CHINESE CHEMICAL LETTERS
·
2011
·Vol. 23
·期 1
·29-32
·
IF 0.775
Wen Hui Zhong,Ying Na Cui,Shen Min Li,Ying Ping Jia,Jing Mei Yin
The carbonylation of phenyl bromide catalyzed by Co(OAc) 2 has been investigated with PhCOPh as a sensitizer under visible light in the presence of basic additive. With strong base CH 3 ONa, PhCOOCH 3 is produced in 70% yield with 100% selectivity , the similar results are also obtained with a stronger base (CH 3 ) 3 CONa. However, with another strong base NaOH, the yield of the ester is only 40%. On the other hand, with weak base NaOAc or ( n -C 4 H 9 ) 3 N, phenyl bromide cannot be carbonylated. The results of carbonylation of the six substituted phenyl bromides suggest that the activities of o , m , p -BrC 6 H 4 CH 3 are similar to phenyl bromide, while the activities of o , m , p -BrC 6 H 4 Cl are higher with the high yields (≥93%) of the corresponding chloro-esters. In addition, the relative position of bromine and chlorine or methyl on phenyl ring has little effect on the activity of the carbonylation .
研究领域:
有机化学
·
光催化
·
均相催化
·
反应机理
·
绿色化学
✓ 已验证
DOI
高影响因子
EUROPEAN POLYMER JOURNAL
·
2021
·
IF 4.598
Yue Li,Zhencai Qu,Kun Wu,Peng Lv,Huifa Meng,Haoting Zheng,Jun Shi,Mangeng Lu,Xiaomei Huang
In this work, a bio-derived char-forming strategy for surface fireproofing was developed. Specifically, a vinyl-modified tannic acid, (VTA) was synthesized by a ring-opening reaction between tannic acid and glycidyl methacrylate. Integration of epoxy acrylate resin, VTA and tri-(glycidyl methacrylate) phosphate (TGMA), a novel UV-curing coating was prepared, which rendered the PET sheets with superior fireproofing effect. PET samples that were surface coated with the designed UV-curing agent displayed a UL-94 V-0 rating. The peak heat release rate (peak HRR) for combustion of PET was reduced by 10.66% upon application of the flame-retardant coating in cone calorimetry tests. However, the total smoke release (TSR) increased by 48.28% due to pyrolysis of tannic acid produces 1,2,3-benzenetriol and carbon dioxide, plus the triol underwent partial combustion with the formation of large amount of particulates. The thermal behavior of cured coating revealed that the presence of high carbon content aromatic tannic acid promoting cationic crosslink and char formation ability. When 40% VTA was added into a coating, the pyrolysis char yield increased by 36.88%. Furthermore, the capability of inhibit heat transfer with the presence of VTA significantly decreased the maximum rate of weight loss for the coating by 85.97%. The increase in the VTA content promoted crosslinking density of the coating, which leads to good rigidity, outstanding abrasion resistance and remarkable water fastness.
研究领域:
高分子材料
·
阻燃化学
·
表面工程
·
绿色化学
·
材料科学
✓ 已验证
DOI
高影响因子
MATERIALS CHEMISTRY AND PHYSICS
·
2022
·
IF 4.778
Zehan Liu,Pengpeng Cheng,Yongfei Li,Ruyan Kang,Jian Zhou,Jia Zhao,Zhiyuan Zuo
With the aim of addressing the growing challenge of approaching the end of Moore's law and von Neumann bottleneck, the evolution of neuromorphic computing based on memristors that emulate the behaviors of the brain has attracted great attention. Organic-inorganic hybrid lead halide perovskites with inherent hybrid ionic-electronic conduction ability have been proposed as promising candidates for memristors to replace traditional charge-based memory. Here we propose MA 0.85 Cs 0.15 PbI 3 memristors with high surface crystallinity and stable operation in the atmospheric environment by mixing inorganic cation Cs + and organic cation MA + . The prepared memristors present excellent resistive switching performances including low operation voltage, high ON/OFF ratio, stable endurance, long retention, and robustness under ambient condition. Besides that, four distinct resistance states have been obtained in the above devices by modifying the operation voltages. Moreover, the resistance switching processes can be controlled both by electrical field and light illumination. Finally, this research provides utilization potentiality in the optical and electrical two-dimension controlled multilevel information devices with a total of five stable resistance states. The present work would offer an effective way to develop multifunctional high-density data-storage applications by storing multiple resistance states in a single unit cell.
