INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2020
·
IF 3.573
Qingshuo Li,Hao Yang,Mengqing Li,Kexin Zhao,Baogen Duan,Chen Zhang,Hongxia Wang,Congzhen Qiao,Haibo Chang,Tong Lin
The cycloaddition of CO2 with epoxide has been a promising way to fix CO2. Developing efficient, low-cost catalysts for this reaction is highly desired. In this paper, we report a novel cocatalyst system that consists of acrylamide and KI for the synthesis of propylene carbonate using CO2 and propylene oxide as starting materials. Different amides (i.e., acrylamide, benzamide, nicotinamide, acetamide, N-isopropylacrylamide, N-tert-butylacrylamide, and N,N-dimethylacrylamide) were combined with different potassium halides to investigate their catalysis capability. KI/acrylamide showed the highest efficiency, and a synergetic effect occurred between acrylamide and KI. At the KI: acrylamide ratio of 1:1 (mol/mol) and concentration of 2.5 mol% for both of them (based on PO), the reaction reached a yield of 95.3%. The catalytic system applies to the cycloaddition reaction using different epoxides. The reaction mechanism was proposed.
研究领域:
化学
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环境科学
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DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2023
·
IF 6.2
Yi Yang Xu,Lei Meng,Miao Miao Zhao,Chu Xin Peng,Fei Yen
While all of the polymorphs of pure NH 4 I and KI are non-polar, we identify that (NH 4 ) 0.95 K 0.05 I is ferroelectric and (NH 4 ) 0.87 K 0.13 I and (NH 4 ) 0.83 K 0.17 I are pyroelectric through measurements of their pyroelectric current and complex dielectric constant. The order to disorder phase transitions occur near 245 K. Magnetic susceptibility measurements indicate that the proton orbitals of the NH 4 + continue to become ordered in the ground state in the (NH 4 ) 1–x K x I system up to x ≤ 0.17. The polar phases are proposed to stem from K + ions disrupting the symmetry of proton-orbital-lattice interactions between the NH 4 + and I – ions. Our work introduces a new pathway for the ordered phases of ammonium-based compounds to potentially become ferroelectric.
研究领域:
材料科学
·
凝聚态物理
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DOI
高影响因子
Polymers
·
2022
·Vol. 14
·期 7
·1413
·
IF 4.967
Yang Yang,Ziyuan Zheng,Jun Lin,Lintao Zhou,Guohua Chen
Polarizer is a key component of the liquid crystal display panel, and the optical properties mainly include transmittance, degree of polarization and chromaticity. Polarizer is made of a multilayer optical film, in which the PVA polarizing film is the core structure for realizing the polarization of the whole polarizer. PVA polarizing film is commonly manufactured through a multi-step craft, including rinsing, dyeing, stretching and correcting. The correction process has a significant impact on the final apparent color and optical properties of the polarizer. In this study, the KI concentration in the correcting tank, ranging from 1% to 3%, was systematically investigated. With the increase in KI concentration, the Raman vibration peak at 160 cm−1representingI5−ions gradually weakened, while the Raman vibration peak at 110 cm−1representingI3−ions gradually increased, indicating that the KI in the correcting tank changed the chemical equilibrium of polyiodide ions in PVA. Then abundant chromophoreI5−ions were consumed andI3−ions generated, so that the apparent color of PVA polarizing film gradually changed from dark blue to dark gray, and the chromaticitya-value andb-value gradually increased. The change in the concentration of dichroic species (I5−andI3−) in PVA polarizing film had directly affected its transmittance in the visible range. From the UV-Vis transmittance spectrum of PVA polarizing film, when theI5−ions were consumed andI3−ions generated, the transmittance of PVA polarizing film in the region of 675–525 nm wavelength increased gradually while the polarization degree also increased.Keywords:PVA polarizing film;correction process;transmittance;chromaticity;degree of polarization
研究领域:
材料科学
·
光学工程
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产品关联
DOI
PubMed
高影响因子
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
·
2021
·Vol. 2021
·期 9
·821-830
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IF 2.524
Xiaoyan Yu,Qin Zhou,Jianbin Xu,Lusheng Liang,Xiaobing Wang,Jihuai Wu,Peng Gao
As univalent cation to the ammonium ions, alkali metal ions become vital alternatives or additives for the A-site ions of lead halide perovskites. They were reported to construct new perovskite structures or bring new features like reduced defect density, suppressed hysteresis, improved power conversion efficiencies (PCEs), stability, etc. In this work, by making an alloyed film of PbI 2 :KI in the first step of the sequential deposition, we find that a low concentration of KI can improve the roughness and microstructure of the PbI 2 film, facilitating the intercalation of ammonium salt into PbI 2 . In comparison, a higher concentration of KI will lead to the formation of K 2 PbI 4 clusters, resulting in perovskite films with decreased quality and high V OC loss in devices. The best-performing device based on one PbI 2 :KI alloy shows an enhanced PCE from 19.60 % to 21.18 %. The study can provide a referential insight into the influence of K + on the formation of perovskite films and the performance of corresponding devices. Graphical In recent years, alkali metal ions have been widely exploited to optimize the performance of perovskite solar cells. This work aims to explore the effect of potassium in the form of PbI 2 :KI alloy on perovskite solar cells. A high-quality perovskite film was fabricated by a two-step method, of which making PbI 2 :KI alloy was the first step. It achieved a power conversion efficiency of 19.60 % to 21.18 %.
