Journal of Spectroscopy
·
2015
·
IF 0.538
Y. J. Li,F. Y. Sun,Y. Zhou,L. Zeng
Different dispersants were added in the dispersion process to improve the efficiency of fluorite flotation. The types and dosage of dispersant on the improvement of fluorite flotation were investigated; when the sodium polyacrylate (SPA) was used as the dispersant and its addition is 0.5%, the concentrate grade of CaF2 increased from 90% to 98% and the fluorite recovery increased from 81% to 85%. Methods of X-ray powder diffraction (XRD), field emission scanning electron microscopy (FESEM), and Energy dispersive X-ray spectrometer (EDX) were used to characterize the sample. According to the analysis of results, the optimal sample consisted of CaF2 and very little CaCO3 in the size range of 0–5 μm. It could be concluded that the mechanism of improvement for the concentrate grade and recovery of CaF2 was attributed to the change of potential energy barrier which caused the separation of particles with different charge. All results indicate that SPA has a great potential to be an efficient and cost-effective dispersant for the improvement of fluorite flotation.
研究领域:
矿物加工工程
·
材料科学与工程
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2018
·Vol. 8
·期 11
·5661-5669
·
IF 2.936
Xun Zhu,Hao Feng,Rong Chen,Qiang Liao,Dingding Ye,Biao Zhang,Jian Liu,Ming Liu,Gang Chen
As a promising technique for multiphase catalytic reactions, the widespread applications of gas–liquid–solid microreactors are still limited by poor durability. Hence, in this work, a method for the preparation of Pd nanocatalysts inside a gas–liquid–solid microreactor was proposed to realize long-term durability using electroless deposition on the polydopamine functionalized surface followed by hydrogen reduction. This method not only increases the utilization efficiency of the Pd ions but also improves the durability of the microreactor. The chemical composition and topography characterization of the fabricated catalyst layer were tested using XPS and FESEM, respectively. The results indicated that the incorporation of hydrogen reduction resulted in nearly all palladium ions being reduced and the palladium nanoparticles were dispersed uniformly on the polydopamine modified surface. The microreactor prepared by this method exhibited high durability and high nitrobenzene conversion as compared to the traditional electroless catalyst deposition. Besides, it was shown that the increased inlet nitrobenzene concentration and flow rates played a negative role in the durability. The longer microreactor exhibited a better durability.
研究领域:
化学工程
·
催化
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
FlatChem
·
2023
·
IF 6.2
Xia Xu,Changchun Chen,Lingxiu Shu,Cheng Cheng,Zhonghai Tang,Yifeng Wang,Lin Pan,Zishen Guan
Water pollution can be efficiently treated by semiconductor photocatalysts under sunlight irradiation. In this study, novel S-scheme SrTiO 3 /ZnIn 2 S 4 composites were successfully fabricated via a facile oil-bath method. And the synthesized samples were then characterized by various characterization techniques together with Density Functional Theory (DFT) calculation. The X-Ray Diffraction(XRD)patterns show that SrTiO 3 /ZnIn 2 S 4 composites are composed of cubic perovskite structure SrTiO 3 and hexagonal phase ZnIn 2 S 4 . The High Resolution Transmission Electron Microscope(HRTEM)and Field Emission Scanning Electron Microscope (FESEM) images showed the intimate contacts between SrTiO 3 and ZnIn 2 S 4 are established to form the heterojunction. The photocatalytic activity of the composite was excellent when degrading organic pollutants, which outperformed that of pristine SrTiO 3 and ZnIn 2 S 4 . The prepared SrTiO 3 /ZnIn 2 S 4 -33% composite sample was proved to have the best photocatalytic activity, with 98 % degradation of organic pollutants under 32 min. The ·O 2 – is the main active reaction species for the degradation of organic pollutants, which was demonstrated by free radical trapping experiment. In addition, the mineralization of organic pollutants during the degradation process was analyzed by Total Organic Carbon (TOC) test. According to a series of experimental and theoretical calculations, the S-scheme heterojunction formed in the SrTiO 3 /ZnIn 2 S 4 composite is put forward for comprehending the photocatalytic degradation of organic pollutants and the formation of free radicals.
