Particuology
·
2020
·
IF 2.787
Zhou Lan,Yangcheng Lu
In this work, we used the inert substances silicone oil and n -hexane to modulate the solvent environment, and in so doing tailor the preparation of magnesium ethoxide (Mg(OEt) 2 ) particles. We found the following: (1) nonpolar n -hexane mainly modulates the polarity of the solvent to control the precipitation rate and size of the Mg(OEt) 2 seeds, thereby triggering accelerated nucleation to form small primary particles; and (2) silicone oil (relatively high polarity and viscosity) facilitates the growth and agglomeration stage, to improve inter-particle dispersion and obtain relatively uniform Mg(OEt) 2 particles. We summarized these findings in a common mechanism for preparing Mg(OEt) 2 particles with uniform morphology, small size, and high bulk density as per the synergistic effect of n -hexane and silicone oil. The ratios of silicone oil and n -hexane are flexible, and afford various regular and well-dispersed Mg(OEt) 2 particles that are 5–30 μm in size and 0.2–0.7 g/cm 3 in bulk density. The nanoparticles thus have the potential to serve in diverse applications such as catalysis.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
FLUID PHASE EQUILIBRIA
·
2017
·
IF 2.473
Kai Kang,Xiaopo Wang
The experimental measurements for liquid densities of n -decane and p -xylene binary mixtures were performed over the entire composition with a high-pressure vibrating-tube densimeter. The temperature ranges for the present measurement were from 293.15 K to 363.15 K and the pressures were reached to 60 MPa. The experimental uncertainty is estimated to be 0.001 with 0.95 confidence level. Experimental density values were fitted by the modified Tammann–Tait equation. The PC-SAFT equation of state and Cibulka's equation was used to predict the densities of n -decane and p -xylene and its mixtures. In addition, derived volumetric properties, such as the excess molar volumes , the isothermal compressibility , and isobaric thermal expansivity, were calculated from the experimental density data. The effects of pressure and temperature on the derived properties were also discussed.
研究领域:
化学工程
·
热力学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHROMATOGRAPHY A
·
2018
·
IF 3.716
Fang Cheng,Mingyang Li,Wei He,Bingbing Sun,Jinyan Qin,Jingping Qu
This article reported a new strategy for resin activation with divinyl sulfone using catalytic oxa-Michael addition in a controllable manner. By screening a variety of organocatalysts, PPh 3 and DMAP stand out with high catalytic efficiency in aprotic solutions. X-ray photoelectron spectroscopy (XPS) analysis indicates high reaction efficiency and less side reactions than traditional aqueous reactions, resulting in high activation density. A maximum activation density of 157.5 ± 1.2 μmol/g resin was achieved in 12 h using PPh 3 as catalyst, which is 1.5 times higher than the traditional aqueous reactions. Followed by conjugation with a chromatographic ligand, i.e. , 4-mercaptoethyl pyridine (MEP), the resin is capable of antibody purification. Using IgG and BSA as model proteins, adsorption isotherms and dynamic binding behavior of the resin samples were investigated. A higher affinity and dynamic binding capacity of IgG was observed on resins with higher ligand density. Finally, the resin samples were applied to the purification of a therapeutic monoclonal antibody from cell culture supernatant. The recovery of the resin samples with high ligand density are 70% higher than those of the commercial resin (MEP HyperCel). Moreover, our method achieves a controllable chromatographic ligand density by varying reaction times, which is useful to clarify the density-affinity relationship and improve process-scale antibody purification.
研究领域:
生物化学
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材料科学
·
生物工程
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产品关联
DOI
PubMed
高影响因子
FLUID PHASE EQUILIBRIA
·
2024
·
IF 2.8
Tao Jia,Weixue Jiang,Jia Yu
The compressed liquid densities of n -pentane(1) + n -dodecane(2) binary mixtures were measured using a high pressure vibrating-tube densimeter at temperatures from 283 K to 363 K, pressures up to 100 MPa, and five different compositions ( x 1 = 0.3778, 0.6230, 0.7968, 0.9051, and 1). The densities of binary mixtures were correlated using the modified Tait equation, and the absolute average deviations of the experimental and calculated values were 0.010 %, 0.019 %, 0.016 %, 0.025 %, and 0.017 %, respectively. In addition, the isothermal compressibility and the isobaric thermal expansivity were calculated from the obtained densities.