研究领域:
材料科学
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光伏技术
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薄膜太阳能电池
·
钙钛矿材料
✓ 已验证
DOI
高影响因子
Molecular Catalysis
·
2019
·
IF 2.938
Qingshuo Li,Haibo Chang,Runming Li,Hongxia Wang,Jichun Liu,Shanhu Liu,Congzhen Qiao,Tong Lin
In this study, we have for the first time demonstrated that succinimide (SI)-KI is an efficient catalyst system to synthesize propylene carbonate (PC) from carbon dioxide (CO 2 ) and propylene oxide (PO) at a solvent-free condition. A synergistic effect was observed between SI and KI that largely increased the reaction yield. It enabled the cycloaddition reaction to take place at 70 °C under a low pressure (0.4 MPa) for only 4 h, with a PC yield as high as 97.5%. The overall condition is milder than the reaction catalyzed by most of the other KI involved co-catalyst systems reported in literatures. The excellent catalytic ability was explained by the increased KI solubility in PO due to the presence of SI and the weak acidity of NH in SI which can be enhanced by KI. A reaction mechanism was proposed based on a reaction kinetics study. SI-KI was applicable to cycloaddition of CO 2 with other epoxides. It may offer an inexpensive, environmentally-friendly route to synthesis of propylene carbonate from CO 2 .
研究领域:
化学
·
环境科学
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产品关联
DOI
高影响因子
CHINESE JOURNAL OF CATALYSIS
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2018
·
IF 3.525
Xiying Fu,Pengtao Xie,Yiwei Lian,Leqin He,Wei Zhao,Tao Chang,Shenjun Qin
A series of zwitterionic-type quaternary ammoniums (ZTQAs) with varying lengths of alkyl chains combined with KI were synthesized and considered as catalysts for the coupling reaction of CO 2 and various terminal epoxides. The prolonged alkyl chain of ZTQAs exhibited temperature-responsive self-separation in propylene carbonate (PC). The interaction between ZTQAs and KI was confirmed by X-ray photoelectron spectroscopy and quantum chemical calculations. This interaction strengthened the nucleophilicity of the I − ion, favoring the catalytic reaction . The 3-(dimethyltetradecylammonium) propane sulfonate (DTPS)/KI showed an excellent yield of PC (95.1%) at 125 °C, 1.5 MPa, and 1 mol% loading of catalyst. The precipitate formed spontaneously from the catalytic system, providing high catalytic activity of the homogeneous catalyst, as well as easy recovery of the heterogeneous catalyst.
