共查询到20条相似文献,搜索用时 15 毫秒
1.
Shaoxin Deng Cheng-Xing Cui Lu Liu Lingyao Duan Jichao Wang Yuping Zhang Lingbo Qu 《中国化学快报》2021,32(3):1177-1180
The development of a practical synthetic method to functionalize hollow mesoporous silica with organic groups is of current intere st for selective adsorption and ene rgy storage applications.Herein,a facile and controllable one-pot approach for the synthesis of monodisperse amino-functionalized hollow mesoporous silica nanoparticles is presented.A novel solid-to-hollow structural transformation procedure of the silica nanoparticles is presented.The structural transformation is easily designed,as obse rved through transmission electro n microscopy,by tailo ring the HCl and N-lauroylsarcosine sodium molar ratio and the water content in the sol-gel.Ordered and radially oriented in situ aminofunctionalized mesochannels were successfully introduced into the shells of the hollow silica nanoparticles.A formation mechanism for the hollow mesoporous silica materials is discussed. 相似文献
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Sheng‐Jie Wang Xiao‐Dong Fan Jie Kong Xin Wang Yu‐Yang Liu Guo‐Bin Zhang 《Journal of polymer science. Part A, Polymer chemistry》2008,46(8):2708-2720
A new controllable approach to synthesize hyperbranched poly(siloxysilanes) via hydrosilylation of A2‐ and B′Bx‐type monomers was developed in this work. A2 monomers (dimethylbis(dimethylsiloxy)siloxane and tetramethyldisiloxane), B′Bx monomers (methylvinyldiallylsilane and vinyltriallylsilane), and the resultant hyperbranched poly(siloxysilanes) were well characterized using FTIR, 1H NMR, 13C NMR, 29Si NMR, and SEC/MALLS. The In situ FTIR results indicate that the controllable polymerization can be carried out quickly and the reaction process was obviously performed in two stages. At the first stage, silicon hydride selectively reacts with vinyl silane groups, which produces intermediate structures with one Si? H and two (or three) allyl groups. Consequently, at the second stage, these intermediates act as new AB2 (or AB3) type monomers and continue to be self‐polymerized to generate hyperbranched polymers. By this novel controllable approach, molecular weights and their polydispersity of the resulted hyperbranched poly(siloxysilanes) can be conveniently regulated via adjusting the process parameters, such as feeding ratio of two monomers. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 2708–2720, 2008 相似文献
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The titania hollow microspheres with incontinuous multicavities were successfully fabricated via an oil/ water(O/W) emulsion process accompanied by sol–gel reaction in the presence of polyvinylpyrrolidone(PVP). In the one-step route, the addition of PVP to the tetrabutyl titanate(TBT) 1-octanol solution as the oil phase of the O/W emulsion clearly expands the size of the cavities inside the microspheres. The and atoleine alters the polarity of the oil phase to affect the interior structure significantly. The Span 80 is used as a stabilizer to preserve spherical shape. A preliminary mechanism based on phaseseparation for the structural evolution of titania hollow microspheres with multicavities is suggested. Zirconia and alumina hollow microspheres with incontinuous multicavities can also be prepared by this one-step route successfully. 相似文献
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We are reporting a novel green approach to incorporate silver nanoparticles (NPs) selectively in the polyelectrolyte capsule shell for remote opening of polyelectrolyte capsules. This approach involves in situ reduction of silver nitrate to silver NPs using PEG as a reducing agent (polyol reduction method). These nanostructured capsules were prepared via layer by layer (LbL) assembly of poly(allylamine hydrochloride) (PAH) and dextran sulfate (DS) on silica template followed by the synthesis of silver NPs and subsequently the dissolution of the silica core. The size of silver nanoparticles synthesized was 60±20 nm which increased to 100±20 nm when the concentration of AgNO(3) increased from 25 mM to 50 mM. The incorporated silver NPs induced rupture and deformation of the capsules under laser irradiation. This method has advantages over other conventional methods involving chemical agents that are associated with cytotoxicity in biological applications such as drug delivery and catalysis. 相似文献
5.
Yang Pan Li Wenjuan Lian Yijun Yu Feng Dai Bin Guo Xuhong Liu Zhiyong Peng Banghua 《Journal of Solid State Electrochemistry》2020,24(4):941-950
Journal of Solid State Electrochemistry - Photoelectrocatalytic (PEC) water splitting technology is used to convert solar energy into hydrogen energy, and has the potential to alleviate energy... 相似文献
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The symmetric H‐phosphonates of carbohydrate and other compounds were conveniently prepared by direct transesterification of the corresponding monohydroxylic compounds with diphenyl phosphite. The approach has the merits of mild reaction conditions and high yields. © 2003 Wiley Periodicals, Inc. Heteroatom Chem 14:208–210, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10130 相似文献
10.
Jing Hua Zhongguang Wang Jian Zhao Jin Zhang Ruying Li Hengyong Nie Xueliang Sun 《Colloid and polymer science》2011,289(7):783-789
A facile approach to attach high-density and uniform gold nanoparticles on individual multi-walled carbon nanotubes (MWNTs)
is achieved. By simple grinding, water-soluble linear polymers poly(4-vinylpyridine) (PVP)-wrapped around nanotubes and thus
rendered them reversibly soluble in water, ethanol, and DMF. Individual tubes are clearly observed after PVP-wrapped nanotubes
were spin-coated onto a silicon wafer. Subsequently, Au nanoparticles were densely decorated on the individual MWNTs by in
situ reduction of HAuCl4 in the homogeneous aqueous solution of MWNTs–PVP to form stable water-dispersible Au/PVP/MWNTs hybrid. Morphology of Au nanoparticles
was determined by scanning electron microscope and atomic force microscope. The diameter of the Au nanoparticles is controlled
in the range of 3.5 to 13.5 nm. The presence of gold nanoparticles with decreased particle size was also detected by UV–Vis
spectroscopy. 相似文献
11.
