MINERALS ENGINEERING
·
2020
·
IF 3.795
Xiaoxiao Qiao,An Liu,Zhihong Li,Jinchuan Fan,Canjin Luo,Panpan Fan,Yizhou Liu,Minqiang Fan
A novel combined reagent dodecylamine (DDA)–2-octanol–kerosene was employed to overcome the problems associated with DDA, that is, DDA has a high freezing point and needs to be acidified with hydrochloric or acetic acid when it is used for flotation. The analysis of the basic physical properties of the agent showed that DDA–2-octanol–kerosene had significant advantages in freezing point and dispersibility and its freezing point can be reduced to below 0 °C. From the flotation results of magnetite, it can be seen that DDA–2-octanol–kerosene has a better selectivity. Response Surface Methodology based on a three-level, three-variable Box–Behnken design (BBD) was employed to define the quadratic relationship between the recovery of quartz and the composition of the mixed agent. The results indicated that the recovery of quartz increased with the increase of DDA or 2-octanol dosage, however, kerosene had a marginal positive effect on the recovery of quartz when the amount of kerosene was less than 0.76 times that of DDA and otherwise a negative effect. This study provides a new method and technical support for its industrial application for the reverse flotation of iron ore for the combination of agents in the field of iron ore flotation. And allows for a deeper macro-level understanding of the interaction between the DDA–2-octanol–kerosene ternary mixed agents.
✓ 已验证
产品关联
DOI
高影响因子
International Journal of Nanomedicine
·
2020
·
IF 5.115
Hao Zhou,Zhiwen Qi,Xingying Xue,Chengzhang Wang
Purpose The aim of this study was to develop a means of improving the bioavailability and anticancer activity of urushiol by developing an urushiol-loaded novel tumor-targeted micelle delivery system based on amphiphilic block copolymer poly(ethylene glycol)-b-poly-(β-amino ester) (mPEG-PBAE).Materials and Methods We synthesized four different mPEG-PBAE copolymers using mPEG-NH2 with different molecular weights or hydrophobicity levels. Of these, we selected the mPEG5000-PBAE-C12 polymer and used it to develop an optimized means of preparing urushiol-loaded micelles. Response surface methodology was used to optimize this formulation process. The micellar properties, including particle size, pH sensitivity, drug release dynamics, and critical micelle concentrations, were characterized. We further used the MCF-7 human breast cancer cell line to explore the cytotoxicity of these micelles in vitro and assessed their pharmacokinetics, tissue distribution, and antitumor activity in vivo.Results The resulting micelles had a mean particle size of 160.1 nm, a DL value of 23.45%, and an EE value of 80.68%. These micelles were found to release their contents in a pH-sensitive manner in vitro, with drug release being significantly accelerated at pH 5.0 (98.74% in 72 h) without any associated burst release. We found that urushiol-loaded micelles were significantly better at inducing MCF-7 cell cytotoxicity compared with free urushiol, with an IC50 of 1.21 mg/L. When these micelles were administered to tumor model animals in vivo, pharmacokinetic analysis revealed that the total AUC and MRT of these micelles were 2.28- and 2.53-fold higher than that of free urushiol, respectively. Tissue distribution analyses further revealed these micelles to mediate significantly enhanced tumor urushiol accumulation.Conclusion The pH-responsive urushiol-loaded micelles described in this study may be ideally suited for clinical use for the treatment of breast cancer.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Physical Chemistry C
·
2020
·
IF 4.189
Meng Liu,Ying-Ying Wang,Yi Liu,Feng-Lei Jiang
Ligand exchange is a critical step for tuning the properties of quantum dots (QDs), as well as functionalization for wide applications. Previous studies have categorized X-, L-, and Z-types of ligands and classified the ligand exchange process accordingly. Many works have investigated the influences of ligand exchange on the optical properties of QDs. To date, however, the thermodynamic implications of ligand exchange are not well understood, and the mechanisms of distinct effects of the ligands of the same type are unclear. To address these issues, ligand exchange reactions of the oleate-capped CdSe QDs with alkylamines of different carbon chain length, namely, n-butylamine (C4Am), n-octylamine (C8Am), n-dodecylamine (C12Am), were investigated using 1H nuclear magnetic resonance (1H NMR) spectroscopy, fluorescence spectroscopy, X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), etc. 1H NMR studies showed that the equilibrium constants (Keq) for the desorption of the Z-type ligand (cadmium oleate) from the surface of CdSe QDs, as promoted by the L-type ligands (alkylamines), were in the order of C4Am > C8Am > C12Am, presumably