查找使用阿拉丁产品的科研文献

Trace Cu(Ⅱ) can enhance the degradation of Orange Ⅱ in Fe(Ⅱ)/hydroxylamine/persulfate system

Jinpeng Wang,Ming Zhang,Runjuan Zhou,Jiyuan Li,Wei Zhao,Wenyuan Chen

This paper explored the effect of trace Cu(Ⅱ) (5 μM) on the degradation of Orange Ⅱ by Fe(Ⅱ)/Hydroxylamine (HA)/Persulfate (PS) system. The results showed that the addition of trace Cu(Ⅱ) not only improved the degradation efficiency of Fe(Ⅱ)/HA/PS system, but also broadened the pH range of Fe(Ⅱ)/HA/PS degradation Orange Ⅱ (2–10). Increasing the dosage of Fe(Ⅱ), Cu(Ⅱ) and PS will promote the degradation of Orange Ⅱ by the Cu(Ⅱ)/Fe(Ⅱ)/HA/PS system. However, the optimal dosage of HA is 0.03 mM. Lower or excessive HA dosage is not conducive to the degradation of Orange Ⅱ by the Cu(Ⅱ)/Fe(Ⅱ)/HA/PS system. Scavenger experiments show that SO 4 ·- is the main reactive oxygen species (ROS) in the Cu(Ⅱ)/Fe(Ⅱ)/HA/PS system. In both acidic and alkaline environments, Cu(Ⅰ) reduced by hydroxylamine can promote the conversion of Fe(Ⅲ) to Fe(Ⅱ). In acidic environment, Fe(Ⅱ) reduced by Cu(Ⅰ) is the reason why trace Cu(Ⅱ) can enhance the efficiency of Fe(Ⅱ)/HA/PS system to degrade Orange Ⅱ. However, in alkaline environment, Cu(I) reduced by hydroxylamine is the main participant in the production of SO 4 ·- by activating persulfate, which is also the main reason for broadening the applicable pH of Fe(Ⅱ)/HA/PS for Orange Ⅱ degradation to alkaline environment.

Metal ions ‘sewing’ isoporous membranes with polystyrene-block-poly (acrylic acid) block copolymer

Juan Cheng,Miao Xu,Panpan Cheng,Wanna Zhang,Nan Li,Yong Wang,Jingying Yang,Kaiyuan Liang,Peng Li,Haizhou Yu,Xiaoyan Qiu

As a representative amphiphilic block copolymer , polystyrene- block -poly (acrylic acid) (PS- b -PAA) has great potential in biomedical applications owing to its pH-responsiveness, antibacterial property and biocompatibility. Self-assembly of PS- b -PAA has been widely investigated with regard to micelles and thin films . Whereas, it is difficult to precipitate PS- b -PAA in water to make membrane due to the high hydrophilicity of PAA blocks. Herein, a process is described to fabricate PS- b -PAA isoporous membranes by combining self-assembly of metal-block copolymer complexes and non-solvent induced phase separation. Different antibacterial metal ions were doped in PS- b -PAA casting solution, which not only enhanced the mechanical property significantly, but also adjusted the pore size of the membranes. The membranes exhibited a pH-responsive release property and excellent separation performance based on size or charge differences. Moreover, the antifouling property was significantly enhanced through the synergistic effect of antibacterial metal ions and PAA segments.

Preparation and drug release property of CO2 stimulus-sensitive poly(N, N-dimethylaminoethyl methacrylate)-b-polystyrene nanoparticles

Xiaohong Wang,Guohua Jiang,Zhen Wei,Xia Li,Bolin Tang

The CO 2 stimulus-sensitive nanoparticles based on poly( N , N -dimethylaminoethyl methacrylate)- b -poly styrene (PDMAEMA- b -PS) were prepared via surfactant-free miniemulsion reversible addition–fragmentation chain transfer (RAFT) polymerization. The as-prepared nanoparticles exhibited core–shell structure with about 120   nm in diameter. Their dispersion/aggregation in water can be adjusted by alternatively bubbling of CO 2 and N 2 . Drug release from these nanoparticles can be accelerated (or delayed) by bubbling (or removing) of CO 2 .

