.352
Yang Fengyu,Xu Jiayu,Zhu Yichun,Wang Yi,Xu Meijuan,Rao Zhiming
Background Agmatine is a member of biogenic amines and is an important medicine which is widely used to regulate body balance and neuroprotective effects. At present, the industrial production of agmatine mainly depends on the chemical method, but it is often accompanied by problems including cumbersome processes, harsh reaction conditions, toxic substances production and heavy environmental pollution. Therefore, to tackle the above issues, arginine decarboxylase was overexpressed heterologously and rationally designed in Corynebacterium crenatum to produce agmatine from glucose by one-step fermentation.Results In this study, we report the development in the Generally Regarded as Safe (GRAS) l-arginine-overproducing C. crenatum for high-titer agmatine biosynthesis through overexpressing arginine decarboxylase based on metabolic engineering. Then, arginine decarboxylase was mutated to release feedback inhibition and improve catalytic activity. Subsequently, the specific enzyme activity and half-inhibitory concentration of I534D mutant were increased 35.7% and 48.1%, respectively. The agmatine production of the whole-cell bioconversion with AGM3 was increased by 19.3% than the AGM2. Finally, 45.26 g/L agmatine with the yield of 0.31 g/g glucose was achieved by one-step fermentation of the engineered C. crenatum with overexpression of speAI534D.Conclusion sThe engineered C. crenatum strain AGM3 in this work was proved as an efficient microbial cell factory for the industrial fermentative production of agmatine. Based on the insights from this work, further producing other valuable biochemicals derived from l-arginine by Corynebacterium crenatum is feasible.
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PubMed
高影响因子
Reaction Kinetics Mechanisms and Catalysis
·
2022
·Vol. 135
·期 2
·795-810
·
IF 1.843
Liu Panli,Shi Shengbin,Gao Lijing,Xiao Guomin
In the present work, three immobilized imidazolium acidic ionic liquid catalysts (ImmHSO 4 -IL, ImmCH 3 SO 3 -IL and ImmH 2 PO 4 -IL) were prepared with silica as carrier and modified with H 2 SO 4 , CH 3 SO 3 H and H 3 PO 4 , which were used as catalysts in the production of furfural from xylan and rice husk. The characteristics of the synthesized catalysts were analyzed by various characterization techniques, and the effects of reaction conditions, including reaction solvent, reaction time, reaction temperature and the amount of catalyst on the yield of furfural were studied in detail. The results showed that the highest yield of furfural reached 72% and 74.6% when using xylan and rice husk as substrates, respectively, which is one of the best furfural yield among literature reports. In addition, the ImmHSO 4 -IL catalyst has excellent selectivity for hemicellulose in rice husk, and the catalyst has high catalytic activity after four cycles. Therefore, the application of ImmHSO 4 -IL catalyst provides a new approach for conversion biomass to furfural. Graphical abstract
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JOURNAL OF NANOPARTICLE RESEARCH
·
2022
·Vol. 24
·期 3
·1-22
·
IF 2.533
Yang Chunyan,Xue Ziwei,Yin Hao,Lu Ke,Liu Wei
In this work, the photodegradation of methylene blue was investigated by constructing a novel photocatalysis reactor, which was filled with aqueous foam. Nanoscale TiO 2 particles were used as photocatalyst. In order to obtain stable foam phase, cetyl trimethyl ammonium bromide (CTAB) was used as the frother, and its suitable initial concentration in the feeding solution was 0.20 g/L. Under the suitable conditions of loading liquid volume 200 mL, initial concentration of TiO 2 nano-catalysts in the feeding solution 5.0 g/L, inner diameter of foam column 18 mm, aperture diameter of gas distributor 125 μm, and circulating velocity of bulk solution 500 mL/h, the maximum degradation