研究领域:
物理化学
·
热力学
✓ 已验证
产品关联
DOI
高影响因子
FLUID PHASE EQUILIBRIA
·
2017
·
IF 2.473
Tao Jia,Shengshan Bi,Jiangtao Wu
Compressed liquid densities of n -decane + n -dodecane binary mixtures were measured with a vibrating-tube densimeter at temperatures from (283–363) K and pressures from (0.1–100) MPa over the whole range of composition . The binary mixtures n -decane (1) + n -dodecane (2) were prepared at mole fractions of ( x 1 = 0, 0.2297, 0.4436, 0.6433 0.7841, and 1.0), respectively. The experimental densities of binary mixtures were successfully correlated with the Tait-type equation, and the absolute average percentage deviations of the experimental and calculated values were 0.048%, 0.055%, 0.059%, 0.058%, 0.068%, and 0.052%, respectively. In addition, the excess molar volume was calculated for whole range of temperature, pressure and composition.
研究领域:
物理化学
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热力学
✓ 已验证
产品关联
DOI
高影响因子
Applied Sciences-Basel
·
2024
·Vol. 14
·期 20
·9232
·
IF 2.5
Tao Jia,Jinpeng Yang,Jia Yu
Understanding the density of CO2+n-decane is crucial for designing and operating CO2capture, transport, and storage. The safety and effectiveness of CO2burial is directly affected by the density of CO2+n-decane mixtures. The liquid densities of CO2(1) +n-decane(2) mixtures with mole fractions of CO2x1= 0, 0.2032, 0.4434, 0.7589, and 0.8947 were measured using a vibrating tube densimeter. The combined expanded uncertainties of density with a level of confidence of 0.95 are estimated to be 0.6 kg·m−3. A total of 221 compressed liquid densities of CO2(1) +n-decane(2) mixtures along the five isotherms betweenT= (283 and 363) K with pressures up to 100 MPa were presented. The densities of mixtures were correlated by the modified Tait equation, resulting in absolute average deviations between the experimental and calculated values of 0.028%, 0.013%, 0.017%, 0.044%, and 0.042%. In addition, the isothermal compressibility, isobaric thermal expansivity, and excess molar volume were derived from the modified Tait equation.
研究领域:
化学工程
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
ChemSusChem
·
2017
·Vol. 10
·期 5
·930-937
·
IF 7.226
Feng-Qiang Xiong,Lipeng Wan,Yue Li,Tiju Thomas,Francis J. DiSalvo,Minghui Yang
Graphical Improving photocatalysts : Sufficient donor density in LaTiO 2 N photocatalysts is essential to generate an efficient internal electric field for charge separation and for high oxidizing power of the holes. On the basis of this understanding, LaTiO 2 N photocatalysts were modified to give a quantum efficiency for water oxidation of 25 % at 450 nm, which is higher than that of conventional LaTiO 2 N. LaTiO 2 N photocatalysts were prepared by thermal ammonolysis of flux-synthesized La 2 Ti 2 O 7 and La 2 TiO 5 , and were investigated for water oxidation. Though LaTiO 2 N derived from La 2 TiO 5 appears defect-free by UV/Vis/near-IR and electron paramagnetic resonance (EPR) spectroscopy, its performance is much lower than that of conventional La 2 Ti 2 O 7 -derived LaTiO 2 N with defects. It is shown by Mott–Schottky analysis that La 2 TiO 5 -derived LaTiO 2 N has significantly lower donor density; this can result in insufficient built-in electric field for the separation of photogenerated electrons and holes. The lower donor density is also consistent with the smaller difference between the Fermi level and the valence-band maximum, which accounts for a lower oxidative power of the holes. In light of this discovery, the donor density was increased substantially by introducing anion vacancies through annealing in Ar. This resulted in improved performance. The CoO x -assisted La 2 TiO 5 -derived LaTiO 2 N annealed at 713 °C has a higher quantum efficiency (25 %) at 450 nm than high-performance conventional CoO x /LaTiO 2 N (21 %).
