PHOTOCHEMISTRY AND PHOTOBIOLOGY
·
2018
·Vol. 94
·期 4
·650-658
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IF 2.214
Rong Liu,Yonggang Zhang
Photoelectrocatalytic (PEC) system greatly improves the migration of photoexcited charges, retards the fast recombination of electron-hole and increases the lifetime of photogenerated holes. In this article, we constructed a novel PEC system to degrade berberine chloride form (BCF). XRD patterns indicated aging time was an important condition for the crystal type of TiO 2, and the best proportion of anatase/rutile was 80/20. The band gap energy of the TiO 2 was 3.01 eV. We demonstrated that a synergistic effect existed between photocatalysis (PC) and electrocatalysis (EC). Besides, we discussed the influence of pH, current density, the amount of catalyst and initial BCF concentration on the degradation of BCF. Electron spin resonance (ESR) through spin trap 5, 5-dimethyl-1-pyrroline-N-oxide (DMPO) and the scavenging experiments suggested that the reactive oxygen species (ROS) were superoxide radicals ( ), hydroxyl radicals (·OH) and sulfate radical ( ) in PEC system. Furthermore, we compared the two pathway of formation DMPO-SO 4 adducts and found that was the most major oxidized species in degrading BCF. We proposed a plausible reaction mechanism. Intriguingly, even under lower current and weaker light conditions, the PEC process maintained its effectiveness, demonstrating the feasibility of the PEC approach.
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高影响因子
JOURNAL OF HAZARDOUS MATERIALS
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2018
·
IF 6.434
Qiongfang Wang,Yisheng Shao,Naiyun Gao,Wenhai Chu,Juxiang Chen,Xian Lu,Yanping Zhu,Na An
UV/persulfate (UV/PS) has been as an efficient method to remove many organic contaminants in water. However, little is known about the impact of UV/PS pretrement on the formation of disinfection byproducts (DBPs) during chlorination of 2,4-Di-tert-butylphenol (2,4-D). This research evaluated that UV/PS preoxidation of 2,4-D greatly decreased the DBPs generation during following chlorination. In the 2,4-D solution without any treatment system (O system), trichloromethane (TCM) as the only detected DBP increased with the increase of chlorine dosage. While the formation of TCM declined with the increase of PS dosage in the PS and UV/PS preoxidation systems and decreased the estimated toxicity accordingly. And it was found the residual PS in system could combine free chlorine to further oxidize 2,4-D. And intermediate products were analysed by high-performance liquid chromatography combined with triple quadrupole mass spectroscopy analysis. In the presence of bromine, the bromodichloromethane augmented first and then slowly decreased while dibromochloromethane and tribromethane increased both in O and UV/PS systems with the increase of [Br − ]. Bromine substitution was decreased by preoxidation of UV/PS. UV/PS could decrease the total-DBPs formation when used in the real water matrix contained 100 μg/L 2,4-D.
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JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
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2018
·Vol. 132
·期 3
·1795-1804
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IF 2.209
Ning Xiangli,Liang Hongbo,Bu Jiang,Xiong Lei,Huang Shengmei,Xu Haitao
A novel tri-substituted triazine in which substituted methacrylated piperzinyl (TMAPT) was synthesized and was then blended with di(acryloyloxy propyl) methyl phosphate (DAPMP) and pentaerythritol triacrylate (PETA) in different ratios to prepare UV curable intumescent flame-retardant coating. Their thermal stabilities and flame-retardant properties were studied by thermogravimetric analysis and limiting oxygen index (LOI), respectively. The results showed that the LOI values of the film increased almost linearly from 19.2% for C 10 N 0 to 25.2% for C 5 N 5 with increasing the content of TMAPT, which showed typical gas-phase flame-retarding mechanism. The FTIR spectra of the cured samples with increasing temperatures were measured, and the results indicated the potential expanding mechanism was that the nitrogen volatiles from TMAPT were wrapped by the char formed by catalyzing of poly(phosphoric acid)s, which was the degradation products of DAPMP. The expansion processes were monitored by a self-made equipment, which indicated the synergetic effect between TMAPT and DAPMP and further demonstrated the expansion mechanism. The sample PETA 4 DAPMP 2 TMAPT 4 (C 4 P 2 N 4 ) had the highest expansion degree of 126 among all samples. Moreover, thermal insulation properties of the cured coating were further measured, which also proved the synergetic effect between TMAPT and DAPMP.