研究领域:
环境科学
·
材料科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF DENTISTRY
·
2021
·
IF 4.379
Kang Li,Zhongni Zhang,Yuhong Sun,Hongye Yang,James Kit Hon Tsoi,Cui Huang,Cynthia Kar Yung Yiu
Objectives To evaluate the anti-proteolytic and cross-linking effect of N -(3,4-dihydroxyphenethyl)methacrylamide (DMA) on the demineralized dentin matrix in vitro . Methods Four experimental solutions were selected: 50% ethanol/water solution (Control); 1, 5, and 10 mmol/L DMA dissolved in 50% ethanol/water solution. Sound human molars were sectioned to produce dentin beams with dimension of 1×1×6 mm. The dentin beams were demineralized with 10% phosphoric acid for 8 h to remove the apatite . The demineralized specimens were randomly separated into four groups and immersed in the four experimental solutions for 1 h. After the treatment , the ultimate tensile strength (UTS), loss of dry mass and the release of hydroxyproline by storing the treated specimens in 0.1 mg/mL collagenase solution for 24 h were assessed. The swelling ratio of another ten specimens from each group were evaluated. The interaction between DMA with dentin matrix was observed under Field Emission Scanning Electron Microscopy (FESEM). UTS data was analyzed by two-way ANOVA followed by Tukey test, and the other data was analyzed by one-way ANOVA followed by Tukey test (α = 0.05). Results The two-way ANOVA factors, different solutions ( p < 0.001), collagenase degradation ( p < 0.001) and their interactions ( p < 0.001) all significantly affected the UTS. The 10 mM DMA treatment significantly decreased the percentage of loss of dry mass, release of hydroxyproline and swelling ratio of demineralized dentin matrix compared to other treatment groups ( p < 0.05). The FESEM observation depicted that with increasing concentration of DMA, the structure of dentin matrix was protected and the porosity within dentin collagen network was decreased. Conclusions The treatment by 10 mM DMA/ethanol solution for 1 hour is capable of enhancing the mechanical properties of demineralized dentin matrix against collagenase degradation and may be clinically useful to improve the durability of hybrid layer. Clinical Significance The 10 mM DMA/ethanol primer may offer an alternative choice for dentists to strengthen the mechanical properties of demineralized dentin matrix and resist its degradation by collagenase.
研究领域:
牙科学
·
材料科学
·
生物材料
✓ 已验证
DOI
PubMed
高影响因子
CERAMICS INTERNATIONAL
·
2022
·
IF 5.532
Hongju Qiu,Weiwei Huang,Yanqiong Zhang,Jin Chen,Lei Gao,Mamdouh Omran,Li Nan,Guo Chen
In the family of inorganic nanomaterials , zirconia is a highly promising functional ceramic with a high refractive index , hardness, and dielectric constant, as well as excellent chemical inertness and thermal stability. These properties are enhanced in nano-zirconia ceramics, because nanopowders have a small particle size, good morphology, and uniform and dispersive distribution. In this study, a co-precipitation process was proposed to synthesise highly dispersed MgO–Y 2 O 3 co-stabilized ZrO 2 nanopowders. The effects of different calcination temperatures on the crystallisation degree and particle dispersion of zirconia nanopowders were characterised by X-ray diffraction (XRD), thermogravimetry-differential scanning calorimetry (TG-DSC), Raman spectroscopy , Fourier transform infrared spectroscopy (FTIR), nitrogen adsorption using the Brunauer–Emmett–Teller (BET) theory, transmission electron microscopy (TEM), and field emission scanning electron microscopy (FESEM). The optimum synthesis conditions were obtained as follows: 6 h of high-energy planetary grinding and calcination at 800 °C in an electric furnace. Under these optimum conditions, the average particle size of the prepared powder was 28.7 nm. This process enriches the literature on the controllable preparation of Mg–Y/ZrO 2 nanopowders obtained by the co-precipitation method.
研究领域:
材料科学
·
纳米技术
·
陶瓷工程
·
化学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
·
2022
·
IF 10.319
Yue Liu,Feng Peng,Guang-Ling Yang,Zhi-Hui Xie,Wenxin Dai,Yuejun Ouyang,Liang Wu,Chuan-Jian Zhong
The utilization of photoelectrochemical cathodic protection (PECCP) enables an indirect corrosion protection of metals with low self-corrosion potential by introducing a metallic nickel interlayer. However, the ability to enhance the PECCP efficiency remains challenging because of the inherent property of the semiconductor. Herein, this ability is demonstrated by coupling a covalent organic framework (TpBD) decorated TiO 2 photoanode (TiO 2 /TpBD) with nickel coating on magnesium alloy for an effective corrosion protection. The composite photoanode showed direct PECCP for the nickel interlayer and indirect corrosion protection of the magnesium alloy. The composite structure of the nanotube array and the covalent organic framework for the photoanode were confirmed by field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). The enhanced photoelectrochemical conversion capability and PECCP performance of the nickel-coated Mg alloy were evidenced by the results from electrochemical and photoelectrochemical measurements including Mott-Schottky curves, photoinduced potential variations, and electrochemical impedance spectroscopy (EIS). Lastly, a corrosion protection mechanism is proposed, where the enhanced PECCP efficiency is attributed to the formation of a direct Z-scheme heterojunction, which is substantiated by the results from valence band (VB) XPS and electron spin resonance characterizations.
研究领域:
材料科学
·
电化学
·
腐蚀科学
·
光电化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）