JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY
·
2019
·Vol. 57
·期 15
·1653-1663
·
IF 2.591
Bin Li,Yan Shi,Zhifeng Fu
Two kinds of Schiff base, N , N ′-dibenzylidene-1,2-diaminoethane (NDBE) and N , N ′-disalicylidene-1,2-diaminoethane, have been found as efficient organic catalyst for reversible complexation-mediated radical polymerization (RCMP) of methyl methacrylate (MMA) for the first time. The polymerization results show obvious features of “living”/controlled radical polymerization. Well-defined and low-polydispersity polymers ( M w / M n = 1.20–1.40) are obtained in RCMP of MMA catalyzed by Schiff base at mild temperature (65–80°C). Moreover, Schiff base also exhibits a particularly high reactivity for RCMP of MMA with in situ formed alkyl iodide initiator. The polymer molecular weight and its polydispersity ( M w / M n is around 1.20) are well controlled even with high monomer conversion. Notably, when the dosage of azo initiator is same as the dosage of iodine, the polymerization could also be realized in the presence of NDBE. The living feature of synthesized polymer is confirmed through the chain extension experiment. In short, Schiff base is a kind of high-efficient catalyst for RCMP and reverse RCMP of MMA, which can be one of the most powerful and robust techniques for polymer synthesis. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 1653–1663
研究领域:
高分子化学
·
聚合物合成
·
催化化学
·
功能材料
·
有机合成方法学
✓ 已验证
DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 112
·111217-111225
·
IF 3.289
Sijie Zhao,Huiru Yang,Cai Zuo,Lu Sun,Liwei Ma,Hua Wei
Star-shaped polymers are attractive as drug carriers due to the integration of relatively easy synthesis compared to the preparation of hyper-branched dendrimers and their potential ability to form unimolecular nanoparticles with enhanced stability to survive the high dilution-associated deformation and subsequently premature drug release in the body fluids and blood during circulation. Clearly, the star structure exerts a significant effect on their bioproperties and potential applications. In this study, three star-shaped amphiphilic copolymers with the same polymer compositions but different star structures were synthesized to investigate the effect of star architecture on their properties as well as potential applications as drug carriers. Three different branched alcohols, 2-(hydroxymethyl) propane-1,3-diol, pentaerythritol and dipentaerythritol with 3, 4, and 6 respective hydroxyl groups were chosen as the starting core to generate the target star-shaped amphiphilic block copolymers composed of hydrophobic poly(ε-caprolactone) (PCL) and hydrophilic poly(oligoethyleneglycol methacrylate) (POEGMA) with 3, 4, and 6 corresponding star arms by a combination of ring-opening polymerization (ROP) and atom transfer radical polymerization (ATRP). Dynamic light scattering (DLS) measurements and pyrene fluorescence probe technique confirmed the capability of the resultant star-shaped amphiphilic copolymers to form unimolecular micelles with average diameters smaller than 50 nm in an aqueous phase. A comparison of the drug loading capacity revealed that the micelles of 4-star-PCL–POEGMA (4s-PCL–POEGMA) exhibited the highest drug loading content (DLC) of all the three formulations. More importantly, in vitro doxorubicin (DOX) release study showed unique pH-mediated drug release behaviors, i.e., dramatically accelerated release at pH 6.0 but a much slower profile at pH 7.4, from these generally recognized “pH-insensitive” 4-arm star-shaped micelles. An acid-triggered degradation and an acid–base titration were performed to further reveal that such interesting pH-responsive drug release behaviors were attributed primarily to the hydrophilic corona of OEG brushes. This study is believed to provide a new insight into the structure–bioproperties relationship of star-shaped polymers, thus should be useful for the future design and development of novel star-shaped polymers for controlled drug delivery.
研究领域:
高分子药剂学
·
纳米医学
·
药物控释
·
生物材料
·
药剂学
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肿瘤治疗
·
纳米载体
✓ 已验证
DOI
高影响因子
JOURNAL OF SOLID STATE CHEMISTRY
·
2021
·
IF 3.498
Xia Hua,Zhihong Gao,Qianqian Wang,Wenming Hao,Xiaoliang Yan,Ruifeng Li
The accumulation of heavy metal on catalysts during petrochemical process produces deactivated catalysts that cannot be directly disposed in nature, due to the high toxicity. The elimination of the detrimental effect of heavy metal ions can be achieved by immobilizing these ions in the form of spinel structure, yet this requires high-temperature calcination . Herein, Ni 2+ ions are stabilized and confined within the surface NiAl 2 O 4 on Al 2 O 3 through hydrothermal process and subsequent low-temperature thermal treatment. The formation of nickel aluminum layered double hydroxide (NiAl-LDH) as intermediate favors the generation of surface aluminate spinel at the temperature as low as 450 °C. The formation of surface spinel is beneficial to restricting the mobility of Ni 2+ ions. The growth and immobilization mechanisms of the surface spinel structure were proposed, which contributes to alternative and promising route for the low-temperature approach of the retention of the heavy metal ions mobility.