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PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2018
·Vol. 20
·期 18
·12808-12816
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IF 3.906
Zhiyong Li,Xiaoqing Yuan,Ying Feng,Yongkui Chen,Yuling Zhao,Huiyong Wang,Qingli Xu,Jianji Wang
Photo-induced conductivity modulation of stimuli-responsive materials is of great importance from the viewpoint of fundamental research and technology. In this work, 5 new kinds of azobenzene-based photo-responsive ionic liquids were synthesized and characterized, and UV/vis light modulation of their conductivity was investigated in an aqueous solution. The factors affecting the conductivity modulation of the photo-responsive fluids, such as photo-isomerization efficiency, photo-regulation aggregation, concentration and chemical structure of the ionic liquids, were examined systematically. It was found that the conductivity of the ionic liquids in water exhibited a significant increase upon UV light irradiation and the ionic liquids with a shorter alkyl spacer in the cation showed a more remarkable photo-induced conductivity enhancement with a maximum increase of 150%. In addition, the solution conductivity was restored (or very close) to the initial value upon an alternative irradiation with visible light. Thus, the solution conductivity can be modulated using alternative irradiation with UV and visible light. Although the reversible photo-isomerization of the azobenzene group under UV/vis irradiation is the origin of the conductivity modulation, the photo-regulated aggregation of the ionic liquid in water is indispensable for the maximum degree of conductivity modulation because UV irradiation can weaken, even break the aggregated cis-isomers of the ionic liquids in an aqueous solution.
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ACS Sustainable Chemistry & Engineering
·
2018
·
IF 6.14
Qiong Wu,Yun Hu,Jijun Tang,Jing Zhang,Cuina Wang,Qianqian Shang,Guodong Feng,Chengguo Liu,Yonghong Zhou,Wen Lei
Novel soybean-oil-based (SBO-based) epoxy acrylate (EA) resins were developed via ring-opening reaction of epoxidized soybean oil (ESO) with hydroxyethyl methacrylated maleate (HEMAMA) precursor, a synthesized unsaturated carboxylic acid having two active C═C groups and a side methyl group. Experimental conditions for the synthesis of the precursor and the SBO-based EA (ESO-HEMAMA) product were studied, and their chemical structures were confirmed by FT-IR, 1H NMR, 13C NMR, and gel permeation chromatography. Subsequently, the volatility of HEMAMA was studied and compared with acrylic acid (AA). Furthermore, gel contents and ultimate properties of the UV-cured ESO-HEMAMA resins were investigated and compared with a commercial acrylated ESO (AESO) resin. At last, UV-curing behaviors of the SBO-based EA resins were determined by real-time IR. It was found that the HEMAMA precursor showed much lower volatility than AA, and the optimal pure ESO-HEMAMA resin possessed a C═C functionality up to 6.02 per ESO and biobased content of 65.4%. Meanwhile, the obtained ESO-HEMAMA biomaterials exhibited much superior properties as compared to the AESO resin. For instance, the obtained pure ESO-HEMAMA material possessed a storage modulus at 25 °C of 1.00 GPa, glass transition temperature (Tg) of 70.1 °C, and tensile strength and modulus of 13.4 and 592.1 MPa, which were 9.4, 3.6, 6.9, and 15.7 times the values of the pure AESO material, respectively. The resulting biomaterial with 30% of hydroxyethyl methacrylate diluent even reached a tensile strength of 28.4 MPa and Tg of 89.0 °C. Therefore, the developed SBO-based EA resins are very promising for applications in UV-curable coatings.
