Reaction Kinetics Mechanisms and Catalysis
·
2022
·Vol. 135
·期 5
·2533-2550
·
IF 1.843
Chen Wei,Bao Zhichang,Zhou Zhiming
A series of non-precious bimetallic NiM x /SiO 2 (M = Zn or Co) catalysts with a fixed Ni loading of 5 wt% and different molar ratios of M/Ni (0.004–1.97) were prepared by glucose pyrolysis and applied to the selective hydrogenation of phenylacetylene. The properties of the catalysts were characterized by N 2 physisorption, CO chemisorption, ICP-OES, TGA, XRD, HRTEM, XPS, and DRIFTS. The activity and selectivity of the bimetallic catalysts could be tuned by varying the Zn/Ni and Co/Ni molar ratios, which were almost independent of the metal particle size (with a similar size of 4.1–5.5 nm), but predominantly determined by the geometric and/or electronic effects of the catalysts. Among all the catalysts studied, NiZn 0.05 /SiO 2 and NiCo 0.09 /SiO 2 presented higher selectivity to styrene (86.3% and 88.0%, respectively) at above 99% conversion of phenylacetylene. The high selectivity of the former was attributed to the geometric and electronic effects of the Ni–Zn alloy, while the latter was due to the geometric effect caused by the addition of Co. The activity and selectivity of NiCo 0.09 /SiO 2 were maintained during six consecutive cycles, indicating its good stability in the selective hydrogenation of phenylacetylene.
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高影响因子
CHEMICAL PAPERS
·
2021
·Vol. 76
·期 1
·123-135
·
IF 2.097
Shen Qiang,Xu Min-Hong,Wu Tao,Pan Guo-Xiang,Tang Pei-Song
Accumulation of tetracycline (TC) in soul and aqueous environments threatens the ecology balance and human health. In this work, Magnetic bentonite (MB) modified with two kinds of starch (corn starch and carboxymethyl starch) were synthesized for removal of TC. The composite materials were characterized by XRD, SEM, VSM and FTIR techniques. The adsorption capacities of TC for raw bentonite (RB), magnetic bentonite (MB), corn starch modified magnetic bentonite (ST-MB) and carboxymethyl starch modified magnetic bentonite (CMS-MB) were evaluated with batch adsorption equilibrium experiments. The modeling of isothermal adsorption and kinetic adsorption for four materials was done. The fitting results shows adsorption of CMS-MB composite follows the Langmuir model and pseudo-second model. The CMS-MB composite showed the best adsorption performance with Langmuir theoretical adsorption maximum of 169.7 mg/g. The adsorbent CMS-MB can be easily separated by magnetic force from solution with extremely low turbidity. The adsorption mechanism was also discussed.
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高影响因子
JOURNAL OF FLUORESCENCE
·
2024
·
IF 2.6
Guo Shanshan,Li Hua
Diabetes, particularly Type 2 Diabetes Mellitus (T 2 DM), is a chronic metabolic disorder with high and increasing global prevalence, characterized by insulin resistance and inadequate insulin secretion. Despite advancements in novel drug delivery systems, widespread and systematic treatment of advanced glycation end products (AGEs) remains challenging due to issues like drug toxicity, low water solubility, and uncontrolled release. Thus, developing nanoplatforms with controlled release capabilities has become a major research focus. Due to its excellent biocompatibility and drug delivery properties, chitosan has attracted considerable attention as a typical biopolymer. In this study, we designed and synthesized an intelligent fluorescence-pH sensitive nanopolymer material using chitosan. We loaded drug 1 and chromium phthalocyanine (CrPc) into folic acid-conjugated carboxymethyl chitosan (FA-CMCS) nanocarriers, forming FA-CMCS@1-CrPc. Comprehensive characterization of FA-CMCS@1-CrPc was conducted using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermal gravimetric analysis (TGA), and gas adsorption analysis (BET). The results indicate that the nanomaterial was successfully synthesized and exhibits excellent specific surface area, biocompatibility, and fluorescence response. Further research revealed that FA-CMCS@1-CrPc not only achieved controlled drug release but also could regulate drug release by adjusting pH. Additionally, due to its strong fluorescence performance, the nanomaterial demonstrated higher detection sensitivity, especially for monitoring the release of 5% trace drugs. An in vitro model of insulin-resistant cells was established to evaluate the effects of the drug delivery system on glucose degradation and AGE-RAGE regulation, providing a foundation for the development of new T 2 DM drugs. Graphical Abstract