percentage of methylene blue was 97.6 ± 1.2%. Atomic force microscopy (AFM) analysis suggested that the entrainment effect of rising bubbles and the circulation flow of bulk solution inside the aqueous foam did not cause the conspicuous aggregation of TiO 2 nano-catalysts under the suitable conditions, but their surface roughness decreased. Meanwhile, foam entrainment had not a significant impact on the polydispersity of TiO 2 nano-catalysts. In contrast to the photodegradation of methylene blue in aqueous solution, the photocatalysis process using aqueous foam is the intensity of light received by TiO 2 nano-catalyst increases, and irradiation period is less. This work is expected to provide new insight into the rational design of photocatalysis reactor, to facilitate the harmless treatment of dyestuff wastewater. Graphical abstract
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JOURNAL OF FLUORESCENCE
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2022
·Vol. 32
·期 3
·983-992
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IF 2.525
Chen Yuliang,Lai Kaijie,Cai Jinmi,Li Yicheng,Wang Haibo
Chirality plays a pivotal role in drugs, agrochemicals and food additives et al. The enantiomers of a chiral molecule often show huge difference in bioactivity, metabolism, and toxicity et al. thereby, the recognition of chiral molecules shows an increasingly important priority. In this paper, a novel method for chiral fluorescence recognition based on anthracene fluorescent dyes (AD) ⊂ water-soluble pillar[5] arene containing phosphonic acid group (PWP[5]) is developed. The AD as guest molecule can complex with PWP [5] to form 1:1 AD ⊂ PWP[5] assembly, and this assembly can be further used as a fluorescent probe to identify D/L-phenylalanine and D/L-phenylalaninol by fluorescent titration. The fluorescence intensity of the assembly was significantly reduced for D-phenylalanine and D-phenylalaninol, while L-phenylalanine or L-phenylalaninol was added to AD ⊂ PWP[5] assembly, the fluorescence intensity of the assembly almost unchanged. Hence, the chiral recognition based on assembly between the achiral fused ring fluorescent dye and achiral PWP[5] was developed.
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高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
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2022
·Vol. 33
·期 10
·7543-7558
·
IF 2.779
Duan Mengtian,Wu Daoxin,Wu Jialun,Tong Haixia
A precipitation process was used to produce Ag 3 PO 4 with an irregular small polyhedral structure and an average size of 200–300 nm. Furthermore, using a simple dissolution precipitation technique, polyhedral Ag 3 PO 4 was successfully deposited on the surface of ZnWO 4 . XRD, SEM, TEM, XPS, UV–Vis DRS, and FT-IR spectroscopy were employed to analyze ZnWO 4 /Ag 3 PO 4 composites. The photocatalytic oxidation ability of composites was assessed using Rhodamine B dye degradation model. The results revealed that ZnWO 4 /Ag 3 PO 4 composite material displayed improved visible-light photocatalytic activity, with 7% ZnWO 4 /Ag 3 PO 4 exhibiting the maximum photocatalytic activity. The degradation rate of RhB was 94.0% after 120 min of visible-light irradiation. Nyquist plot indicates that 7% ZnWO 4 /Ag 3 PO 4 composites show the smallest diameter, suggesting a more effective separation of photogenerated electron–hole pairs and faster interface charge transfer. The photocatalytic activity of ZnWO 4 /Ag 3 PO 4 composites does not deteriorate considerably after four cycles, indicating their high stability. The active species capture tests show that h + and •OH are possible reactive species in the degradation reaction. Finally, the p-n heterojunction mechanism is proved by the discussion of the band structure. This study demonstrates that ZnWO 4 /Ag 3 PO 4 photocatalytic composites can be utilized to degrade contaminants.