研究领域:
材料科学
·
纳米电子学
·
凝聚态物理
·
信息存储技术
·
类脑计算
✓ 已验证
DOI
高影响因子
RSC Advances
·
2022
·Vol. 12
·期 13
·8145-8153
·
IF 4.036
Yulei Gao,Xiang Di,Fenfen Wang,Pingchuan Sun
Amorphous polymer-based room temperature phosphorescence (RTP) materials exhibiting tunable emission colors have received tremendous attention and are extremely challenging to prepare. Herein, polyacrylamide-based RTP materials with tunable multicolor emission were prepared via copolymerizing phosphor with concentration dependent luminescence colors and acrylamide with different molar ratios. The hydrogen bonding interactions and chemically crosslinked structures in these polymers effectively restrict the mobility of phosphors and activate efficient RTP emission. The molar ratio of phosphor and acrylamide has a significant influence on the photophysical properties of these polymers, which can be used to fabricate multicolor materials. In addition, the RTP intensity decreases with increasing humidity due to the disassociation of hydrogen bonding by adsorption of water, manifesting as a humidity sensor. Benefiting from the distinguishable RTP lifetimes and the responsiveness to humidity, triple encoding for information encryption is successfully realized.
研究领域:
高分子化学
·
分析化学
·
材料科学
·
传感器技术
·
信息安全
✓ 已验证
DOI
高影响因子
CURRENT APPLIED PHYSICS
·
2023
·
IF 2.4
WenXin Zhang,Hao Li,Haofei Cong,Ruifu Zhou,Yuanbin Qin,Peilong Xu,Xuhai Liu,Fengyun Wang
One-dimensional wide band-gap metal oxide semiconductors demonstrate enormous potential in high-performance ultraviolet photodetectors. Here, via tuned zinc oxide (ZnO) concentration ratio and heterojunction structure as well as decent V TH value, we electrospun tin zinc oxide (SnZnO X ) nanowires for photoelectronic conversion function. The constructed optimized photodetectors based on Sn 8 Zn 2 O X nanowires can exhibit a remarkable detectivity of 1.77 × 10 16 Jones, excellent responsivity of 2.23 × 10 3 A/W and relative high sensitivity over 10 4 . In addition to the excellent photodetection performance, Sn 8 Zn 2 O X nanowire devices exhibit nonvolatile memory effect , which can maintain the light-induced low resistance state at 5 V without light. Moreover, a voltage of 30 V was applied to Sn 8 Zn 2 O X nanowires devices to realize light-writing state switching to bias-erasing state, and the device could come back to their initial high resistance state. These results indicate SnZnO X nanowires devices possess a tremendous potential in the circuit design of the artificial visual system.
研究领域:
材料科学
·
纳米电子学
·
光电子学
·
半导体器件
·
人工视觉系统
✓ 已验证
DOI
高影响因子
BIOSENSORS & BIOELECTRONICS
·
2013
·
IF 5.437
Yaqi Hu,Zhonghua Xue,Hongxia He,Ruixia Ai,Xiuhui Liu,Xiaoquan Lu
A novel light “on–off” photoelectrochemical sensing for the sensitive determination of hydroquinone was developed based on the porphyrin-functionalized Au nanoparticles on graphene (porphyrin/AuNPs/graphene). Gold nanoparticles (AuNPs) were firstly modified onto graphene sheets using NaBH 4 as reductant and the porphyrin/AuNPs/graphene nanocomposites were then synthesized by self-assembly decoration of sulfhydryl porphyrin on AuNPs modified graphene sheets by S–Au bond. The porphyrin/AuNPs/graphene nanocomposites were characterized by transmission electron microscopy , X-ray photoelectron , and ultraviolet–visible absorption spectroscopies . The nanocomposites showed good dispersion in water and on indium tin oxide (ITO) surface. The resulting porphyrin/AuNPs/graphene modified ITO electrode showed good photoelectrochemical behavior toward the oxidation of hydroquinone (HQ) at 0 V under white light illumination. The proposed photoelectrochemical method could detect hydroquinone with a wide linear response ranging from 20 to 240 nM ( R =0.9914). The detection limit was 4.6 nM for HQ ( S / N =3). Thus, the nanocomposites would be expected to be a novel photoactive material for photoelectrochemical biosensing.