研究领域:
化学工程
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环境科学
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产品关联
DOI
高影响因子
Advanced Optical Materials
·
2022
·Vol. 10
·期 21
·2201053
·
IF 10.05
Xiao-Kai Gong,Lan Li,Jian-Ping Xu,Ru-Kun Ding,Zhao-Wei Zhang,Qian Li,Long Liu,Xiao-Song Zhang
Lead-free halide double perovskites continue to draw increasing attention in view of their nontoxicity and stability compared to lead-based perovskites. High-end full-color displays and white light illumination are based on blue-light excitation. However, the excitation of blue light of lead-free halide double perovskites Cs 2 AgInCl 6 at room temperature faces a great challenge, which is crucial to its commercial application. In this study, Cs 2 Ag 0.6 Na 0.4 In 0.8 Bi 0.2 Cl 6 / x KBr(KI), which can be excited under blue light, have been synthesized by solid-phase compression method. Under blue-light excitation, Cs 2 Ag 0.6 Na 0.4 In 0.8 Bi 0.2 Cl 6 /16KBr and Cs 2 Ag 0.6 Na 0.4 In 0.8 Bi 0.2 Cl 6 /16KI emit 605 nm orange light and 665 nm red light, respectively. Based on that, orange and red light-emitting devices are fabricated excited by blue light. The performance of blue-light excitation can not only make the double perovskites widely used in light-emitting devices, but also as a light-emitting down-shift layer in photovoltaic devices to improve the performance of photovoltaic modules. With the Cs 2 Ag 0.6 Na 0.4 In 0.8 Bi 0.2 Cl 6 /16KBr, the power conversion efficiency of the Si solar cell increases 4.80% and 8.14% under the sunlight and white light-emitting devices, respectively. The blue-light excitation of lead-free double perovskites at room temperature offers greater development potential in the field of display devices and optoelectronics.
研究领域:
材料科学
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光学工程
·
能源技术
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产品关联
DOI
高影响因子
RSC Advances
·
2015
·Vol. 5
·期 126
·103797-103802
·
IF 3.84
Ying Ma,Li Xu,Wei Chen,Chao Zou,Yun Yang,Lijie Zhang,Shaoming Huang
A facile method for synthesizing hollow Au/Pt nanostructures is reported; this strategy involves using small sized Au nanoparticles (NPs) as seeds and KI as growth modifier. Under polyvinylpyrrolidone (PVP) and potassium iodide (KI), small sized Au NPs evolved to plate-like nanostructures due to Ostwald ripening. The nanoplates served as templates for selectively growing Pt on {110} facets. Under high temperature, I− was oxidized to I2 by O2. The formed I2 and KI etched Au on {111}, generating hollow nanostructures. Through adjusting the reaction conditions, dendrite sphere-like nanostructures could also be prepared. The prepared bimetallic Au/Pt nanostructures exhibited high catalytic performance compared with sphere-like Pt.
研究领域:
材料科学
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纳米技术
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL RESEARCH
·
2013
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IF 0.596
Liang Zhou,Yuanfeng Liu,Zhenhong He,Yanping Luo,Feng Zhou,Erlei Yu,Zhenshan Hou,Wumanjiang Eli
An efficient reaction of epoxides with carbon dioxide to generate the corresponding cyclic carbonates employing pentaerythritol/KI, does not need solvent.
研究领域:
化学
·
催化反应
✓ 已验证
DOI
高影响因子
MOLECULAR BIOTECHNOLOGY
·
2024
·
IF 2.4
Chen Ya,Zhu Congcong,Tai Zongguang,Lian Tianyan,Zhu Quangang,Chen Zhongjian
Apoptosis is a natural physiological process of programmed cell death. It is essential for maintaining the homeostasis of the body and the immune system. The dysfunction of apoptosis can lead to the development of autoimmune diseases. In psoriasis, the dysfunction of keratinocyte proliferation manifests as an impairment of apoptosis. Cordycepin is the major active component in cordyceps militaris and has pharmacological effects, including regulation of apoptosis. The pharmacological mechanism of Cordycepin in psoriasis remains unclear. In this study, bioinformatics analysis revealed that the mechanism may be associated with the p53 apoptotic pathway. Further, we confirmed in the experiments that cordycepin inhibited the interleukin (IL)-17A-induced proliferation of HaCaT cells and down-regulated the expression of proliferating cell nuclear antigen (PCNA) and Ki-67. Regulating the expression of apoptotic proteins BAX, Bcl-2, and p53 promote apoptosis. Further investigation of the upstream pathway of apoptosis revealed that cordycepin could normalize the abnormal p53-mouse double minute 2 (MDM2) feedback loop. In vivo results showed that the cordycepin gel could effectively improve imiquimod (IMQ)-induced psoriasis-like skin lesions in mice, and the p53-MDM2 pathway was verified at the protein level. In conclusion, the anti-psoriasis effect of Cordycepin and its potential mechanism have not been discussed in detail. However, our work supports the idea that Cordycepin can be further developed as an Active Pharmaceutical Ingredient (API) for the treatment of psoriasis.
