CANADIAN JOURNAL OF CHEMICAL ENGINEERING
·
2022
·Vol. 101
·期 3
·1591-1601
·
IF 2.5
Renjie Deng,Yao Tian,Huajie Liu,Weiwei Yan
This work presents a novel heterogeneous catalytic system for the preparation of para -nitrotoluene ( p -NT) with nitrogen dioxide (NO 2 ) as a nitrating agent in the presence of oxygen (O 2 ). By applying dealuminated Hβ zeolite treated with oxalic acid (Hβ-Ox) as a catalyst, p -NT can be obtained with high conversion (90.5%) and selectivity (72.6%). In addition, it can be recycled at least five times without a significant decrease in catalytic activity. This result demonstrates that the catalyst has high efficiency, good stability, and regenerability. Meanwhile, the characteristics of pristine Hβ and different dealuminated Hβ zeolites modified with organic and inorganic acids were systematic contrastive studied using X-ray diffraction (XRD), nitrogen (N 2 ) adsorption-desorption, Fourier-transform infrared (FT-IR), scanning electron microscope (SEM), temperature-programed desorption of ammonia (NH 3 -TPD), pyridine adsorption infrared (Py-FT-IR), and solid state 27 Al nuclear magnetic resonance ( 27 Al MAS-NMR). Finally, the higher conversion and para -selectivity over Hβ-Ox also give a reasonable explanation in this paper.
研究领域:
化学工程
·
催化材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF ENVIRONMENTAL MANAGEMENT
·
2023
·
IF 8.7
Minghui Liu,Yutong Zhao,Quanzhong Cheng,Bingyang Tian,Ming Tian,Jian Zhang,Hui Zhang,Tianyan Xue,Tao Qi
Residual oil containing platinum group metals (PGMs), which is under-researched, can easily pose resource waste and environmental risks. PGMs feature as scarce strategic metals, and inorganic acids and potassium salts are also considered valuable. An integrated process for the harmless treatment and recovery of useful resources from residual oil is proposed herein. This work developed a zero-waste process based on the study of the main components and characteristics of the PGM-containing residual oil. The process consists of three modules: pre-treatment for phase separation, liquid-phase resource utilisation, and solid-phase resource utilisation. Separating the residual oil into liquid and solid phases allows for the maximum recovery of valuable components. However, concerns about the accurate determination of valued components emerged. Findings revealed that Fe and Ni are highly susceptible to spectral interference in the PGMs test when using the inductively coupled plasma method. After studying 26 PGM emission lines, Ir 212.681 nm, Pd 342.124 nm, Pt 299.797 nm, and Rh 343.489 nm were reliably identified. Finally, formic acid (81.5 g/t), acetic acid (117.2 kg/t), propionic acid (291.9 kg/t), butyric acid (3.6 kg/t), potassium salt (553.3 kg/t), Ir (27.8 g/t), Pd (10960.0 g/t), Pt (193.1 g/t), and Rh (109.8 g/t) were successfully obtained from the PGM-containing residual oil. This study provides a helpful reference for the determination of PGM concentrations and high-value utilisation of PGM-containing residual oil.
研究领域:
环境科学
·
冶金工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2019
·Vol. 136
·期 21
·47482
·
IF 2.188
Dandan Bao,Yuntao Xie,Shenglin Ma,Zhibing Wu,Ji-Gang Piao
Lignin is considered one of the main biorenewable polymers from natural resources. Each year, a large amount of lignin is generated as a waste byproduct of the pulping process in the paper industry. However, it is seldom treated as a value-added material because of its undefined structure, the diverse methods of isolation and processing, and the origin of the material; these greatly hinder its application. Therefore, it is of great significance to explore new potential applications of this readily available yet underappreciated natural product. In this study, we developed a preparation method of lignin-based microstructures or nanostructures via self-assembly. We created various self-assembled nanostructures, including nanocubes, nanorods, nano-octahedrons, nanobranches, and other morphologies, by choosing different types of simple inorganic acids at various pHs. Some of these nanostructures have never been reported. These structures were fully characterized with scanning electron microscopy, ultraviolet–visible spectroscopy, and dynamic light scattering. All of them were uniform and stable. They displayed little or no cytotoxicity to cells in vitro at concentrations up to 1024 μg/mL. We hope the results of this study provide some insight for the future development of new applications of lignin-based materials. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136 , 47482.
研究领域:
材料科学
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纳米技术
·
生物材料
·
可持续化学
✓ 已验证
DOI
高影响因子
Nanoscale Research Letters
·
2021
·Vol. 16
·期 1
·1-13
·
IF 4.703
Liu Rongtao,Zhang Shiyang,Zhao Chen,Yang Dong,Cui Tingting,Liu Yidong,Min Yonggang
Conductive and degradable nanofibrous scaffolds have great potential in promoting cell growth, proliferation, and differentiation under an external electric field. Although the issue of inferior electrical conductivity in body fluids still exists, polyaniline (PANI)-based degradable nanofibers can promote cell adhesion, growth, and proliferation.
To investigate whether the effect is caused by the PANI morphology, we selected three inorganic acids as dopants in the process of PANI in situ oxidative polymerization: hydrochloric acid, sulfuric acid, and perchloric acid. The obtained polyaniline/polylactic acid (PANI/PLA) composite nanofibers were characterized via SEM, FTIR, and XPS analysis, and we confirmed that the PLA nanofibers were successfully coated by PANI without any change to the porous structure of the PLA nanofibers. The in vitro mechanical properties and degradability indicated that the oxidation of acid dopants should be considered and that it was likely to have a higher oxidation degradation effect on PLA nanofibers. The contact angle test demonstrated that PANI/PLA composite nanofibers with different surface morphologies have good wettability, implying that they meet the requirements of bone tissue engineering scaffolds. The surface roughness and cell viability demonstrated that different PANI morphologies on the surface can promote cell proliferation. The higher the surface roughness of the PANI, the better the biocompatibility. Consequently, the regulated surface morphology of PANI/PLA composite nanofibers via different acids doping has positive effect on biocompatibility in tissue engineering.
研究领域:
材料科学
·
生物材料
·
组织工程
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纳米技术
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生物医学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
PARTICLE & PARTICLE SYSTEMS CHARACTERIZATION
·
2023
·Vol. 40
·期 10
·2300049
·
IF 2.7
Dong Yan,Zhiying Zhang,Yun Liu,Yan Guan,Dongming Sun
Since 2015, m-phenylenediamines (mPD) have become a popular carbon source for the synthesis of carbonized polymer dots (CPDs). However, their exact fluorescence mechanism is still obscure. To elucidate this, inorganic acids that are carbon-free are chosen as additives for a comparative study. It is found that the green fluorescence quantum yield (nearly 80%), photostability, and reaction yield (over 90%) can be enhanced by introduction of most of inorganic acids with moderate amount. Besides, green-blue dual emission is observed in acid-assisted groups. UV-vis absorption, Fourier-transform infrared spectroscopy, and surface-enhanced Raman scattering results indicate that the green fluorescence center is composed of quinoid rings, whereas the blue fluorophore contains benzenoid rings. Moreover, room-temperature afterglow with lifetime up to 1.25 s is observed exclusively in acid-assisted CPDs composites with urea/biuret. The blue chromophore is proposed to be the origin of the triplet level that induces the long afterglow. This work provides an in-depth understanding on the macromolecular structures of CPDs derived from phenylenediamines, and contributes a new line of thought to the origin of phosphorescence in N-doped carbon dots.
研究领域:
材料科学
·
化学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
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