研究领域:
环境催化
·
材料化学
·
工业化学
·
固体化学
·
污染控制
✓ 已验证
DOI
高影响因子
JOURNAL OF LUMINESCENCE
·
2022
·
IF 4.171
Lin Xiang,Xianju Zhou,Yongjie Wang,Li Li,Sha Jiang,Guotao Xiang,Chuan Jing,Jingfang Li,Lu Yao
Near infrared (NIR) light emitting phosphors have attracted more and more attention with the development of science and technology . Herein, we report a series of environmentally-friendly low-cost Fe 3+ -activated ZnGa 2 O 4 phosphors which exhibit intense broadband NIR light emitting. According to density functional theory (DFT) calculations, ZnGa 2 O 4 host possesses an indirect wide bandgap. The emission of the Fe 3+ -doped phosphors demonstrates a wide band spanning from 650 to 850 nm, with the maximum at 720 nm and a full width at half maxima (FWHM) of 70 nm, showing a large overlap with the absorption of phytochromes (PR and PFR). The luminescence intensity remains at 71% when the temperature is raised to 423 K. The phosphors are fabricated into light emitting diodes (LEDs) which produces strong NIR emission with CIE color coordinates of (0.65, 0.31). All these results suggest that ZnGa 2 O 4 :Fe 3+ is a promising NIR luminescent material , which is expected to be a candidate for indoor plant culture LEDs.
研究领域:
材料科学
·
光电子学
·
农业生物技术
·
固体物理
·
无机化学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2024
·
IF 5.8
Yuxing Sun,Lei Zhao,Juan Yang,Xiang Wang,Huanjun Peng,Jingdong Peng
Light absorption range, recycling stability and charge transfer efficiency are key to the performance of photocatalytic material. Based on these targets, a Al doped TiO 2 catalyst was synthesized by the evaporation-induced process, after processed by NaBH 4 reduction, the black TiO 2 doped with Al was finally prepared. Uv-vis DRS, EPR and XPS analyses confirm the expanded light absorption window (300 nm - 1000 nm) and the introduction of abundant oxygen vacancy after the reduction process. The final product BTiO 2 /Al-0.5 has a degradation rate of about 84 % over the tetracycline hydrochloride within 60 minutes, the reaction rate constant (k) is 10.6 times higher than the unreduced sample. The dramatic change of photocatalytic ability can be assigned to the broadened visible light absorption , increased charge separation efficiency, narrowed band gap and defect-enriched oxygen vacancy . This work offers insights into the fabrication of TiO 2 catalyst and the introduction of oxygen defect.
研究领域:
材料科学
·
光催化
·
环境功能材料
·
纳米材料
·
表面化学
·
半导体催化
✓ 已验证
DOI
高影响因子
JOURNAL OF FOOD SCIENCE AND TECHNOLOGY-MYSORE
·
2014
·Vol. 52
·期 5
·3072-3078
·
IF 2.024
Song Lianjun,Zhi Junli,Zhang Pingan,Zhao Qiuyan,Li Ning,Qiao Mingwu,Liu Jie
In this study, a new method was developed to produce biodegradable material using soy protein isolate (SPI) as matrix. The blend films were successfully prepared by casting the aqueous dispersions of SPI and polyamic acid salt (PAS) solution. The effects of blending and PAS content on the structure of the resultant films were investigated by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), differential scanning calorimetry (DSC) analyses, scanning electron microscopy (SEM). Furthermore, film thickness, water vapor permeability (WVP), water barrier and mechanical properties were measured. The result showed that there exists strong intermolecular interactions between SPI and PAS, which played an important role in forming a homogeneous structure of the blend films. Moreover, the incorporation of PAS enhanced the water barrier and mechanical properties of the films. This is a simple way to prepare biodegradable films compared with other methods and the blend films have the potentiality to be used as food packaging and biomedical materials instead of synthetic polymer.