highlighting the small steric barrier of ligands with short carbon chain. In addition, the ligand exchange was studied by fluorescence titration at varied temperatures from a perspective of ligand adsorption following the desorption of cadmium oleate. The binding constants were of magnitude 103 M–1. A “two-step ligand exchange” (TSLE) model was developed to describe the ligand desorption–adsorption process with thermodynamic perspectives. The increased length of the carbon chain brought not only increasing steric barrier but also increasing van der Waals interactions, exhibiting a double-edged sword effect in ligand exchange. The ligand exchange with C8Am contributed the most negative value of ΔH and ΔS since the van der Waals interactions between C8Am and neighboring ligands were stronger than that for C4Am, whereas its steric barrier was weaker than that of C12Am. These demonstrated the importance of ligand–ligand interactions, relatively less documented in the previous studies, besides the predominance of the nanocrystal–ligand interactions. UV–vis absorption spectroscopic and fluorescence lifetime studies further showed that the ligand exchange with all three alkylamines affected optical properties of CdSe QDs to some extent. Powder X-ray diffraction (XRD) and transmission electron microscopy (TEM) results showed that the ligand exchange process basically did not affect the crystal structure and core size of the CdSe QDs. Our work had proposed a conceivable mechanism for ligand exchange, elucidated the thermodynamic implications, and provided a reasonable guidance for selection of suitable ligands.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2020
·
IF 4.65
Fu Yang,Liuzhu Zhou,Shuying Gao,Xuyu Wang,Jin Chen,Aihua Yuan,Edison Huixiang Ang
Combining different active states of metal species together in special configuration might trigger interesting synergetic effect for catalytic process. As a proof-of-concept, the present study has developed an ingenious approach to reach functional mesoporous molecular sieve which in-situ encapsulates two different states of highly-active FeOx inside centered core and nano-tunnel of mesoporous silica , respectively. The α-Fe 2 O 3 in-situ immobilized nanoneedles coated by the porous silica afford ∼5 nm diameter, plus highly-dispersed Fe 2 O 3 cluster-like species attachment in confined mesopore, which synergistically contributes to high activity and stabilization of catalyst. The combined iron oxides in special configuration deliver an appreciable catalytic activity in phenol hydroxylation (46.4% conversion, 87.9% benzenediol selectivity) during multiple catalytic cycles, compared to some reported results, which benefited from accelerating production of oxidative free radicals from H 2 O 2 and the tailored micrpopore (∼1.4 nm) which could enhance the catalytic selectivity of targeted products. Furthermore, the photocatalytic antimicrobial effect of Fe catalyst against Escherichia coli was also demonstrated via the constructed synergy of two FeOx nanospecies with assistance of light.
✓ 已验证
产品关联
DOI
高影响因子
ORGANIC ELECTRONICS
·
2020
·
IF 3.31
Weikun Lin,Gengxu Chen,Enlong Li,Hongxing Xie,Gang Peng,Weijie Yu,Huipeng Chen,Tailiang Guo
All inorganic perovskite quantum dots (PeQDs) of CsPbX 3 (X = Cl, Br, I, or their mixture) are regarded as promising candidates for photovoltaics and optoelectronic devices owing to their excellent and unique optical and electronic properties. However, their inherent poor stability severely limits their practical applications. Herein, aiming at improving their stability and photoluminescence (PL) properties, a novel surface capping ligand strategy was performed via directly synthesizing CsPbX 3 quantum dots (QDs) by hot injection method with straight-chain n-alkylmonoamine instead of conventional organic amine (oleylamine) as ligands. With stronger intermolecular interaction and denser alignment, n-alkylmonoamine ligands would form a stable protective layer on the surface of PeQDs. As a result, the n-alkylmonoamine capped CsPbBr 3 QDs exhibited remarkable long-term storage with 70% of PLQY retaining after 30 days in the open air, impressive water resistance for over 1 h in water, significant photostability with hour-scale laser exposure, and high thermal stability with 60% of PLQY retaining after heating at 80 °C for over 60 min. In addition, by blending the CsPbBr 3 QDs with polymer as the gate dielectric , novel light-erasable transistor memories were fabricated based on the device architecture of a floating-gate transistor memory (FGOTM). Acting as dense charge tunneling layers for charge trapping materials (PeQDs) in light-erasable transistor memory, the alkylmonoamine ligand layers led to significant broadening of memory windows, presenting various charge capture abilities of the PeQDs with the different capping ligands.