研究领域:
材料科学
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环境科学
✓ 已验证
DOI
高影响因子
JOURNAL OF CHROMATOGRAPHY A
·
2013
·
IF 4.612
Hui-Li Lu,Dong-Qiang Lin,Dong Gao,Shan-Jing Yao
Hydrophobic charge-induction chromatography (HCIC) is a novel technology for antibody purification. The ligand densities and pore properties of HCIC resins have significant effects on the separation behavior of protein, however, the understandings are quite limited. In the present work, new HCIC ligand, 2-mercapto-1-methylimidazole (MMI) was coupled to three agarose matrices with different pore sizes. A series of MMI resins with different ligand density and pore size was prepared by the control of ligand coupling. The adsorption isotherms and kinetics on the series of MMI resins were investigated with bovine serum immunoglobulin as the model IgG, and the effects of salt addition were studied. The Langmuir equation and pore diffusion model were used to fit the experimental data, and the influences of ligand density, pore size and salt addition on the saturated adsorption capacity, the dissociation constant and the effective diffusivity were discussed. It was found that the adsorption capacities and the effective pore diffusion coefficient increased with the increase of ligand density and pore size. The effects of salt addition on the adsorption behaviors were dependent on the ligand density. For low ligand density the IgG adsorption was salt-promoted, while the resins with high ligand density showed a salt-independent property. The results indicated that for a given protein the ligand density and pore size of HCIC resins should be optimized for improving the protein adsorption.
研究领域:
生物化学
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蛋白质纯化
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分离科学
✓ 已验证
DOI
PubMed
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2020
·
IF 3.573
Jing Yang,Yingdan Cui,Mingyang Chen,Yan Wang,Shijie Xu,Songgu Wu,Jingkang Wang,Junbo Gong
Spherulitic growth, categorized as central multidirectional growth and unidirectional growth via small-angle branching, has increasingly been explored as a method to improve the flowability and bulk density of needle-like crystals. However, the formation of two categories of spherulites in solutions is still unclear. In this work, the formation mechanism of two categories of spherulite was studied in a supercooled nitroguanidine (NQ) aqueous solution with a small amount of gelatin. It is proposed that spherulitic growth depends on the initial morphology of the crystallite, wherein the gelatin concentration, temperature, and initial supersaturation play a vital role. Gelatin can significantly inhibit NQ nucleation, promote branching, and modify the morphology of NQ subunits. At high initial supersaturation and low temperatures, the aspect ratio of the crystal precursor increases and branching is accelerated, so that the lateral faces provide more branching sites than the end faces to promote the unidirectional growth. In comparison, high temperatures promoting the multipoint branching should be mainly responsible for the formation of cauliflower-like spherulites. Furthermore, the bulk densities of the cauliflower-like and compact spherulites of NQ are about triple those of needle-like crystals and their evolutions were observed. Compared with the reported methods, the macromolecule-induced spherulitic growth of NQ without an organic solvent is a green method and will have a bright future for the design and fabrication of other organic spherulites.
研究领域:
晶体工程
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材料科学
·
物理化学
·
药物制剂
·
软物质物理
✓ 已验证
DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2024
·
IF 8
Yunyan Liang,Fangying Sun,Shaohua Qu,Xiaomeng Zhou,Li Shang
Nanozymes are emerging as an attractive alternative to natural enzymes for a wide range of biological applications, but the effect of surface ligands’ density on the catalytic activity of nanozymes remains largely unclear. Herein, taken gold nanoclusters (AuNCs) as a model nanozyme, glutathione-protected AuNCs (GSH-AuNCs) with three different ligand densities: low ( l -AuNCs), medium ( m -AuNCs), and high ( h -AuNCs) were synthesized and the role of ligand density on the catalytic activity of GSH-AuNCs was systematically investigated. It was disclosed that a relatively lower ligand density is favorable for the peroxidase-like catalytic activity due to weaker steric hindrance effects. Consequently, colorimetric detection of biothiols (e.g., cysteine) and acetylcholinesterase activity was successfully achieved based on the peroxidase property of ligand density-optimized AuNCs , which exhibit a detection limit of 0.08 μM and 0.005 mU/mL, respectively. Moreover, application of the present system for detection of acetylcholinesterase activity in human serum samples was successfully demonstrated. This study provides new avenues for designing robust nanozymes with enhanced catalytic performances for application in biocatalysis as well as biosensing.