A novel design of self-assembled metal-organic frameworks MIL-53(Fe) modified resin as a catalyst for catalytic degradation of tetracycline

Xiangyu Wang,Wei Zhang,Xu Zhang,Lang Ran,Quanlin Zhao,Binze Zou,Lincheng Zhou,Zhengfang Ye

Chloromethyl styrene-divinylbenzene (PS–Cl) resin was usually chemically modified for the adsorption of heavy metal ions in wastewater. However, this work will introduce a new application of resin for catalytic degradation of antibiotics. The core-shell PS-NH 2 @MIL-53(Fe) catalyst was fabricated by simple two-step route including chemical synthesis and step-by-step self-assembly strategy. The catalysts exhibited excellent catalytic activity toward the degradation of tetracycline (TC) in the presence of H 2 O 2 , with a degradation efficiency and degradation rate constant ( k ) of 94.15% and 0.05643 min −1 within initial 20 min, respectively. Moreover, the mineralization and stability of PS-NH 2 @MIL-53(Fe) both showed excellent performance. The advantage of PS-NH 2 @MIL-53(Fe) is that the degradation efficiency of TC could be modulated by the number of self-assembly. Additionally, we utilized the Yellow River water to explore the effect of the catalyst for TC removal in the actual wastewater treatment . Meanwhile, several possible catalytic degradation pathways were analyzed on the basis of using HPLC-MS to detect the intermediates generated in the process of catalytic degradation, and a potential catalytic degradation mechanism was proposed. In brief, the new application of amination resin modified by MIL-53(Fe) in catalytic degradation of TC shows promising prospect, especially in the field of environmental remediation.

Molecular docking simulation reveals the lipase–substrate binding mechanism in the enzymatic synthesis of diacylglycerol-enriched vegetable oils

Run Liu,Yi Zhang,Yuanzhi Xu,Zhonghui Liu,Jinhang Chen,Kheng-Lim Goh,Yufei Zhang,Mingming Zheng

Diacylglycerol (DAG) is a functional lipid that is naturally present in vegetable oils in limited concentrations (1 %–5 %). This study proposed an enzymatic method to afford high-content-DAG vegetable oils via a reaction catalyzed by an immobilized lipase, PS@OMS-C 8 , using high-speed homogenization and molecular distillation. Results indicated that 48.6 % DAG was initially obtained through the enzymatic glycerolysis of rapeseed oil with glycerol, of which 90.2 % was sn -1,3-DAG. PS@OMS-C 8 maintained 35.5 % DAG content after 10 reuse cycles, confirming its catalytic stability; this was attributed to lipase immobilization on the ordered mesoporous silica that significantly improve the secondary protein structures, including α-helix and β-sheet, thereby strengthening the rigidity of PS@OMS-C 8 . In addition to producing DAG-enriched rapeseed oil, other edible oils with 39.4 %–50.2 % DAG content were obtained, as revealed via molecular docking simulation. This study offers new strategies for the sustainable synthesis of vegetable oils with a high content of functional lipids high-content functional lipids.

Adsorptive removal of fluoride from drinking water using porous starch loaded with common metal ions

Lingyun Xu,Guijie Chen,Chuanyi Peng,Huanhuan Qiao,Fei Ke,Ruyan Hou,Daxiang Li,Huimei Cai,Xiaochun Wan

In this study, porous corn starch was loaded with Zr, Al, Fe or La to produce the composites PS-Zr, PS-Al, PS-Fe and PS-La. Fluoride adsorption from water was tested at different biosorbent dosages, contact times, solution pH values and initial fluoride concentrations. The biosorbents were characterized by microscopy and spectroscopy. PS-Zr was shown superior defluoridation capacity over a pH range of 3.0–9.0. The adsorption process could be described by the Langmuir isotherm model and the Lagergren pseudo-second-order kinetic model. The maximum fluoride adsorption capacity calculated to be for PS-Zr was 25.41   mg/g. Our results revealed that PS-Zr could be employed as an effective biosorbent for removal of fluoride from drinking water.

Effective Structure Control of Colloidal Molecules and the Morphology Evolution Mechanism Investigation

Wei Zhang,Hua Cheng,Rui Pan,Yi Gong,Zhengya Gan,Rui Hu,Jianjun Ding,Xian Zhang,Xingyou Tian

Colloidal molecules (CMs), nonspherical clusters of a small number of particles, can be used as building blocks for self-assembly applications. Here, we propose a novel one pot method for CMs synthesis. First, poly(N-isopropylacrylamide-co-acrylic acid) (P(NIPAM-co-AA)) microgels were prepared by soap-free emulsion polymerization as seed particles, then monomer styrene and cross-linking agent divinylbenzene (DVB) were added, which could be polymerized by the remaining free radicals on the seed surface in situ. P(NIPAM-co-AA)-PS colloidal molecules with a series of morphologies such as popcorn-like, CO2-like, NH3-like, CH4-like and so on could be obtained. The effects of satellite colloid viscosity, interfacial tension, and polymer chain mobility on the number of satellite colloid have been investigated, and the formation mechanism of CMs is proposed based on morphology evolution investigation. Compared with the existing CM synthesis techniques, our method enables fabricating CMs from vinyl monomer in a facile and efficient way, and the scientific finding regarding the CMs formation will guide the CMs fabrication toward salable and reliable direction.