研究领域:
生物材料学
·
高分子科学
·
食品科学
·
包装工程
·
生物医学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2020
·Vol. 137
·期 43
·49320
·
IF 2.52
Zhenggang Luo,Huijian Ye,Jiawei Hu,Te Hu,Boyuan Zhang,Xuanhe Zhang,Lixin Xu
A strategy for preparing ethylene-vinyl acetate (EVA)/graphene nanocomposites from liquid-phase exfoliated graphene has been explored with the use of a pyrene-functionalized hyperbranched polyethylene (HBPE) ternary copolymer, HBPE@Py@PMA, as stabilizer for graphite exfoliation. The HBPE@Py@PMA was synthesized by combining the Pd-diimine-catalyzed chain walking ternary ethylene copolymerization and atomic transfer radical polymerization techniques and has been confirmed to possess a HBPE core simultaneously bearing pyrene terminal groups and polymethacrylate side chains. As stabilizer, it is found to effectively promote graphite exfoliation in CHCl 3 to render high-quality few-layer graphene with an efficiency as high as 43%. Meanwhile, it can be steadily adsorbed on the exfoliated graphene surface to concurrently render functionalized graphene well dispersible in EVA matrix with strong interfacial interactions. This allows us to obtain EVA/graphene nanocomposites from resulting graphene dispersion through simple solution mixing process. By adding only 0.5 wt% of graphene, the dielectric constant of resulting composite increases by 55% compared to pure EVA, with a dielectric loss only 0.012. The role mechanism of the HBPE@Py@PMA for promoting graphite exfoliation in CHCl 3 and the formation of EVA/graphene nanocomposites from the resulting graphene has been proposed.
研究领域:
高分子化学
·
纳米复合材料
·
材料科学
·
胶体与界面化学
·
功能高分子
✓ 已验证
DOI
高影响因子
CELLULOSE
·
2016
·Vol. 23
·期 4
·2539-2548
·
IF 3.195
He Hui,Hou Xunan,Ma Beibei,Zhuang Linzhou,Li Chuanfa,He Shihong,Chen Shuixia
Viscose fiber was oxidized with sodium periodate to prepare a reactive dialdehyde viscose fiber (DAVF) containing abundant aldehyde groups. A solid amine adsorbent (DAVF-PEI) with high amino density for CO 2 capture was then prepared by modifying DAVF with polyethylenimine (PEI). Response surface methodology (RSM) based on a three-level, three-factorial design was used to optimize the synthesis conditions of DAVF, in which multiple linear regression equations of aldehyde content and fiber mass loss degree were constructed. The well-designed DAVF was then employed as a support to graft with PEI via Schiff base reaction to prepare a solid amine fiber (DAVF-PEI) for CO 2 adsorption. The experimental results verified that DAVF-PEI possessed good thermo-stability and high CO 2 adsorption capacity (4.11 mmol/g). DAVF-PEI also showed promising regeneration performance, which could maintain almost the same adsorption capacity for CO 2 after ten adsorption and desorption recycles.
研究领域:
材料化学
·
环境科学
·
高分子科学
·
化学工程
·
吸附分离
·
碳捕集技术
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2021
·
IF 8.128
Xin-yu Hu,Mao-xiang Jing,Hua Yang,Quan-yao Liu,Fei Chen,Wei-yong Yuan,Le Kang,Dong-hong Li,Xiang-qian Shen
Poor room-temperature ionic conductivity and lithium dendrite formation are the main issues of solid electrolytes. In this work, rod-shaped alumina incorporation and graphite coating were simultaneously applied to poly (propylene carbonate) (PPC)-based polymer solid electrolytes (Wang et al., 2018). The obtained alumina modified solid electrolyte membrane (Al-SE) achieves a high ionic conductivity of 3.48 × 10 −4 S/cm at room temperature with a wide electrochemical window of 4.6 V. The assembled NCM622/Al-SE/Li solid-state battery exhibits initial discharge capacities of 198.2 mAh/g and 177.5 mAh/g at the current density of 0.1 C and 0.5 C, with the remaining capacities of 165.8 mAh/g and 161.3 mAh/g after 100 cycles respectively. The rod-shaped structure of Al 2 O 3 provides fast transport channels for lithium ions and its Lewis acidity promotes the dissociation of lithium salts and release of free lithium ions. The lithiophilic Al 2 O 3 and Graphite form intimate contact with metallic Li and create fast Li + conductive layers of Li-Al-O layer and LiC 6 layer, thus facilitating the uniform deposition of Li and inhibiting Li dendrite formation during long-term cycling. This kind of composite Al-SE is expected to provide a promising alternative for practical application in solid electrolytes.
