LIQUID CRYSTALS
·
2019
·
IF 3.078
Duo Wang,Yuan-Yuan Quan,Qing-Qing He,Ji-Wen Hu,Mei Tian,Ying-Gang Jia,Dan-Shu Yao
Two series of novel four-arm azobenzene liquid crystal molecules were designed and synthesized, and their mesophase properties, photo-induced transition were studied. Two series of mesogenic arms were screened with different length of flexible chain (the carbon number n of flexible chain is 4, 6, 8, 10) using methoxy and nitro as terminal substituents R. The four-arm azobenzene LCs were synthesized by introducing the mesogenic arms into cholic acid. FACAE-O-n, FACAE-N-n all belonged to photosensitive thermotropic enantiotropicnematic LCs. For methoxyl series, melting transitions (Tm), liquid crystal-isotropic transitions (Ti) and mesogenic ranges decreased with the increase of carbon numbers in flexible chain both on heating and cooling. The mesophase performance of FACAE-O-4 was the most excellent. For nitro series, Tm and Ti on heating and cooling decreased with the increase of carbon numbers. Nevertheless, mesogenic ranges increased with the increase of carbon numbers only on heating. The cooling mesogenic ranges showed a trend of rising firstly and then falling, reaching the maximum 103.1oC (n=8). Under ultraviolet irradiation, there was no red shift. The intensity of maximum absorption has changed with the increase of ultraviolet irradiation time. After photo-induced, Tm and Ti on heating and cooling of the four-arm LCs decreased, and the mesogenic ranges became shorter.
研究领域:
材料化学
·
液晶研究
·
有机合成
✓ 已验证
DOI
高影响因子
APPLIED CATALYSIS A-GENERAL
·
2020
·
IF 5.006
Feng Lin,Yulong Ma,Yonggang Sun,Xiuqin Men,Yingbo Zhu,Tingting Gao,Kanghe Zhao
Strategies for catalytic lignin depolymerization to yield ethylbenzene chemicals are green, sustainable and environmentally friendly methods. In this study, a series of Ni-CeO 2 /H-ZSM-5 catalysts were prepared via the precipitation method, which catalytically degraded the β-O-4 chemical bonding structure to yield ethylbenzene chemicals. The 2-(2-methoxy-phenoxy)-1-phenylethanol substance (β-O-4) was selected as a typical lignin model compound for the investigation of the intrinsic depolymerization mechanism and the catalytic performance. The results demonstrated that the introduced CeO 2 active phase can effectively promote the catalytic conversion of the β-O-4 chemical bonding structure to ethylbenzene chemicals. Physicochemical data demonstrate that the reaction pathways and hydrogenation selectivity were effectively regulated and controlled by the tuning of the dehydration and hydrogenolysis processes via the introduction of CeO 2 , which realized the selective adjustment of the redox properties and the surface valence states of active species in the catalytic process due to its excellent oxygen transfer performance.
研究领域:
催化化学
·
生物质转化
·
材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2021
·
IF 10.588
Junyin Pan,Lijia Zhou,Haihua Chen,Xiaohan Liu,Chenlu Hong,Du Chen,Bingjun Pan
The involved interaction information concerning adsorbate-adsorbate and adsorbate-adsorbent is indispensable for developing and optimizing adsorption treatment of dye wastewater. Single and bi-solute adsorption of methyl orange (MO), indigo carmine (IC), and methylene blue (MB) on polystyrene anion exchanger (PsAX), defunctionalized version of PsAX (DF-PsAX), and hyper-cross-linked polystyrene adsorbent (MN200) were investigated to obtain a mechanistic understanding. Under acidic condition, higher adsorption efficiencies of PsAX due to extra intermolecular interactions of MO between the protonated tertiary amine group and the sulfate groups were observed, while strong alkaline condition is favorable for the adsorption of IC and MB by PsAX. MN200 exhibited much larger adsorption capacity toward MB than that toward MO or IC, because the fused-rings structure of MB is more polarizable and can form stronger nonionic intermolecular attractions with the matrix structure of polystyrene adsorbents. Bi-solute adsorption reveals that MO has obvious competitive effect toward IC adsorption at low concentrations, but it is not the case for the adsorption at high concentrations, where IC molecules can form intermolecular H-bonding interactions to defend the competition. the thermodynamic parameters confirm the endothermic and spontaneous nature of MO adsorption by PsAX, and ≈ 48 KJ mol −1 of the enthalpy change (∆H) imply the adsorption is not just physical absorption . Additionally, water/ethanol mixture solution of NaCl can almost thoroughly regenerate the exhausted PsAX, whereas only aqueous solution without ethanol is invalid.