研究领域:
分析化学
·
纳米生物技术
·
环境监测
·
电化学
·
生物传感器
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·Vol. 50
·期 14
·25541-25547
·
IF 5.1
Hang Zhang,Ahsan Nawaz,Feiyu Huang,Zhiping Zhang,Hongfei Liu
Orthorhombic In 0.5 Sc 1.5 Mo 3 O 12 thin films have been synthesized using the sol-gel spin coating . Influences of post-annealing temperatures on crystal structure, morphology, negative thermal expansion (NTE) and optical performances of the thin films were studied using XRD , SEM, XPS, high-temperature XRD and UV–Vis–NIR spectrophotometer. XRD and SEM results show that as-prepared thin film is in an amorphous state with a smooth and dense surface. Orthorhombic In 0.5 Sc 1.5 Mo 3 O 12 thin films were obtained after post-annealing in 550–750 °C. The higher the annealing temperature in 550–750 °C, the better the crystallinity of orthorhombic In 0.5 Sc 1.5 Mo 3 O 12 thin films . In addition, the grain size of the In 0.5 Sc 1.5 Mo 3 O 12 thin film also grows as the annealing temperature increases. The resulting orthorhombic In 0.5 Sc 1.5 Mo 3 O 12 thin films exhibit anisotropic NTE. Its volumetric coefficient of thermal expansion (CTE) is −3.44 × 10 −6 °C −1 , while the CTEs in a -, b - and c -axis directions are −4.70 × 10 −6 °C −1 , 5.37 × 10 −6 °C −1 , and -4.10 × 10 −6 °C −1 in 25–700 °C, respectively. In addition, the transmittance of orthorhombic In 0.5 Sc 1.5 Mo 3 O 12 thin films post-annealed at 750 °C is around 87.75 %–95.03 %.
研究领域:
材料科学
·
无机非金属材料
·
功能薄膜
·
热膨胀调控
·
光学材料
✓ 已验证
DOI
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2015
·Vol. 17
·期 29
·19457-19464
·
IF 4.493
Ganwei Zhang,Jiwen Hu,Yuanyuan Tu,Guping He,Fei Li,Hailiang Zou,Shudong Lin,Gonghua Yang
The diblock copolymer poly[2,2,2-trifluoroethyl methacrylate-r-styrene]-block-poly[(2-cinnamoyloxyethyl methacrylate)] [P(TFEMA-r-Sty)-b-PCEMA] was synthesized via atom transfer radical polymerization. The copolymer underwent self-assembly in TFEMA/CH2Cl2 to form spherical micelles. Photo-cross-linking of the PCEMA domains of these micelles yielded cross-linked nanoparticles. The cross-linked nanoparticles were subsequently cast from CH2Cl2/methanol solvent mixtures at methanol volume fractions of more than 30% to yield rough surfaces bearing small nanobumps on micron-sized aggregations that were connected together to form cross-linked nanoparticles. These surfaces were superhydrophobic with a water contact angle of 161 ± 1° and a sliding angle of 6 ± 1°. Spraying these nanoparticles onto substrates exhibiting microscale roughness, such as filter paper, by a traditional coating technique also created superhydrophobic surfaces. A thin layer of nanoscale spherical protrusions was observed on the microscale fibers of filter paper by scanning electron microscopy. The coated filter paper samples exhibited a water contact angle and a sliding angle of 153 ± 1° and 9 ± 1°, respectively.
研究领域:
高分子化学
·
材料科学
·
表面科学
·
纳米技术
·
功能材料
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2020
·
IF 10.652
Simin Gu,Mao Xia,Cheng Zhou,Zihui Kong,Maxim S. Molokeev,Li Liu,Wai-Yeung Wong,Zhi Zhou
The discovery of novel Mn 4+ -doped oxide red phosphor with suitable spectrum for plant growth is a hot issue in the recent years due to the characteristic red photoluminescence of 2 E g → 4 A 2 transition in Mn 4+ ions. Generally, the emission position of Mn 4+ is hard to tune because of specific crystal field in most phosphors. In this work, tunable luminescence property with obvious red shift in the spectra is observed in the Mn 4+ -doped SrMgAl 10-y Ga y O 17 red phosphor via simple substitution of Ga 3+ for Al 3+ , and crystal field theory and nephelauxetic effect are employed to explain this phenomenon. Meanwhile, the Ga 3+ dopant changes the shape of the spectra because Ga 3+ dopant guides the replacement site of Mn 4+ and changes the luminescence center. Improved emission intensity is obtained because appropriate Ga 3+ doping leads to larger band gap and reduces non-radiative transitions. Phosphor-converted LED (pc-LED) devices fabricated with blue chip (470 nm) and the as-obtained SrMgAl 10-y Ga y O 17 :1.0%Mn 4+ phosphors emit bright blue and red light, which fit the absorption regions of plant pigments well, thus SrMgAl 10-y Ga y O 17 :Mn 4+ phosphor can be a candidate for plant growth LED light.