研究领域:
纳米生物学
·
生物传感
·
酶学
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产品关联
DOI
高影响因子
JOURNAL OF SEPARATION SCIENCE
·
2016
·Vol. 39
·期 16
·3130-3136
·
IF 2.741
Tao Liu,Dong-Qiang Lin,Cun-Xiang Wang,Shan-Jing Yao
Hydrophobic charge-induction chromatography is a new technology for antibody purification. To improve antibody adsorption capacity of hydrophobic charge-induction resins, new poly(glycidyl methacrylate)-grafted hydrophobic charge-induction resins with 5-aminobenzimidazole as a functional ligand were prepared. Adsorption isotherms, kinetics, and dynamic binding behaviors of the poly(glycidyl methacrylate)-grafted resins prepared were investigated using human immunoglobulin G as a model protein, and the effects of ligand density were discussed. At the moderate ligand density of 330 μmol/g, the saturated adsorption capacity and equilibrium constant reached the maximum of 140 mg/g and 25 mL/mg, respectively, which were both much higher than that of non-grafted resin with same ligand. In addition, effective pore diffusivity and dynamic binding capacity of human immunoglobulin G onto the poly(glycidyl methacrylate)-grafted resins also reached the maximum at the moderate ligand density of 330 μmol/g. Dynamic binding capacity at 10% breakthrough was as high as 76.3 mg/g when the linear velocity was 300 cm/h. The results indicated that the suitable polymer grafting combined with the control of ligand density would be a powerful tool to improve protein adsorption of resins, and new poly(glycidyl methacrylate)-grafted hydrophobic charge-induction resins have a promising potential for antibody purification applications.
研究领域:
生物化学
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蛋白质工程
·
分离科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Materials Chemistry B
·
2023
·Vol. 11
·期 34
·8228-8240
·
IF 7
Weiwei Fei,Xiuli Wang,Jia Guo,Changchun Wang
The design of targeting agent-conjugated systems is attracting much attention in cell targeted delivery and cancer therapy. However, quantitative study of the ligand density and binding efficiency is still limited due to the technical matters and tedious work involved. In this article, benzoboroxole-modified core–shell magnetic nanoparticles (MSP-AOPB NPs) as a drug carrier model were fabricated and transferrin (Tf) was immobilized on the nanoparticle surface in a site-oriented manner (Tf-MSP-AOPB NPs). The preparation conditions were investigated in detail to optimize the Tf binding efficiency. A suitable reaction temperature, time or initial feeding amount could significantly increase the Tf binding amount. The maximum Tf binding amount on the MSP-AOPB NPs was 184 mg g−1, and the targeting ligand density on the surface could be well controlled by simply adjusting the reaction conditions. In vitro studies demonstrated the excellent Tf-mediated targeting ability and enhanced cellular uptake efficacy by varying the ligand density. The optimal ligand binding amount for achieving the highest cellular uptake efficiency was 94 mg Tf/g, which corresponds to a ligand binding density of about 0.05 Tf/nm2, and the binding efficiency of conjugation was higher than 90%. Moreover, Tf-MSP-AOPB NPs prepared by a site-oriented conjugation strategy showed the best cell targeting ability, and their cellular uptake amount was 25 and 127 times higher than that of physical adsorption and EDC/NHS coupling reaction in HepG2 cells, respectively. This study provides a facile site-oriented bioconjugation technique for different kinds of antibodies, and a suitable ligand density can be easily attained to enhance the cellular uptake efficacy, which shows great significance for targeted delivery and cancer therapy.
研究领域:
纳米技术
·
药学
·
生物医学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）