Polymer Chemistry
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2022
·Vol. 13
·期 22
·3367-3376
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IF 5.364
Xinyue Guo,Huanv Mao,Chunyan Bao,Decheng Wan,Ming Jin
In this work, three dyes based on fused carbazole–coumarin–ketone structures were designed and synthesized. These dyes were named CCK–Me, CCK–Ph, and CCK–Tol in accordance with their different substituents. Their excellent absorption properties can match the wavelength band of visible light-emitting diodes (LEDs) (i.e., 405–450 nm). Density functional theory calculations, steady-state photolysis, and electron spinning resonance spin trapping experiments were performed to explain the photophysical and photochemical mechanisms of the dyes. These dyes are available as one- or two-component type II photoinitiators (PIs). Both kinds can efficiently initiate the polymerization of acrylate monomers via two different mechanisms under 405–450 nm LED irradiation. Notably, CCK–Tol exhibited excellent photobleaching ability when initiated alone, making it ideal for deep curing. The polymeric samples were up to 57 mm thick. Remarkably, the photolysis product of CCK–Tol showed satisfactorily low cytotoxicity. The above excellent properties showed the great potential application of the dyes in various photocuring materials, especially dental materials and thick three-dimensional structures.
研究领域:
材料科学
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化学
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生物医学工程
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DOI
高影响因子
Polymer Chemistry
·
2017
·Vol. 8
·期 9
·1579-1588
·
IF 5.375
Zhiquan Li,Weizhen Shen,Xiaoya Liu,Ren Liu
Simultaneous thiol-based hybrid photopolymerization is an efficient and versatile tool to prepare interpenetrating polymeric networks. A highly active photoinitiator is essential for an efficient simultaneous hybrid reaction. In this paper, several unimolecular photoinitiators, which contain thioxanthone derivatives as chromophores as well as free radical generators, and 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) as a latent alkaline species, were straightforwardly prepared in two steps. The photolysis study indicated that under 405 nm LED light irradiation, the photoinitiators can produce free radicals and a strong base simultaneously via a photodecarboxylation mechanism. The generated active species are highly efficient in catalyzing thiol–yne–epoxy hybrid polymerization without post-exposure baking and the properties of the hybrid network can be tailored by adjusting the compositional ratios of the formulations. The photocured materials using unimolecular photoinitiators exhibit superior thermal and mechanical properties compared to those prepared using a bimolecular initiation system from the literature. The presented strategy to realize simultaneous thiol–yne–epoxy hybrid photopolymerization shows potential for the fabrication of optical devices with enhanced refractive index and improved mechanical properties.
研究领域:
材料科学
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化学工程
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DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Tao Li,Amal Abdelhaleem,Wei Chu,Shengyan Pu,Fei Qi,Jing Zou
The degradation of pyrimethanil (PYR) was investigated through the activation of oxone by the S-TiO 2 (ST) photocatalyst under visible LED irradiation. The catalyst characterization revealed that the sulfur doping mechanism was based on the cation (S 6+ ) substitution of Ti 4+ in TiO 2 lattice. The optimal molar ratio of S/Ti at 0.25 was proven efficient in the PYR degradation. Influences of various reaction parameters including ST loading, oxone dosage, PYR concentration, and initial solution pH were examined. SO 4 •- , • OH, 1 O 2 , O 2 •- , and h + were found to be the reactive species generated in the ST/Oxone/Vis LED process. Different natural water constituents exerted dissimilar effects because of the generation of additional reactive species or their radical scavenging capabilities. Moreover, the reusability test indicates the ST photocatalyst is reusable and stable. A series of degradation intermediates was detected via four major degradation pathways. Overall, the ST/Oxone/Vis LED process was demonstrated to be a promising approach for the removal of organic pollutants.