研究领域:
药理学
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皮肤科
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分子生物学
·
免疫学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF MOLECULAR MEDICINE
·
2015
·Vol. 36
·期 5
·1282-1290
·
IF 2.088
Bin Gao,Lei Shen,Ke-Wu He,Wei-Hua Xiao
The aim of the present study was to examine the apoptosis of the hepatocellular carcinoma cell line, HepG2, induced by treatment with folic acid-conjugated silica-coated gold nanorods (GNRs@SiO2-FA) in combination with radiotherapy, and to determine the involvement of apoptosis-related proteins. An MTT colorimetric assay was used to assess the biocompatibility of GNRs@SiO2-FA. The distribution of GNRs@SiO2-FA into the cells was observed using transmission electron microscopy (TEM). HepG2 cells cultured in vitro were divided into the following 4 groups: i)the control group (untreated), ii) the GNRs@SiO2-FA group, iii) the radiotherapy group (iodine 125 seeds) and iv) the combination group (treated with GNRs@SiO2-FA and iodine 125 seeds) groups. The apoptosis of the HepG2 cells was detected by flow cytometry. The concentration range of <40 µg/ml GNRs@SiO2-FA was found to be safe for the biological activity of the HepG2 cells. GNRs@SiO2-FA entered the cytoplasm through endocytosis. The apoptotic rates of the HepG2 cells were higher in the GNRs@SiO2-FA and radiotherapy groups than in the control group (P<0.05). The apoptotic rate was also significantly higher in the combination group than the GNRs@SiO2-FA and radiotherapy groups (P<0.05). Taken together, these findings demonstrate that the combination of GNRs@SiO2-FA and radiotherapy more effectively induces the apoptosis of HepG2 cells. These apoptotic effects are achieved by increasing the protein expression of Bax and caspase-3, and inhibiting the protein expression of Bcl-2 and Ki-67. The combination of GNRs@SiO2-FA and radiotherapy may thus prove to be a new approach in the treatment of primary liver cancer.
研究领域:
癌症研究
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纳米技术
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分子生物学
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放射生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF LUMINESCENCE
·
2026
·
IF 3.8
Ou Hai,Yuxin Deng,Xin An,Peng Li,Keke Guan,Hang Li,Jiaxin Qin,Weikang Dong,Yuanting Wu
CsPbI 3 perovskite quantum dots demonstrate tremendous potential in display and lighting technologies due to their excellent luminescent properties. However, conventional synthesis methods typically involve toxic reagents and complex procedures, which not only pose severe safety and environmental risks but also present long-term, serious challenges to the stability of the resulting products. Developing efficient and convenient synthesis strategies to achieve controllable preparation of high-quality red perovskite quantum dots represents a significant research direction in this field. Based on the concept of green synthesis, this study develops a spray-drying method using only water as the solvent to prepare CsPbI 3 perovskite quantum dots. In this method, CsPbI 3 perovskite quantum dots crystallize directly within KI, which not only achieves effective isolation from the external environment but also provides an iodine-rich atmosphere. Meanwhile, it effectively suppresses agglomeration of quantum dots, thereby enabling a rapid one-step synthesis of highly stable perovskite quantum dots. The prepared CsPbI 3 quantum dot crystals exhibit excellent performance, with a full width at half maximum (FWHM) of merely 43 nm. Thanks to the protection of the KI matrix, the obtained powder exhibits excellent phase stability in air, along with good redispersibility, facilitating its incorporation into ink systems. We have successfully applied it to patterned fluorescent anti-counterfeiting labels and further integrated it with blue GaN chips to fabricate red light-emitting diode (pc-LED) prototype devices with high brightness and color purity. The successful implementation of this method has significantly advanced its practical application in optoelectronic devices such as light-emitting diodes (LEDs) and wide-color-gamut displays.
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DOI
高影响因子
危险品化学品经营许可证（带存储）