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PubMed
高影响因子
Drug Delivery and Translational Research
·
2021
·Vol. 12
·期 3
·589-602
·
IF 4.617
Zhang Qihong,Feng Zongmiao,Ren Wei,Zhao Yunchun,Dushkin Alexandr V.,Su Weike
Hypertension is a common disease for human with high morbidity and mortality, and olmesartan medoxomil (OM) is widely used in the therapy of hypertension. However, poor water solubility and low bioavailability limit its widespread use. To improve the effect of OM, a ternary OM solid dispersion consisting of hydroxypropyl- β -cyclodextrin (HP- β- CD) and hydroxypropyl methylcellulose (HPMC) was prepared by mechanochemical method. The best preparation parameters were OM/HP- β -CD/HPMC-E5 with mass ratio of 1:2.6:1 and milling time of 4 h. Under the optimal preparation conditions, the solubility of the ternary solid dispersion could be increased by 12 times as compared with pure OM. Due to the addition of HPMC-E5, the solid dispersion had sustained release performance with prolonged release time of 12 h. Furthermore, in vivo study demonstrated that the prepared solid dispersion could afford significantly improved bioavailability of ~ 3-fold in comparison with pure drug. Hence, the prepared ternary solid dispersion of OM may be a promise delivery system for clinical application. Graphical abstract
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高影响因子
NPG Asia Materials
·
2022
·Vol. 14
·期 1
·1-11
·
IF 10.761
Jian Gang,Jiao Yong,Feng Liang,Meng Qingzhen,Yang Ning,Zhu Shangtao,Lü Minfeng,Wong Ching-Ping
Dielectric substances exhibit great potential for high-power capacitors due to their high stability and fast charge–discharge; however, a long-term challenge is to enhance energy density. Here, we propose a poly(vinylidene fluoride) (PVDF) composite utilizing BaTiO 3 nanoparticle@TiO 2 nanosheet (BT@TO ns) 2D nanohybrids as fillers, aiming at combining the interfacial strategy of using a core–shell filler and the electron scattering of a 2D filler to improve the energy density. With 4 wt% filler, the composite possesses the largest breakdown strength ( E b ) of 561.2 MV m −1 , which is significantly enhanced from the 407.6 MV m −1 of PVDF, and permittivity of 12.6 at 1 kHz, which is a 23% increase from that of PVDF. A superhigh energy density of 21.3 J cm −3 with an efficiency of 61% is obtained at 550 MV m −1 . The 2D BT@TO ns-filled composite exhibits a higher energy density than composites filled with core–shell 1D BT@TO nws or non-core–shell 0D BT, 1D TO, or 2D TO particles. The E b and energy density improvements are attributed to the buffer layer-based interface engineering and enhanced area scattering of electrons caused by the 2D hybrids, an effect similar to that of a ping-pong paddle to scatter electric field-induced charge migrations in composites. Thus, an effective hybrid strategy is presented for achieving high-performance polymer composites that can be used in energy storage devices.
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高影响因子
Sugar Tech
·
2020
·Vol. 22
·期 6
·1138-1147
·
IF 1.198
Li Xin,Deng Ligao,Li Yi,Li Kai
Polylactic acid (PLA) is biodegradable and biocompatible, but some of its functional properties limit its commercial application. To improve the properties of PLA without destroying other useful characteristics, a composite film consisting of microcrystalline cellulose (MCC) and PLA was prepared. In this research, MCC was obtained from bagasse bleached pulp by hydrochloric acid hydrolysis. After being modified by a silane coupling agent (KH550), the MCC was used as reinforcement in the PLA matrix. The degradation performance of the composite film was explored using degradation experiments in which the film was buried in soil. According to the single-factor experiments, the best composite formulation was 3% KH550, 20% KH550-MCC and 15% acetyl tributyl citrate. The results showed that the interfacial compatibility of the MCC/PLA composite films was improved after MCC was modified with KH550. This research showed that the addition of MCC can enhance the degradation rate of MCC/PLA composite films.