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2020
·
IF 10.652
Jinze Lyu,Lele Zhou,Junwei Shao,Zhen Zhou,Junxian Gao,Ji Li,Yuming Dong,Zhenyu Wang
Light absorption efficiency directly affects the photocatalytic degradation rate of volatile organic compounds (VOCs). Herein, we synthesized a TiO 2 hierarchical structure with a nanoscale hollow cavity and ultrathin nanosheet-assembled shell to efficiently harvest light. The micromorphology, light absorption, and charge separation of the prepared catalysts were analyzed via transmission electron microscopy, scanning electron microscopy, UV–vis diffuse reflectance, and surface photovoltage measurements. The adsorption and photocatalytic degradation of toluene and acetone were conducted to evaluate the catalysts’ performance in VOC elimination. The prepared TiO 2 /H 2 Ti 3 O 7 composite, FTHS, exhibited a spiny hollow morphology at the nanoscale, thereby considerably increasing its surface area and light absorption capacity compared with conventional TiO 2 hollow spheres (THS). Moreover, the optimized structure of FTHS enhanced the charge separation and electron accumulation on the catalysts’ surface. Owing to these advantages, FTHS showed evidently higher adsorption amount, removal rate, and mineralization efficiency of toluene and acetone than THS.
✓ 已验证
产品关联
DOI
高影响因子
DALTON TRANSACTIONS
·
2020
·Vol. 49
·期 18
·6119-6126
·
IF 4.174
Jinyuan Zhang,Huaimin Gu
Owing to their environmentally friendly characteristic, InP-based quantum dots (QDs) show great potential in various fields as an alternative to Cd-based QDs. However, the current mainstream synthesis process, the (TMS)3P-based injection method, still faces many challenges, such as the high cost of (TMS)3P and complex temperature control. In contrast, the solvothermal method is considered to be more feasible and reproducible. Despite its potential advantages, little has been done to understand how the precursors influence the synthesis of InP QDs using the solvothermal method. In this research, InZnP/ZnS QDs were synthesized using practical phosphorus precursors (DEA)3P or (DMA)3P. Through the feasible regulation of zinc, indium, phosphorus and sulfur precursors, the band gap of the QDs could be widely and accurately tuned, and a much wider photoluminescence wavelength ranging from 484 nm to 651 nm could be achieved. Furthermore, InI3 and InBr3 contributed to the blueshift in the PL wavelengths, and the combination of (DEA)3P, (DMA)3P, n-DDT and t-DDT refined the PL wavelength with a small tuning gap of 5 nm.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of the Iranian Chemical Society
·
2021
·Vol. 19
·期 3
·847-860
·
IF 2.019
Shi Laishun,Ji Tong,Gong Xuedi,Chen Yawen
A series of novel amphoteric surfactants containing amide groups with different hydrophobic carbon chain lengths were synthesized by using fatty amines with different carbon chain lengths, acrylamide and sodium chloroacetate as raw materials. The surface performance parameters and the thermodynamic functions of the surfactants in aqueous solution with different hydrophobic carbon chain length were determined and analyzed by the surface tension and conductivity. The surfactants were started to form pre-micellization before reaching the critical micelle concentration in the solution from the molar conductance-concentration squared curve and the apparent activation energy-concentration curve. According to the water separation time and the foaming performance experiments, as the hydrophobic carbon chain length grows, the emulsifying ability and defoaming property become better. The surfactants synthesized from octadecylamine belong to rapid-set emulsifier of asphalt.
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Bio Materials
·
2021
·
IF 0
Hui-Zhen Yang,Ji Zhang,Yu Guo,Lin Pu,Xiao-Qi Yu
Nonviral gene vectors with stimulus responsiveness and self-reporting properties have broad application prospects in gene therapy. Herein, we developed a nanosized reduction-responsive cationic liposomal vector formed from DNS(Zn), in which a naphthalimide–sulfonamide group was used as the glutathione (GSH)-responsive group to generate a blue fluorescence signal at 458 nm. Macrocyclic polyamine (cyclen) was used as a cationic headgroup to facilitate Zn(II) coordination, which may reduce the cytotoxicity and improve transfection efficiency. The Zn-free and nonresponsive analogues were used for comparison. Fluorescent assays revealed that the GSH response of DNS(Zn) could increase the blue fluorescence signal and improve the DNA release in cells. The title material also showed higher positive ζ-potential than its nonresponsive analogue, resulting in stronger DNA binding ability and better cellular uptake. These advantages made DNS(Zn) a good candidate for nonviral gene delivery, and the transfection efficiency in HeLa cells was distinctly higher than that of its analogue and the commercially available transfection reagent. Besides plasmid DNA, DNS(Zn) could also deliver small interfering RNA (siRNA) with good gene silencing efficiency, extending the application of the liposomes. These results suggest that DNS(Zn) can serve as a highly efficient nucleic acid delivery vector with reduction-responsive fluorescence self-reporting ability in tumor cells.