研究领域:
环境科学
·
催化化学
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DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
·
2020
·
IF 6.155
Sheng Guo,Zhixiong Yang,Huali Zhang,Wei Yang,Jun Li,Kun Zhou
A simple sol-gel approach is proposed herein to fabricate CaFe 2 O 4 for the degradation of various organic pollutants (rhodamine B (RhB), tetracycline hydrochloride, humic acid, and methylene orange) under LED light irradiation mediated by peroxymonosulfate (PMS). The results indicate that the calcination temperature can significantly influence the performance of CaFe 2 O 4 for PMS activation, and the CaFe 2 O 4 sample obtained at 800 °C (CaFe 2 O 4 -800) exhibits the best efficiency in degrading RhB, which is much higher than that of Fe 2 O 3 -800. This can be attributed to the efficient separation of photogenerated electrons (e − ) and holes (h + ) by PMS, which is validated by transient photocurrent response and photoluminescence measurements. Results from density functional theory calculations indicate that the valence band of CaFe 2 O 4 -800 exhibits a high concentration of carriers and weak localization of electrons, which are favorable for PMS activation. Radical scavenging results confirm that h + and O 2 • − are the dominant reactive species. Moreover, CaFe 2 O 4 -800 not only demonstrated a stable performance during eight cycling runs with negligible iron leaching but also exhibited excellent degradation efficiency under natural water and sunlight. Finally, the mechanism and pathway of RhB degradation by the CaFe 2 O 4 -800/PMS/LED system are also proposed. This work presents the enormous prospect of CaFe 2 O 4 as an environmentally benign photocatalyst for PMS activation.
研究领域:
环境科学
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材料科学
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产品关联
DOI
高影响因子
RSC Advances
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2016
·Vol. 6
·期 80
·77093-77099
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IF 3.289
Guangxue Chen,Xiaoyuan Guan,Ruixin Xu,Junfei Tian,Fachuang Lu,Minghui He,Jianwen Yang
A series of thioxanthone dicarboxamide derivatives (TX-DCAs) containing hydrogen donors as one-component photoinitiators (PIs) have been prepared. In particular, the photoreactivity of these PIs was remarkably improved due to the covalent binding of the N-phthalimido derivative and type II chromophore thioxanthone. These derivatives exhibit interesting shifted absorption so that they can be utilized as versatile PIs upon exposure to various violet and visible LEDs (365 nm, 385 nm, 395 nm and 405 nm), and can efficiently actuate the free radical photopolymerization of acrylates.
研究领域:
材料科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
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2015
·
IF 7.435
Yaowen Gao,Zhuoyue Zhang,Simiao Li,Jin Liu,Linyu Yao,Yixi Li,Hui Zhang
Activation of persulfate (PS) by ultraviolet (UV) light or metal catalysts has been extensively studied, however, little is known about the activation of persulfate by clay-based catalysts in the presence of visible light-emitting diode (LED) irradiation. Herein, a novel kaolinite-supported iron oxide (K-Fe)/PS/Vis process for the degradation of Rhodamine B (RhB) from aqueous solution is reported. It was found that although persulfate can degrade RhB via a non-radical reaction, the excited RhB molecule (RhB * ) and the Fe(II) species formed on the catalyst surface can effectively activate persulfate to generate radicals which degrade RhB under visible light irradiation. On the basis of quenching experiments and electron paramagnetic resonance (EPR) studies, it is suggested that the free radicals produced from persulfate coupled with the surface-adsorbed radicals formed on the catalyst were responsible for the degradation of the dye via RhB * . Moreover, the K-Fe catalyst showed excellent reusability and stability with a low level of iron leaching. The findings of this work demonstrate a new pathway for activation of persulfate, which could effectively degrade organic pollutants and also provide some new insights into persulfate remediation of contaminated water.