Cui Lifeng Pu Tingting Shen Zhangfeng Li Shasha Kang Shifei Xia Qineng Wang Yangang Li Xi 《Research on Chemical Intermediates》2019,45(4):2167-2177
Research on Chemical Intermediates - Novel Pd/TiO2 nanotube arrays (Pd/TNTAs) were fabricated by introducing Pd nanoparticles onto TNTAs via a facile deposition–reduction method. Pd... 相似文献
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Dong Yunzhao Li Tingcheng You Xiangqian You Qingliang Sun Lang Xie Guangyong 《Research on Chemical Intermediates》2022,48(3):1151-1158
Research on Chemical Intermediates - Dichlorobenzonitriles are important organic intermediates for the production of many fine chemicals and are produced most economically and environment-friendly... 相似文献
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K. Uma S. Ananthakumar R. V. Mangalaraja K. P. O. Mahesh T. Soga T. Jimbo 《Journal of Sol-Gel Science and Technology》2009,49(1):1-5
Nanocrystalline ZnO nanorods were successfully grown by ultrasonication using an acidic ethanolic zinc acetate precursor solution
followed by a flow coating process and annealing at 600 °C. The ZnO nanorods obtained were hexagonal in shape and showed a
high degree of uniformity in size and distribution. These samples were characterized by X-ray diffraction (XRD), energy dispersive
X-ray (EDX) spectroscopy, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and Raman spectrophotometry
and the results are discussed. This approach appears to be the easiest way to fabricate bulk ZnO nanorods. 相似文献
15.
Shuangfei Xiang Ting Li Weifu Dong Qinghua Lu 《Journal of polymer science. Part A, Polymer chemistry》2018,56(21):1469-1474
In this article, we report a synergistic strategy to develop dual physically cross-linked tough hydrogels via one-pot bulk copolymerization of N-vinyl-2-pyrrolidone, acrylic acid, and stearyl methylacrylate (SMA) without any adscititious surfactant. Due to synergic effects of hydrogen bonding and hydrophobic association, the resulted dual physically cross-linked hydrogels (DP Gel) with ultra-wide range adjustable Young's modulus (0.08–45.6 MPa), tensile stress (0.7–6.9 MPa), and toughness (3.3–23.1 MJ m−3). Stretching to 300%, DP Gel exhibited fast recoverability that remained ~95% of initial dissipated energy after resting in 60 °C for 3 min. Finally, scanning electron microscopy revealed that the microstructure of hydrogel changed from phase separation structure to micro phase separation as SMA added, which accounted for excellent performance of DP Gel. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2018 , 56, 1469–1474 相似文献
16.
Wu D Wang L Xu K Song J Fun HK Xu J Zhang Y 《Chemical communications (Cambridge, England)》2012,48(8):1168-1170
Starting from readily available phenanthrenequinone and alkenes, biaryl containing medium-ring bislactones could be easily prepared through sequential photocycloaddition-photooxidation reactions with good yields and diastereoselectivity. 相似文献
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A synthesis of deethyldesoxycamptothecin via the reaction of two readily accessible synthons is described. One of the synthons constitutes the ABC ring system of camptothecin, while the second provides all the C atoms of the rings D and E. The synthetic approach is suited for the total synthesis of camptothecin analogues. 相似文献
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A facile aqueous route to synthesize highly ordered mesoporous polymers and carbon frameworks with Ia3d bicontinuous cubic structure 总被引:1,自引:0,他引:1
Zhang F Meng Y Gu D Yan Y Yu C Tu B Zhao D 《Journal of the American Chemical Society》2005,127(39):13508-13509
By employing an organic-organic self-assembly in a dilute aqueous solution, novel ordered bicontinuous cubic mesoporous polymers and carbons with Iad symmetry are directly synthesized. 相似文献
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《Tetrahedron》1986,42(20):5693-5706
The base catalyzed autoxidation of 3-oxo-Δ4 steroids in aprotic media at circa -25°C occurs nearly exclusively at C2 of the A-ring, generating rapidly (< 4 hrs) and in high yield the corresponding enol (2-hydroxy-3-oxo-Δ1,4 analog) When the reaction is then allowed to continue at room temperature for several days, the enol is further autoxidized to the related lactol (1-hydroxy-2-oxa-3-oxo-Δ4 analog) in overall yields generally in the range of 85–95%. Sodium borohydride reduction of the lactol yields the pharmacologically important 2-oxasteroids. 相似文献
20.
He J Perez MT Zhang P Liu Y Babu T Gong J Nie Z 《Journal of the American Chemical Society》2012,134(8):3639-3642
Asymmetric multicomponent nanoparticles (AMNPs) offer new opportunities for new-generation materials with improved or new synergetic properties not found in their individual components. There is, however, an urgent need for a synthetic strategy capable of preparing hybrid AMNPs with fine-tuned structural and compositional complexities. Herein, we report a new paradigm for the controllable synthesis of polymer/metal AMNPs with well-controlled size, shape, composition, and morphology by utilizing interfacial polymerization. The hybrid AMNPs display a new level of structural-architectural sophistication, such as controlled domain size and the number of each component of AMNPs. The approach is simple, versatile, cost-effective, and scalable for synthesizing large quantities of AMNPs. Our method may pave a new route to the design and synthesis of advanced breeds of building blocks for functional materials and devices. 相似文献