✓ 已验证
产品关联
DOI
PubMed
APPLIED SURFACE SCIENCE
·
2021
·
IF 6.707
Bin Yang,Wanzhong Yin,Jin Yao,Qiuyue Sheng,Zhanglei Zhu
This investigation focused on the collection performance and sorption mechanisms of decaethoxylated stearylamine (DSA) applied as a new high-selectivity hornblende collector, to further extend the use of DSA for efficiently recovering siderite from hornblende. The collecting ability of DSA to both minerals was explored via a series of flotation experiments. Flotation results illustrated that in comparison with DDA, DSA displayed an excellent collection performance for the hornblende flotation, whereas it hardly collected siderite. With 0.18 mM DSA, siderite could be efficiently separated from hornblende at pH 6.30 through reverse flotation. The selective collection mechanisms of DSA for hornblende were uncovered via surface wettability, X-ray photoelectron spectroscopy (XPS), surface electrical properties, infrared spectrum (IR) characterizations, and molecular dynamics (MD) simulations. Contact angle detection indicated that DSA strengthened the surface hydrophobicity of hornblende instead of siderite, which promoted the strong collection of hornblende. Besides, surface electrical detection and IR analyses suggested that the intense DSA sorption toward the hornblende was due to the combination of electrostatic adsorption and hydrogen bonding interaction. It was demonstrated by XPS results that larger amounts of DSA were adsorbed onto hornblende than siderite, and the O sites of hornblende were involved in electrostatic attraction and hydrogen bonding interaction. Furthermore, MD simulations further revealed that compared with siderite, the intense adsorption of DSA on the hornblende was due to the hydrogen bond and electrostatic interactions between its amino group and the hornblende surface, as evidenced by a much smaller interaction distance and very negative electrostatic energy. Therefore, DSA can be utilized as an efficient collector for collecting hornblende to achieve the desiliconization of the siderite flotation.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2021
·
IF 6.165
Bin Yang,Wan-Zhong Yin,Jin Yao,Zhang-Lei Zhu,Hao-Ran Sun,Ke-Qiang Chen,Li-Ying Wang
Different adsorption behaviors of the collector on the mineral surface play a crucial part in the flotation separation of different minerals by selectively modifying the wettability of mineral surfaces. In this investigation, to effectively remove quartz from hematite via reverse flotation, decaethoxylated stearylamine (DEOSA) was first introduced as a high-performance collector for quartz. The selective collecting performance and differential adsorption mechanisms of DEOSA for both hematite and quartz were studied by flotation experiments and surface analysis. Flotation results suggested that DEOSA displayed excellent collecting capacity for quartz against hematite and the effective removal of quartz from hematite was achieved. Adsorption capacity measurements and surface wettability analysis demonstrated that much larger amounts of DEOSA adsorbed onto quartz than hematite significantly enhanced the quartz surface hydrophobic whether the depressant starch was present or not, which resulted in the excellent flotation performance of quartz. Surface electrical characterization and Fourier transform infrared (FTIR) analysis further proved that the combination of hydrogen bonding and electrostatic attracting force enhanced the strong adsorption of DEOSA onto the quartz, achieving the efficient collection performance of DEOSA for quartz. Based on these findings, DEOSA can be used potentially as a strong-collection and high-performance quartz collector for recovering hematite from quartz via reverse flotation.
✓ 已验证
产品关联
DOI
高影响因子
APPLIED ORGANOMETALLIC CHEMISTRY
·
2021
·Vol. 35
·期 11
·e6393
·
IF 4.105
Xiaoli Song,Yaming Pang,Liguo Gao
In this paper, dodecylamine (DDA) is used as the template, and ethyl orthosilicate (TEOS) is used as the silicon source. The HMS molecular sieve is prepared by in situ synthesis and modified by Cu, Ce, and Cu/Ce. The Cu/Ce-HMS molecular sieve catalyst was synthesized for the first time. Scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), and Fourier transform infrared spectrometer (FTIR) were used to characterize the synthesized composite molecular sieve. The results showed that the metal was loaded on the HMS intact and did not change the morphology of the HMS. A mixture of n-hexane and dibenzothiophene (DBT) was used as the model oil, and the oxidation removal of DBT in the model oil was used as a probe reaction to study the photocatalytic oxidative desulfurization performance of the composite catalyst. The results show that the desulfurization rate after modification is Cu/Ce-HMS molecular sieve > Cu-HMS molecular sieve > Ce-HMS. Finally, we explored the reaction mechanism of catalyst desulfurization. The results of ultraviolet diffuse reflectance showed that the modified molecular sieve Cu/Ce-HMS had a smaller band gap, greater reaction activity, and stronger photocatalytic performance, which is benefit to improve the desulfurization efficiency. We report a simple and effective preparation method of composite molecular sieve catalyst, which provides a certain reference for future desulfurization research.
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）