研究领域:
环境科学
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催化化学
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产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
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2017
·
IF 6.065
Yaowen Gao,Yixi Li,Linyu Yao,Simiao Li,Jin Liu,Hui Zhang
Catalysts are known to activate peroxides to generate active radicals (i.e., hydroxyl radical ( OH) and sulfate radical (SO 4 − )) under certain conditions, but the activation of peroxides in the absence of catalysts under visible light irradiation has been rarely reported. This work demonstrates a catalyst-free activation of peroxides for the generation of OH and/or SO 4 − through photoexcited electron transfer from organic dyes to peroxides under visible LED light irradiation, where Rhodamine B (RhB) and Eosin Y (EY) were selected as model dyes. The formation of OH and/or SO 4 − in the reactions and the electron transfer from the excited dyes to peroxides were validated via electron paramagnetic resonance (EPR), photoluminescence (PL) spectra and cyclic voltammetry (CV). The performance of the peroxide/dye/Vis process was demonstrated to be altered depending on the target substrate. Meanwhile, the peroxide/dye/Vis process was effective for simultaneous decolorization of dyes and production of active radicals under neutral even or basic conditions. The findings of this study clarified a novel photoexcitation pathway for catalyst-free activation of peroxides under visible light irradiation, which could avoid the secondary metal ion (dissolved or leached) pollution from the metal-based catalysts and expand the application range of the peroxide-based catalytic process.
研究领域:
环境科学
·
化学
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产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2019
·
IF 8.355
Chi Zhang,Yi Li,Jie Li
Waterborne human viruses, with ubiquitous prevalence in aquatic environments, extremely low infectious doses, and high resistance to common disinfection processes, pose a substantial threat to human health. Herein, for the first time, a photocatalytic membrane reactor (PMR) driven by visible light emitting diodes (Vis-LEDs) was applied for effective water disinfection of human adenoviruses. The photocatalyst used in the PMR was selected to be a metal-free heterojunction (named as CNO) with the advantages of visible-light-response, efficient virucidal effects, green properties and easy recovery via microfiltration. The disinfection performance of the Vis-LED PMR towards human adenoviruses was improved by adjusting operation with response surface methodology (RSM). Based on twenty sets of operating data, a semi-empirical model was established with a high accuracy of R 2 = 0.9622 for predicting the final adenovirus inactivation after 300-min operation. The optimal operating solution was found to be 5.00-log MPN/mL, 320.30 mg/L and 502.65 min for initial virus concentration (IVC), photocatalyst loading (PL) and hydraulic retention time (HRT), respectively. Under the optimized operation, all human adenoviruses were completely inactivated without regrowth, accompanied by severe damage to capsids, within 600 min in the Vis-LED PMR. In addition, the CNO photocatalyst could be retained inside the reactor via low-energy microfiltration with excellent recovery (99.9 wt%) but without obvious chemical or structural changes. Our work can offer a simple, effective, economical and eco-friendly water disinfection device against resistant pathogenic microbes, with controllable efficiency by facilely varying operating solutions.
研究领域:
环境科学
·
公共卫生
·
生物工程
✓ 已验证
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2016
·
IF 8.328
Yaowen Gao,Simiao Li,Yixi Li,Linyu Yao,Hui Zhang
Photocatalysis based on metal-organic frameworks (MOFs) is being actively investigated as a potential technology in visible light harvesting and utilizing processes. Herein we report that MIL-53(Fe), an earth-abundant Fe-containing MOF material, shows photocatalytic activity for the degradation of Acid Orange 7 (AO7) from aqueous solution under visible LED light irradiation, yet the photocatalytic performance of bare MIL-53(Fe) was not satisfactory due to the fast recombination of photoinduced electron-hole pairs. This can be effectively overcome by adding the external electron acceptor (e.g., persulfate, PS) to the catalytic process. The accelerated photocatalytic degradation of AO7 is demonstrated by the result that the degradation efficiency of AO7 in the MIL-53(Fe)/PS/Vis process reached almost 100% within 90 min as compared to only 24% under the identical experimental conditions for the MIL-53(Fe)/Vis process. To investigate the mechanism of the MIL-53(Fe)/PS/Vis process, photoluminescence (PL) spectra, electrochemical measurements and electron paramagnetic resonance (EPR) analysis were performed. It was concluded that the efficient separation of photogenerated electrons and holes by the introduced PS and the subsequent formation of reactive radicals resulting from the activation of PS by photogenerated electrons accounted for the accelerated photocatalytic degradation of AO7 in the MIL-53(Fe)/PS/Vis process. Furthermore, the applicability of MIL-53(Fe) used in the persulfate-mediated photocatalytic process was systematically investigated in terms of the identification of reactive radicals, the reusability and stability of the photocatalyst, as well as the effect of operating parameters. The findings of this work highlighted the great potential of MOFs as photocatalysts and elucidated a new opportunity for persulfate remediation of contaminated water.