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高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2018
·Vol. 136
·期 10
·47170
·
IF 1.901
Hui Zhang,Hao Yang,Baoqing Shentu
Surface modification of titanium dioxide (TiO 2 ) nanoparticles (NPs) by silane coupling agents and the ultraviolet-C (UV-C) aging behavior of silicone rubber (SiR) incorporated with the modified TiO 2 NPs were investigated in this work. The SiR samples incorporated with TiO 2 NPs displayed excellent stability against the UV-C radiation. In order to improve the dispersion of TiO 2 NPs in the SiR matrix, the surface of TiO 2 NPs was modified with 3-aminopropyl triethoxysilane and 3-trimethoxysilyl propyl methacrylate, respectively. The surface modification of TiO 2 NPs was characterized by thermal gravimetric analysis and Fourier transform infrared spectroscopy. The dispersion stability of the pristine TiO 2 NPs and surface silane-modified TiO 2 NPs was evaluated in an organic solvent (toluene). Effect of surface modified TiO 2 NPs on the UV-C aging behavior of SiR was evaluated in terms of the change of surface morphology, tensile properties, hardness, crosslinking density, and surface microstructure before and after the UV-C aging. The results showed that surface modification of TiO 2 NPs with silane coupling agents could improve the dispersion of TiO 2 NPs in the SiR matrix. Moreover, the SiR with modified TiO 2 NPs showed an improved aging resistance to the UV-C radiation, compared with the samples with pristine TiO 2 NPs. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136 , 47170.
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COMPOSITES COMMUNICATIONS
·
2018
·
IF 0
Zhitong Zhao,Anran Mao,Weiwei Gao,Hao Bai
Over exposure of UV light could cause serious damages to human being, such as DNA damage, skin aging and cancer, cataract and so on. Hence, there is an urgent need to develop optically transparent materials as windows, glasses and protection film etc. to filter UV light. In the present study, a homogeneous polyvinyl alcohol (PVA)/zinc oxide (ZnO) film was fabricated via a facile in situ method by controlling the reaction of Zn 2+ with OH - ions and the dehydration process of Zn(OH) 4 2- throughout PVA hydrogel matrix. The obtained PVA/ZnO film can absorb over 99% of UV light at wavelength region between 200 and 350 nm, and its optical transparency in the visible region was similar to that of neat PVA film (87–90%). In addition, this hybrid film was flexible (~5% strain at fracture) with excellent tensile strength (130–140 MPa), and able to be easily modulated onto various substrates as UV-protection film. Overall, this facile, low cost in situ fabrication method with environment-friendly nature could be applicable to various hydrogel systems for developing novel transparent UV-shielding nanocomposites with desired properties.
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ACS Omega
·
2018
·
IF 0
Jingcheng Liu,Jiancheng Cao,Zhen Zhou,Ren Liu,Yan Yuan,Xiaoya Liu
Two series of ultraviolet (UV)-cured self-healing polyurethane (PU) oligomers were synthesized through a prepolymer process from isophorone diisocyanate (IPDI) or 1,6-hexamethylene diisocyanate (HDI), polycarbonate diol (PCDL) of varying molecular weight (500, 1000, and 2000 Da), and chemically modified cyclotriphosphazene as hard cores were introduced. The synthesized oligomers contained rigid aromatic rings as “hard cores” and long fatty chains as “flexible arms”. Nuclear magnetic resonance spectrometer (H NMR) and Fourier transform infrared spectroscopy were used to characterize the structures of the oligomers. In addition, the UV-cured self-healing PU coatings were prepared by designing some coating formulations with the PU oligomers. The self-healing properties and mechanical properties of the UV-cured coatings were investigated. The results revealed that the coatings had self-healing properties based on hydrogen bonds. As the molecular weight of PCDL decreased, the coatings exhibited increased hardness, tensile strength, and glass transition temperature. Furthermore, the coatings exhibited excellent thermostability. The results proved the application prospects of the self-healing coatings with high repair efficiency and excellent mechanical properties.