研究领域:
材料科学
·
电化学
·
能源存储
·
固态离子学
·
纳米复合材料
·
锂金属电池
✓ 已验证
DOI
高影响因子
JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY
·
2013
·Vol. 51
·期 7
·1559-1564
·
IF 3.543
Xiao-Hui Liu,Yun-Hai Yu,Di Jia,Bo-Wen Cheng,Fei-Jun Zhang,Hui-Na Li,Peng Chen,Shan Xie
Single electron transfer living radical polymerization of methyl methacrylate catalyzed by the in situ prepared Cu(0) at ambient temperature was first examined using various metallic powders, including Zn(0), Ni(0), Mg(0), and Fe(0). Importantly, the polymerization initiated with Ni(0)/EBiB/CuBr 2 /PMDETA system exhibited optimal living/controlled nature and generated polymers with polydispersity index as low as 1.04 for 75.27% conversion and controlled molecular weights close to theoretical ones. A wide of range of Cu(II) salts were also investigated as catalyst sources instead of CuBr 2 . The recycling of Ni(0) was very convenient due to its magnetic property, which enables its extensive application. © 2013 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013
研究领域:
高分子化学
·
材料科学
·
催化化学
·
有机合成
·
功能材料
✓ 已验证
DOI
高影响因子
CHEMICAL RESEARCH IN CHINESE UNIVERSITIES
·
2015
·Vol. 31
·期 4
·585-589
·
IF 0.875
Wei Qi,Wang Liyuan
Molecular glass resist has been considered as one of the best choices for a new generation of lithography. In this work, a new type of photoactive compound was obtained by the esterification of tannic acid with 2-diazo-1-naphthoquinone-4-sulfonyl chloride(2,1,4-DNQ-Cl) and ditertbutyl dicarbonate. The new obtained compound possessed both a photosensitive group of diazonaphthoquinone sulfonate(2,1,4-DNQ) and a group of acidolytic protection. Upon the irradiation of the compound under 365 nm light, the former group was photolyzed and converted into indene carboxylic acid along with a small amount of sulfonic acid, which could lead to the deprotection of the latter group. As a result, a novel i-line molecular glass photoresist was formed with the chemical modification of tannic acid. The experimental results show that the modificated compound had a fair solubility in many organic solvents. The lithographic performance of the resist was evaluated on an i-line exposure system with high photosensitivity and resolution as well.
研究领域:
材料科学
·
微纳加工
·
高分子化学
·
光电子学
·
半导体工艺
✓ 已验证
DOI
高影响因子
Analytical Methods
·
2016
·Vol. 8
·期 24
·4926-4933
·
IF 1.915
Dejiang Rao,Qinglin Sheng,Jianbin Zheng
Herein, we report a simple and attractive self-assembly strategy for preparing graphene oxide–multiwalled carbon nanotube–(1-pyrenemethylamine)–gold (GO–MWCNT–PMA–Au) nanocomposites using 1-pyrenemethylamine (PMA) as a coupling agent. The morphology and composition of the nanocomposites were characterized by transmission electron microscopy (TEM), X-ray powder diffraction (XRD) and energy-dispersive X-ray spectroscopy (EDS). Further, a non-enzymatic nitrite sensor was fabricated by immobilizing GO–MWCNT–PMA–Au nanocomposites on a glassy carbon electrode (GCE). To obtain the optimal electrochemical experimental conditions, the effects of pH value and the volume of the as-prepared Au nanoparticle suspension were carefully investigated. Its electrochemical sensing properties were studied by cyclic voltammetry and differential pulse voltammetry. The electrochemical investigation showed that the GO–MWCNT–PMA–Au nanocomposites exhibited good catalytic performance for the oxidation of nitrite. The nitrite electrochemical sensor presented a wide linear range from 2.0 × 10−6 to 1.0 × 10−2 mol L−1, a high sensitivity of 483.51 μA mM−1 cm−2 and a low detection limit of 0.67 μmol L−1 at a signal-to-noise ratio of 3 (S/N = 3). It also exhibited good anti-interference capability and stability. This paper provides a self-assembly strategy for preparing nanocomposites which are used to construct improved electrochemical sensors.
研究领域:
分析化学
·
纳米生物技术
·
电化学传感
·
环境监测
·
食品安全
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）