研究领域:
环境科学
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材料科学
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化学工程
·
光化学
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产品关联
DOI
高影响因子
PROGRESS IN ORGANIC COATINGS
·
2022
·
IF 6.206
Zhaoxian Tang,Yanjing Gao,Shengling Jiang,Jun Nie,Fang Sun
In this work, four ethyl cinnamoylformate derivatives photoinitiators (ECFs), which have good photobleaching ability and excellent cytocompatibility in LED-triggered photopolymerization , were designed and synthesized by a simple two-step reaction. The potential initiating and photobleaching mechanisms of ECFs under visible LED were researched by ultraviolet−visible absorption spectroscopy , nuclear magnetic resonance, high−resolution mass spectroscopy and electron spin resonance . The as-prepared photoinitiators ethyl p-methoxycinnamoyl formate (O-ECF) and ethyl p -methylmercaptocinnamoyl formate (S-ECF) exhibited much higher initiating rate under 405 nm and 455 nm LED compared to the commercial photoinitiator 2-isopropylthioxanthone (ITX). More significantly, carbon‑carbon double bonds of ECFs can polymerize in the presence of tertiary amine under the irradiation of 455 nm or 405 nm LED, which endows ECFs with good photobleaching performance and excellent migration stability and cytocompatibility. Furthermore, ECFs are able to greatly initiate deep-layer photopolymerization under 455 nm LED and the photopolymerization depth reached 7.0 cm after the irradiation for 20 min. This work also affords a new perspective for designing photoinitiators with good photobleaching performance.
研究领域:
材料科学
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化学
·
高分子科学
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生物医学工程
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产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2022
·
IF 9.136
Tingting Song,Xiaoyan Meng,Huayu Wang,Chao Zhang,Ming Ge
Heterogeneous photocatalysis/persulfate oxidation process has been regarded as a promising technology for antibiotic contaminants removal. Magnetic ZnFe 2 O 4 /Ag composite catalyst was synthesized to activate peroxydisulfate (PDS) toward tetracycline (TC) degradation under the visible-LED-light irradiation. The synergistic effect of ZnFe 2 O 4 and Ag endowed the optimized ZFO/Ag-15 with excellent photocatalytic performance for PDS activation and TC degradation, and 90.06 % of TC (20 mg/L) was efficiently degraded after 80 min of reaction. Ag can enhance the visible light absorption of ZnFe 2 O 4 and accelerate the separation of photo-induced electron/hole pairs, thereby promoting the generation of O 2 − and SO 4 − radicals. In addition, Ag can directly activate PDS to generate SO 4 − . Although the catalytic performance of magnetic ZFO/Ag-15 gradually decreased after each cycle due to the corrosion of Ag and the formation of inactive AgO, the catalytic activity of used catalyst was partially recovered by heat treatment. Quenching experiments and EPR tests indicated that the free radical (O 2 − , SO 4 − and OH) and non-free radical ( 1 O 2 , h + ) oxidation processes cooperated to degrade TC in Vis-ZFO/Ag-15/PDS system. The effect of operational factors (PDS concentration, temperature, solution pH, coexisting inorganic anions and humic acid) on TC degradation was investigated, and TC removal from the different water matrices (river water, tap water and secondary effluent) was also evaluated. The degradation products were detected using LC-MS and the possible TC degradation pathways were established.
研究领域:
环境科学
·
化学工程
·
材料科学
·
水处理
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）