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高影响因子
CHEMICAL PAPERS
·
2020
·Vol. 75
·期 3
·1279-1289
·
IF 1.68
Yu Li,Chen Nanjun,Chen Wenjiao,Liu Cailin,Ren Xianyan,Yang Haijun,Lin Shudong
In Liquid Phase Catalytic Exchange (LPCE), the strength and hydrophobicity of styrene-divinylbenzene copolymer (SDB) carrier are key limitation factors for practical applications. In this paper, a surface-modified nano-SiO 2 (KH570-SiO 2 ) was used to improve the strength and hydrophobicity of SDB. Then, copolymerization of KH570SiO 2 with St, DVB to produce KH570-SiO 2 /SDB, Divinyl benzene (DVB), styrene (St) glycidyl methacrylate (GMA) to produce KH570-SiO 2 /GMA/SDB. The two kinds of new carriers were characterized by scanning electron microscope, static water contact angle, N 2 adsorption–desorption, transform infrared spectrometry and thermogravimetric analysis. Compared with SDB, both KH570-SiO 2 /SDB and KH570SiO 2 /GMA/SDB show better performances, such as a higher hydrophobicity(147° and 145°, respective), a higher strength(107.11 N and 115.37 N, respectively), a better thermal stability(373.8 and 435.67 ℃, respectively), and a larger specific surface area(487.253 and 463.673 m 2 /g, respective). The Nickel ion was uesd as the model ion of Platinum ion. And then the Ni 2+ adsorption performances of KH570-SiO 2 /SDB and KH570-SiO 2 /GMA/SDB were studied. Experiments show that KH570-SiO 2 /GMA/SDB has a much higher adsorption rate and a bigger adsorption amount. Refinement indicates that the adsorption behaviors of SDB, KH570-SiO 2 /SDB and KH570-SiO 2 /GMA/SDB with Ni 2+ are according to pseudo-first-order kinetic. The adsorption of SDB and KH570-SiO 2 /GMA/SDB obeyed Freundlich isotherm, while the adsorption of KH570-SiO 2 /SDB obeyed Langmuir isotherm.
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高影响因子
Nature Communications
·
2020
·Vol. 11
·期 1
·1-11
·
IF 12.121
Liang Chao,Zhang Xun,Xia Shuixin,Wang Zeyu,Wu Jiayi,Yuan Biao,Luo Xin,Liu Weiyan,Liu Wei,Yu Yi
Alkali metals are widely studied in various fields such as medicine and battery. However, limited by the chemical reactivity and electron/ion beam sensitivity, the intrinsic atomic structure of alkali metals and its fundamental properties are difficult to be revealed. Here, a simple and versatile method is proposed to form the alkali metals in situ inside the transmission electron microscope. Taking alkali salts as the starting materials and electron beam as the trigger, alkali metals can be obtained directly. With this method, atomic resolution imaging of lithium and sodium metal is achieved at room temperature, and the growth of alkali metals is visualized at atomic-scale with millisecond temporal resolution. Furthermore, our observations unravel the ambiguities in lithium metal growth on garnet-type solid electrolytes for lithium-metal batteries. Finally, our method enables a direct study of physical contact property of lithium metal as well as its surface passivation oxide layer, which may contribute to better understanding of lithium dendrite and solid electrolyte interphase issues in lithium ion batteries.
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高影响因子
Communications Chemistry
·
2021
·Vol. 4
·期 1
·1-12
·
IF 6.581
Ge Xuan,Hu Qiaodan,Yang Fan,Xu Jun,Han Yanfeng,Lai Pingsheng,Qin Jingyu,Li Jianguo
The crystallization processes of titanates are central to the fabrication of optical and electrical crystals and glasses, but their rich polymorphism is not fully understood. Here, we show when and how polymorphic selection occurs during the crystallization of barium titanate (BaTiO 3 , BT) using in situ high energy synchrotron X-ray diffraction and ab initio molecular dynamic simulation. An anomalous structure transition is found in molten BT during cooling across the cubic-hexagonal transition temperature, which enables nucleation selection of BT by manipulating the undercooling: a cubic phase is preferred if nucleation is triggered at large undercooling, whereas a hexagonal phase is promoted at small undercooling. We further reveal that the nucleation selection between the cubic and the hexagonal phase is regulated by the intrinsic structure property of the melt, in particular, the degree of polymerization between Ti-O polyhedra. These findings provide an innovative perspective to link the polymorphic crystallization to the non-isomorphic structure transition of the melt beyond the conventional cognition of structural heredity.