研究领域:
材料科学
·
光电子学
·
固体化学
·
农业光生物学
·
发光材料
✓ 已验证
DOI
高影响因子
MICROCHEMICAL JOURNAL
·
2022
·
IF 5.304
Xu Chu,Tao Chen,Yan Cao
This paper reports a simple, rapid and sensitive fluorescence sensor for the parallel determination of iron (III) (Fe 3+ ), terbium (III) (Tb 3+ ) and europium (III) (Eu 3+ ) ions using Carbon Dot (CD) serving as a fluorescence probe. The Carbon Dot (CD), which was synthesized via an acid-cutting method using anthracite coal as the carbon source, was found to have rich carboxyl and hydroxyl groups on its surface. The fluorescence of the as-prepared CD can be selectively quenched by the Fe 3+ ion via non-radiative electron-transfer, and furthermore, the as-prepared CD can also sensitize the luminescence of both Tb 3+ and Eu 3+ ions through the antenna effect and enhance the fluorescence of Tb 3+ and Eu 3+ by more than several orders of magnitude. Therefore, the as-prepared CD was applied as a fluorescence probe towards the parallel determination of Fe 3+ , Tb 3+ and Eu 3+ and exhibited detection limits in 0.019, 0.10 and 0.79 μM, respectively. The fluorescence quenching mechanism and energy transfer mechanism were also studied in details.
研究领域:
分析化学
·
环境监测
·
纳米材料
·
荧光探针
·
生物传感
✓ 已验证
DOI
高影响因子
JOURNAL OF MOLECULAR CATALYSIS A-CHEMICAL
·
2016
·
IF 3.958
Lei Zhao,Baoyue Zhang,Xin Xiao,Feng Long Gu,Rui-Qin Zhang
Active species such as holes, electrons, hydroxyl radicals ( OH), and superoxide radical anions ( O 2 − ) involved in the photocatalytic oxidation of benzyl alcohol (BA) into benzaldehyde (BAD) on TiO 2 under ultraviolet (UV) light were investigated by adding corresponding scavengers. The experimental results show that the oxidation of BA into BAD is driven mainly by the holes and OH radical. The role of dissolved O 2 was studied by bubbling N 2 through the reaction. The results show that the dissolved O 2 is, to some extent, the source of OH. Additional density functional theory (DFT) calculations identified two H-abstraction pathways ( R abs OH and R abs α). The structure of the R abs OH product is less stable and tends to transfer resulting in the R abs α product. The holes are the main driving force for the abstracting of H from BA. The OH radical combines with the H-abstract product to form a precursor of product BAD, detected by LC–MS technique ( m / z 123), which then undergoes an intramolecular dehydration reaction to form BAD. The results will help to select the optimal active species for the photocatalytic oxidation of BA into BAD on TiO 2 under UV light.
研究领域:
物理化学
·
光催化
·
环境化学
·
材料化学
·
理论计算化学
✓ 已验证
DOI
高影响因子
Desalination and Water Treatment
·
2024
·
IF 1
Qing Zhang,Zhenping Ma,Xin Jing,Hao-Yang Mi,Yuejun Liu,Songwei Li
The polyamide (PA) reverse osmosis (RO) membranes prepared by interfacial polymerization at a free aqueous–organic interface always suffer from polymerization instability on the free-interface and low chlorine resistance. Focusing on these problems, in this study, a new approach was proposed which introduced an additional buffer layer to assist the free-interfacial polymerization (BLFIP). And due to the adjustment of the mitigation of the organic phase and water phase on the free-interface, defect-free PA membranes with significantly improved surface smoothness were successfully prepared by the proposed BLFIP process and the resultant membranes demonstrated superior desalination performance compared to the PA membranes prepared with the previous technique. With the optimized concentration of 0.3 wt.% trimesoyl chloride (TMC) and 0.6 wt.%, m-xylylenediamine, the prepared BLFIP PA membrane showed salt rejection rate of 92.55%, 92.01%, 83.99% and 95.16%, to Na 2 SO 4 , MgSO 4 , NaCl and methyl orange, respectively at 5 bar, while maintained a water flux of about 2 Lm –2 h –1 bar –1 . More importantly, the BLFIP PA membrane possesses excellent long-term stability, and chlorine resistance comparing with traditional PA membranes based on TMC and m-phenylenediamine, which demonstrated the new method in this study paved a facile way for preparing RO filtration membranes with outstanding performance in seawater desalination.
研究领域:
材料科学
·
膜分离技术
·
环境工程
·
水处理
·
高分子化学
·
界面化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）