研究领域:
环境科学
·
化学工程
✓ 已验证
DOI
高影响因子
MATERIALS LETTERS
·
2021
·
IF 3.423
Chenguang Yang,Dale Xie,Sheng Wang
Herein, the palygorskite/polyaniline/ZnO (Pal/PANI/ZnO) nanocomposites were synthesized by using facile two-step solution method with palygorskite as a carrier. It was confirmed that the introduction of palygorskite can effectively prevent the free agglomeration of polyaniline shells and ZnO rods. Interestingly, the acquired ternary nanocomposites show excellent microwave absorption properties in multi frequency bands. Specifically, the optimized sample exhibits a minimum reflection loss (RL) value of −57.75 dB at 5.52 GHz in the C band, with an additional RL peak of −47.44 dB at 15.60 GHz at a thickness of merely 1.88 mm in the Ku band. Meanwhile, the effective absorption bandwidth (RL < - 10 dB) reaches 6.56 GHz in the range of 11.44–18.00 GHz at a thickness of 2.08 mm. Therefore, our results could contribute to the design of palygorskite based nanocomposites as the high-absorption and strong-bandwidth microwave absorbers.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
Surfaces and Interfaces
·
2022
·
IF 6.137
Kezhong Wu,Zejin Wang,Hui Zhao,Bei Ruan,FeiFei Nie,Rufen Chen,Mingxing Wu
The development of transition metal compounds (TMCs) and conductive polymers composite catalysts substitute for the traditional scarce Pt-based catalysts of counter electrodes (CEs) has been recognized as one of the distinguishing paths to enhance power conversion efficiency (PCE) and decrease manufacturing costs of dye-sensitized solar cells (DSSCs). At present, various thin film preparations have been developed and applied to prepare assortment CEs. Herein, both polyaniline (PANI) and CuWO 4 film were prepared, and further to fabricate layer-by-layer composite CEs of CuWO 4 /PANI, PANI/CuWO 4 , CuWO 4 /PANI/CuWO 4 , PANI/CuWO 4 /PANI, aiming to promote the charge transfer capability and thus improve catalytic activity. And then, PANI, CuWO 4 and four composite layered CEs obtained PCE values of 5.14, 5.64, 5.96, 6.21, 4.96 and 4.24% toward the regeneration of I 3 − /I − redox couples in the assembled DSSCs, respectively. Particularly, the fascinating performance of the bilayer PANI/CuWO 4 CEs inherits the excellent electrical conductivity and the abundant porous structure of PANI skeletons for effective electrolyte diffusion. Meanwhile, the CuWO 4 layer was coupled to the layers of PANI by thermal activation annealing treatment to furnish rich inner active sites for the regeneration of I 3 − /I − couples. Benefit from the synergistic effects of PANI and CuWO 4 , the as-prepared PANI/CuWO 4 CEs manifests the highest PCE of 6.21%, indicating an inspiring strategy by the layered assembly Pt-free CEs with the cost effective and high-performance as an alternative Pt-based catalyst for DSSC.
研究领域:
材料科学
·
能源科学
✓ 已验证
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2020
·
IF 9.038
Tianhong Nie,Xing Yang,Hanbo Chen,Karin Müller,Sabry M. Shaheen,Jörg Rinklebe,Hocheol Song,Song Xu,Fengchang Wu,Hailong Wang
In this study, the influence of the aging process of pig-(PB) and P. orientalis -(POB) derived biochars on the sorption capacity of the biochar-treated soils for cadmium (Cd) and zinc (Zn) with and without the co-existence of diethyl phthalate (DEP) was investigated. Additionally, the surface and internal characteristics of biochars were determined before and after their aging in soils. The PB-treated soil had a higher sorption capacity for Cd 2+ and Zn 2+ than the POB-treated soil. The sorption capacity of the biochar-treated soils for Cd 2+ and Zn 2+ increased with biochar application rates. After aging, the abundance of oxygen-containing functional groups on the biochar surface, and the pH and organic carbon content of the biochar-treated soils significantly increased, thereby improving the sorption capacity for Cd 2+ and Zn 2+ . The sorption capacities of biochar-treated soils for Cd 2+ and Zn 2+ followed the order of 1-month aging > 6-month aging > fresh. The co-existence of DEP enhanced the sorption capacity of the fresh biochar-treated soils for Cd 2+ and Zn 2+ , whereas this enhancing effect disappeared for the aged biochar treatments. Our findings provide insights into the interactions between mixed contaminants in biochar-amended soils and the long-term efficacy of biochar treatments on metal sorption to soils.