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EUROPEAN FOOD RESEARCH AND TECHNOLOGY
·
2022
·Vol. 248
·期 5
·1299-1309
·
IF 3.498
Feng Zhihui,Li Ming,Li Yifan,Yin Junfeng,Wan Xiaochun,Yang Xiaogen
White teas are produced in the simple process of withering and drying the tender leaves of the plant Camellia sinensis. Tea aroma created in this way exhibits a unique profile. Studies were carried out on the molecular contributors to the aroma character of the four well-known traditional white teas: Baihaoyingzhen (BHYZ), Baimudan (BMD), Gongmei (GM), and Shoumei (SM). Volatiles of the tea infusions were enriched by solvent partitioning followed by solid-phase extraction (SPE). The highly volatile compounds were captured by headspace solid-phase microextraction (HS SPME). Gas chromatography–olfactometry (GC-O) experiments discovered 37 odor-active components. Quantitation of aroma compounds was achieved using the method of standard addition (SAM). Calculation of odor activity value (OAV) and aroma reconstitution experiments revealed that the aroma profiles of the four white teas were attributed by 15 compounds, although a total of 179 volatile components were found in the extracts. BHYZ had distinct floral, fruity, and sweet characters, while BMD, GM, and SM had stronger woody and fermented notes. The major aroma contributors to the floral and sweet characters were geraniol and linalool for BHYZ and BMD; 2-phenylethanol and phenylacetaldehyde for GM and SM. The compounds produced from amino acid reactions during tea manufacturing, e.g. dimethyl sulfide, 3-methylbutanal, phenylacetaldehyde, etc., formed the basis of fruity and refreshing attributes. Degradation products of glycosides and carotenoids, such as geraniol, linalool, and ionones, contributed to the essential floral and sweet characters of the white teas.
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JOURNAL OF NANOBIOTECHNOLOGY
·
2022
·Vol. 20
·期 1
·1-12
·
IF 9.429
Hong Liping,Pan Mingfei,Yang Xiao,Xie Xiaoqian,Liu Kaixin,Yang Jingying,Wang Shan,Wang Shuo
In this study, a thermo-sensitive molecularly imprinted fluorescence sensor was developed for the specific detection of β-Lactoglobulin (β-LG) allergen in milk products. The metal–organic frameworks (MIL-100) with a high specific surface area was coated on the surface of upconversion micro-particles (UCMPs). As the core, an imprinted polymer layer allowing for swelling and shrinking with response to temperature was prepared, which exhibited high adsorption and mass transfer capabilities for β-LG allergen. The fluorescence intensity of UCMPs@MIL-100@MIP decreased linearly with the concentration of β-LG in the range of 0.1–0.8 mg mL−1, and the limit of detection was 0.043 mg mL−1. The imprinting factor reached 3.415, which indicated that excellent specificity of the UCMPs@MIL-100@MIP for β-LG allergen. In the analysis of β-LG allergen in actual milk samples, the proposed UCMPs@MIL-100@MIP fluorescence sensor produced reliable and accurate results (recovery: 86.0–98.4%, RSD: 2.8–6.8%), closely related to the results of standard HPLC method (correlation coefficient: 0.9949), indicating that its feasibility in the detection of β-LG allergen.Graphical Abstract
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高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2022
·Vol. 57
·期 5
·3348-3359
·
IF 4.682
Zhang Liren,Jiang Yingqiu,Zhou Lingyue,Jiang Zhihong,Li Lu,Che Wenbo,Yu Youming
Abstract Transparent wood (TW) is a promising optical material, which provides a potential choice for windows applications. As a polymer composite material, the mechanical, thermal stability, and flame retardant of TW are crucial properties in practical applications. In this study, the delaminated Ti 3 C 2 T x (MXene) were dispersed into polyvinyl alcohol (PVA) and then infiltrated into delignified wood to prepare MXene-reinforced transparent wood (TW-MXene). The MXene addition leads to an interlocking mechanism between MXene fillers with a polymer matrix (e.g., PVA, cellulose scaffold), thereby improving the tensile strength of TW. Besides, the dynamic mechanical analysis also proved that the tensile strength of TW-MXene is significantly higher than pure transparent wood with changing the temperature at −50 to 150 °C. The TW added with 1 wt% MXene maintained a lower thermal conductivity of 0.31 W m −1 K −1 , and it showed better UV resistance than TW. Besides, the thermal decomposition rate of TW-MXene composite slows down, and its weight loss rate decreases with the addition of MXene. Furthermore, the presence of 1 wt% MXene endowed TW with 9.3 and 22.0% reductions for PHRR and THR, respectively. This strategy provides an insight into the development of high-performance transparent wood composites with the potential to be used in building fields. Graphical abstract
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危险品化学品经营许可证（带存储）