Preparation and properties of Pue-loaded HA-ADH-PS nanomicelles

Huiru Wang,Yuanyuan Li,Yunpeng Min,Hang Zhang,Linkun Hao,Ru Zhang,Yunying Jiang,Yimin Song

One-step synthesis of Ag@PS nanospheres via flash nanoprecipitation

Xianxiang Hu,Zhijie Zhang,Yao Lu,Rui Liu,Lei Sun,Ivan P. Parkin,Xia Zhang

In the work reported, we utilized a facile flash nanoprecipitation process to generate Ag nanoparticles@nanospheres polymer composites. Ag nanoparticles can be loaded onto the polymeric polystyrene (PS) nanosphere surface using a simple and inexpensive method through in situ growth; the amount of loaded Ag nanoparticles and the size of holes on the PS surface prepared by flash nanoprecipitation can be fine-tuned by changing the pH of the water medium and the PS nanoparticles should have a greater specific area. The as-synthesized Ag@PS composite nanoparticles obtained via the one-step and continuous preparation route show high catalytic activity in the reduction reaction of 4-nitrophenol. Importantly, the nanoparticles show no loss of catalytic performance over five cycles.

The influence of PS nanoparticle on dielectric properties of LLDPE

Liu Yuyao,Yao Ruixiang,Tong Yujie,Lu Yaqing,Guo Qiyang

Nanoparticles (NPs), especially inorganic NPs, have been used as fillers to improve the insulation properties of polymers. However, inorganic NPs is difficult to disperse well in polymer matrix, which inhibit the development of insulating nanocomposites for high-voltage direct current power cable. Therefore, it is necessary to improve the dispersion of NPs in the polymer matrix in order to make NPs play a greater role. In this work, polystyrene NPs (PS-NPs) were synthesized and used as fillers to improve the insulation properties of LLDPE. SEM images show that PS-NPs are monodispersed in LLDPE matrix without thermal fusion when the content of PS-NPs is less than 1 wt%. The results of DSC illustrate that the addition of PS-NPs had no effected on thermal behavior of LLDPE. With the introduction of PS-NPs, the DC breakdown strength of LLDPE/PS-NPs is first increased and then decreased. The highest value of 346.5 kV/mm is obtained by PS-0.1 with 0.1 wt% of PS-NPs. The electric conductivity of all LLDPE/PS-NPs composites are decreased comparing with neat LLDPE. Meanwhile, PS-NPs had no significant influence on the dielectric permittivity and dielectric loss of the complex. Therefore, PS-NPs is an alternative option to improve the insulating performance, and our results provide a way for the development of nanocomposites insulating material.

Amphoteric polymeric photonic crystal with U-shaped pH response developed by intercalation polymerization

Hongwei Xia,Junpeng Zhao,Cong Meng,Ying Wu,Yijie Lu,Jingxia Wang,Yanlin Song,Lei Jiang,Guangzhao Zhang

Amphoteric one-dimensional photonic crystal (PC) based on polystyrene-b-poly(2-vinyl pyridine) (PS-b-P2VP) block copolymer was developed by intercalation polymerization of acrylic acid and 2-hydroxyethyl methacrylate in the partly quaternized P2VP (QP2VP) layers. The amphoteric PC reversibly exhibits a high first Bragg peak position (λmax > 700 nm) at both acidic and basic pH values where the QP2VP layers are positively and negatively charged respectively. The minimum λmax (300 nm) at pH 5.5 can be observed due to charge screening. The PC with a U-shaped pH response also shows good durability.

Preparation of carbon-based hybrid particles and their application in microcellular foaming and flame-retardant materials

Zhicai He,Zhengping Zhao,Shengwei Xiao,Jintao Yang,Mingqiang Zhong

Polymeric microcellular foams with high strength and light weight are very important for industrial applications. However, regulating their cell structure and their weak flame retardancy are problematic. We designed single-arm POSS-based ionic liquids ([bel-POSS][PF6]), and constructed hybrid composites based on physical interaction between ionic liquids and carbon-based materials in PS microcellular foaming. Ionization of bel-POSS could result in a quaternary ammonium reaction and ion-exchange reaction, and the carbon materials exhibit good dispersion through blending. The prepared hybrid composites showed high CO2 adsorption. Conical calorimeter tests showed that PS composite materials could reduce the heat release rate, total heat release, toxic gases (CO2 and CO) release, and amount of smoke generated. These carbon materials could affect PS micropore structure, including the cell diameter and density. Upon addition of 5 wt% of carbon materials, the hole diameter decreased by >50%, and the hole density increased nearly ten folds.