研究领域:
环境科学
·
土壤学
✓ 已验证
DOI
高影响因子
CATALYSIS SURVEYS FROM ASIA
·
2021
·Vol. 26
·期 1
·35-45
·
IF 3.106
Shan Shufeng,Tian Yiting,Chen Feifei,Wu Shikui,Zhou Rujin,Xie Ying,Li Ning,Zeng Xingye,Lin Cunhui,Yu Wei
NiMoS supported on ZSM-5 with different Si/Al ratio, crystallite size and pore structure was prepared by incipient impregnation method and applied in 1, 3, 5-trimethylbenzene (1, 3, 5-TMB) hydrodealkylation (HDAK). The physicochemical properties of samples were characterized by XRD, FTIR, SEM, N 2 adsorption–desorption, NH 3 -TPD, Py-FTIR, H 2 -TPR, HRTEM and TGA. It is demonstrated that for microporous NiMoS/ZSM-5, acid amount and crystallite size of HZSM-5 are key factors affecting HDAK performance. The larger acid amount and smaller crystallite size can promote the conversion of 1, 3, 5-TMB, especially the dealkylation reaction, resulting in higher BTX yield. Compared to NiMoZ-3, mesopores in micro-mesoporous NiMoAKZ-3 are beneficial to accessibility of 1, 3, 5-TMB to NiMoS and acid sites in close proximity, and the diffusion of reactant and product molecules inside pores, thus resulting in superior HDAK performance of NiMoAKZ-3. Moreover, the reaction network of 1, 3, 5-TMB HDAK was revealed according to product distribution. Graphic Abstract NiMoS supported on ZSM-5 was developed for heavy aromatic hydrodealkylation (HDAK). Acid amount and crystallite size of microporous ZSM-5 are key factors affecting 1,3,5-trimethylbenzene (1,3,5-TMB) HDAK. Mesopores inside ZSM-5 facilitate accessibility of 1,3,5-TMB to NiMoS and acid sites in close proximity and improve HDAK performance.
研究领域:
催化化学
·
材料科学
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF PHARMACEUTICS
·
2021
·
IF 5.875
Hongji Liu,Jinju Nie,H.C. Stephen Chan,Hailu Zhang,Liang Li,Hongqing Lin,Henry H.Y. Tong,Ande Ma,Zhengzheng Zhou
Herein, we reported a new bergenin : 4-aminobenzamide ( BGN-4AM ) cocrystal with significantly enhanced solubility and low hygroscopicity probed from two aspects such as phase solubility diagrams and theoretical calculations. Compared with anhydrous BGN , BGN-4AM solubilities in water and different buffer solutions (pH = 1.2, 4.5, 6.8) increase significantly. It is noted that BGN-4AM solubility in pH = 6.8 buffer solution presents 32.7 times higher than anhydrous BGN . Interestingly, BGN-4AM (0.31 ± 0.07%) showcases lower hygroscopicity than anhydrous BGN (9.31 ± 0.16%). The predicted and experimental solubilities agree with each other when considering solubility product ( K sp ) and solution binding constant ( K 11 ) in phase solubility diagrams, indicating the solution complexes formation occurs. Further crystal surface-water interactions and Bravais, Friedel, Donnay-Harker (BFDH) analyses based on Density Functional Theory with dispersion correction (DFT- d ) methods support the enhanced solubility. The water probe demonstrates an average interaction energy of −6.48 kcal/mol on the 002 plane of BGN-4AM , and only −5.47 kcal/mol on the 011 plane of BGN monohydrate. The lower lattice energy of BGN-4AM guarantees its lower hygroscopicity than BGN monohydrate. BGN-4AM with enhanced solubility and low hygroscopicity can be a potential candidate for further formulation development.
研究领域:
药剂学
·
理论化学
✓ 已验证
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2020
·
IF 9.038
Chenchen Wang,Panpan Huang,Chunsheng Qiu,Jing Li,Shuailong Hu,Liping Sun,Yaohui Bai,Fu Gao,Chaocan Li,Nannan Liu,Dong Wang,Shaopo Wang
This study was to investigate the occurrence, migration and health risk of phthalic acid esters (PAEs) in tap water , barreled water and bottled water in Tianjin, China. Six priority controlled PAEs were measured, among which the detection frequency of butyl benzyl phthalate (BBP), dibutyl phthalate (DBP) and di(2-ethylhexyl) phthalate (DEHP) was 100%, while the others were not detected. The concentration of DEHP was higher than BBP and DBP in all the samples. The initial ∑ 3 PAEs concentrations in tap water, barreled water and bottled water were 2.409 ± 0.391 μg/L, 1.495 ± 0.213 μg/L and 1.963 ± 0.160 μg/L, respectively. Boiling tap water could reduce the PAEs content to an extent, but they increased significantly in hot tap water contacting with disposable plastic cups. The migration of PAEs in barreled water and bottled water were positively correlated with storage time and temperature, which could be described by exponential models. The hazard indexes of PAEs in different types of drinking water were very low. However, the human carcinogenic risks of DEHP will reach the maximum acceptable risk level of 10 −6 when bottled water is stored for 8.8 days at 40 °C, 7.7 days at 50 °C, or 6.1 days at 60 °C.