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高影响因子
WOOD SCIENCE AND TECHNOLOGY
·
2022
·Vol. 56
·期 6
·1761-1781
·
IF 2.898
Xu Yang,Xu Yongjian,Chen Hao,Xiong Jianhua,Gao Minlan
Cellulose nanocrystals (CNCs) are difficult to redisperse after drying unless chemical modification or adding additives has been adopted. The production, transportation and application of CNCs in large-scale are restricted owing to the poor redispersion ability. To this end, CNCs with redispersion ability were successfully extracted by nickel chloride hydrate enhanced deep eutectic solvent (Ni-DES), which is composed of choline chloride and oxalic acid dihydrate, from microcrystalline cellulose. C 2 O 4 2− and Ni 2+ are integrated with each other owing to the incorporation of deionized water at the end of Ni-DES extraction. As a result, the particles of NiC 2 O 4 ·2H 2 O are found on the surface of obtained CNCs. The NiC 2 O 4 ·2H 2 O particles, which can be removed by acid-washing, are beneficial to the redispersion of dried CNCs because they can prevent the formation of hydrogen bond during CNCs drying, as demonstrated by the results of SEM, XRD and size distribution. In addition, the results of FTIR, XRD, SEM, and TEM reveal that the crystalline structure, chemical structure, and microstructure morphology of CNCs are scarcely varied during the drying and redispersion. Nevertheless, the slight flocculation of CNCs is unavoidable during the drying and redispersion, which is responsible for the insignificant depravation in the size and size distribution of redispersed CNCs. Fortunately, the satisfied redispersion ability of CNCs is obtained by Ni-DES extraction. It is obvious that using Ni-DES for the extraction of redispersible CNCs can provide a potential strategy for improving the economic and environmental viability of CNC industrial production and application.
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高影响因子
IONICS
·
2019
·Vol. 26
·期 1
·1-11
·
IF 2.289
Xu Ruhui,Zhang Keyu,Wei Runhong,Yuan Meimei,Zhang Yenan,Liang Feng,Yao Yaochun
A facile, low cost, and low equipment-requirement preparation route of Si/C composite was developed. Naturally porous flour was carbonized through a conformal carbonization process and a further activation process in vacuum, obtaining flour-derived porous carbon (FPC) with ample pores. FPC was used to load nano-silicon through electrostatic adsorption method. Si-FPC was coated by sucrose-derived carbon (SC) shell by aqueous evaporation method to obtain Si-FPC-SC. Benefitting from FPC’s good dispersion for silicon, 40%-Si-FPC delivers a reversible capacity of 1562 mAh g −1 , equivalent to 83% of pure nano-silicon’s reversible capacity, an outstanding rate performance of 761 mAh g −1 at 1 A g −1 current density. The final 30%-Si-FPC-SC exhibits a reversible capacity of 937 mAh g −1 at 0.1 A g −1 , a cyclic retention of 82.3% after 100 cycles. Furthermore, the synthetic method of Si/C composites offers a universal idea for the research of high-capacity anode materials for lithium-ion batteries.
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高影响因子
RESEARCH ON CHEMICAL INTERMEDIATES
·
2019
·Vol. 46
·期 3
·1715-1734
·
IF 2.064
Li Liuxing,Liu Huijun,Li Wei,Liu Kai,Tang Ting,Liu Juan,Jiang Wenkang
Cyclodextrin-based nanosponges (CDNS) are a novel kind of polymers belonged to cross-linked derivatives of cyclodextrins, and they are safe, biodegradable materials with appreciable toxicity to the environment. In this work, CDNS were fabricated in one-step solvothermal method by β-cyclodextrin (β-CD) and diphenyl carbonate (DPC), for the removal of dyestuffs from wastewater using two of the familiar dyes as the model contaminant. It was systematically investigated by the influence of the amount of adsorbent, the molar ratio of β-CD and DPC, pH, time, and initial concentration. Experimental results showed the maximum adsorption capacities of Basic red 46 and Rhodamine B were 101.43 mg/g and 52.33 mg/g, the adsorption behavior of two contaminants followed pseudo-second-order model and the Langmuir monolayer adsorption models. The differences in adsorption capacities on two model contaminants might due to the influence of dye structure. In conclusion, cyclodextrin-based nanosponges are a promising kind of environment-friendly materials in water treatment.
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高影响因子
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