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CELLULOSE
·
2019
·Vol. 26
·期 13
·8153-8164
·
IF 3.917
Yang Maiping,Liu Weiqu,Jiang Chi,Xie Yankun,Shi Hongyi,Zhang Fengyuan
Abstract Self-cleaning, photocatalysis and UV shielding cotton fabric was fabricated through a mild, facile and efficient method via ZnO/polydimethylsiloxane coatings. No fluorinated materials were employed during the preparation process. The modified cotton presented a high superhydrophobicity, with a water contact angle of 160.4° and water shedding angle of 6.0°. The SEM, EDS and XPS tests were used to investigate the differences of microstructures and chemical compositions of fabrics before and after coating. The robustness of the coated fabric was demonstrated in many aspects, such as immersing in acid and basic solutions, different organic solvents and abrasion test. In addition, the as-prepared superhydrophobic surface displayed excellent self-cleaning due to the synthesis function of superhydrophobicity and photocatalysis. The UV durability and UV shielding characteristics were also investigated. These properties promote the multifunctional cotton fabric as a satisfied candidate in various promising fields. Graphic abstract
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高影响因子
REACTIVE & FUNCTIONAL POLYMERS
·
2019
·
IF 3.074
Nan Zheng,Xuan Zhang,Xin Min,Jie Liu,Wenge Li,Xiaohui Ji
A novel robust and flexible superhydrophobic fluoropropyl methylsiloxane-dimethylsiloxane multi-block copolymer containing methacryloxyl group was synthesized via ring-opening polymerization, followed by macromolecular modification using 3-(trimethoxsilyl) propyl methacrylate (TMPMA). The propionyloxy group of MAc(PTFMS- alt -PDMS) could be crosslinked under UV irradiation , and its silicon methoxy group (-SiOCH 3 ) was simultaneously condensed under moisture ambient, so as to acquire both higher crosslink density and adhesion strength duo to the dual-curing mode. After coating and curing MAc(PTFMS- alt -PDMS) on the surface of cotton fabric, a robust superhydrophobic elastomer coating was obtained. The elastomer exhibited excellent mechanical properties with a tensile strength >4.0 Mpa and an elongation at break >300%. Moreover, the elastomer exhibited superhydrophobic properties (contact angle CA > 150 o ) and good adhesion properties (shear strength >3.7 Mpa) on various inorganic and organic substrates such as steel, glass, paper, and polyethylene (PE) films, with the assistant of the hydrophobic silica particles. The excellent flexibility and adhesive strength of the MAc(PTFMS- alt -PDMS) allowed a PE film to be bent at a large angle (120 o ). The results obtained here demonstrate that this material has good application prospects where flexible superhydrophobic coatings are desired.
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RSC Advances
·
2019
·Vol. 9
·期 43
·24915-24921
·
IF 3.049
Ting Ju,Zhiliang Zhang,Yang Li,Xinfeng Miao,Jianbing Ji
With the severe energy and environmental issues, lignin has received increasing attention as a renewable biomass feedstock. The development of lignin-based nanoparticles provides a new route to the valorization of lignin. In this work, we propose a simple continuous method to prepare lignin nanoparticles (LNS) using a microchannel reactor. Polyvinylpyrrolidone (PVP)/sodium dodecyl sulfate (SDS) were selected as stabilizers. Spherical-like lignin nanoparticles with an average size of 13 nm were obtained in a T-shaped microchannel reactor. The effects of solvent species, PVP/SDS mass ratio, and lignin solution flow rate on the size of LNS were investigated. The as-prepared LNS had a good stability during 60 days-storage and were used as an additive to form UV-shielding composite films with poly(vinyl alcohol) (PVA). Compared with raw lignin, the addition of LNS could enhance the UV-shielding efficacy by 13.3% in the ultraviolet spectrum (250 nm). The present work suggests that the microchannel reactor is a promising continuous approach to prepare LNS with versatile applications.
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高影响因子
COMPOSITES PART B-ENGINEERING
·
2017
·
IF 4.727
Tong Zhang,Bo Jiang,Yudong Huang
A novel polymerizable benzophenone photoinitiator containing acryloxy (BPA) was synthesized. The photopolymerization of photosensitive methacrylic-silicone resins (MASR) initiated by BPA was studied. Results show that BPA is an efficient photoinitiator, which could generate radicals from the photolysis reaction and be consumed via copolymerizing with MASR. The designed UV-curing silicone resins system initiated by BPA showed a high carbon-carbon double bonds conversion above 80% after 20 s UV radiation. In addition, reduced graphene oxide (rGO)-TiO 2 composites were elaborated by hydrothermal reaction . The synergistic effects from graphene and TiO 2 further enhanced the carbon-carbon double bonds conversion of MASR to 86% with 15 s UV irradiation, demonstrating that the incorporated rGO-TiO 2 significantly improve the formulation UV-curing reactivity. Additionally, UV-cured MASR with rGO-TiO 2 showed an excellent thermal stability. This work proposes an efficient strategy to improve the polymerization degree of UV-curable photosensitive silicone resins.
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危险品化学品经营许可证（带存储）