研究领域:
环境科学
·
公共卫生
✓ 已验证
DOI
高影响因子
ANALYTICA CHIMICA ACTA
·
2021
·
IF 6.558
Qi Liu,Shushu Ding,Rui Gao,Guoyue Shi,Anwei Zhu
ATP-sensitive potassium (K ATP ) channels couple intracellular metabolism to the electrical activity by regulating K + flux across the plasma membrane, thus playing an important role in both normal and pathophysiology. To understand the mechanism of ATP regulating biological ion channels, developing an ATP-responsive artificial nanochannel is an appealing but challenging topic because K ATP channel is a heteromultimer of two subunits (potassium channel subunit (Kir6.x) and sulfonylurea receptor (SUR)) and exhibit dynamic functions with adjustability and reversibility. Inspired by the structure of K ATP channels, we designed a smart copolymer modified nanochannel that may address the challenge. In the tricomponent poly( N -isopropylacrylamide) (PNIPAAm, PNI)-based copolymer system, phenylthiourea was used to bind the phosphate units of nucleotides and phenylboronic acid was introduced to combine the pentose ring of the nucleoside unit. Besides, a –COOH group with electron-withdrawing property was added into the phenylthiourea units, which may promote the hydrogen-bond-donating ability of thiourea . Specially, the smart copolymer not only provided static binding sites for recognition but also translated the recognition of ATP into their dynamic conformational transitions by changing the hydrogen-bonding environments surrounding PNIPAAm chains, thus achieving the gating function of nanochannel, which resembled the integration and coordination of Kir6.x and SUR units in active K ATP . The ATP-regulated ion channel exhibited excellent stability and reversibility. This study is the first example showing how to learn from nature to assemble the ATP-responsive artificial nanochannel and demonstrate the possible mechanism of ATP gating.
研究领域:
生物化学
·
材料科学
·
分子生物学
✓ 已验证
DOI
高影响因子
POLYMER
·
2021
·
IF 4.43
Chong Gao,Hongbo Gu,Ai Du,Heng Zhou,Duo Pan,Nithesh Naik,Zhanhu Guo
Herein, we have reported that the polyaniline (PANI), as a polymeric catalyst, exhibits an outstanding efficiency for the curing of phthalonitrile resin as verified by differential scanning calorimetry (DSC) with a high enthalpy, in which the triazine structure is the dominating curing products as confirmed in the Fourier transform infrared (FTIR) spectra. Thermogravimetric analysis (TGA) and nanoindentation tests have been carried out to investigate the thermal and mechanical properties of the cured PANI/phthalonitrile resin. The results demonstrate that the PANI/phthalonitrile resin not only manifests a high char yield up to 24.7% at temperature of 850 °C in the air atmosphere, but also possesses an improved hardness that is 81.8% higher than that of regular small molecule of amine catalyst/phthalonitrile resin.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
LIQUID CRYSTALS
·
2014
·
IF 2.349
Kun Hu,Yiwei Xu,Pei Chen,Aiai Gao,Weisong Du,Xinbing Chen,Zhongwei An
Series of fluorinated compounds, 2-(3′,5′-difluoro-4′-alkoxybiphenyl-4-yl)-benzoxazole derivatives (nFBx), were prepared and characterised. Their phase transition behaviour was investigated by differential scanning calorimetry and polarising optical microscopy. In the case of carbon atoms in the alkoxy chain between 4 and 10, they exhibited enantiotropic mesophases with the mesophase ranges of 12–119°C and 23–152°C on heating and cooling for compounds bearing different substituents (H, CH3, Cl, and NO2). With the exception of nitro-substituted compounds, the nFBx series displayed intense photoluminescence emission at 380–385 nm in methylene chloride solution when they were excited at their absorption maxima. Compared to non-fluorinated analogues, fluorinated compounds nFBx (apart from nitro-substituted compounds) exhibited much lower melting points, but comparable or slightly narrower mesophase ranges during both heating and cooling, which were attributed to the disruption of the side-to-side intermolecular packing caused by the two lateral fluoro substituents.
研究领域:
材料科学
·
化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）